[Interest] Qt 5.8 font detection vs Qt 5.3.2 font detection

[Nguyen Huu Minh]

Hello,

My apologies if this question has been asked before. We are upgrading our Qt 
application running on Lubuntu 32-bit from Qt 5.3.2 to Qt 5.8. One of the 
issues we have ran into is font handling. The Qt 5.3.2 version of our 
application detects the system fonts fine (the directories under 
/usr/share/fonts). However when starting the Qt 5.8 version we get this error:

"QFontDatabase: Cannot find font directory"

The directory that QFontDatabase looks at is "/usr/local/lib/lib/fonts", which 
of course does not exists.

The Qt 5.3.2 we use this the one that was provided by qt.io. The Qt 5.8 version 
we compiled from source on a virtual machine.

We can get one of the directories to work by setting QT_QPA_FONTDIR, but our 
fonts are scattered over many directories.

What is the proper way of solving this problem?

Did we forget to configure some setting when compiling Qt 5.8 or has there been 
a change in behaviour and do we need to move all our fonts to one location?

Greetings,

Huu Minh Nguyen
R Project Engineer Electronics

huuminh.ngu...@vandewiele.com


Van de Wiele Company or its affiliates do not accept legal responsibility for 
the contents of this message.  The views or opinions presented are solely those 
of the author and do not necessarily represent those of Van de Wiele Company or 
any of its affiliates.





_

Mail Disclaimer
___
Interest mailing list
Interest@qt-project.org
http://lists.qt-project.org/mailman/listinfo/interest

Re: [Interest] Qt at the C++20 era

[Corentin]

It was my understanding that Herb has a somewhat working clang-based
prototype  ? Do you think that will be made available at some point ?
It would be fun to try to properly implement Qt meta object system  (maybe
using Olivier's Verdigris as a starting point) and provide feedback based
on that.

One other feature I'd like to see is to have access to [[attributes]] from
within the static reflection api ( for which there are currently multiple
competing proposals if I understand correctly ?)



Corentin


Le mar. 2 mai 2017 à 15:21, Giuseppe D'Angelo  a
écrit :

> On 01/05/17 21:59, Thiago Macieira wrote:
> > If not, this is vapourware.
>
> To clarify (I was there during Herb's talk at ACCUCONF2017):
>
> Herb said clearly that all of that is currently not official, not even
> proposed, so the final thing (if there will be one) could also be
> completely different.
>
> The talk was the first time this stuff got showcased publicly. It was
> just neat that he used Qt (and moc) as an example of what the new syntax
> would unlock.
>
> P0633R0 does *not* deal with Herb's proposal because there isn't one
> (it's indeed quoted as "private communication").
>
> My 2 c,
> --
> Giuseppe D'Angelo | giuseppe.dang...@kdab.com | Senior Software Engineer
> KDAB (UK) Ltd., a KDAB Group company | Tel: UK +44-1625-809908
> <+44%201625%20809908>
> KDAB - The Qt, C++ and OpenGL Experts
>
> ___
> 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] black screen with iOS app over airplay?

[Patrick Stinson]

Hello! Has anyone else had a problem with Qt apps only showing as a black 
screen when mirroring an iOS device over airplay? Other apps display fine, but 
then the AirPlay display turns black when the Qt app is brought to the front.

Granted, I am using Reflector 2 to show the iPad screen on my Mac with latest 
macOS Sierra, (in order to show the iPad on a projector), but it just uses the 
AirPlay protocol on the iOS end so I assume it is a problem with the Qt iOS 
view.

Thanks!

smime.p7s
Description: S/MIME cryptographic signature
___
Interest mailing list
Interest@qt-project.org
http://lists.qt-project.org/mailman/listinfo/interest

Re: [Interest] Question regarding Qt Android service

[Jason H]

I don't know how services differ from activities, but having done quite a few things with activities, I say yes, the Android Service/Activity start sthe Qt Thread. I don't know of anyway for the OD to start Qt directly... For my activity I have a platform shim that uses a single ton that has to deal with tings when there is no platform shim yet created (it's created i the main() of the Qt thread)

 

 

 

 

Sent: Wednesday, May 10, 2017 at 12:44 PM
From: "Bernhard B" 
To: interest@qt-project.org
Subject: [Interest] Question regarding Qt Android service






Hi,
 
a quick question regarding Qt Android service: Is it guaranteed, that the Qt thread will always start after the Android service has started? Or is it possible that the Qt thread starts before the Android service is fully initialized and started?
 
