Re: [Interest] HLS Streaming in Qt?
Qt, natively does not support HLS. It'll depend on the backend that QtMultimedia uses on a particular platform. So check if the iOS backend supports (which it ideally should as HLS is from Apple too). I haven't played with QtMultimedia in a while so I'm not sure if juts passing an m3u8 url will work out of the box. HTH, -mandeep On Thu, Oct 16, 2014 at 3:17 AM, Eckerle Andreas ecke...@pearl.de wrote: Dear all, I would like to make an app for iOS and android featuring a HLS stream. Does Qt support HLS streaming maybe using a QML component? Especially on Android HLS support seems to be limited with Android versions below 4.4 so just opening a webView and using HTML5 video object will probably not work with many devices running with android 4.1 -4.3 Does maybe someone knows a link to an example of how to do HLS streaming with Qt? Thanks and best regards, Andreas ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest
Re: [Interest] Parallel state and local transactions issue
For both GUI and Controller parallel states, local transactions are used. Local transactions are a particular type of transactions which means that any sub-state contained in the source state can reach the target state, and this is represented by the First state's incoming arrow. Its a specification suitable to reduce the number of transactions, like parallel states. So, as you can see, for both GUI and Controller, the First state is reachable from any parallel substate. The problem is that whenever I trigger this transaction, the specific parallel state exits (which may be correct), but even its container exits (Parallel-container), causing exiting even for the other parallel state (which is not a good behavior imho). Exiting parallel state when any of the 'sibling' state exists is, IMO, as per the hierarchical statechart specs (CMIIW). Although, it's still not clear to me from your diagram as to how do you do a transition from, say, 'third' state to 'first' state. If the the arrows are representing transitions, I see a transition set on the GUI state (which should be parent of all 3 states within it) whose target state is 'first'. I assume you're sending an event which triggers _this_ transition? Is GUI also the top-level parallel state? It'll be good if you can send a small example showing the implementation of this diagram. That way we can see how the various transitions have been set. HTH, -mandeep ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest
Re: [Interest] Parallel state and local transactions issue
From your state machine (SM) diagram it's not clear how GUI SM transitions from 'third' to 'first' state. Do you have a transition from third state to first state? Note, if you're exiting _any_ of the parallel SMs and then re-entering it (which seems to be your case), then ALL parallel SMs will exit and re-enter. This might explain why the controller SM is ending up in first state when you exit the GUI SM. HTH, -mandeep On Mon, Oct 13, 2014 at 3:32 AM, Alessandro Lonardi alessandro.lona...@edalab.it wrote: Hi, I'm having a trouble with a state machine particular case (using Qt 5.3). My state machine has two parallel macro-states. One is meant to model the GUI evolution, the other one is meant to model the controller evolution. Since in both states there's a complex structure, for practicability, I use a local transition to reach some important states from any other states. I've provided a simplified schematic at http://gdurl.com/l9km. As you see for both Controller and GUI sub-states, the first state is reachable from any other state. Using this state machine structure, whenever a local transition triggers, it will cause an exit() from the Parallel-container state, resetting the other independent parallel state. For instance, with reference to the proposed example, suppose to be in Controller's Second state and in the GUI Third state. If the GUI local transaction is triggered (to reach its First state), even for the Controller parallel state that happens, since the Parallel-Container for some reason exits and re-enters in itself (which should not happen since the local transactions doesn't start from it). In order to make the thing working anyway, I've made a wrapper state for each parallel state (i.e. GUI-wrapper and Controller-wrapper), which intercepts the exit, without involving the other parallel states into a reset a caused by a global Parallel-container exiting and re-entering. I think that this is an issue worthy of discussion. Hope that helps, and thanks in advance for any clearance. Alessandro. ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest
Re: [Interest] problem converting QVariant UserType to Int
Output:
=
UserTypeClass ctor 0x7fff6aa02710 3 - 3
UserTypeClass copy 0x7fff6aa02710 to 0x194eb20 3 (UserType copied into
QVariant)
UserTypeClass::toInt 0x7fff6aa026f0 false 26537440 (1st conversion
failed, where did 26537440 come from?)
Seems like uninitialized value from a THIRD UserTypeClass @
0x7fff6aa026f0. I'm curious as to where this 3rd object came from?!
UserTypeClass::toInt 0x194eb20 true 3 (second attempt seems correct, I
expect 3.)
main(): value = 3
=
The call to value.toInt(b) in main generates a call to
QVariant::qNumVariantToHelper, which can do 2 attempts to make the
conversion, both of which call back to UserTypeClass::toInt():
from QVariant.cpp:
template typename T
inline T qNumVariantToHelper(const QVariant::Private d,
const HandlersManager handlerManager, bool *ok, const T val)
{
...some code omitted...
T ret = 0;
if ((d.type = QMetaType::User || t = QMetaType::User)
QMetaType::convert(val, d.type, ret, t)) {
return ret;
}
if (!handlerManager[d.type]-convert(d, t, ret, ok) ok)
*ok = false;
return ret;
}
The first conversion attempt fails because UserTypeClass::toInt() finds
m_Data 3. I had to contrive that restriction to demonstrate the
problem. Since I am able to return false, the second conversion is tried
next and it turns out to be the correct one. Note that 'this' from the
copy of UserTypeClass (line 2 of output) is the same as 'this' from the
second attempt at conversion (line 4 of output).
Am I doing this correctly? What is the difference between the two
conversion attempts in QVariant::qNumVariantToHelper?
Thanks,
glenn
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Re: [Interest] Gstreamer support
On Fri, Aug 8, 2014 at 8:00 AM, Nikos Chantziaras rea...@gmail.com wrote: On 08/08/14 17:46, pritam.ghang...@gmail.com wrote: Got that working. Configure script looks for Gstreamer only if phonon is enabled. Video through Phonon might not be the best experience. You might want to look into QtGStreamer instead. it's provides by GStreamer itself: http://gstreamer.freedesktop.org/modules/qt-gstreamer.html I had much more success with it than with Phonon and got very solid video playback. Phonon video, especially in Qt 4, is extremely glitchy. Unlike Phonon, which is a multimedia framework with different backends (one of which is GStreamer) QtGstreamer is a Qt binding for Gstreamer and provides all the low level access you'd expect when using GStreamer directly. I would say its a tad cumbersome to use, but you get full control over everything and IMO better suited for embedded systems. -mandeep ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest
Re: [Interest] Gstreamer support
On Thu, Aug 7, 2014 at 7:38 AM, pritam.ghang...@gmail.com pritam.ghang...@gmail.com wrote: Hi I am compiling Qt for an embedded broadcom 97405 platform. Final target is to get html5 video tag working. The whole build system and paltfrom is a little dated and I am stuck with qt 4.8.1 Intially I was getting GStreamer support : no in configure output You can add '-v' option to configure and see which test is failing that results in this output. From there it should just be matter of seeing the test program and figuring out what it needs. HTH, -mandeep ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest
Re: [Interest] Can't download file with QNetworkAccessManager: connection closed
On Sun, Jun 8, 2014 at 4:08 PM, Nikos Chantziaras rea...@gmail.com wrote: On 08/06/14 07:48, Thiago Macieira wrote: Em dom 08 jun 2014, às 06:05:20, Nikos Chantziaras escreveu: It fails even without the redirection. I only used sf.net instead of sourceforge.net in order to make the code smaller for posting here. So this will also fail: QNetworkRequest request(QUrl(http://qtads.sourceforge.net/COPYING;)); I can reproduce it here. Traffic sniffing and strace reveal it's a server bug. The server closed the connection. [...] $ curl -A Mozilla/5.0 http://qtads.sourceforge.net/COPYING curl: (56) Recv failure: Connection reset by peer Like I said, server bug. Thanks, Thiago. It seems Mozilla/5.0 is the only user-agent this happens with. Could it be that there's some reason to reject connections with that user-agent? If yes, it might be a good idea to change the default user-agent set by Qt. I thought Mozilla/5.0 was used to specifically _avoid_ such issues!! Ironically it seems to be the cause of one now! -mandeep I reported this in SF's tracker: https://sourceforge.net/p/forge/site-support/7857/ ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest
Re: [Interest] BUG? QTimer in QThread
On Tue, May 13, 2014 at 5:33 PM, Filip Piechocki fpiecho...@gmail.com wrote: I would like to mention, that in the first email the thread is never started and without starting the thread I would not expect much to happen in this thread :) I was about to say the same! :) -mandeep BR, Filip Piechocki On Tue, May 13, 2014 at 2:00 PM, Mandeep Sandhu mandeepsandhu@gmail.com wrote: Thanks Mandeep, the problem was caused by the timer starting in the constructor and then moved by moveToThread, as André pointed out. I don't really understand why is it so, but well, it works :) I'm glad it worked for you, although the example I sent you starts the timer in the c'tor only (and later moveTothread is called) and still works. Could it be a Qt-on-Mac issue (maybe you can compile my example on your setup and test)? -mandeep Thanks! ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest
Re: [Interest] Debugging tip for QNetworkReply
On Tue, May 6, 2014 at 12:43 AM, Jason Kretzer ja...@gocodigo.com wrote: Turns out, a bug on the portal. However, I would not have seen that had someone not mentioned looking at the logs for portal. It was a bug where under certain You can actually. Just look for the QNetworkRequest::HttpStatusCodeAttribute in the incoming reply. It'll have the HTTP status code (in your case this would've been 302). -mandeep circumstances a redirect is issued(302). Thank you every one. -Jason //// Jason R. Kretzer Lead Application Developer ja...@gocodigo.com 606.792.0079 //// On May 5, 2014, at 3:40 AM, Mandeep Sandhu mandeepsandhu@gmail.com wrote: So there's a sizable difference between the file that works (600KB) and the one that doesn't (55MB). * Could it be a memory issue on your system? Have you tested higher sizes after which it starts failing? * What does reply-error() return when this problem occurs (you had mentioned the error 'string', but not the exact error code)? * Does the webserver run on the same machine or is it over the network? * What HTTP status code does the webserver respond with for the failed request (it'll probably be there in the logs) If it's possible, you could run a packet sniffer and check which side (client or server) closes the connection first. Also, it's best to check reply-error() before proceeding to write the file. HTH, -mandeep On Mon, May 5, 2014 at 1:12 AM, Jason Kretzer ja...@gocodigo.com wrote: Windows 7 Professional Qt V5.2.1 Mime is application/zip -- will check on the logs and get back Size of the zip that works is ~600kb. -Jason -Original Message- From: Mandeep Sandhu [mailto:mandeepsandhu@gmail.com] Sent: Sunday, May 04, 2014 3:25 AM To: Jason Kretzer Cc: Thiago Macieira; interest@qt-project.org Subject: Re: [Interest] Debugging tip for QNetworkReply A couple of questions to help debug further. * What platform are you running this on and what's the version of Qt? * What is the MIME type set by the webserver when responding to your request (you can check it by dumping the headers received) * According to the webserver logs, how much data was returned for the problematic zip file? * Whats the size of the zip that works? -mandeep On Sat, May 3, 2014 at 11:47 PM, Jason Kretzer ja...@gocodigo.com wrote: The zip that fails and is unreadable is a 1k file. The zip that I am attempting to download is ~55MB. The 1k zip also cannot be opened by a zip program nor a text editor. Is there a way I can tell what the failure is? Perhaps, I can use wireshark to see the traffic and see the http response codes from the server. They should be 200, I would think since I can use a browser and get the zip(s) that way. Perhaps a way to look through the request/reply objects to see what is going on? -Jason -Original Message- From: interest-bounces+jason=gocodigo@qt-project.org [mailto:interest-bounces+jason=gocodigo@qt-project.org] On Behalf Of Thiago Macieira Sent: Friday, May 02, 2014 5:05 PM To: interest@qt-project.org Subject: Re: [Interest] Debugging tip for QNetworkReply Em sex 02 maio 2014, às 10:45:16, Jason Kretzer escreveu: I am using the following code to download zip files from a url. The only thing that changes is the “id” in the url(one for each zip). Anyway, the code always works on one of the zip files, but never works on the other. Both zips are on the server. Both zips are downloadable, if I access the url(s) from a web browser. What I am looking for is primarily direction on how to go about effectively debugging this. I tried using reply-errorString() right after loop.exec() — but it returns only reply-“Unknown Error” whether the download is successful or not. It should also be noted that on failure a file is created but is not a readable zip file. Why is it not readable? Is the file too short? Is it corrupted? Please compare the result with what was supposed to be there. -- Thiago Macieira - thiago.macieira (AT) intel.com Software Architect - Intel Open Source Technology Center ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest
Re: [Interest] Debugging tip for QNetworkReply
So there's a sizable difference between the file that works (600KB) and the one that doesn't (55MB). * Could it be a memory issue on your system? Have you tested higher sizes after which it starts failing? * What does reply-error() return when this problem occurs (you had mentioned the error 'string', but not the exact error code)? * Does the webserver run on the same machine or is it over the network? * What HTTP status code does the webserver respond with for the failed request (it'll probably be there in the logs) If it's possible, you could run a packet sniffer and check which side (client or server) closes the connection first. Also, it's best to check reply-error() before proceeding to write the file. HTH, -mandeep On Mon, May 5, 2014 at 1:12 AM, Jason Kretzer ja...@gocodigo.com wrote: Windows 7 Professional Qt V5.2.1 Mime is application/zip -- will check on the logs and get back Size of the zip that works is ~600kb. -Jason -Original Message- From: Mandeep Sandhu [mailto:mandeepsandhu@gmail.com] Sent: Sunday, May 04, 2014 3:25 AM To: Jason Kretzer Cc: Thiago Macieira; interest@qt-project.org Subject: Re: [Interest] Debugging tip for QNetworkReply A couple of questions to help debug further. * What platform are you running this on and what's the version of Qt? * What is the MIME type set by the webserver when responding to your request (you can check it by dumping the headers received) * According to the webserver logs, how much data was returned for the problematic zip file? * Whats the size of the zip that works? -mandeep On Sat, May 3, 2014 at 11:47 PM, Jason Kretzer ja...@gocodigo.com wrote: The zip that fails and is unreadable is a 1k file. The zip that I am attempting to download is ~55MB. The 1k zip also cannot be opened by a zip program nor a text editor. Is there a way I can tell what the failure is? Perhaps, I can use wireshark to see the traffic and see the http response codes from the server. They should be 200, I would think since I can use a browser and get the zip(s) that way. Perhaps a way to look through the request/reply objects to see what is going on? -Jason -Original Message- From: interest-bounces+jason=gocodigo@qt-project.org [mailto:interest-bounces+jason=gocodigo@qt-project.org] On Behalf Of Thiago Macieira Sent: Friday, May 02, 2014 5:05 PM To: interest@qt-project.org Subject: Re: [Interest] Debugging tip for QNetworkReply Em sex 02 maio 2014, às 10:45:16, Jason Kretzer escreveu: I am using the following code to download zip files from a url. The only thing that changes is the “id” in the url(one for each zip). Anyway, the code always works on one of the zip files, but never works on the other. Both zips are on the server. Both zips are downloadable, if I access the url(s) from a web browser. What I am looking for is primarily direction on how to go about effectively debugging this. I tried using reply-errorString() right after loop.exec() — but it returns only reply-“Unknown Error” whether the download is successful or not. It should also be noted that on failure a file is created but is not a readable zip file. Why is it not readable? Is the file too short? Is it corrupted? Please compare the result with what was supposed to be there. -- Thiago Macieira - thiago.macieira (AT) intel.com Software Architect - Intel Open Source Technology Center ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest
Re: [Interest] Debugging tip for QNetworkReply
A couple of questions to help debug further. * What platform are you running this on and what's the version of Qt? * What is the MIME type set by the webserver when responding to your request (you can check it by dumping the headers received) * According to the webserver logs, how much data was returned for the problematic zip file? * Whats the size of the zip that works? -mandeep On Sat, May 3, 2014 at 11:47 PM, Jason Kretzer ja...@gocodigo.com wrote: The zip that fails and is unreadable is a 1k file. The zip that I am attempting to download is ~55MB. The 1k zip also cannot be opened by a zip program nor a text editor. Is there a way I can tell what the failure is? Perhaps, I can use wireshark to see the traffic and see the http response codes from the server. They should be 200, I would think since I can use a browser and get the zip(s) that way. Perhaps a way to look through the request/reply objects to see what is going on? -Jason -Original Message- From: interest-bounces+jason=gocodigo@qt-project.org [mailto:interest-bounces+jason=gocodigo@qt-project.org] On Behalf Of Thiago Macieira Sent: Friday, May 02, 2014 5:05 PM To: interest@qt-project.org Subject: Re: [Interest] Debugging tip for QNetworkReply Em sex 02 maio 2014, às 10:45:16, Jason Kretzer escreveu: I am using the following code to download zip files from a url. The only thing that changes is the “id” in the url(one for each zip). Anyway, the code always works on one of the zip files, but never works on the other. Both zips are on the server. Both zips are downloadable, if I access the url(s) from a web browser. What I am looking for is primarily direction on how to go about effectively debugging this. I tried using reply-errorString() right after loop.exec() — but it returns only reply-“Unknown Error” whether the download is successful or not. It should also be noted that on failure a file is created but is not a readable zip file. Why is it not readable? Is the file too short? Is it corrupted? Please compare the result with what was supposed to be there. -- Thiago Macieira - thiago.macieira (AT) intel.com Software Architect - Intel Open Source Technology Center ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest
Re: [Interest] One MediaPlayer on two VideoOutput elements?
On Fri, May 2, 2014 at 12:52 PM, Neuer User auslands...@gmx.de wrote: Just wanted to try out the QmlVideoTee example, but it seems I am missing something: qabstractvideosurface.h: No such file or directory #include qabstractvideosurface.h Try this instead: #include QAbstractVideoSurface Qt headers that users use are w/o the .h suffix. HTH, -mandeep ^ Where do I find that file? Cheers Michael Am 30.04.2014 17:22, schrieb Lopes Yoann: On Apr 30, 2014, at 12:36 PM, Neuer User wrote: Hi I need to show an RTSP video played by a MediaPlayer element on two different VideoOutput elements. I can't get it to work. Only the last VideoOutput in the code works. Am I doing something wrong? Or is this just not expected to work? If so, how should I achieve this? I don't want to use shader elements as this certainly reduces performance a lot. It's currently a limitation. The fact that it can be done in QML is misleading, it's more clear with the C++ API where you can only set a video output on a media source, and not the other way around. We should support this in a future release, it doesn't involve many changes. In the meantime the easiest solution, as you mentioned, is to use the ShaderEffect element. There are other (hack-ish) solutions to do this but it requires more work. Here's an example doing just that: https://github.com/marseyeah/QmlVideoTee ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest
Re: [Interest] One MediaPlayer on two VideoOutput elements?
Replying to the list... On Fri, May 2, 2014 at 2:43 PM, Neuer User auslands...@gmx.de wrote: Am 02.05.2014 11:04, schrieb Mandeep Sandhu: On Fri, May 2, 2014 at 12:52 PM, Neuer User auslands...@gmx.de wrote: Just wanted to try out the QmlVideoTee example, but it seems I am missing something: qabstractvideosurface.h: No such file or directory #include qabstractvideosurface.h Try this instead: #include QAbstractVideoSurface Qt headers that users use are w/o the .h suffix. HTH, -mandeep Thanks. I just got it working by adding: QT += qml multimedia to the .pro file. What would be the preferred solution? This way or your suggestion? Both actually! :) The module include that you did (QT += ...) is a MUST as that tells qmake which other 'extension' modules your app needs (for linking and header includes). By default only the QtCore and QtGui are part of the QT config. As for the include header, it's standard practice in Qt application code to include C++ style headers (i.e w/o .h suffix) and use the camel-case notation for header name. HTH, -mandeep ^ Where do I find that file? Cheers Michael Am 30.04.2014 17:22, schrieb Lopes Yoann: On Apr 30, 2014, at 12:36 PM, Neuer User wrote: Hi I need to show an RTSP video played by a MediaPlayer element on two different VideoOutput elements. I can't get it to work. Only the last VideoOutput in the code works. Am I doing something wrong? Or is this just not expected to work? If so, how should I achieve this? I don't want to use shader elements as this certainly reduces performance a lot. It's currently a limitation. The fact that it can be done in QML is misleading, it's more clear with the C++ API where you can only set a video output on a media source, and not the other way around. We should support this in a future release, it doesn't involve many changes. In the meantime the easiest solution, as you mentioned, is to use the ShaderEffect element. There are other (hack-ish) solutions to do this but it requires more work. Here's an example doing just that: https://github.com/marseyeah/QmlVideoTee ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest
Re: [Interest] QNAM timeout is way too long
On Mon, Apr 21, 2014 at 10:58 PM, Scott Aron Bloom scott.bl...@onshorecs.com wrote: I have code, that sends a http request via QNetworkAccessManager. Unfortunately, there are times, where the network on the machine will be up, but the connection to the internet is down.. Or the internet is up, but the backend server is down. Meaning, there is no way for my application to “know” don’t bother trying to connect. If you're running on a Linux system, you could try changing the default TCP timeout by changing /proc/sys/net/ipv4/tcp_syn_retries or /proc/sys/net/ipv4/tcp_keepalive_time depending on what stage you're getting stuck at. Although this would be a platform specific hack and would affect other applications too. -mandeep ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest
Re: [Interest] Which thread implementation is best to trigger external library via timers
1. Subclassing QThread: I've read you should avoid that, so I don't really consider it Not really. Search the archives, where we've had this discussion numerous times before! :) The conclusion was that there's no 1 right or wrong way. It has to be taken on a case-by-case basis. 2. Move it to thread: networkWorker-moveToThread(thread); 3. High level API's: QtConcurrent/QRunning The requirements are: - Run infinite - stop only when requested - Needs to run threads event loop - Able to call slots via queued events and the most critical part - direct function calls synchronized via Mutexes from main thread I've decided to use option 2 but wonder about the following two questions: - If I have moved NetworkWorker into its own thread, in which thread is QTimer running and can I be sure even when the main thread is overloaded, the worker thread still emits and delivers QTimer events? I think, QTimer will run in whatever thread it's parent is in and since NetworkWorker will parentless (for moveTothread() to work properly) it should run in the worker thread. Though you might want to start it _after_ moving NetworkWorker to the new thread so that timer events are delivered to it's event loop. - There are some methods I still have to call from the main thread, because I cannot really connect them via queued signal/slots. E.g. getIP() const or getKnownServers() const. So I still need to call it from a place in the main thread to get data out of the object: QString ip = networkWorker-getIP(); Is this still safe to use (of course getIP() is synchronized via a mutex) or are there any other cleaner solutions? It should be ok, if the resource access is serialized with a mutex. I couldn't gather from your explanation as to why you need an event loop in the thread? There are no signals being emitted by the worker. If getIP() is ok being a direct call, and if there's only the main thread trying to set values, then I guess even setIP() could be a direct call (serialzed access via mutex ofcourse). Just my 2 cents. HTH, -mandeep ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest
Re: [Interest] Which thread implementation is best to trigger external library via timers
A example looks like: Timer to ping the server on regular basis: - QTimer::timeout connected to slot sendPing(); - when the pong is received, the signal void pongReceived is emitted, this can be evaluated by the application. But as said, there are methods in the worker, I need return data immediately, e.g. getKnownServers, isConnected etc. Your answer helped me already a lot. Thank you very much. So I'll go for this approach. You've chosen the right option of moveToThread() then. Good luck, -mandeep ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest
Re: [Interest] Compile a console app for the Raspberry Pi
Have you tried the instructions here? http://qt-project.org/wiki/RaspberryPi_Beginners_guide HTH, -mandeep On Thu, Apr 10, 2014 at 5:14 PM, Petko Ditchev pditc...@gmail.com wrote: Hello everyone, I thinking now about how to approach the problem in the title. I have a small console app (a filter for mic input) that uses Qt libs, and I want to deploy it on the Pi. It uses some Qt5 features so Qt4 from the repos isn't an option. I was thinking about building it statically, but I'm not sure what the steps for that are (on ARM). So is that the process : 1.Cross-compile Qt5 libs (with --static) to be compatible with the RPi CPU. 2.Build the app with that Qt lib. 3.Deploy to the Pi 4.Benefit Or am I missing something? Petko ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest
Re: [Interest] Json support for Qt5 QML - code review needed
Qt5 already has Json support in the form of QJsonDocument and co. Do you use QJson* classes underneath as well or you've implemented your own JSON parsing? Couldn't JSONPath be modelled using the existing QJson* classes? I could volunteer for reviewing too if you can point to us your repo/code. -mandeep On Sat, Apr 5, 2014 at 7:00 PM, Jay Sprenkle jspren...@gmail.com wrote: Good morning, I'm looking for a code review for an open source project. I've implemented Json support for use with Qt5 QML. It's in several parts. A C++ version of JsonPath. If you've used XPath then this should be familiar. JsonPath is XPath for JSON. QJsonPath allows selecting arbitrary subsets of a json object given a search string. A QML item to translate a JSON string, apply JsonPath and provide a Qt QJsonDocument. A QML item to take a QJsonDocument and provide a Qt list model that you can use with Qt's standard control ListView. Used together you can request data from an arbitrary web service (or file), pull out a subset, and display it using the Qt controls. The code works but I think someone with better knowledge of Qt's model/view system could help make it better. Any takers? Thanks Jay -- -- Psychiatrist to patient: Don't worry. You're not deluded. You only think you are. ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest
Re: [Interest] QThread
On Tue, Mar 25, 2014 at 2:49 AM, Alan Ezust alan.ez...@gmail.com wrote: If you're using Qt 5.2 or later, there is a new API you can use. Call isInterruptionRequested() in your loop, http://qt-project.org/doc/qt-5/qthread.html#isInterruptionRequested And call requestInterruption() from outside. http://qt-project.org/doc/qt-5/qthread.html#requestInterruption I guess this makes it possible for you to avoid the whole atomic/volatile thing alltogether. Hmmm...this looks handy! Thanks for pointing it out. -mandeep ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest
Re: [Interest] dynamic library question
However, if KSP is enabled, the kernel might realise the pages are identical and drop one copy. I would recommend you don't depend on it, so simply don't duplicate the files. Doesn't KSP scan only the pages that have been explictly marked as mergeable via madvise? Why would the dynamic linker use such flag on the libraries it maps into memory? (It would be pointless in the vast majority of the cases except in OP's scenario?) Just to be clear, you guys are talking about KSM (kernel samepage merging) right? -mandeep ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest
Re: [Interest] Q_PROPERTY, Subclass and calling SuperClasses signal
https://bugreports.qt-project.org/browse/QTBUG-7684?focusedCommentId=124122page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel So it seems that moc can not support something that is perfectly legal to do? The link you pointed out already mentions that you need to declare the NOTIFY signal in the same class as the one declaring the property. So thats the main issue here. I guess you will have to rejig your base class. BTW, why would you want to have just the signal in the base class and not the property itself? Is the base class like an interface? -mandeep ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest
Re: [Interest] QtProperty System
On Fri, Feb 21, 2014 at 1:31 PM, Graham Labdon graham.lab...@avalonsciences.com wrote: Hi I have been reading about Qt's property system, in particular the NOTIFY optional specifier. Can NOTIFY be used with non Qml/QtQuick applications? Yes you can. NOTIFY is not specific to Qml, rather it's just a way of specifying a 'property changed' signal (similar to read/write functions for a property). -mandeep Thanks ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest
Re: [Interest] metaObject from class name
On Fri, Feb 14, 2014 at 4:20 PM, Graham Labdon graham.lab...@avalonsciences.com wrote: Hi In my application I have a class name as a string This is the name of a class derived from QObject. Now what I would like to do is the get metaObject for this class from the string Is this at all possible? I don't think that that's possible. You could store the static meta object in hashmap with the class name as the key, but then this would require you to know all possible class names before-hand. HTH, -mandeep Many thanks ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest
Re: [Interest] Brightness QT API on embedded linux
Your screen driver for the embedded h/w should have something for it. Maybe a sysfs interface or ioctl. HTH, -mandeep On Thu, Feb 13, 2014 at 3:55 PM, Bo Thorsen bthor...@ics.com wrote: Den 13-02-2014 06:53, Ramakanthreddy Kesireddy skrev: Hi, Am current using Qt4.8.5 sdk on embedded linux using linux framebuffer plugin as backend. Is there any QT API to change the brightness of underlying system? No, unfortunately not. You have to go to Linux specific help pages for this. Bo. -- Bo Thorsen, European Engineering Manager, ICS Meet me at our quickstarts across Europe in March. London, Dublin, Copenhagen, Hamburg, Munich and Zurich. See this page: http://ics.com/qt-quickstart ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest
Re: [Interest] Ip-Cam MJPEG with QT 4.8
Do you have GStreamer ported to your particular embedded h/w? Qt uses GStreamer for all the multimedia heavy-lifting on Linux based systems. So if you have GStreamer plugins working for your h/w then it should work via Qt too as thats what Qt'll be using internally. -mandeep On Wed, Feb 12, 2014 at 12:02 AM, Simone cjb.sw.nos...@gmail.com wrote: Hello, does somebody know how to display a video stream from an IP camera, which support MJPEG format? Is it possible with QT 4.8 ? My target system is an embedded linux device. Thanks Simone ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest
Re: [Interest] Confusion regarding Qt 5 build on Windows
Thx Guys! For now, I've disabled widgets too. -mandeep On Mon, Feb 10, 2014 at 2:36 PM, Koehne Kai kai.koe...@digia.com wrote: -Original Message- From: interest-bounces+kai.koehne=digia@qt-project.org [mailto:interest-bounces+kai.koehne=digia@qt-project.org] On Behalf Of Mandeep Sandhu Sent: Monday, February 10, 2014 9:57 AM To: Interest@qt-project.org Subject: Re: [Interest] Confusion regarding Qt 5 build on Windows Isn't GUI as super-set of the Widgets module? No, widgets is a module that depends on gui. As in, if I don't want GUI, I don't want Widgets too, right? I was expecting both to be disabled. What am I missing here? Nothing, just that the Windows configure is apparently missing a sanity check here, i.e. https://codereview.qt-project.org/#change,77762 Apparently, I was missing somethingthe -no-widgets option. I think I forgot that in the new modularized structure of Qt, widgets is a separate module. But still, shouldn't the QWidgets headers be generated? Or is -no-gui with widgets enabled not a valid option? It's not a valid option. I guess that is sanity checked in the qmake logic somewhere, otherwise the build should've failed much before the autotests :) Regards Kai ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest
Re: [Interest] https://github.com/ayoy/qoauth support OAuth2?
On Sun, Feb 9, 2014 at 1:16 PM, tangk ta...@lemote.com wrote: hi all: The package with https://github.com/ayoy/qoauth support OAuth2.0 protocol or OAuth1? It looks like this supports only OAuth 1. Have a look at O2, which has support for OAuth 2 and specialization classes for Facebook, Twitter etc which makes connecting to these services very easy. https://github.com/pipacs/o2 HTH, -mandeep thanks very much. ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest
Re: [Interest] New window in Qt makes the application activate
As part of a (partly mistaken) emulation of some ancient Macintosh API's I was calling QWidget::activateWindow(). If the application is not active, that both makes the window active, and it makes the application active. I guess it's debatable whether activateWindow() should activate the application. I expected that it would just make the window the active window (painted with active appearance, ready to accept focus, title bar buttons with active appearance, etc.) or ready to be the active window when the application activated. The application can be activated via a click in the Dock icon, which doesn't select a window to be the active window, so whatever was active (or made active when the application is not active?) previously now becomes the active window. Wow...so much active-ity in this para! :) Maybe we can refer this to the Guinness Records for the most number of occurrences of a word! :P BTW, thanks for sharing the solution. -mandeep ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest
Re: [Interest] QEventLoop -- not sure I am correctly using this
//now some condition occurs, I want the worker on the inside to start
doing its thing
manager-startWorker();
I assume your worker object (which runs inside another thread) will have
public slots to start/stop its work.
If so, you can either connect a signal from the main thread to these slots
or use the invokeMethod API to call these slots on some event. Since the
worker object resides in a different thread, your slot invocation will be
queued and will get run in the worker thread's context.
HTH,
-mandeep
…
…
…
//now some other condition occurs, I want the worker on the inside to stop
doing its thing
manager-stopWorker();
Alternatively, through the signal/slot mechanism. Regardless, will the
above pull it out of its thread?
Thanks,
-Jason
*- - - - - - - - - - - - - - - - - - - - - - -*
*Jason R. **Kretzer*
*Application Developer*
*Google # 606-887-9011 606-887-9011*
*Cell # 606-792-0079 606-792-0079*
*ja...@gocodigo.com ja...@gocodigo.com*
*“quidquid latine dictum sit altum videtur”*
On Dec 4, 2013, at 12:46 AM, Mandeep Sandhu mandeepsandhu@gmail.com
wrote:
On Tue, Dec 3, 2013 at 10:39 PM, Jason Kretzer ja...@gocodigo.com wrote:
Ah, I see! Now I understand what you mean.
I rewrote my “player” object to use a Qtimer that fires every 1 second
and is started/stopped according to signals. However, it still has the
same problem where the timer won’t fire sometimes for extended periods. I
guess that means something in the overall eventloop is blocking it. So, I
believe I will try to implement it in the worker kind of format you have
below where I can put the timer in a thread.
Also, as Thiago already suggested, while you're debugging, print out the
thread ID from the worker thread and main thread objects just so that you
know that they're running in different threads.
-mandeep
I appreciate the help!
-Jason
*- - - - - - - - - - - - - - - - - - - - - - -*
*Jason R. **Kretzer*
*Application Developer*
*Google # 606-887-9011 606-887-9011*
*Cell # 606-792-0079 606-792-0079*
*ja...@gocodigo.com ja...@gocodigo.com*
*“quidquid latine dictum sit altum videtur”*
image001.png
On Dec 2, 2013, at 11:58 PM, Mandeep Sandhu mandeepsandhu@gmail.com
wrote:
Hi Jason,
As Andre pointed out, have an 'outer' class manage the worker object
and thread for you instead of doing it from within your worker.
Eg:
SomeManagerClass::SomeManagerClass(QObject *parent) : QObject(parent)
{
worker = new MyWorker(); // parentless
workerThread = new QThread(); // parentless
// Move worker object to new thread
worker-moveToThread(workerThread);
connect(worker, SIGNAL(workFinished()), this, SLOT(onWorkFinished()));
workerThread-start();
}
...
...
SomeManagerClass::~SomeManagerClass()
{
workerThread-quit();
workerThread-wait();
}
As for you event loop, I don't see any obvious issues.
I guess the reason you decided to wait for 1 second using an ev loop,
rather than have a slot handle the timeout was to make the code look
simple (synchronous)?
What platform are you running this on?
-mandeep
On Tue, Dec 3, 2013 at 1:59 AM, an...@familiesomers.nl wrote:
Hi,
It looks to me, that you're indeed doing it wrong. It seems you're
trying to let your backgroundtaskmanager both manage a thread and be
_in_ that thread. That is not the way to go. I'd separate the two
issues. If you want the backgroundTaskManager to run in it's own thread,
then either just make it a front for a backend implementation that you
move to a thread managed by backgroundTaskManager, or just let let the
whole backgroundTaskManager be unconcerned with what thread it runs in,
and have whoever creates/owns/manages it be responsible for moving it to
a separate thread if that is desirable.
Then about your use of QEventLoop: no, I'd not use it this way.
QEventLoop is not meant as an escape to 'pause' execution of your
method. If you want to wait for about a minute, why not use a QTimer
directly? I don't see a need for QEventLoop here at all.