I want to call a JAVA function via JNI from the Qt thread right after the start, so I need to make sure that the Android service is fully initialized and up at that point. Can that be guaranteed?
 
Thanks,
Bernhard
___ 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 5.8 performance regression in android application

[Tomas Konir]

2017-05-11 12:27 GMT+02:00 Лагнер, Сергей :

> Hi, Tomas.
>
> Your notice is very valuable. Indeed, we have significant amount of http
> requests and
> we start them right after page has been created. Therefore if it costs
> much, transition
> animation can freeze.
> One thing I can not understand. I thought Qt makes almost all network
> calculations in a
> background thread. Is it not true?
>

Network calculations are processing on background thread, but i expect,
that you are creating QNetworkRequest in main thread.
DH calculations are in QNetworkRequest constructor.
You can simple measure how long takes new QNetworkRequest() on 5.6 and 5.8
(android is best testing platform for this due to lack of CPU power)


>
> Do you know the fix is going to be backported to 5.8? Or can I work around
> it?
> As I see 5.9 is not ready yet.
>

Current 5.8 is unfixed. Maybe 5.8.1 if it will exists.
5.9 is close to beta and should be ready in two or three weeks (i hope
because i have similar problem)

Tom


>
> One more thing, I can't find jira ticket about this regression. Can you
> share it?
>
> 2017-05-11 14:59 GMT+07:00 Tomas Konir :
>
>> Hi
>>
>> You wrote, that you have app which uses internet.
>> If you are using many http requests, you may be affected with regression
>> in network access manager, which computes DH keys for each http request
>> (even though you are doing only plain http).
>> DH computation is very CPU intensive and for me causes massive slowdown
>> on android and noticeably slowdown on PC (http intesive application).
>> This is fixed in upcoming 5.9.
>>
>> Tom
>>
>>
>> 2017-05-11 9:45 GMT+02:00 Лагнер, Сергей :
>>
>>> Hello all.
>>>
>>> We are going to upgrade Qt from 5.6 to 5.8 for our android application.
>>> I've got the build with Qt 5.8 and it much slower.
>>>
>>> First of all I mean animations.
>>> We use Qml StackView and we animate transitions between pages.
>>> With 5.6 this animations are smooth, but with 5.8 they are laggy.
>>> It freezes 3 or 4 times each transition.
>>>
>>> One more example, we have a photo gallery page. All photos come from the
>>> internet.
>>> Once transition to the page is done, Qt 5.6 already has a number of
>>> photos to show.
>>> 5.8 only shows first picture after a while.
>>>
>>> I know that my problem is not concrete enough, but maybe you know smth
>>> that
>>> was changed between 5.6 and 5.8 that is very important to check or
>>> modify
>>> to get better performance.
>>>
>>> We use QtQuickCompiler if it's matter.
>>>
>>>
>>> ___
>>> Interest mailing list
>>> Interest@qt-project.org
>>> http://lists.qt-project.org/mailman/listinfo/interest
>>>
>>>
>>
>>
>> --
>> Tomas Konir
>> Czech Republic
>>
>>
>


-- 
Tomas Konir
Czech Republic
___
Interest mailing list
Interest@qt-project.org
http://lists.qt-project.org/mailman/listinfo/interest

Re: [Interest] Qt 5.8 performance regression in android application

[Лагнер , Сергей]

Almost all parts have been done with Qt Quick Controls 1.
Very few use qt labs controls(Controls 2.0 in case 5.8)
We are going to upgrade to Controls 2.0 but it has not been done yet.