As to why your setup doesn't work and your eventloop seems blocked
during your background task: I guess you gave your BackgroundTaskManager
a parent object? That won't work. A whole parent/child tree must live in
the same thread. So, I guess your BackgroundTaskManager did not actually
get moved to the thread at all.
André
Jason Kretzer schreef op 02.12.2013 20:27:
Maybe that last bit would be a bit more clear.
The first qDebug statement writes out — I have it set to give the
time when it is written as well — but the qDebug does not write
until after the heavy task is completed in backgroundtaskmanager. Any
other time, this performs as expected, ticking along every second.
-Jason
_- - - - - - - - - - - - - - - - - - - - - - -_
_JASON R. __KRETZER_
_ _
_APPLICATION DEVELOPER_
_Google # 606-887-9011_
_Cell # 606-792-0079_
_Jason@gocodigo.com_
_ _
_“QUIDQUID
Re: [Interest] QEventLoop -- not sure I am correctly using this
On Tue, Dec 3, 2013 at 10:39 PM, Jason Kretzer ja...@gocodigo.com wrote:
Ah, I see! Now I understand what you mean.
I rewrote my “player” object to use a Qtimer that fires every 1 second and
is started/stopped according to signals. However, it still has the same
problem where the timer won’t fire sometimes for extended periods. I guess
that means something in the overall eventloop is blocking it. So, I
believe I will try to implement it in the worker kind of format you have
below where I can put the timer in a thread.
Also, as Thiago already suggested, while you're debugging, print out the
thread ID from the worker thread and main thread objects just so that you
know that they're running in different threads.
-mandeep
I appreciate the help!
-Jason
*- - - - - - - - - - - - - - - - - - - - - - -*
*Jason R. **Kretzer*
*Application Developer*
*Google # 606-887-9011 606-887-9011*
*Cell # 606-792-0079 606-792-0079*
*ja...@gocodigo.com ja...@gocodigo.com*
*“quidquid latine dictum sit altum videtur”*
On Dec 2, 2013, at 11:58 PM, Mandeep Sandhu mandeepsandhu@gmail.com
wrote:
Hi Jason,
As Andre pointed out, have an 'outer' class manage the worker object
and thread for you instead of doing it from within your worker.
Eg:
SomeManagerClass::SomeManagerClass(QObject *parent) : QObject(parent)
{
worker = new MyWorker(); // parentless
workerThread = new QThread(); // parentless
// Move worker object to new thread
worker-moveToThread(workerThread);
connect(worker, SIGNAL(workFinished()), this, SLOT(onWorkFinished()));
workerThread-start();
}
...
...
SomeManagerClass::~SomeManagerClass()
{
workerThread-quit();
workerThread-wait();
}
As for you event loop, I don't see any obvious issues.
I guess the reason you decided to wait for 1 second using an ev loop,
rather than have a slot handle the timeout was to make the code look
simple (synchronous)?
What platform are you running this on?
-mandeep
On Tue, Dec 3, 2013 at 1:59 AM, an...@familiesomers.nl wrote:
Hi,
It looks to me, that you're indeed doing it wrong. It seems you're
trying to let your backgroundtaskmanager both manage a thread and be
_in_ that thread. That is not the way to go. I'd separate the two
issues. If you want the backgroundTaskManager to run in it's own thread,
then either just make it a front for a backend implementation that you
move to a thread managed by backgroundTaskManager, or just let let the
whole backgroundTaskManager be unconcerned with what thread it runs in,
and have whoever creates/owns/manages it be responsible for moving it to
a separate thread if that is desirable.
Then about your use of QEventLoop: no, I'd not use it this way.
QEventLoop is not meant as an escape to 'pause' execution of your
method. If you want to wait for about a minute, why not use a QTimer
directly? I don't see a need for QEventLoop here at all.
As to why your setup doesn't work and your eventloop seems blocked
during your background task: I guess you gave your BackgroundTaskManager
a parent object? That won't work. A whole parent/child tree must live in
the same thread. So, I guess your BackgroundTaskManager did not actually
get moved to the thread at all.
André
Jason Kretzer schreef op 02.12.2013 20:27:
Maybe that last bit would be a bit more clear.
The first qDebug statement writes out — I have it set to give the
time when it is written as well — but the qDebug does not write
until after the heavy task is completed in backgroundtaskmanager. Any
other time, this performs as expected, ticking along every second.
-Jason
_- - - - - - - - - - - - - - - - - - - - - - -_
_JASON R. __KRETZER_
_ _
_APPLICATION DEVELOPER_
_Google # 606-887-9011_
_Cell # 606-792-0079_
_Jason@gocodigo.com_
_ _
_“QUIDQUID LATINE DICTUM SIT ALTUM VIDETUR”_
_ _
On Dec 2, 2013, at 2:14 PM, Jason Kretzer ja...@gocodigo.com wrote:
Good Day,
I have in my application, two classes. When the application starts
up, one of the classes -backgroundtaskmanager - gets instantiated.
In the constructor, a QTimer is started to timeout every 5 minutes
and call runTasks. The instantiation is then moved to a separate
thread so that it can run without impacting the rest of the
application.
Here are the contents of the constructor.
QTimer* timer = new QTimer(this);
connect(timer, SIGNAL(timeout()), this, SLOT(runTasks()));
timer-start(30); //fiveminutes
thread = new QThread();
this-moveToThread(thread);
thread-start();
The second class -player- is instantiated in the main thread. Once
it is instantiated, it begins doing other tasks. Basically, a method
is called with the following code. This code is designed to make the
while loop delay for one second before executing the rest of the
loop (one second-ish, I know it is not perfect but it has good
enough resolution for what I need).
while(!taskQueue.isEmpty()) {
qDebug() “BEFORE
Re: [Interest] QNetworkAccessManager and HTTP persistent connection
On Thu, Nov 28, 2013 at 12:26 PM, iMath 2281570...@qq.com wrote: Thank you for your prompt! I think I should give my question a clear description. The Connection:keep-alive is in the reply header, when I call close() of the reply, the connection is still on ,I wonder how can I send a second request to the server using this connection in such case ? If I just simply make a second request like the following manager-get(QNetworkRequest(QUrl(url))); Are you sending your next request to the same host or a different one? And if it's a different one is it the first request to that host? -mandeep ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest
Re: [Interest] QNetworkAccessManager and HTTP persistent connection
Please reply to the whole list and not to me individually. Maybe someone on this list might have a more specific answer. Both pipelined and persistent connections use a single TCP connection. But in pipelining, the client can send multiple requests WITHOUT WAITING for a response from the server whereas in persistent connections the second (or subsequent) responses are sent only after receiving response of the previous request: http://en.wikipedia.org/wiki/HTTP_pipelining If the server has not sent a Connection: Close then closing the connection from the client _might_ to be a bug. How are you ascertaining that the client is initiating the close? Does the packet sniffer show the client sending a FIN packet? -mandeep On Wed, Nov 27, 2013 at 12:21 PM, iMath 2281570...@qq.com wrote: HTTP persistent connection, also called HTTP keep-alive, or HTTP connection reuse, is the idea of using a single TCP connection to send and receive multiple HTTP requests/responses, as opposed to opening a new connection for every single request/response pair.(http://en.wikipedia.org/wiki/HTTP_persistent_connection) Connection:keep-alive is in the response header. I want to send my a second http request using the same connection that was setup when the first HTTP request was made. how can this be achieved through Qt? -- Original -- From: Mandeep Sandhu;mandeepsandhu@gmail.com; Date: Tue, Nov 26, 2013 08:50 PM To: iMath2281570...@qq.com; Cc: Interest@qt-project.orginterest@qt-project.org; Subject: Re: [Interest] QNetworkAccessManager and HTTP persistent connection I think I was wrong in telling you that HTTP persistent connection was same as HTTP pipelining. They aren't. In HTTP pipelining multiple HTTP requests can be made w/o waiting for response of each connection. Whereas in HTTP persistent connection (default as you said in HTTP 1.1), the same TCP connection is used for sending HTTP request one-after-another. Can you check if the the outgoing HTTP request has the Connection: keep-alive set in its (HTTP) header. Also, I've read that sometimes webservers will send a Connection: Close header in its response in which case the client will close it's connection, so check if the webserver is playing nice with your request. Which webserver are you testing against? HTH, -mandeep On Tue, Nov 26, 2013 at 5:19 PM, iMath 2281570...@qq.com wrote: unfortunately ,it doesn't work on Qt4/WinXP I have set request.setAttribute(QNetworkRequest::HttpPipeliningAllowedAttribute, true); but the attribute QNetworkRequest::HttpPipeliningWasUsedAttribute in the reply is false . -- Original -- From: Mandeep Sandhu;mandeepsandhu@gmail.com; Date: Tue, Nov 26, 2013 02:14 PM To: iMath2281570...@qq.com; Cc: interestinterest@qt-project.org; Subject: Re: [Interest] QNetworkAccessManager and HTTP persistent connection On Sat, Nov 23, 2013 at 7:15 PM, iMath 2281570...@qq.com wrote: HTTP 1.1 supports persistent connection by default, so I want to send my a second http request using the same connection that was setup when the first HTTP request was made. how can this be achieved through Qt? I think you meant HTTP pipelining (that's the jargon used inside Qt code). I'm not 100% sure but in Qt5, the default _should_ be to use HTTP pipelining. In any case, you can explcitly check in the reply object if pipelining was indeed used or not. Check for the QNetworkRequest::HttpPipeliningWasUsedAttribute attribute in your reply. Alternately, you can try and explicitly request this behaviour by setting the n/w request attribute: request.setAttribute(QNetworkRequest::HttpPipeliningAllowedAttribute, true); If it still doesn't work, then it might be a bug. What platform are you running your on, BTW? HTH, -mandeep If I simply make the second request after the first one finished like the following QNetworkAccessManager *manager = new QNetworkAccessManager(this); connect(manager, SIGNAL(finished(QNetworkReply*)), this, SLOT(replyFinished(QNetworkReply*))); manager-get(QNetworkRequest(QUrl(http://qt-project.org;))); it seems a new TCP connection to the server will be initiated (I have checked with a network sniffer) The experiment also says: If the reply is deleteLater() or abort() within finished() signal, the connection will be closed. ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest
Re: [Interest] Qt HTTP access to Exchange
I have single stepped through all of the network code and I just can't find any place where this fails. It looks like Exchange just closes the socket without giving me an error. You can confirm this with a packet sniffer to see which end initiated the close. My URL to the server is something like https://mail.somewhere/EWS/Exchange.asmx;. I sent this a post request with an XML body. Just to eliminate the obvious, you're not getting any SSL errors right (or being silently ignored)? I can see that the receiver requests the body data, but then the line is How do you see the receiver request the body data? I think the POST data is sent along in the request itself. The receiver will be expecting the POST data to be present after the HTTP headers. silently dropped. The finished signal is emitted from the request and error() says there's no error. I have tried different things for the username and password. First attempt is to do the same as I do for usernames without a domain: url.setUserName(connector-userName()); url.setPassword(connector-password()); This doesn't work for usernames with domain info. I have also tried removing those, expecting a authenticationRequired or proxyAuthenticationRequired. No such call is coming. I have also tried url encoding the domain\username but that didn't work either. The domain name might be case-sensitive, so you can verify if the correct case is being used. HTH, -mandeep ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest
Re: [Interest] Qt HTTP access to Exchange
The domain name might be case-sensitive, so you can verify if the correct case is being used. The credentials are correct. I just don't know how to let Qt have them in the proper way. Then it might be worth while to use a packet sniffer like wire-shark (or some such) to see if the TCP connection is being abruptly closed (by either client or server) or are you receiving some HTTP response from the exchange server which then leads to the client closing the connection. MS Exchange is known to non-standard compliant behaviour so I wouldn't be surprised if it's doing something unexpected! :) HTH, -mandeep Bo. -- Bo Thorsen, European Engineering Manager, ICS Integrated Computer Solutions. Delivering World-Class Applications http://ics.com/services ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest
Re: [Interest] QNetworkAccessManager and HTTP persistent connection
I think I was wrong in telling you that HTTP persistent connection was same as HTTP pipelining. They aren't. In HTTP pipelining multiple HTTP requests can be made w/o waiting for response of each connection. Whereas in HTTP persistent connection (default as you said in HTTP 1.1), the same TCP connection is used for sending HTTP request one-after-another. Can you check if the the outgoing HTTP request has the Connection: keep-alive set in its (HTTP) header. Also, I've read that sometimes webservers will send a Connection: Close header in its response in which case the client will close it's connection, so check if the webserver is playing nice with your request. Which webserver are you testing against? HTH, -mandeep On Tue, Nov 26, 2013 at 5:19 PM, iMath 2281570...@qq.com wrote: unfortunately ,it doesn't work on Qt4/WinXP I have set request.setAttribute(QNetworkRequest::HttpPipeliningAllowedAttribute, true); but the attribute QNetworkRequest::HttpPipeliningWasUsedAttribute in the reply is false . -- Original -- From: Mandeep Sandhu;mandeepsandhu@gmail.com; Date: Tue, Nov 26, 2013 02:14 PM To: iMath2281570...@qq.com; Cc: interestinterest@qt-project.org; Subject: Re: [Interest] QNetworkAccessManager and HTTP persistent connection On Sat, Nov 23, 2013 at 7:15 PM, iMath 2281570...@qq.com wrote: HTTP 1.1 supports persistent connection by default, so I want to send my a second http request using the same connection that was setup when the first HTTP request was made. how can this be achieved through Qt? I think you meant HTTP pipelining (that's the jargon used inside Qt code). I'm not 100% sure but in Qt5, the default _should_ be to use HTTP pipelining. In any case, you can explcitly check in the reply object if pipelining was indeed used or not. Check for the QNetworkRequest::HttpPipeliningWasUsedAttribute attribute in your reply. Alternately, you can try and explicitly request this behaviour by setting the n/w request attribute: request.setAttribute(QNetworkRequest::HttpPipeliningAllowedAttribute, true); If it still doesn't work, then it might be a bug. What platform are you running your on, BTW? HTH, -mandeep If I simply make the second request after the first one finished like the following QNetworkAccessManager *manager = new QNetworkAccessManager(this); connect(manager, SIGNAL(finished(QNetworkReply*)), this, SLOT(replyFinished(QNetworkReply*))); manager-get(QNetworkRequest(QUrl(http://qt-project.org;))); it seems a new TCP connection to the server will be initiated (I have checked with a network sniffer) The experiment also says: If the reply is deleteLater() or abort() within finished() signal, the connection will be closed. ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest
Re: [Interest] QNetworkAccessManager and HTTP persistent connection
On Sat, Nov 23, 2013 at 7:15 PM, iMath 2281570...@qq.com wrote: HTTP 1.1 supports persistent connection by default, so I want to send my a second http request using the same connection that was setup when the first HTTP request was made. how can this be achieved through Qt? I think you meant HTTP pipelining (that's the jargon used inside Qt code). I'm not 100% sure but in Qt5, the default _should_ be to use HTTP pipelining. In any case, you can explcitly check in the reply object if pipelining was indeed used or not. Check for the QNetworkRequest::HttpPipeliningWasUsedAttribute attribute in your reply. Alternately, you can try and explicitly request this behaviour by setting the n/w request attribute: request.setAttribute(QNetworkRequest::HttpPipeliningAllowedAttribute, true); If it still doesn't work, then it might be a bug. What platform are you running your on, BTW? HTH, -mandeep If I simply make the second request after the first one finished like the following QNetworkAccessManager *manager = new QNetworkAccessManager(this); connect(manager, SIGNAL(finished(QNetworkReply*)), this, SLOT(replyFinished(QNetworkReply*))); manager-get(QNetworkRequest(QUrl(http://qt-project.org;))); it seems a new TCP connection to the server will be initiated (I have checked with a network sniffer) The experiment also says: If the reply is deleteLater() or abort() within finished() signal, the connection will be closed. ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest
Re: [Interest] Best practices for settings
On Mon, Nov 18, 2013 at 5:03 PM, Philipp Kursawe phil.kurs...@gmail.com wrote: I am also currently struggling how to wire up changes to QSettings with the lack of signals/slots. Some of my plugins depend on global app settings but with QSettings its impossible for them to get notified about changes in settings. I thought subclassing QSettings is a good idea, until I found it it does not use virtual functions I could overload. How about writing a wrapper class with QProperties for all the settings you want to store. This class internally uses QSettings for writing them to persistent storage. You'll have to make it a singleton though. The notifications can come from the usual property changed signals. This way you can also control which properties are read-only and which ones can be changed. HTH, -mandeep ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest
Re: [Interest] Best practices for settings
On Mon, Nov 18, 2013 at 5:24 PM, André Somers an...@familiesomers.nl wrote: Tomasz Siekierda schreef op 17-11-2013 17:29: The settings class is a Singleton, and all options are accesible through member variables (private + getters and setters, or public - if you prefer). Although I personally believe Singletons are evil, they can be useful - and this is one of the place where the benefits outweight the problems. Singletons really are evil indeed. However, Qt already provides one, and you might as well use it: QApplication. We usually make our settings object a member of our own QApplication-derived Application class. That way, it is available where needed, but we don't have another singleton. Do you provide any sort of access restrictions to the settings. Eg: if some modules should only be able to read a particular setting and not change it, where would you enforce this? in the module itself or somewhere else or is this something not relevant in your context? Thanks, -mandeep André ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest
Re: [Interest] QProgressDialog not showing processEvents()
You have two viable approaches here: * break up the saving method into chunks. That is, do a small part of the work of the saving, queue the next piece of work to be done, and return to the eventloop. The eventloop will then trigger the next queued piece of the work being done. This way, there is no need for processEvents() at all. * move your saving code to a worker object, and execute it in a separate thread. Also, no need to use processEvents, as the heavy lifting is done outside of the GUI thread. I'd too suggest the separate thread method as it's more generic and will across different scenario's. The only thing that you need to worry about is that your thread's actions are in sync with what the GUI is showing. Eg: in case you provide a cancel button, you'll have to inform the worker thread to abort and wait for it to exit cleanly. HTH, -mandeep ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest
Re: [Interest] Network configuration from qt under linux
On Sun, Nov 10, 2013 at 7:25 AM, nate.y...@gmail.com wrote: If your system can be customized, that will be easy. Install NetworkManager on your system. And use dbus to communicate with the NetworkManager daemon. We too used NM for configuring network interfaces on our embedded board. We had to cross-compile NM from source though it wasn't very straightforward as NM had a lot of dependencies. We also had to change some code to make it detect the ethernet interface on our board. Communication was done over dbus using QtDbus. HTH, -mandeep At 2013-11-10 05:26:35,Simone cjb.sw.nos...@gmail.com wrote: Hello, We developed an application that need to configure all the network configurations from our GUI. We must let the end user be able to configure the device network configuration from a user friendly interface, without doing it by command line :-) Now, I have googled a bit but seems that qt don't support this, could you confirm it? There is an alternative solution to do this? Our system is based on an ARM cpu, and linux embedded (v2.6.35.3). The parameters we want to be able to change are - DHCP or STATIC mode - IP addr. - SUBNET - DNS - GATEWAY Does someone have any suggestion? Thanks so much Simone ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest
Re: [Interest] What for does qt5gui need OpenGL?
For Qt4 JSON support, I've used Eeli Reilins QtJSON and been very happy with it: https://github.com/da4c30ff/qt-json. I recommend it. We've been using Flavio Castelli's QJson in our embedded project with Qt4 and it's worked out well. http://qjson.sourceforge.net/ HTH, -mandeep Bo. -- Bo Thorsen, European Engineering Manager, ICS Integrated Computer Solutions. Delivering World-Class Applications http://ics.com/services ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest
Re: [Interest] QtDBus interface design question
The only solution I can imagine is to pass the entire table in one DBus message, but how. I cannot pass the objects itself, because I cannot How about returning an array of strings in the method call? Both are valid DBus types and you could probably concatenate the various properties using a delimiter and tokenize them at the receiver end. I'm no dbus expert and have mostly used QtDbus to communicate with existing services, like NetworkManager etc, so CMIIW! :) HTH, -mandeep transfer an QObject via DBus. Creating plain structs and pass them is an option but is rather dirty to me. How are DBus experts handling this? I know our DBus interface is quite complex and most others are far easier, but there must be a solution. I'm still a DBus noob, so any hint how to change the design would be very very welcome. Thanks very much Roland ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest
[Interest] Need help in testing a feature on OSX
Hi All, Is there a noble soul out there willing to spend some time in helping me test out a feature on OSX?! :) The noble soul should have a working qt source build setup on OSX. I'm working on small feature for specifying custom DNS server to QDnsLookup (QTBUG-30166). I wanted to test out the feature on OSX, but I don't have a machine handy (it's tested on Windows and Linux). Can someone with a working setup test the following patches for build failures? https://codereview.qt-project.org/#change,66701 https://codereview.qt-project.org/#change,66702 https://codereview.qt-project.org/#change,68447 It would be even more awesome if someone got the time to test out the change with the modified dnslookup example in this patchset! :) For testing with an IPv4 nameserver address, run: $ ./examples/network/dnslookup/dnslookup -s 8.8.8.8 www.google.com For testing with an IPv6 nameserver address (if you have a working IPv6 setup), run: $ ./examples/network/dnslookup/dnslookup -s 2001:4860:4860:: www.google.com In the output you should see a bunch of IPv4 address for the host name passed (on Linux, to be doubly sure that the system configured nameserver's are not being used, I used to comment out the entries in /etc/resolv.conf). Please let me know if you need more info. Thanks for your time! Regards, -mandeep ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest
Re: [Interest] Qt based LRU container?
I wrote a ordered map sometime back using a QHash and QLinkedList. https://github.com/mandeepsandhu/qt-ordered-map In the 'examples' section, I've implemented a simple LRU cache using the ordered map. https://github.com/mandeepsandhu/qt-ordered-map/tree/master/examples/lrucache Once the capacity of the cache is reached and a new item is inserted, we take the first element of the ordered map, which is the least recently used item, and remove it. You could easily modify this code to emit a signal when this eviction happens. HTH, -mandeep On Sat, Oct 19, 2013 at 11:13 PM, Mark mark...@gmail.com wrote: Hi, Does anyone know of an LRU based container for Qt? I'm specifically looking for an implementation that notifies me when something gets removed due to LRU kicking in. QCache would be nearly OK for my needs, but it doesn't notify me when something drops out due to LRU kicking in. I prefer if the container itself is a list though a map/hash would work for me as well. Cheers, Mark ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest
[Interest] OSX newbie question on Qt5 src build
Hi All, I have a old iMac running OSX 10.5.8 (Xcode 3.1). Is it possible to build Qt5 on it or is it tool old a version? I'm following the guide here, but the minimum version of OSX/Xcode is not mentioned (probably there isn't?): http://qt-project.org/wiki/Building_Qt_5_from_Git Any tip is appreciated. Thanks, -mandeep ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest
Re: [Interest] OSX newbie question on Qt5 src build
On Wed, Oct 16, 2013 at 3:07 PM, Till Oliver Knoll till.oliver.kn...@gmail.com wrote: Am 16.10.2013 um 09:35 schrieb Mandeep Sandhu mandeepsandhu@gmail.com: Hi All, I have a old iMac running OSX 10.5.8 (Xcode 3.1). Is it possible to build Qt5 on it or is it tool old a version? Given that not even Snow Leopard 10.6 is supported *for development* anymore (but IIRC you can still *deploy* your Qt applications on 10.6) I don't think you can compile Qt 5.x out of the box on OS X 10.7. Unless you are prepared to fiddle around with the sources (mostly the Objective C sources which interface with the Cocoa etc. API, I assume) and/or manually upgrade your compiler. Thanks all for your quick inputs. I was working on a network related feature in Qt5 and wanted to test it on a *BDS platform. I had an old iMac handy so thought I could use it for testing. But I guess now I need to pay Apple for upgrading the OS on it! :/ -mandeep Cheers, Oliver ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest
Re: [Interest] serialization of QStateMachine for recovery mode
Well, in general I would consider working with this approach and automatically adding those transitions between the start state and all other states. QTransition could be derived to QRecoveryTransition that throws only if a QRecoveryEvent is posted. But then we would need to keep some kind of a reference to the current state within the state machine. And I saw no opportunity to address the current state in QSM. Automatically adding a unique ID might help here... QSM has an API QStateMachine::configuration(). This doesn't exactly give you the lowest level state the SM is currently in but ALL the states (lowest + all it's parent states). I had similar requirement where I wanted to know the lowest level child state the SM is in. So I wrote a small state tracker so to speak, which had a state property which was changed by the Qt SM using its property assignment features. But as my intention is to use this approach in a work flow driven application that takes care of building up a set of data I also will have to take care of keeping data and state machine consistent. If some data would be lost but the state machine is recovered to a later state then we would end up in an inconsistent state! So recovering any state without check of data is critical. So my current approach is to recover the data and set up a special QRecoveryState/-Transition connection with guards on data elements that once an QRecoveryEvent is posted automatically goes all the way to the right state. Would that be a considerable approach? You can also look at having a different initial state (QAbstractState::setInitialState()) based on if the app started normally or in recovery mode, but then you'd loose any history that you might've had (if using history states in the SM). HTH, -mandeep Great discussion! Best Regards, Ingmar ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest
Re: [Interest] Interest Digest, Vol 25, Issue 32
P.S. ..second try again because of this horrible HTML mail mess most of the apps produce... Actually all your mails are coming through to this ML even the HTML formatted ones! :) -mandeep ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest
Re: [Interest] serialization of QStateMachine for recovery mode
On Fri, Oct 11, 2013 at 12:05 AM, Ingmar Wegner iweg...@gmx.de wrote: Hi list, we are planning of using QStateMachine (excellent work, guys!) for a workflow driven application (tasks). I am thinking of an architecture in which tasks have their own state machine (QState) that will be connected to the application state machine (QStateMachine) as sub states. (Has anyone done something like this so far? ...I guess so!) Yes, we have done something similar. We've used QSM as a UI controller for our embedded Qt application. I think QSM is one of the best but most underrated features of Qt! :) I am thinking of separating state machine logic from the implementation of the actions (e.g. data driven algorithms) that are triggered by transitions; so a task and a task_state_machine class for each task. The way we did it was that each of our UI widgets used a represent a state of the QSM, and would be 'activated' when the QSM entered that state (via onEntry() and onExit() callbacks). For states that have more complex interactions, you can have a child state machine further mapping the sub-states. You can also look at having parallel state machines for reducing the number of inter-dependent states (see the ex in QSM docs). Critical here is the feature to serialize the application state machine and the intended task state machines as I want to have a fallback if somebody pulls the plug (crash recovery)! Once the application comes back on it shall check for a possible crash and if so recover the state it was in before the crash. I couldn’t find any documentation / blog / forum question on this so far so here it is. Has anybody yet considered doing something similar? I don't think QSM provides this feature. The thing is that you might have arrived at the current QSM state after a some set of events and transitions when the app crashed. It'll be quite an overhead to store all this info in the QSM, especially if history states were involved. One lame way for restoring state would be to keep track of al the events that were posted to the SM and sort of replay those events to the SM when the app attempts a recovery (to reach the target state when the crash happened). But this is not optimal as the event chain for a long running app might be quite long. A fallback would be to rebuild the state by analyzing data that was serialized as regularly done for crash recovery. But this would make the state machine pattern complex! Any ideas / experiences? What do you mean by 'data' here? I don't think there's a way to directly jump to a nested state without going through transitions from the top level state, but it's been a while since I used QSM (used in 4.6/4.7) so I could be wrong here. HTH, -mandeep Best Regards, Ingmar ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest
Re: [Interest] Looking for third party Qt libraries
On Wed, Oct 9, 2013 at 11:51 AM, André Somers an...@familiesomers.nlwrote: Op 9-10-2013 7:34, Cornelius Schumacher schreef: On Tuesday 08 October 2013 06:48:38 BRM wrote: Cool - I don't have any at this time, but it's good information to have and I'm sure others here do; and yes, listing the license is perhaps the one change that would be good to do - even for the Open Source libraries. The license is already listed, but we should add some way of filtering for the license. Not only for the license, but on many other things. I, for one, do not like to go through a huge list of libraries one at a time. Rather, I'd like to use some keywords to search for libraries that seem to offer the component I'm after. +1 to that. We could have a 'tags' field in the manifest JSON which can be made searchable or used in filters. -mandeep ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest
Re: [Interest] Install both Qt5 and Qt4.7 at one Ubuntu
I think both Qt4 and 5 are there in the Ubuntu apt repos. Though I'm not sure if they'll play nice if _both_ are installed from apt (eg which qmake will be used?). Maybe you can install one of them directly (eg: by downloading Qt5 pre-built binaries from qt-project.org) and the other one from apt. Basically you just need to use the right qmake for building your apps. Eg: you can have 'qmake5' point to the Qt5 qmake binary and use that for building Qt5 apps while 'qmake' uses the Qt4 binary. HTH, -mandeep On Mon, Oct 7, 2013 at 3:21 PM, Николай Шатохин n.shatok...@gmail.comwrote: Hello. I need Qt4.7 for developing apps for embedded systems and Qt5 for desktop apps. Is it possible to install it both in Ubuntu 13.04 without conflicts? Best regards, Nick ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest
Re: [Interest] Install both Qt5 and Qt4.7 at one Ubuntu
On Mon, Oct 7, 2013 at 8:32 PM, Thiago Macieira thiago.macie...@intel.comwrote: On segunda-feira, 7 de outubro de 2013 05:30:11, Jonathan Greig wrote: they should play nicely, look for qtchooser and use it to switch between the two: qtchooser -run-tool=qmake -qt=qt5 make Or, more simply: qmake -qt5 make This syntax looks much simpler/cleaner. Thanks for the pointer. -mandeep ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest
Re: [Interest] Qt on PS4 and SteamOS
On Thu, Oct 3, 2013 at 5:57 PM, Phil Hannent p...@hannent.co.uk wrote: On 3 October 2013 05:07, Mandeep Sandhu mandeepsandhu@gmail.com wrote: On Wed, Oct 2, 2013 at 2:43 PM, Mojmír Svoboda mojmir.svob...@warhorsestudios.cz wrote: * Mandeep Sandhu mandeepsandhu@gmail.com [2013-09-30 16:08:44 +0530]: As for PS4 I don't know what OS it runs. You might have to add a QPA plugin for it for running Qt on its graphics stack. It is a fork of FreeBSD, with OpenGL. Thanks for info. I'll remember this! :) So it should be possible to use Qt here. Caution should be taken with that, although parts of BSD have been seen in the development hardware for PS4 it isn't to say that it is BSD. Windows NT used to have a BSD network stack if my memory serves. As for the OpenGL part, well Sony have the libGCM library for graphics and the PSGL API, its build along the lines of OpenGL ES but optimised for their consoles. So you cannot expect it to be standards compliant. Ok. though if their BSD variant can POSIX apps, then at least non-GUI part (or Qtcore+Qtnetwork) can be expected to run at least. I would not expect a QPA for the PS4 any time soon. If the gfx libs are proprietary then I gues there's not much hope for a QPA plugin, unless somebody partners with them to make one. -mandeep Phil ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest
Re: [Interest] QThread, correct exit.
On Sat, Sep 28, 2013 at 3:14 PM, Alexander Syvak alexander@gmail.comwrote: Hello, how to correctly stop a QThread execution? I am using thread.quit(); thread.terminate(); Don't terminate. Quitting and waiting should be sufficient. thread.wait(500); Without terminate() thread wait forever. Each thread is executing an event loop only (object is moved into thread). Is there anything else the thread could be stuck on? Busy looping somewhere? Waiting for a syscall? HTH, -mandeep ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest
Re: [Interest] QMapint64_t significantly slower than QMapint32_t
On Sun, Sep 22, 2013 at 4:42 PM, Konstantin Tokarev annu...@yandex.ruwrote:
22.09.2013, 13:24, Etienne Sandré-Chardonnal etienne.san...@m4x.org:
I don't, I have very only strong conviction from tests on a big large
program. I was hoping that someone had an idea about the cause... Would
this help to make one?
I did a quick test : inserting 1000 items in a QMapint32_t, int
and QMapint64_t, int using rand() for key and value, measuring the delay
with QDateTime::currentMsecsSinceEpoch.
The int32 version took about 2100ms while the int64 took about 2300ms.
So maybe this is only a memory cache issue. The difference is higher in
my app (measured with a profiler), maybe because it decreases cache
efficiency of other code parts.
Using gcc 4.8.0 mingw64 rubenvb build, with Qt 4.8.1
Etienne
Now try std::mapint32_t, int and std::mapint64_t, int - red-black tree
should work faster than QMap's skiplist.
Out of curiosity i tried measuring the insert, iteration and removal times
of QMap, QHash and std::map. The test included inserting numbers
(sequentially), iterating over all entries and then removing a random
number from it (Test app attached.).
Here are my results (g++ (Ubuntu/Linaro 4.7.3-1ubuntu1) 4.7.3, Intel core
i7, 1.2GHz, 8 GB RAM).
$ ./qtvsstl 1000
Timing insertion of 1000 items...
QMap : 1737 msecs
QHash : 821 msecs
STL map : 5458 msecs
Timing iteration over 1000 items...
QMap : 156 msecs
QHash : 202 msecs
STL map : 173 msecs
Timing removal of random item from 1000 items...
Map : 0 msecs
Hash : 0 msecs
STL map : 0 msecs
STL map seems to be the slowest for insertion.
I don't have the data handy, but some ppl say that skip lists perform
better than RB tree's for large data sets and are more 'friendly' to
concurrent programming. I'm not sure if thats the reason why Qt containers
use skip lists instead of Rb/AVL trees.
HTH,
-mandeep
--
Regards,
Konstantin
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#include QCoreApplication
#include QMap
#include QHash
#include QTime
#include QDebug
#include map
int main(int argc, char *argv[])
{
//QCoreApplication a(argc, argv);
int itemCount = 0;
bool ok = false;
if (argc 1) {
itemCount = QString(argv[1]).toInt(ok);
if (!ok) {
qWarning() \nError! Enter a valid number.;
qDebug() \nUsage:\n\t *argv number of items for testing\n;
return 1;
}
} else {
qDebug() \nUsage:\n\t *argv number of items for testing\n;
return 1;
}
//Qt containers
QMapint, int qmap;
QHashint, int qhash;
//STL containers
std::mapint, int stlmap;
QTime timer;
qDebug() Timing insertion of itemCount items...;
timer.start();
for (int i=0; iitemCount; i++) {
qmap.insert(i, i);
}
qDebug() QMap : timer.elapsed() msecs;
timer.start();
for (int i=0; iitemCount; i++) {
qhash.insert(i, i);
}
qDebug() QHash : timer.elapsed() msecs;
timer.start();
for (int i=0; iitemCount; i++) {
stlmap.insert(std::pairint, int(i, i));
}
qDebug() STL map : timer.elapsed() msecs;
qDebug() \nTiming iteration over itemCount items...;
int dummy = 0;
timer.start();
foreach (int val, qmap.values()) {
dummy += val;
}
qDebug() QMap : timer.elapsed() msecs;
dummy = 0;
timer.start();
foreach (int val, qhash.values()) {
dummy += val;
}
qDebug() QHash : timer.elapsed() msecs;
dummy = 0;
timer.start();
for (std::mapint, int::iterator it=stlmap.begin(); it!=stlmap.end(); ++it) {
dummy += it-second;
}
qDebug() STL map : timer.elapsed() msecs;
qDebug() \nTiming removal of random item from itemCount items...;
int rand = qrand() % itemCount;
timer.start();
qmap.remove(rand);
qDebug() Map : timer.elapsed() msecs;
rand = qrand() % itemCount;
timer.start();
qhash.remove(rand);
qDebug() Hash : timer.elapsed() msecs;
rand = qrand() % itemCount;
timer.start();
stlmap.erase(rand);
qDebug() STL map : timer.elapsed() msecs;
//return a.exec();
return 0;
}
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Re: [Interest] qmake exclude modules
Will webkit work w/o network?