2017-05-11 15:24 GMT+07:00 ekke :

> are you using QtQuickControls1 or QtQuickControls2 ?
>
> Am 11.05.17 um 09:45 schrieb Лагнер, Сергей:
>
> Hello all.
>
> We are going to upgrade Qt from 5.6 to 5.8 for our android application.
> I've got the build with Qt 5.8 and it much slower.
>
> First of all I mean animations.
> We use Qml StackView and we animate transitions between pages.
> With 5.6 this animations are smooth, but with 5.8 they are laggy.
> It freezes 3 or 4 times each transition.
>
> One more example, we have a photo gallery page. All photos come from the
> internet.
> Once transition to the page is done, Qt 5.6 already has a number of photos
> to show.
> 5.8 only shows first picture after a while.
>
> I know that my problem is not concrete enough, but maybe you know smth
> that
> was changed between 5.6 and 5.8 that is very important to check or modify
> to get better performance.
>
> We use QtQuickCompiler if it's matter.
>
>
>
> ___
> Interest mailing 
> listInterest@qt-project.orghttp://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] Qt 5.8 performance regression in android application

[Лагнер , Сергей]

Hi, Tomas.

Your notice is very valuable. Indeed, we have significant amount of http
requests and
we start them right after page has been created. Therefore if it costs
much, transition
animation can freeze.
One thing I can not understand. I thought Qt makes almost all network
calculations in a
background thread. Is it not true?

Do you know the fix is going to be backported to 5.8? Or can I work around
it?
As I see 5.9 is not ready yet.

One more thing, I can't find jira ticket about this regression. Can you
share it?

2017-05-11 14:59 GMT+07:00 Tomas Konir :

> Hi
>
> You wrote, that you have app which uses internet.
> If you are using many http requests, you may be affected with regression
> in network access manager, which computes DH keys for each http request
> (even though you are doing only plain http).
> DH computation is very CPU intensive and for me causes massive slowdown on
> android and noticeably slowdown on PC (http intesive application).
> This is fixed in upcoming 5.9.
>
> Tom
>
>
> 2017-05-11 9:45 GMT+02:00 Лагнер, Сергей :
>
>> Hello all.
>>
>> We are going to upgrade Qt from 5.6 to 5.8 for our android application.
>> I've got the build with Qt 5.8 and it much slower.
>>
>> First of all I mean animations.
>> We use Qml StackView and we animate transitions between pages.
>> With 5.6 this animations are smooth, but with 5.8 they are laggy.
>> It freezes 3 or 4 times each transition.
>>
>> One more example, we have a photo gallery page. All photos come from the
>> internet.
>> Once transition to the page is done, Qt 5.6 already has a number of
>> photos to show.
>> 5.8 only shows first picture after a while.
>>
>> I know that my problem is not concrete enough, but maybe you know smth
>> that
>> was changed between 5.6 and 5.8 that is very important to check or modify
>> to get better performance.
>>
>> We use QtQuickCompiler if it's matter.
>>
>>
>> ___
>> Interest mailing list
>> Interest@qt-project.org
>> http://lists.qt-project.org/mailman/listinfo/interest
>>
>>
>
>
> --
> Tomas Konir
> Czech Republic
>
>
___
Interest mailing list
Interest@qt-project.org
http://lists.qt-project.org/mailman/listinfo/interest

Re: [Interest] Android low latency BLE scanning

[ekke]

AFAIK changing LE Timeout only reduces or enhances the amount of time
while Qt tries to discover devices nearby
in my apps I normaly 'know' the device I'm searching and so I check each
discovered device and if it's the one I was looking for, I cancel
discovery to speed things up

Am 11.05.17 um 11:44 schrieb Denis Shienkov:
> QBluetoothDeviceDiscoveryAgent::setLowEnergyDiscoveryTimeout(intmsTimeout)
> ?
>
> 2017-05-11 12:06 GMT+03:00  >:
>
> Hi,
> Android supports several scan modes when scanning for BLE devices:
> 
> https://developer.android.com/reference/android/bluetooth/le/ScanSettings.html
> 
> 
>
> It seems that Qt uses balanced scan mode as device discovery takes
> some time.I want to use SCAN_MODE_LOW_LATENCY in my Qt Android app
> - I need fast BLE device discovery.
>
> Is setting scan mode possible in Qt Android?
>
> Best regards
>
> Martin
>
> ___
> 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] Android low latency BLE scanning

[Alex Blasche]

Hi,

In short there is no way at this point in time.