I think it depends on the network module. Same might be true for other
modules, but I'm not sure.
HTH,
-mandeep
On Wed, Sep 18, 2013 at 3:19 PM, Phil Hannent p...@hannent.co.uk wrote:
Hi,
I am trying to remove some Qt modules that I don't need at the moment,
however qmake isn't outputting a Makefile with the expected syntax. In
my .pro file I have:
QT += core gui webkit
greaterThan(QT_MAJOR_VERSION, 4) {
message(Using QT5)
QT += widgets
QT += webkitwidgets
QT -= printsupport
QT -= sensors
QT -= qml
QT -= opengl
QT -= quick
QT -= network
QT -= multimedia
QT -= multimediawidgets
}
CONFIG = qt warn_on debug_and_release
So I am expecting things like QtSensors not to be in the includes or
LIBS of the Makefile.Release however they are there. Is there some
sort of dependency with webkit that drags in the other modules?
Regards
Phil
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Re: [Interest] Playing MP4 and FLV with QMediaPlayer
The trick is this, I can put this on several different machines - all are Windows 7 Pro: 1.) machine 1 - development box, can play some mp4s but not others (all h264) 2.) machine 2 - personal household box, will play the sampleFile mp4 sometimes 3.) machine 3 - COMPLETELY clean windows 7 pro install, aside from the code above, has nothing installed on it, NEVER plays the mp4. All 3 machines can play the sampleFile.mp4 in Windows Media Player. As a final note, none of these will play FLV either. Pointers anyone? What am I missing here? QtMultimedia relies on 'backends' to work on different OS'. For Windows I think it uses 'DirectShow'. Is that installed and working properly on the machines you're trying? Here's more detail on the state of art: http://qt-project.org/wiki/Qt_Multimedia_Backends Places where video is not playing, it's possible that there's no support for the codec/container in the backend being used (DirectShow or some other). HTH, -mandeep Thanks! -Jason ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest
Re: [Interest] MultiCast problem. QAbstractSocket::ShareAddress no effect?
On Tue, Sep 10, 2013 at 5:39 PM, Guido Seifert warg...@gmx.de wrote: QAbstractSocket::AddressInUseError The bound address is already in use As I said: The QAbstractSocket::ShareAddress mode has not effect. This SO QnA throws some light on the murky world of SO_REUSEADDR! :) http://stackoverflow.com/questions/14388706/socket-options-so-reuseaddr-and-so-reuseport-how-do-they-differ-do-they-mean-t Though according to this answer, it's possible to bind more than 1 UDP socket to the exact same host:port combo as long as all of them use SO_REUSEADDR _before_ binding (which is what your code is doing I think?). Could be a regression as Thiago mentioned. -mandeep Guido On Tue, 10 Sep 2013 17:31:13 +0530 Mandeep Sandhu mandeepsandhu@gmail.com wrote: What does QAbstractSocket::error() say when the 2nd bind() call fails? Maybe that'll give some hint about the error. -mandeep ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest
Re: [Interest] Qt Application deployment across platforms
On Wed, Sep 4, 2013 at 12:07 PM, Ramakanthreddy Kesireddy ramakanthreddy.kesire...@techmahindra.com wrote: Hi, I would like to know if I develop a Qt application, can it be deployed across platforms like linux,OSX and Android without recompiling for Specific platform like that of HTML5 application.? It can be deployed w/o recompiling ...though there's no knowing whether it'll work. Thanks and Regards, Ramakanth -- DISCLAIMER: This email (including any attachments) is intended for the sole use of the intended recipient/s and may contain material that is CONFIDENTIAL AND PRIVATE COMPANY INFORMATION. Any review or reliance by others or copying or distribution or forwarding of any or all of the contents in this message is STRICTLY PROHIBITED. If you are not the intended recipient, please contact the sender by email and delete all copies; your cooperation in this regard is appreciated. ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest
[Interest] Qt based Ordered Map container
Hi All, Sometime (almost 2 yrs!) back we had a discussion here about having a new container type in Qt which would be like a QMap, except that it stored keys in their insertion order. This was mostly inspired by a Python data-structure - OrderedDict ( http://docs.python.org/library/collections.html#collections.OrderedDict). Recently, I had some free time on hand and so though of implementing it using existing Qt containers. Here's the code for it: https://github.com/mandeepsandhu/qt-ordered-map It's not a core container in itself as it uses existing Qt containers for most of the implementation (much like the Python implementation). For storing the data I use a QHash and for keeping the key (insertion) order, I use a QLinkedList. The value stored in the hash, is actually a pair - of the user provided value and a QLinkedList _iterator_ which points to the item inserted in the linklist. This makes it quite easy and fast to delete items from these 2 containers in constant time. The performance of this container is similar to QHash except when you want all the values from it, as that requires first fetching the keys from the linklist and then using that to fetch the values from the hash table. It provides a sub-set of QMap API, complete with const and non-const iterators (you can use 'foreach' for iterating over all the values in their insert order). In case you want to use such a container, please try it out and let me know your feedback. Thanks, -mandeep ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest
Re: [Interest] Qt based Ordered Map container
In case you want to use such a container, please try it out and let me know your feedback. You need to use Boost.MultiIndex. Thanks for pointing this out. I haven't used Boost much so didn't know about it. This looks like quite a flexible container where it has different indexes for the data stored within (like an RDBMS). -mandeep -- Regards, Konstantin ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest
Re: [Interest] QNAM::get() spawns three processess and opens file descriptors which I am unable to close
My problem is that, whenever I call manager-get(), this spawns 3 processess, which I am unable to shut down. After a while (running many requests) there were a huge amount of running processess and open file descriptors. They are consuming RAM and running out of max open file descriptor limit... Every time I call manager-get(request) 3 new processess are spawnt. I am using Qt 4.8.4 on Debian 5. You're not supposed to explicitly do anything with these threads. They're probably started by QNAM for doing the network operations asynchronously and a caller has no control over them. How many such requests are you dispatching in parallel? Looks like you're hitting your systems resource limit. You can either increase this limit (using ulimit), or restrict the number of simultaneous outgoing requests (by doing it in batches). I don't see a bug here. HTH, -mandeep I have also checked the bugtracker and have found a few closed reports: https://bugreports.qt-project.org/browseMaybe you're running out of resouerce/QTBUG-20148https://bugreports.qt-project.org/browse/QTBUG-20148 https://bugreports.qt-project.org/browse/QTBUG-20851 _gs ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest
Re: [Interest] QNAM::get() spawns three processess and opens file descriptors which I am unable to close
On Wed, Aug 28, 2013 at 5:45 PM, gsmember gs gsmem...@hotmail.de wrote: Thanks for your reply, in gerneral I do one request after the other. Always with the same QNAM object. After a hour I have about 600 running processess and 1024 (which is the user limit) open file descriptors. Do you have a sample program which illustrates this problem? -mandeep -- Date: Wed, 28 Aug 2013 16:31:34 +0530 Subject: Re: [Interest] QNAM::get() spawns three processess and opens file descriptors which I am unable to close From: mandeepsandhu@gmail.com To: gsmem...@hotmail.de CC: interest@qt-project.org My problem is that, whenever I call manager-get(), this spawns 3 processess, which I am unable to shut down. After a while (running many requests) there were a huge amount of running processess and open file descriptors. They are consuming RAM and running out of max open file descriptor limit... Every time I call manager-get(request) 3 new processess are spawnt. I am using Qt 4.8.4 on Debian 5. You're not supposed to explicitly do anything with these threads. They're probably started by QNAM for doing the network operations asynchronously and a caller has no control over them. How many such requests are you dispatching in parallel? Looks like you're hitting your systems resource limit. You can either increase this limit (using ulimit), or restrict the number of simultaneous outgoing requests (by doing it in batches). I don't see a bug here. HTH, -mandeep I have also checked the bugtracker and have found a few closed reports: https://bugreports.qt-project.org/browseMaybe you're running out of resouerce/QTBUG-20148https://bugreports.qt-project.org/browse/QTBUG-20148 https://bugreports.qt-project.org/browse/QTBUG-20851 _gs ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest
[Interest] Strange problem in template class (Iterator as value type of a QHash)
Hi All,
I'm writing a template class which contains a QHash. Now if I try to store
an Iterator (of a QList) as the _value_ of this Hash then it fails to
compile.
Here's the sample code:
template typename K, typename V
class TemplateTest
{
public:
TemplateTest()
{
QHashK, QLinkedListV::iterator h;
Q_UNUSED(h);
}
private:
K k;
V v;
};
Error:
templatetest.h:13: error: type/value mismatch at argument 2 in template
parameter list for 'templateclass Key, class T class QHash'
templatetest.h:13: error: expected a type, got 'QLinkedListV::iterator'
templatetest.h:13: error: invalid type in declaration before ';' token
However, if I keep the value as a QList (remove iterator) it compile fine.
Whats the problem with storing a Iterator as the value?
Thanks,
-mandeep
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Re: [Interest] Strange problem in template class (Iterator as value type of a QHash)
Error from Clang:
error: template argument for template type parameter must be a type; did
you forget 'typename'?
It' right, in that I need to use typename 'somewhere', I just didn't know
where (and why).
I finally fixed it doing a typedef of this dependent type, which also makes
it easy to type! :)
template typename K, typename V
class TemplateTest
{
typedef typename QLinkedListV::iterator iter;
public:
TemplateTest()
{
QHashK, iter h;
Q_UNUSED(h);
}
...
There's a nice explanation about 'typename' keyword here:
http://pages.cs.wisc.edu/~driscoll/typename.html
Note: use proper compiler next time.
Note: Using g++, which is a _very_ proper compiler. It even has a
-pedantic switch! ;)
$ g++ --version
g++ (Ubuntu/Linaro 4.7.3-1ubuntu1) 4.7.3
Regards,
-mandeep
Error:
templatetest.h:13: error: type/value mismatch at argument 2 in template
parameter list for 'templateclass Key, class T class QHash'
templatetest.h:13: error: expected a type, got
'QLinkedListV::iterator'
templatetest.h:13: error: invalid type in declaration before ';' token
However, if I keep the value as a QList (remove iterator) it compile
fine.
Whats the problem with storing a Iterator as the value?
Thanks,
-mandeep
,
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Re: [Interest] Strange problem in template class (Iterator as value type of a QHash)
On Fri, Aug 23, 2013 at 10:34 PM, Konstantin Tokarev annu...@yandex.ruwrote: 23.08.2013, 20:39, Mandeep Sandhu mandeepsandhu@gmail.com: Error from Clang: error: template argument for template type parameter must be a type; did you forget 'typename'? It' right, in that I need to use typename 'somewhere', I just didn't know where (and why). Clang shows a caret where you need to insert typename. It just does not explain why. Thanks for the info. I'll try Clang sometime. Regards, -mandeep -- Regards, Konstantin ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest
Re: [Interest] Strange problem in template class (Iterator as value type of a QHash)
On Fri, Aug 23, 2013 at 10:24 PM, Constantin Makshin cmaks...@gmail.comwrote:
g++ isn't bad at all, but sometimes its error messages may be quite
confusing/cryptic.
Agreed.
Rather in some cases it _did_ tell me that i needed to prefix 'typename' in
given line, but unfortunately in this stmt it chose a more cryptic message!
:/
-mandeep
On Aug 23, 2013 8:39 PM, Mandeep Sandhu mandeepsandhu@gmail.com
wrote:
Error from Clang:
error: template argument for template type parameter must be a type;
did you forget 'typename'?
It' right, in that I need to use typename 'somewhere', I just didn't know
where (and why).
I finally fixed it doing a typedef of this dependent type, which also
makes it easy to type! :)
template typename K, typename V
class TemplateTest
{
typedef typename QLinkedListV::iterator iter;
public:
TemplateTest()
{
QHashK, iter h;
Q_UNUSED(h);
}
...
There's a nice explanation about 'typename' keyword here:
http://pages.cs.wisc.edu/~driscoll/typename.html
Note: use proper compiler next time.
Note: Using g++, which is a _very_ proper compiler. It even has a
-pedantic switch! ;)
$ g++ --version
g++ (Ubuntu/Linaro 4.7.3-1ubuntu1) 4.7.3
Regards,
-mandeep
Error:
templatetest.h:13: error: type/value mismatch at argument 2 in
template parameter list for 'templateclass Key, class T class QHash'
templatetest.h:13: error: expected a type, got
'QLinkedListV::iterator'
templatetest.h:13: error: invalid type in declaration before ';' token
However, if I keep the value as a QList (remove iterator) it compile
fine.
Whats the problem with storing a Iterator as the value?
Thanks,
-mandeep
,
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Re: [Interest] Difference between QUrl::fromEncoded and QUrl::fromPercentEncoding ?
It seems completely understandable to me. A URL is: URL = [scheme :] [authority] [path] [? query] [# fragment] with authority = // [userinfo @] [host] [: port] (technically, a URL cannot have an empty scheme, but a URL reference can, and QUrl parses like that) Since the input had no :, there was no scheme. Since the input had no //, it also had no authority. That means everything from the beginning until ? or # was the path. Since there was no ? or #, everything in the input was parsed as path. Ok. I thought the scheme, host etc was being interpreted _after_ decoding the string. Also, if we are getting a percent encoded 'string' from external source, whats the correct way of making it into a QUrl? The URL was parsed correctly as it came. The question is why your external source gave you that URL which is not what you wanted it to be. A Url like the one in this post is quite possible if it came as part of another url (eg: a url encoded as a parameter). Thanks for the clarification. -mandeep ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest
Re: [Interest] Difference between QUrl::fromEncoded and QUrl::fromPercentEncoding ?
On Tue, Aug 13, 2013 at 4:14 PM, Richard Turner tur...@yiran.org wrote: Hi, QString str = http%3A%2F%2F192.168.1.1%3A80%2Fservlet%2Fcom.mcdonalds.report.view.excel.ExcelReportServlet%3Ffile%3D4162%26columns%3D0%26srcType%3DdefineBean%26width%3D0%26height%3D0%26reportParamsId%3D101767%26cachedId%3D4163%26t_i_m_e%3D1376389959473pageStyle=0; QUrl downloadUrl1 = QUrl::fromEncoded(str.toUtf8());QUrl downloadUrl2 = QUrl::fromPercentEncoding(str.toUtf8()); assert(downloadUrl1.toString() == downloadUrl2.toString()); assert(downloadUrl1 == downloadUrl2); Why is the second assertion fails when the first assertion still passes? What is the underlying difference between QUrl::fromEncoded and QUrl::fromPercentEncoding? I think you're using Qt4 since the first assert is passing (in Qt5 it would've failed as the default arg to QUrl::toString() has changed). QUrl::fromEncoded assumes the string is ASCII encoded only. Is there a non-ASCII char somewhere in that url? -mandeep Thanks! Richard ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest
Re: [Interest] Difference between QUrl::fromEncoded and QUrl::fromPercentEncoding ?
Hi Thiago, On Tue, Aug 13, 2013 at 11:20 PM, Thiago Macieira thiago.macie...@intel.com wrote: On quarta-feira, 14 de agosto de 2013 00:35:47, Richard Turner wrote: OK. Now the problem is, when I use downloadUrl1(result from fromEncoded) to make a QNetworkRequest (HTTP GET), I always detect an error: Protocol is unknown. When I switch to use downloadUrl2, all is good. That was expected. Look at what your URL was: http%3A%2F%2F192.168.1.1%3A80%2Fservlet%2Fcom.mcdonalds.report.view.excel.ExcelReportServlet%3Ffile%3D4162%26columns%3D0%26srcType%3DdefineBean%26width%3D0%26height%3D0%26reportParamsId%3D101767%26cachedId%3D4163%26t_i_m_e%3D1376389959473pageStyle=0 Try pasting that in a browser and see what happens. The behaviour differs because QUrl::fromEncoded tries to interpret that as a URL. It has no scheme, so the entire thing is the path of the URL. Since it The docs of QUrl::fromEncoded() (Qt 4.8) state : input is assumed to be in encoded form, containing only ASCII characters. Why does it assumes the input to be only the path? Is the caller expected to explicitly 'set' the scheme on a url returned by it? If so, the docs statement looks incomplete. However, in the above url if we decode all percent-encoded chars upto the port, then the scheme starts getting detected. This behaviour seems confusing at best. Also, if we are getting a percent encoded 'string' from external source, whats the correct way of making it into a QUrl? QUrl url; url.setUrl(QUrl::fromPercentEncoding(encodedUrlString)); Thanks, -mandeep ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest
Re: [Interest] Some questions on QSettings, qmlRegisterType() and setContextProperty
Have a look at O2, a Qt based OAuth library to see if it'll work for you:
https://github.com/pipacs/o2
It works well with QML, works with Qt4 5, stores tokens in (customizable)
QSettings in an encrypted form and has good support for OAuth 1 and 2.
HTH,
-mandeep
On Sat, Aug 10, 2013 at 11:05 AM, Jayesh Bhoot mister.bh...@gmail.comwrote:
Short, but informative reply. :)
2., but calling init in C++ componentComplete() (derive from
QQmlParserStatus as well) automatically, taking the input from
properties set in QML.
I want to clarify something here. The C++ OAuth2 class provides the data
and logic to the OAuth2Browser QML window. It has a structure something
like this:
class OAuth2 : public QObject
{
Q_OBJECT
Q_PROPERTY(QUrl oauthUrl READ oauthUrl)
public:
explicit OAuth2(QObject *parent = 0);
explicit OAuth2(QString appId, QUrl redirectUrl, QStringList
permissions, QObject *parent = 0);
QUrl oauthUrl() const;
signals:
void oauthSucceeded(QString userAccessToken);
void oauthFailed();
public slots:
void onBrowsingUrlChanged(const QUrl url);
private:
QString parseUserAccessToken(const QUrl url) const; // called by
onBrowsingUrlChanged()
static const QString m_oauthEndPoint;
QString m_appId;
QUrl m_redirectUrl;
QStringList m_permissions;
QString m_userAccessToken;
};
This is how the QML class uses it:
Window {
id: oauth2Browser
width: 500
height: 500
ColumnLayout {
anchors.fill: parent
WebView {
objectName: Browser
id: browser
Layout.fillHeight: true
Layout.fillWidth: true
url: oauth2.oauthUrl
onUrlChanged: oauth2.onBrowsingUrlChanged(browser.url)
}
Label {
id: loadingStatus
Layout.fillWidth: true
text: browser.loadProgress + % loaded.
}
}
}
Thus, its the C++ class that sets the properties, and not the QML window
that does it. By your method, I assumes that I would have to derive OAuth2
from QQmlParserStatus in order to track properties set by QML window.
However, its the other way round - QML window takes data from an instance
of the C++ class.
How should I proceed then?
Also, feel free to point out if my current design is flawed.
qmlRegisterType is better than setContextProperty, because that way
the flow is controlled from QML (and a lack of constructor arguments
is correct for declarative design, you can do additional property
based initialization in componentComplete). Good QML design has C++
expose functionality to QML but lets QML control the entire UI flow
(including window creation/handling).
I agree with preferring qmlRegisterType over setContextProperty. But
wouldn't your C++ QQmlParserStatus::componentComplete() approach work only
if the data comes from QML to C++? I think that would be the case most of
the time. But how should I handle the other way round, like in my case, or
say, while grabbing data from database or application settings?
1. Is exposing QSettings directly to QML UI a good idea?
Directly? Not a good idea, but possible. The new Qt.labs.settings API
aims to address this deficiency:
https://codereview.qt-project.org/#change,59149
I will look forward to using this.
On Sat, 10 Aug 2013 03:34:19 +0530, Alan Alpert 4163654...@gmail.com
wrote:
On Fri, Aug 9, 2013 at 8:12 AM, Jayesh Bhoot mister.bh...@gmail.com
wrote:
I will try explaining my confusion through the application I am
currently
developing.
My application (based on Qt5.1 + Qt Quick Controls) interacts with
Facebook API to manage a Facebook Page. I am trying to keep the QML code
(for UI) as separate as possible from the C++ core.
Now, an OAuth2 implementation is required to be able to interact with
Facebook API. For that, I have a C++ OAuth2 class, the constructor of
which has the following signature:
OAuth2::OAuth2(QString appId, QString redirectUrl, QStringList
permissions);
Now, as the OAuth process requires a browser, I have also implemented an
OAuthBrowser.qml, which uses OAuth2 to complete an authorization.
I have the following options to expose OAuth2 class to OAuth2Browser:
1. Instantiate OAuth2 and use setContextProperty() to expose the
instance
to OAuth2Browser. However, this means my C++ code has to deal with the
UI
code. The more baffling issue is that OAuth2Browser is a secondary
window.
When a user clicks on a Authorize window on the MainWindow, then an
AppController C++ object (connected to MainWindow) will launch the
OAuth2Browser window. Thus, the instantiation code of OAuth2Browser
would
go deep down inside a AppController method. It would have been good if
only main.cpp had to deal with the window creation.
2. Use qmlRegisterType(). In this case, I can't pass
Re: [Interest] Qt not resolving URLs
On Tue, Aug 6, 2013 at 11:30 AM, Thiago Macieira thiago.macie...@intel.comwrote: On terça-feira, 6 de agosto de 2013 11:17:35, Mandeep Sandhu wrote: On Tue, Aug 6, 2013 at 10:21 AM, Tom Isaacson tom.isaac...@navico.comwrote: I've added a simple browser page to my application using the demo code in Qt 4.8 as a base: [QTDIR]\demos\browser This works fine in Windows, but when I rebuild the app and try it on my embedded Linux device it fails. While experimenting I found I could load www.google.com by resolving the IP address and using that instead. I added the following code to my app: QHostInfo hostInfo = QHostInfo::fromName(m_url); Just to eliminate the obvious, m_url here contains a valid url? Or, better yet: does *not* contain a valid URL? Oops, yes! It takes a host name or IP addr string as input. -mandeep QHostInfo::fromName takes a host name. Not a URL. -- Thiago Macieira - thiago.macieira (AT) intel.com Software Architect - Intel Open Source Technology Center ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest
Re: [Interest] running directfb on desktop
Some more info on the status of DirectFB with Qt5: http://qt-project.org/wiki/DirectFBAndQt -mandeep On Tue, Aug 6, 2013 at 2:30 PM, Mandeep Sandhu mandeepsandhu@gmail.comwrote: During Qt 4 days, you could use qvfb (Q Virtual Frambuffer) for running applications built for Qt embedded. I'm not sure if it's still valid as Qt5 required openGL support. Maybe it's possible via the DirectFB openGL extension - DirectFBGL. HTH, -mandeep On Tue, Aug 6, 2013 at 2:14 PM, Juha Vuolle juvuo...@gmail.com wrote: Hi, was wondering if it is possible to run qt applications with directfb QPA on deskop? I just tried it but I seem to get segfault at directfb qpa backingstore constructor IDirectFBWindow *dfbWindow = static_castQDirectFbWindow *(window-handle())-dfbWindow(); where window-handle() is null. Other than that there are not much errors in the startup logs (some joystick related warnings). I see a window flashing quickly. I was wondering if I'm missing some obvious stuff I need to setup for this to work? (My setup: lubuntu 13.04, self-compiled about 3 weeks old Qt 5) any hints appreciated, Juha if its any use: ./analogclock -platform directfb ~~| DirectFB 1.2.10 |~~ (c) 2001-2008 The world wide DirectFB Open Source Community (c) 2000-2004 Convergence (integrated media) GmbH (*) DirectFB/Core: Single Application Core. (2012-05-21 06:43) (*) Direct/Thread: Started 'VT Switcher' (-1) [CRITICAL OTHER/OTHER 0/0] 8388608... (*) Direct/Thread: Started 'Linux Input' (-1) [INPUT OTHER/OTHER 0/0] 8388608... (*) DirectFB/Input: Power Button (1) 0.1 (directfb.org) (*) Direct/Thread: Started 'Linux Input' (-1) [INPUT OTHER/OTHER 0/0] 8388608... (*) DirectFB/Input: Sleep Button (2) 0.1 (directfb.org) (*) Direct/Thread: Started 'Linux Input' (-1) [INPUT OTHER/OTHER 0/0] 8388608... (*) DirectFB/Input: AT Translated Set 2 keyboard (3) 0.1 (directfb.org) (*) Direct/Thread: Started 'Linux Input' (-1) [INPUT OTHER/OTHER 0/0] 8388608... (*) DirectFB/Input: VirtualBox USB Tablet (4) 0.1 (directfb.org) (*) Direct/Thread: Started 'Linux Input' (-1) [INPUT OTHER/OTHER 0/0] 8388608... (*) DirectFB/Input: VirtualBox mouse integration (5) 0.1 (directfb.org) (*) Direct/Thread: Started 'Linux Input' (-1) [INPUT OTHER/OTHER 0/0] 8388608... (*) DirectFB/Input: ImExPS/2 Generic Explorer Mouse (6) 0.1 (directfb.org ) (*) Direct/Thread: Started 'Keyboard Input' (-1) [INPUT OTHER/OTHER 0/0] 8388608... (*) DirectFB/Input: Keyboard 0.9 (directfb.org) (*) Direct/Thread: Started 'Joystick Input' (-1) [INPUT OTHER/OTHER 0/0] 8388608... (!!!) *** ONCE [Joystick sends JS_EVENT_INIT events, make sure it has been calibrated using 'jscal -c' ] *** [../../../inputdrivers/joystick/joystick.c:99 in joystick_handle_event()] (*) DirectFB/Input: Joystick (1) 0.9 (directfb.org) (!!!) *** WARNING [out of memory] *** [../../../src/core/input.c:1133 in init_axes()] (*) Direct/Thread: Started 'Joystick Input' (-1) [INPUT OTHER/OTHER 0/0] 8388608... (*) DirectFB/Input: Joystick (2) 0.9 (directfb.org) (!!!) *** WARNING [out of memory] *** [../../../src/core/input.c:1133 in init_axes()] (*) Direct/Thread: Started 'PS/2 Input' (-1) [INPUT OTHER/OTHER 0/0] 8388608... (*) DirectFB/Input: IMPS/2 Mouse (1) 1.0 (directfb.org) (*) Direct/Thread: Started 'PS/2 Input' (-1) [INPUT OTHER/OTHER 0/0] 8388608... (*) DirectFB/Input: IMPS/2 Mouse (2) 1.0 (directfb.org) (*) DirectFB/Genefx: MMX detected and enabled (*) DirectFB/Graphics: MMX Software Rasterizer 0.6 (directfb.org) (*) DirectFB/Core/WM: Default 0.3 (directfb.org) (*) FBDev/Surface: Allocated 640x480 32 bit LUT8 buffer (index 0) at offset 0 and pitch 2560. (!) [11851:0.000] -- Caught signal 11 (at 0x10, invalid address) -- ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest
Re: [Interest] running directfb on desktop
During Qt 4 days, you could use qvfb (Q Virtual Frambuffer) for running applications built for Qt embedded. I'm not sure if it's still valid as Qt5 required openGL support. Maybe it's possible via the DirectFB openGL extension - DirectFBGL. HTH, -mandeep On Tue, Aug 6, 2013 at 2:14 PM, Juha Vuolle juvuo...@gmail.com wrote: Hi, was wondering if it is possible to run qt applications with directfb QPA on deskop? I just tried it but I seem to get segfault at directfb qpa backingstore constructor IDirectFBWindow *dfbWindow = static_castQDirectFbWindow *(window-handle())-dfbWindow(); where window-handle() is null. Other than that there are not much errors in the startup logs (some joystick related warnings). I see a window flashing quickly. I was wondering if I'm missing some obvious stuff I need to setup for this to work? (My setup: lubuntu 13.04, self-compiled about 3 weeks old Qt 5) any hints appreciated, Juha if its any use: ./analogclock -platform directfb ~~| DirectFB 1.2.10 |~~ (c) 2001-2008 The world wide DirectFB Open Source Community (c) 2000-2004 Convergence (integrated media) GmbH (*) DirectFB/Core: Single Application Core. (2012-05-21 06:43) (*) Direct/Thread: Started 'VT Switcher' (-1) [CRITICAL OTHER/OTHER 0/0] 8388608... (*) Direct/Thread: Started 'Linux Input' (-1) [INPUT OTHER/OTHER 0/0] 8388608... (*) DirectFB/Input: Power Button (1) 0.1 (directfb.org) (*) Direct/Thread: Started 'Linux Input' (-1) [INPUT OTHER/OTHER 0/0] 8388608... (*) DirectFB/Input: Sleep Button (2) 0.1 (directfb.org) (*) Direct/Thread: Started 'Linux Input' (-1) [INPUT OTHER/OTHER 0/0] 8388608... (*) DirectFB/Input: AT Translated Set 2 keyboard (3) 0.1 (directfb.org) (*) Direct/Thread: Started 'Linux Input' (-1) [INPUT OTHER/OTHER 0/0] 8388608... (*) DirectFB/Input: VirtualBox USB Tablet (4) 0.1 (directfb.org) (*) Direct/Thread: Started 'Linux Input' (-1) [INPUT OTHER/OTHER 0/0] 8388608... (*) DirectFB/Input: VirtualBox mouse integration (5) 0.1 (directfb.org) (*) Direct/Thread: Started 'Linux Input' (-1) [INPUT OTHER/OTHER 0/0] 8388608... (*) DirectFB/Input: ImExPS/2 Generic Explorer Mouse (6) 0.1 (directfb.org) (*) Direct/Thread: Started 'Keyboard Input' (-1) [INPUT OTHER/OTHER 0/0] 8388608... (*) DirectFB/Input: Keyboard 0.9 (directfb.org) (*) Direct/Thread: Started 'Joystick Input' (-1) [INPUT OTHER/OTHER 0/0] 8388608... (!!!) *** ONCE [Joystick sends JS_EVENT_INIT events, make sure it has been calibrated using 'jscal -c' ] *** [../../../inputdrivers/joystick/joystick.c:99 in joystick_handle_event()] (*) DirectFB/Input: Joystick (1) 0.9 (directfb.org) (!!!) *** WARNING [out of memory] *** [../../../src/core/input.c:1133 in init_axes()] (*) Direct/Thread: Started 'Joystick Input' (-1) [INPUT OTHER/OTHER 0/0] 8388608... (*) DirectFB/Input: Joystick (2) 0.9 (directfb.org) (!!!) *** WARNING [out of memory] *** [../../../src/core/input.c:1133 in init_axes()] (*) Direct/Thread: Started 'PS/2 Input' (-1) [INPUT OTHER/OTHER 0/0] 8388608... (*) DirectFB/Input: IMPS/2 Mouse (1) 1.0 (directfb.org) (*) Direct/Thread: Started 'PS/2 Input' (-1) [INPUT OTHER/OTHER 0/0] 8388608... (*) DirectFB/Input: IMPS/2 Mouse (2) 1.0 (directfb.org) (*) DirectFB/Genefx: MMX detected and enabled (*) DirectFB/Graphics: MMX Software Rasterizer 0.6 (directfb.org) (*) DirectFB/Core/WM: Default 0.3 (directfb.org) (*) FBDev/Surface: Allocated 640x480 32 bit LUT8 buffer (index 0) at offset 0 and pitch 2560. (!) [11851:0.000] -- Caught signal 11 (at 0x10, invalid address) -- ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest
Re: [Interest] running directfb on desktop
Maybe the answer lies in the way you compiled Qt5. What options did you give for the platform plugin? I myself have not used the QPA plugins, so can't say what the state of the DirectFB QPA plugin is. Maybe somebody else can chime in? Also, your DFB version is quite old which might causing problems. Is upgrade to a newer version an option? -mandeep On Tue, Aug 6, 2013 at 3:43 PM, Juha Vuolle juvuo...@gmail.com wrote: Hi Mandeep, I had a quick look at the wiki which says the DFBGL is not used. I can see there is some related code in the DFB QPA but I don't see it being used. I think The other EGL - OpenGL integration mentioned on the wiki would require some tweaking into qdirectfb_egl.cpp or perhaps even at egl library. For now it doesn't even compile for me (seems my directfb libs are a tad too old and missing an enum) but foremost the mesa egl API I'm using doesn't appreciate the m_eglSurface = eglCreateWindowSurface(dfbScreen-eglDisplay(), config, dfbSurface(), NULL); where the NativeWindowType is IDirectFbSurface*. thanks for the replies, Juha 2013/8/6 Mandeep Sandhu mandeepsandhu@gmail.com Some more info on the status of DirectFB with Qt5: http://qt-project.org/wiki/DirectFBAndQt -mandeep On Tue, Aug 6, 2013 at 2:30 PM, Mandeep Sandhu mandeepsandhu@gmail.com wrote: During Qt 4 days, you could use qvfb (Q Virtual Frambuffer) for running applications built for Qt embedded. I'm not sure if it's still valid as Qt5 required openGL support. Maybe it's possible via the DirectFB openGL extension - DirectFBGL. HTH, -mandeep On Tue, Aug 6, 2013 at 2:14 PM, Juha Vuolle juvuo...@gmail.com wrote: Hi, was wondering if it is possible to run qt applications with directfb QPA on deskop? I just tried it but I seem to get segfault at directfb qpa backingstore constructor IDirectFBWindow *dfbWindow = static_castQDirectFbWindow *(window-handle())-dfbWindow(); where window-handle() is null. Other than that there are not much errors in the startup logs (some joystick related warnings). I see a window flashing quickly. I was wondering if I'm missing some obvious stuff I need to setup for this to work? (My setup: lubuntu 13.04, self-compiled about 3 weeks old Qt 5) any hints appreciated, Juha if its any use: ./analogclock -platform directfb ~~| DirectFB 1.2.10 |~~ (c) 2001-2008 The world wide DirectFB Open Source Community (c) 2000-2004 Convergence (integrated media) GmbH (*) DirectFB/Core: Single Application Core. (2012-05-21 06:43) (*) Direct/Thread: Started 'VT Switcher' (-1) [CRITICAL OTHER/OTHER 0/0] 8388608... (*) Direct/Thread: Started 'Linux Input' (-1) [INPUT OTHER/OTHER 0/0] 8388608... (*) DirectFB/Input: Power Button (1) 0.1 (directfb.org) (*) Direct/Thread: Started 'Linux Input' (-1) [INPUT OTHER/OTHER 0/0] 8388608... (*) DirectFB/Input: Sleep Button (2) 0.1 (directfb.org) (*) Direct/Thread: Started 'Linux Input' (-1) [INPUT OTHER/OTHER 0/0] 8388608... (*) DirectFB/Input: AT Translated Set 2 keyboard (3) 0.1 (directfb.org) (*) Direct/Thread: Started 'Linux Input' (-1) [INPUT OTHER/OTHER 0/0] 8388608... (*) DirectFB/Input: VirtualBox USB Tablet (4) 0.1 (directfb.org) (*) Direct/Thread: Started 'Linux Input' (-1) [INPUT OTHER/OTHER 0/0] 8388608... (*) DirectFB/Input: VirtualBox mouse integration (5) 0.1 (directfb.org) (*) Direct/Thread: Started 'Linux Input' (-1) [INPUT OTHER/OTHER 0/0] 8388608... (*) DirectFB/Input: ImExPS/2 Generic Explorer Mouse (6) 0.1 ( directfb.org) (*) Direct/Thread: Started 'Keyboard Input' (-1) [INPUT OTHER/OTHER 0/0] 8388608... (*) DirectFB/Input: Keyboard 0.9 (directfb.org) (*) Direct/Thread: Started 'Joystick Input' (-1) [INPUT OTHER/OTHER 0/0] 8388608... (!!!) *** ONCE [Joystick sends JS_EVENT_INIT events, make sure it has been calibrated using 'jscal -c' ] *** [../../../inputdrivers/joystick/joystick.c:99 in joystick_handle_event()] (*) DirectFB/Input: Joystick (1) 0.9 (directfb.org) (!!!) *** WARNING [out of memory] *** [../../../src/core/input.c:1133 in init_axes()] (*) Direct/Thread: Started 'Joystick Input' (-1) [INPUT OTHER/OTHER 0/0] 8388608... (*) DirectFB/Input: Joystick (2) 0.9 (directfb.org) (!!!) *** WARNING [out of memory] *** [../../../src/core/input.c:1133 in init_axes()] (*) Direct/Thread: Started 'PS/2 Input' (-1) [INPUT OTHER/OTHER 0/0] 8388608... (*) DirectFB/Input: IMPS/2 Mouse (1) 1.0 (directfb.org) (*) Direct/Thread: Started 'PS/2 Input' (-1) [INPUT OTHER/OTHER 0/0] 8388608... (*) DirectFB/Input: IMPS/2 Mouse (2) 1.0 (directfb.org) (*) DirectFB/Genefx: MMX detected and enabled (*) DirectFB/Graphics: MMX Software Rasterizer 0.6 (directfb.org) (*) DirectFB/Core/WM: Default 0.3 (directfb.org) (*) FBDev/Surface: Allocated 640x480 32 bit LUT8 buffer (index 0) at offset 0 and pitch 2560
Re: [Interest] Qt not resolving URLs
On Tue, Aug 6, 2013 at 10:21 AM, Tom Isaacson tom.isaac...@navico.comwrote: I've added a simple browser page to my application using the demo code in Qt 4.8 as a base: [QTDIR]\demos\browser This works fine in Windows, but when I rebuild the app and try it on my embedded Linux device it fails. While experimenting I found I could load www.google.com by resolving the IP address and using that instead. I added the following code to my app: QHostInfo hostInfo = QHostInfo::fromName(m_url); Just to eliminate the obvious, m_url here contains a valid url? -mandeep ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest
Re: [Interest] QTimer and QThread
On Wed, Jul 31, 2013 at 2:31 PM, Alexander Syvak alexander@gmail.comwrote: Here's the snippet below from implementation of the run method. The class inherits a class inheriting QThread. ... screenshot_qtmr = new QTimer;//(this); screenshot_qtmr-moveToThread(this); This stmt is not necessary as the QTimer instance is created in the new thread itself. qDebug() connect(screenshot_qtmr, SIGNAL(timeout()), this, SLOT(on_screenshot_timeout())); qDebug() connect(this, SIGNAL(kill_tmr()), screenshot_qtmr, SLOT(stop())); The on_screenshot_timeout() will get called in the context of main thread, not this new thread. Hope thats what you intended. screenshot_qtmr-start(freq*1000); anal_qmr = new QTimer;//(this); anal_qmr-moveToThread(this); qDebug() connect(anal_qmr, SIGNAL(timeout()), SLOT(on_analize_timeout())); qDebug() connect(this, SIGNAL(kill_tmr()), anal_qmr, SLOT(stop())); anal_qmr-start(state_analizer_tmr_interval); if ( !state_analizer_tmr_id ) return; exec();while ( !stop ); Whats the point of this while loop here? You'll return from exit if someone calls exit() on it. Wouldn't you want to quit after that? Your slot should get called, unless the timer has been stopped due to some reason. Are you certain the timer is running (eg it's not been stopped by the kill_tmr() signal)? HTH, -mandeep } Here's an ouput run() ./13_7_31_10_49_2_974 ./13_7_31_10_49_2_974 exists ./13_7_31_10_49_2_974 has 'write' permission for other ./13_7_31_10_49_2_974/S0 directory was created true true true true run() ./13_7_31_10_49_2_974 ./13_7_31_10_49_2_974 exists ./13_7_31_10_49_2_974 has 'write' permission for other ./13_7_31_10_49_2_974/S1 directory was created true true true true It never enters those method specified on timeout(). Why? ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest
Re: [Interest] QTimer and QThread
1) From QTimer documentation: *Qt uses the timer's **thread affinityhttps://qt-project.org/doc/qt-4.8/qobject.html#thread ** to determine which thread will emit the **timeout()https://qt-project.org/doc/qt-4.8/qtimer.html#timeout **signal. Because of this, you must start and stop the timer in its thread; it is not possible to start a timer from another thread.* But you starts timer from source thread. Timer will not starts. From the same doc (just the prior sentence): In multithreaded applications, you can use QTimer in any thread that has an event loop. To start an event loop from a non-GUI thread, use QThread::exec(). I think the OP's code satisfies the requirements. He has an event loop running in the QThread and is calling start() from that thread. You should use something like: screenshot_qtmr = new QTimer;//(this); screenshot_qtmr-setInterval(freq*1000); screenshot_qtmr-moveToThread(this); qDebug() connect(this, SIGNAL(started()), screenshot_qtmr, SLOT(start())); qDebug() connect(screenshot_qtmr, SIGNAL(timeout()), this, SLOT(on_screenshot_timeout())); qDebug() connect(this, SIGNAL(kill_tmr()), screenshot_qtmr, SLOT(stop())); //screenshot_qtmr-start(freq*1000); // do not do it 2) In you sample on_screenshot_timeout will be executed in main thread, maybe you need change connect(screenshot_qtmr, SIGNAL(timeout()), this, SLOT(on_screenshot_timeout()));toconnect(screenshot_qtmr, SIGNAL(timeout()), this, SLOT(on_screenshot_timeout()), Qt::DirectConnection);? DirectConnection will only change in which thread context the slot gets called, but it should still get called at least (provided the timer is running) -mandeep ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest
Re: [Interest] QMap and thread-safe.
On Fri, Jul 26, 2013 at 11:57 AM, Sze Howe Koh szehowe@gmail.comwrote:
On 26 July 2013 12:57, Mandeep Sandhu mandeepsandhu@gmail.com wrote:
On Thu, Jul 25, 2013 at 9:04 PM, Thiago Macieira
thiago.macie...@intel.com
int inc(int foo)
{
return foo++; // not atomic anywhere
Why? Because of the way foo is being received in this function, i.e by
reference (so any operation on foo has and added level of indirection)?
Because that's simply a shorthand for 3 separate operations. See
http://stackoverflow.com/questions/10503737/is-increment-an-integer-atomic-in-x86
Well, thats why I asked the previous question, i.e if foo is of machine
word size or less, _then_ will the compiler generate the atomic fetch and
add instruction or will that have to be done explicitly by the programmer?
I understand that any (programming) language statement that results in
multiple processor instructions will not be atomic (I'm not considering
explicit lock being done in the program), since instruction from other
processes/threads can be scheduled in-between.
I guess I better write a small program and see for myself what are the
instructions generated for it! :)
-mandeep
Regards,
Sze-Howe
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Re: [Interest] QMap and thread-safe.
On Fri, Jul 26, 2013 at 12:30 PM, Thiago Macieira thiago.macie...@intel.com wrote: On sexta-feira, 26 de julho de 2013 10:27:28, Mandeep Sandhu wrote: Doing both at the same time is not atomic anywhere unless you use specialised fetch-and-add instructions, which the compiler never generates for you. By both here, you mean fetch AND add, right? Right And in x86 such a operation (add) on a machine word is atomic w/o using special instructions? ADD is atomic, but usually an atomic increment is done with LOCK ADD, to ensure that no other processor is trying to access the same memory location. The compiler will never generate a LOCK. In other words, ADD is atomic for single-CPU operations. As soon as there's more than one CPU, it isn't enough. Got it. Thanks for clearing this up! -mandeep ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest
Re: [Interest] QMap and thread-safe.
On Thu, Jul 25, 2013 at 9:04 PM, Thiago Macieira
thiago.macie...@intel.comwrote:
On quinta-feira, 25 de julho de 2013 13:40:55, Mandeep Sandhu wrote:
If that increment was not atomically implemented (and to be honest,
right
now I don't know whether a foo++ is atomic - I don't think it is, is
it?)
and again two threads
Atomicity of foo++ would depend on the data type of foo, right? Maybe if
it's a short, the increment will be atomic. Thought the correct way would
be to use atomic types (or maybe use the gcc atomic extensions).
Incrementing an integer type the size of the machine's word or smaller is
atomic on x86, but not on most RISC machines (machines with
read-modify-update
incrementing). Incrementing a type that is larger than the machine word,
such
as long long on x86, is not atomic.
Retrieving the value of a type the size of a machine's word or smaller is
usually atomic everywhere. It is on all architectures that Qt supports.
Doing both at the same time is not atomic anywhere unless you use
specialised
fetch-and-add instructions, which the compiler never generates for you.
By both here, you mean fetch AND add, right? And in x86 such a operation
(add) on a machine word is atomic w/o using special instructions?
Eg if I had code like this running on a x86 machine:
short foo;
foo++;
Will the increment be atomic or do I have to explicitly make it so by doing
something extra?
I'm being specific because foo++ can be both things and it's impossible to
know
if your code was retrieving the value before the increment:
int inc(int foo)
{
return foo++; // not atomic anywhere
Why? Because of the way foo is being received in this function, i.e by
reference (so any operation on foo has and added level of indirection)?
Thanks,
-mandeep
}
--
Thiago Macieira - thiago.macieira (AT) intel.com
Software Architect - Intel Open Source Technology Center
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Re: [Interest] Qt signal when system is awakened
I'm not aware of any such signal coming to Qt from the OS. Does the session ID have an expiry time? If you can detect such a (expiry) timeout, maybe you can initiate a re-fetch automatically (using timers)? -mandeep On Wed, Jul 24, 2013 at 10:46 AM, Tony Rietwyk t...@rightsoft.com.auwrote: Hi Everybody, My application connects to cloud servers and obtains a session id used in subsequent interactions. Some clients are using the app on laptops. They rarely shutdown their system, and just close the lid, which puts the OS (Windows or OSX) to sleep. Hours or days later, they open the lid and see my app still running. They perform some actions, then get an error when the app tries to continue the session with the cloud server. I have temporarily increased the timeouts in the cloud service, but that is not very satisfactory. Is there a Qt signal when the system state changes to or from sleep or hibernate? How have others handled this situation? Thanks! Tony ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest
Re: [Interest] QMap and thread-safe.
On Wed, Jul 24, 2013 at 12:20 PM, André Somers an...@familiesomers.nlwrote: Op 23-7-2013 13:34, Giuseppe D'Angelo schreef: On 23 July 2013 13:25, Bill Crocker william.croc...@analog.com wrote: Hi all: The QMap class states that all member functons are reentrant, but if I populate a map at program start-up (with QStrings, let's say) and I do not change its contents from then on... I should be able to treat the member function ::contains() and any other member function which does not modify the map as thread-safe. Is true? Probably yes, although totally undocumented. (There has been some discussion before the release of 5.0 -- about whether we should make it official that using only const methods on containers makes them thread safe, but I don't remember the outcome...) HTH, Well, if I understood Herb Sutters talk[1] on this correctly, that basically *is* the meaning of const nowadays... André [1] http://channel9.msdn.com/posts/C-and-Beyond-2012-Herb-Sutter-You-dont-know-blank-and-blank Thanks for sharing this link. It was very informative. (BTW, this applies only to C++11) Also, doesn't a const (old sense of the word) member function mean - I'm not going to alter the state of the object ? If so, that would make it thread-safe in the special scenario (mentioned by OP) where only reads are being attempted, right? Can an implementation make it thread-unsafe while still being const (again considering only the special read-only scenario)? -mandeep -- You like Qt? I am looking for collegues to join me at i-Optics! ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest
Re: [Interest] QMap and thread-safe.
A const method can't affect other threads, but other threads can affect a const method. Suppose a const function is reading a large data object. If the object wasn't locked, other threads could modify it while the first function is in the middle of reading it, potentially corrupting the result of the first function. You're right. But I was asking about the specific senario the OP mentioned, i.e with only readers operating on an object, no writers. Thanks, -mandeep Sze-Howe ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest
Re: [Interest] QMap and thread-safe.
On Wed, Jul 24, 2013 at 8:40 PM, Thiago Macieira thiago.macie...@intel.comwrote: On quarta-feira, 24 de julho de 2013 12:59:31, Mandeep Sandhu wrote: http://channel9.msdn.com/posts/C-and-Beyond-2012-Herb-Sutter-You-dont-know -blank-and-blank Thanks for sharing this link. It was very informative. (BTW, this applies only to C++11) It does not apply to anything. What I meant with it applies to C++11, is that the C++11 standard library now follows/respects the correct meaning of const, i.e all std lib's const functions are thread safe and in turn they expect user defined const functions to be thread-safe as well. Though as you mentioned, is not enforced by the language. The only thing thats tying it up with C++11 is that the correct interpretation of const is being followed in the new C++11 std lib, isn't this what he meant in the talk? CMIIW. This is an idea by Herb Sutter and, to be honest, I agree with him that const *should* mean that. But it doesn't. The language does not enforce anything. There's no way to guarantee that the user code in a const function is actually thread-safe. It's very easy to break out of the safety: const_cast mutable But having a mutable in a const function is (logiaclly) right. Rather thats how, Herb explains, one would implement a thread-safe const function. On the other hand doing a const_cast, in a const function, looked more of a work-around to make the compiler happy. -mandeep -- Thiago Macieira - thiago.macieira (AT) intel.com Software Architect - Intel Open Source Technology Center ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest
Re: [Interest] DBus on X11 using Qt5
On Wed, Jul 24, 2013 at 6:25 PM, Ramakanthreddy Kesireddy
ramakanthreddy.kesire...@techmahindra.com wrote:
Hi,
I would like to understand why the below code snippet doesnot
works(Filesystem path doesnot returns any) in Ubuntu 12.04 minimal version
where as It works fine in Ubuntu 12.04 desktop version on target tegra3
device.
What is a Ubuntu minimal? Is this some build of Ubuntu w/o the desktop
components?
Have you tried getting a reply from the interface using dbus-send command?
Also, why not use a proxy object to talk to the service. Its a lot easier
and less error-prone.
See:
http://techbase.kde.org/Development/Tutorials/D-Bus/Accessing_Interfaces#Using_Classes_Generated_From_D-Bus_XML
HTH,
-mandeep
QDBusMessage Reply;
QDBusInterface* Connection= new
QDBusInterface(DISK_SERV,HAL_MGR_PATH,DISK_SERV,QDBusConnection::systemBus(),
this);
Reply = Connection-call(EnumerateDevices);
if( QDBusMessage::ReplyMessage == Reply.type())
{
QDBusArgument dbusarg = qvariant_castQDBusArgument(Reply.arguments()[0]);
dbusarg.beginArray();
while(!dbusarg.atEnd())
{
QVariant variant = dbusarg.asVariant();
QDBusObjectPath dbusObjectPath = qvariant_castQDBusObjectPath
(variant);
mFileSystemPaths.append(dbusObjectPath.path());
}
dbusarg.endArray();
}
delete Connection;
Please let me know if there are any dependencies on DBUS for the above
code to work
On linux systems as this code retrieves the file system path like
/dev/sda1 for example.
Thanks and Regards,
Ramakanth
* *
* *
*From:* Ramakanthreddy Kesireddy
*Sent:* 17 July 2013 17:37
*To:* interest@qt-project.org
*Subject:* DBus on X11 using Qt5
Hi,
Please let me know how can we verify if DBus is working on X11(Ubuntu
12.04 Minimal)
or if there are any dependent packages to be installed for DBus.
Iam using Qt5.0.2 sdk.
Thanks and Regards,
Ramakanth
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Re: [Interest] QMap and thread-safe.
On Thu, Jul 25, 2013 at 10:36 AM, Thiago Macieira thiago.macie...@intel.com
wrote:
On quinta-feira, 25 de julho de 2013 10:00:20, Mandeep Sandhu wrote:
What I meant with it applies to C++11, is that the C++11 standard
library
now follows/respects the correct meaning of const, i.e all std lib's
const functions are thread safe and in turn they expect user defined
const functions to be thread-safe as well.
Ah, that changes things. Yes, if the Standard Library now enforces const
member = thread-safe, that's great. It is how the Qt value-type classes
have
behaved since Qt 4.0, even though we haven't documented that.
The big question is whether they're thread-safe among themselves, or if
they
are thread-safe even if another thread is calling a non-const method.
I would not expect the latter case. It's extremely hard to do and, to be
honest, does not have much value. One thing that we tell people is to treat
the Qt value-type containers as they'd treat an int or char. In that
case,
if we apply the same logic about const container to const int, for
which
many reads are thread-safe, as long as no thread is doing a write, then the
const methods are thread-safe as long as no non-const method is called.
Right, there's no way to guarantee thread-safety of const functions, when
non-const functions are being invoked by other threads.
Although one could make them explicitly thread-safe by using (mutex) locks.
But then there's nothing that const is helping us achieve here.
very easy to break out of the safety:
const_cast
mutable
But having a mutable in a const function is (logiaclly) right. Rather
thats
how, Herb explains, one would implement a thread-safe const function.
On the other hand doing a const_cast, in a const function, looked more
of a
work-around to make the compiler happy.
Both mean the same thing: they allow you to modify the internals inside a
const method. If you don't do it carefully, you can cause problems.
Take a very simple case of mutable:
class String
{
ushort *utf16;
mutable char *cached_latin1;
public:
char *latin1() const
{ if (!cached_latin1) cached_latin1 = toLatin1(); return
cached_latin1; }
};
The function above is not thread-safe. If two threads at the same time call
that function while cached_latin1 is null, both of them might allocate
memory
and one of them will probably leak the other's pointer.
Yeah, one would have to protect access to cached_latin1 using a mutex lock.
Thanks,
-mandeep
--
Thiago Macieira - thiago.macieira (AT) intel.com
Software Architect - Intel Open Source Technology Center
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Re: [Interest] void pointers
On Tue, Jul 16, 2013 at 9:19 PM, Phil Hannent p...@hannent.co.uk wrote: Hi, I have a codebase that is using a C library and Qt. I have some legacy code where structs from the C library are stored in a Qt/C++ class using: void *userData; Is this an example where I should replace the void * with a QSharedPointer or a QWeakPointer? The answer would depend on whether you're sharing this pointer with other classes and/or whether your class is taking ownership of this data. If it's for private use within your Qt/C++ class then, as other have said, you don't need a shared ptr. However, if you're sharing this data with others, and they can potentially delete it, then it's a good idea to keep it as a shared ptr. CMIIW. HTH, -mandeep Regards Phil Hannent ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest
Re: [Interest] Qt build system
On Tue, Jul 16, 2013 at 2:38 AM, Christian Gagneraud chg...@gna.org wrote:
On 16/07/13 08:57, Carl Schumann wrote:
Hi,
I am using Qt in an environment where there is already a build
infrastructure in place. Because of the amount of per-existing non-Qt
code it is not feasible to build everything with qmake, e.g., because
slot is actually a very common variable and argument name in our
existing code base.
Therefore, I am trying to add Qt build support to our existing build
system only for the programs that need it. I would like to understand
what the motivation is for the second command in the link rule of the
qmake-generated Makefile please:
$(TARGET): $(OBJECTS)
$(LINK) $(LFLAGS) -o $(TARGET) $(OBJECTS) $(OBJCOMP) $(LIBS)
{ test -n $(DESTDIR) DESTDIR=$(DESTDIR) || DESTDIR=.; }
test $$(gdb --version | sed -e 's,[^0-9]\+\([0-9]\)\.\([0-9]\).*,\1\2,;q')
-gt 72 gdb --nx --batch --quiet -ex 'set confirm off' -ex save
gdb-index $$DESTDIR -ex quit '$(TARGET)' test -f $(TARGET).gdb-index
objcopy --add-section '.gdb_index=$(TARGET).gdb-index' --set-section-flags
'.gdb_index=readonly' '$(TARGET)' '$(TARGET)' rm -f $(TARGET).gdb-index
|| true
Hi Carl,
I'm not an expert with all of these, but obviously, the second command
adds a GDB index section to the binary target if GDB version is greater
than 7.2, according to [1], it speeds up GDB when debugging.
The index is generated with gdb --nx --batch ... and the section added
with objcopy --add-section ...
Also, this part is added in the Debug builds only.
-mandeep
Hope this helps.
Chris
[1] http://sourceware.org/gdb/onlinedocs/gdb/Index-Files.html
If it makes a difference this is Qt 4.8.4.
Thanks for your time.
Sincerely,
Carl Schumann
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[Interest] Qt 5.1 online installer issue: Unable to uncheck QtCreator from install options
I'm trying to install Qt5.1 on my system (Ubuntu 13.04, 32-bit). The issue is that when choosing the components to install, it's not letting me uncheck the Tools option. I don't want to install the creator that comes bundled (it's the older 2.7.2) as I want to install the latest 2.8 one separately. Even if I click on Deselect All button, the Tools option still remains enabled. Any clues as to why this is happening and how to fix it? Thanks, -mandeep ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest
Re: [Interest] Qt 5.1 online installer issue: Unable to uncheck QtCreator from install options
Thanks Sergio, I've noted my observations on the bug report. -mandeep On Fri, Jul 12, 2013 at 5:10 PM, Sergio Ahumada sergio.ahum...@digia.comwrote: Hi, On 07/12/2013 01:22 PM, Mandeep Sandhu wrote: I'm trying to install Qt5.1 on my system (Ubuntu 13.04, 32-bit). The issue is that when choosing the components to install, it's not letting me uncheck the Tools option. I don't want to install the creator that comes bundled (it's the older 2.7.2) as I want to install the latest 2.8 one separately. Even if I click on Deselect All button, the Tools option still remains enabled. Any clues as to why this is happening and how to fix it? Thanks, -mandeep I think this is an KnownIssue, see https://bugreports.qt-project.org/browse/QTBUG-28101 AFAIU, there are some technical problems why QtCreator needs to be mandatory, but I don't have the details. Maybe you can comment on the JIRA task. Cheers, -- Sergio Ahumada Release Engineer - Digia, Qt ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest
Re: [Interest] Triggering Actions on Application Close
Here's a good article on how to handle unix signals the Qt way (i.e via
it's event loop):
http://qt-project.org/doc/qt-4.8/unix-signals.html
HTH,
-mandeep
On Wed, Jul 10, 2013 at 5:53 PM, franki fra...@franki.eu.org wrote:
Dnia wtorek, 9 lipca 2013 o 00:33:44 Mitchell Verter napisał(a):
How do I trigger cleanup actions on application close?
I need to write out temporary objects and a footer to a file whenever
the Application is closed.
I've tried several approaches, but none of them produces any result
when I Force Quit by hitting the red button within QtCreator.
More specifically, I have tried to connect:
QObject::connect(myApplication, SIGNAL(aboutToQuit()),
myMainWindow, SLOT(closeFileSlot()));
(note that I am using a QApplication rather than a QCoreApplication --
I'm not sure if it makes a difference)
and also
connect(myMainWindow, SIGNAL(destroy()), myMainWindow,
SLOT(closeFileSlot()));
Neither of these approaches seems to successfully trigger the
closeFileSlot() Any suggestions about what the right technique might be?
Hi
If you are doing this on Linux, I've made it like this:
in header:
#include signal.h
...
public slots:
void terminate(bool fromSignal);
.
};
extern C void terminate_wrapper(int dummy);
in cpp file:
in main class constructor:
GlobalVariable= (void*)this;
signal(SIGTERM,terminate_wrapper);
void MainClass::terminate(bool fromSignal) {
qDebug()MainClass::terminate;
... close my services
qApp-quit();
}
void terminate_wrapper(int dummy) {
MainClass *myApp=(MainClass*)GlobalVariable;
myApp-terminate(true);
}
So every time I hit red button in QtCreator it sends SIGTERM to
application,
my wrapper catches it and I can do clean up.
regards
Marek
Thanks
Mitchell
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Re: [Interest] Hiding a shared lib? Linux of course.
On Fri, Jul 5, 2013 at 3:33 AM, Guido Seifert warg...@gmx.de wrote: Yep, I know the pains of the Qt3 - Qt4 transition. I still had to work with Qt3 programs two years ago. But when it comes to pain... if I may translate a German proverb: Better an end with pain than pain without end. I like this proverb...will be good as an email signature! :P Guido The Qt 3 to 4 change is what taught us not to break everything. Despite the script, porting code was a painful process. KDE took 3½ years doing it, from the first Qt 4.0 betas in June 2004 to the actual KDE 4.0 release in Jan 2008 (requiring Qt 4.3 at the time). We had to support Qt 3 for an awfully long period of time -- 4 years -- after 4.0 was out. -- Guido Seifert warg...@gmx.de ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest
[Interest] Simple doubt on file i/o
Hi, I wanted to know if I'm doing file i/o the right way in one of my apps. I'm writing a small helper class for one of my applications which is supposed to store data, in the form of key-value pairs, in a file. This is very similar to QSettings but w/o any fancy groups/sections that it provides. So lets assume that I have to use a file based approach only! :) It provides 2 functions - get(key) and a set(key, value) and they behave exactly like QMaps equivalent functions, i.e if the key exists, it'll overwrite the value, else it'll add a new entry. This class takes either a filename as input or a QFile itself. Assumptions:There won't be much data written to the file (max 1-2 KB). The set function will not be called very often (probably once or twice in the lifetime of the app). The get fxn will be called a little more often. Here's what I do in the 2 functions (skipping error condition checks keep it simple): get(key): * Open the file in Read-Only mode. * Parse the data and prepare a QMap of the key-value pairs. * Close the file * Return the value for the key set(key, value): * Open the file in Read-Only mode. * Parse the data and prepare a QMap of the key-value pairs. * Close the file * Open the file in Write-Only Truncate mode * Insert the new key-value in the map * Write the map * Close the file In the set function I'm opening the file twice - once to read it's content and prepare the map and next I open it in truncate mode as I want to wipe off the existing data and write the new data afresh. Is there a simpler way to achieve what I'm doing with a file? I'm assuming the 2 open-close calls in set() are ok as it won't be called very often. Thoughts? Thanks, -mandeep ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest
Re: [Interest] Simple doubt on file i/o
On Thu, Jun 27, 2013 at 12:58 PM, Arne Dirks arne.di...@iathh.de wrote: On 06/27/2013 08:56 AM, Mandeep Sandhu wrote: get(key): * Open the file in Read-Only mode. * Parse the data and prepare a QMap of the key-value pairs. * Close the file * Return the value for the key set(key, value): * Open the file in Read-Only mode. * Parse the data and prepare a QMap of the key-value pairs. * Close the file * Open the file in Write-Only Truncate mode * Insert the new key-value in the map * Write the map * Close the file Is there a reason why you read the file every time you get/set something? Couldn't you read the file once during application startup, Yes, there's a reason. The data fetched by the app is via a _relatively_ expensive network handshake with a remote service. The data returned is not much and hence I thought it better to write it the moment i receive it. There's a possibility that the app might be closed/crash due to some external factors and if I have it in memory (as a map) then I'd have to the network op all over again. -mandeep store the data in a map and only write it out again when your application terminates, provided anything has changed at all? arne ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest
Re: [Interest] Simple doubt on file i/o
On Thu, Jun 27, 2013 at 1:01 PM, alexander golks a...@golks.de wrote: Thoughts? i would use a cache QMap, and keep it in sync just when needed. fill the cache from file on load/construction/first access, write the cache to file on destruction, thus you won't have any file access during setter/getter functions. you can do file handling in a thread to not block callers, you can force a write via timeout signal, e.g. do threaded sync to file after 5 seconds of last change to cache. I agree with this method, though I believe it's a bit of an overkill for my simplistic requirement. Also, after the first access, the contents of the file will be cached in the filesystem cache itself (which is in memory). Though there'll still be the overhead of making a syscall to access that. Thanks, -mandeep and: pay attention to thread-safety if you need it. -- /* * An honest tale speeds best being plainly told. * -- William Shakespeare, Henry VI */ ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest
Re: [Interest] Simple doubt on file i/o
On Thu, Jun 27, 2013 at 1:09 PM, Nishant Parashar nishsi...@gmail.comwrote: Since the data is very less. Read the file once during start-up of app and prepare the in-memory QMap. This QMap is used for any set/get calls by the app, don't read/write to file. Finally when we exit the app, write the QMap to file wiping out old contents. The only problem here is that if the app unexpectedly quits, then I've lost this data. As I mentioned earlier, since this data is fetched over the n/w I'd rather commit it immediately. Thanks, -mandeep On 27 June 2013 12:26, Mandeep Sandhu mandeepsandhu@gmail.com wrote: Hi, I wanted to know if I'm doing file i/o the right way in one of my apps. I'm writing a small helper class for one of my applications which is supposed to store data, in the form of key-value pairs, in a file. This is very similar to QSettings but w/o any fancy groups/sections that it provides. So lets assume that I have to use a file based approach only! :) It provides 2 functions - get(key) and a set(key, value) and they behave exactly like QMaps equivalent functions, i.e if the key exists, it'll overwrite the value, else it'll add a new entry. This class takes either a filename as input or a QFile itself. Assumptions:There won't be much data written to the file (max 1-2 KB). The set function will not be called very often (probably once or twice in the lifetime of the app). The get fxn will be called a little more often. Here's what I do in the 2 functions (skipping error condition checks keep it simple): get(key): * Open the file in Read-Only mode. * Parse the data and prepare a QMap of the key-value pairs. * Close the file * Return the value for the key set(key, value): * Open the file in Read-Only mode. * Parse the data and prepare a QMap of the key-value pairs. * Close the file * Open the file in Write-Only Truncate mode * Insert the new key-value in the map * Write the map * Close the file In the set function I'm opening the file twice - once to read it's content and prepare the map and next I open it in truncate mode as I want to wipe off the existing data and write the new data afresh. Is there a simpler way to achieve what I'm doing with a file? I'm assuming the 2 open-close calls in set() are ok as it won't be called very often. Thoughts? Thanks, -mandeep ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest
Re: [Interest] Simple doubt on file i/o
On Thu, Jun 27, 2013 at 1:56 PM, André Hartmann andre.hartm...@iseg-hv.dewrote: Hello, QSettings uses specific locations for storing its contents. I don't think one can specify which file to use to QSettings. Sure you can. Just use QSettings::IniFormat and see here: http://doc.qt.digia.com/4.6/qsettings.html#QSettings-4 The only problem I can see is, if you want to store and read non-ASCII data. But if I remember correctly, you can also set the file encoding with setIniCodec() (since Qt 4.5) Thanks André/René. I somehow missed this API in QSettings. Regards, -mandeep Regards, André My application already uses QSettings for storing app wide settings. The data I plan to store in the file is sensitive and I'd like to store it in a specific location only (like an encrypted partition). Another way is to store the data after encrypting it but I'm not doing that right now as I don't have a good management facility on my (embedded) platform. -mandeep André -- You like Qt? I am looking for collegues to join me at i-Optics! ___ Interest mailing list Interest@qt-project.org mailto:Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest
Re: [Interest] Desktop deployment
Hi, We too use a custom build step for packaging all the binaries/libraries/resources for deployment, though this step is done outside of qmake from a top-level Makefile. We are almost building a mini Linux distribution for our embedded product, so the final packaging step involves copying all built stuff from different sub-projects (many of which have their own build-systems) into a common area which is used as-is for deployment. We have a 'install' dir for almost all our projects (main app, Qt libs, external libraries etc). The final packaging step involves cherry picking the correct files from this install dir and copying it over in a release dir (we also modify some files like qt.conf in this step to reflect the directory structure in use in the release dir). HTH, -mandeep On Thu, Jun 20, 2013 at 12:09 PM, Stephen King stephen.k...@domino-uk.comwrote: Hi, We use a custom build step in our .pro file to copy everything into a single directory ready for deployment (onto WinCE in our case). I think that using qmake you have all of the information you need for example the QT variable holds which Qt modules you're using so you can use that to figure out which Qt Dlls to copy. Then again if you're doing everything in VisualStudio it might be easier to just create an installer for internal consumption from within VS, it's pretty easy to just drag in the dependencies. Regards, Steve -Original Message- From: interest-bounces+stephen.king=domino-uk@qt-project.org [mailto: interest-bounces+stephen.king=domino-uk@qt-project.org] On Behalf Of Yves Bailly Sent: 20 June 2013 07:13 To: Interest@qt-project.org Subject: Re: [Interest] Desktop deployment Le 20/06/2013 01:16, Alex Malyushytskyy a écrit : I just wanted to point that you must to deploy all dependencies not only Qt. You will have to deploy VC CRTs at least if your application has no other dependencies. I'm perfectly aware of this. Here my problem is more in the case where I just want to copy my exe to someone's else computer (which already have already all the needed standard runtimes installed). Creating a full-fledged, customer-targeted installer is another matter, which is already nicely handled. Regards, -- /- Yves Bailly - Software developer -\ \- Sescoi RD - http://www.sescoi.fr -/ The possible is done. The impossible is being done. For miracles, thanks to allow a little delay. ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest Visit our website at http://www.domino-printing.com This Email and any files transmitted with it are intended only for the person or entity to which it is addressed and may contain confidential and/or privileged material. Any reading, redistribution, disclosure or other use of, or taking of any action in reliance upon, this information by persons or entities other than the intended recipient is prohibited. If you are not the intended recipient please contact the sender immediately and delete the material from your computer. E-mail may be susceptible to data corruption, interception, viruses and unauthorised amendment and Domino UK Limited does not accept liability for any such corruption, interception, viruses or amendment or their consequences. Domino UK Limited. Registered in England. Registered Number:1750201. Registered Office Address: Trafalgar Way, Bar Hill, Cambridge, CB23 8TU. ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest
Re: [Interest] Terminating a QThread
On Fri, Jun 21, 2013 at 1:36 PM, francois cellier f_cell...@yahoo.frwrote:
Dear all,
Even if I know that it can be dangerous to terminate a thread, I need to
do it for my application.
The function that run into the thread is like a long linear sequence of
code that has not been designed in a signal/slot way. Moreover, in my
thread, I need an eventloop as I use in it some TCP or UDP Qt sockets.
I have tried the worker approach with the following code and I did not
find a way to terminate the thread :
For my thread class :
1. ThreadEx::ThreadEx(QObject http://qt-project.org/doc/QObject.html
*parent) :
2. QThread http://qt-project.org/doc/QThread.html(parent)
3. {
4. }
5.
6. void ThreadEx::run()
7. {
8. QThread http://qt-project.org/doc/QThread.html::
setTerminationEnabled(true);
9. exec();
10. }
For my worker class:
1.
ObjectInThread::ObjectInThread(QObjecthttp://qt-project.org/doc/QObject.html
*parent) :
2. QObject http://qt-project.org/doc/QObject.html(parent)
3. {
4. }
5.
6.
7. void ObjectInThread::run()
8. {
9.int compteur = 0;
10. //here i am using a loop instead of the long linear flow but it
is not a loop in the real code
11. while(1)
12. {
13. qDebug() compteur;
14. compteur++;
15. Sleep(1000);
16. }
17. }
You use a condition variable in your loop here, which will exit out of the
run() function. This variable can be set from your stop() slot (protected
by a mutex if needed).
In your main(GUI) thread you can wait for your worker thread to exit:
m_thread-quit();
m_thread-wait();
HTH,
-mandeep
This should cleanly exit the thread.
Moreover I tried the other way of using QThread that consists in
inheriting the QThread class and overriding the run method with the code :
void ThreadEx::run()
{
int compteur = 0;
while(1)
{
qDebug() compteur;
compteur++;
sleep(1);
}
}
In that case terminate works but I do not have an eventloop as I did not
call the exec method.
Is this the expected behaviour ?
I am using Qt5.1 on centOS / RedHat 6.2. I have also tried this on Windows
with no more success.
Thanks for your help,
François
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