QtBluetooth uses Android's BluetoothAdapter.startScan() which does not take a 
ScanSettings field. This function is deprecated in favour of 
BluetoothLeScanner.startScan but QtBluetooth has not made this jump yet. Only 
the new scanner API supports the scan setting you are after. Another problem is 
that the new API required Android v21. Since Qt supports much lower Android 
versions the new API is not a complete replacement. 

 Could you please file a suggestion in bugreports.qt.io? This way your request 
finds its way into QtBluetooth eventually. It is the first time I heard 
somebody wanting access to it. Thank you.

--
Alex

> -Original Message-
> From: Interest [mailto:interest-bounces+alexander.blasche=qt.io@qt-
> project.org] On Behalf Of dusek.mar...@email.cz
> Sent: Thursday, 11 May 2017 11:07
> To: interest@qt-project.org
> Subject: [Interest] Android low latency BLE scanning
> 
> Hi,
> Android supports several scan modes when scanning for BLE devices:
> https://developer.android.com/reference/android/bluetooth/le/ScanSettings.ht
> ml
> 
> It seems that Qt uses balanced scan mode as device discovery takes some time.I
> want to use SCAN_MODE_LOW_LATENCY in my Qt Android app - I need fast BLE
> device discovery.
> 
> Is setting scan mode possible in Qt Android?
> 
> Best regards
> 
> Martin
___
Interest mailing list
Interest@qt-project.org
http://lists.qt-project.org/mailman/listinfo/interest

Re: [Interest] Android low latency BLE scanning

[Denis Shienkov]

QBluetoothDeviceDiscoveryAgent::setLowEnergyDiscoveryTimeout(int msTimeout)
?

2017-05-11 12:06 GMT+03:00 :

> Hi,
> Android supports several scan modes when scanning for BLE devices:
> https://developer.android.com/reference/android/bluetooth/
> le/ScanSettings.html
>
> It seems that Qt uses balanced scan mode as device discovery takes some
> time.I want to use SCAN_MODE_LOW_LATENCY in my Qt Android app - I need fast
> BLE device discovery.
>
> Is setting scan mode possible in Qt Android?
>
> Best regards
>
> Martin
>
> ___
> 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 5.8 performance regression in android application

[ekke]

are you using QtQuickControls1 or QtQuickControls2 ?

Am 11.05.17 um 09:45 schrieb Лагнер, Сергей:
> Hello all.
>
> We are going to upgrade Qt from 5.6 to 5.8 for our android application.
> I've got the build with Qt 5.8 and it much slower. 
>
> First of all I mean animations.
> We use Qml StackView and we animate transitions between pages. 
> With 5.6 this animations are smooth, but with 5.8 they are laggy. 
> It freezes 3 or 4 times each transition.
>
> One more example, we have a photo gallery page. All photos come from
> the internet. 
> Once transition to the page is done, Qt 5.6 already has a number of
> photos to show.
> 5.8 only shows first picture after a while.
>
> I know that my problem is not concrete enough, but maybe you know smth
> that 
> was changed between 5.6 and 5.8 that is very important to check or modify 
> to get better performance.
>
> We use QtQuickCompiler if it's matter.
>
>
>
> ___
> 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 5.8 performance regression in android application

[Tomas Konir]

Hi

You wrote, that you have app which uses internet.
If you are using many http requests, you may be affected with regression in
network access manager, which computes DH keys for each http request (even
though you are doing only plain http).
DH computation is very CPU intensive and for me causes massive slowdown on
android and noticeably slowdown on PC (http intesive application).
This is fixed in upcoming 5.9.

Tom


2017-05-11 9:45 GMT+02:00 Лагнер, Сергей :

> Hello all.
>
> We are going to upgrade Qt from 5.6 to 5.8 for our android application.
> I've got the build with Qt 5.8 and it much slower.
>
> First of all I mean animations.
> We use Qml StackView and we animate transitions between pages.
> With 5.6 this animations are smooth, but with 5.8 they are laggy.
> It freezes 3 or 4 times each transition.
>
> One more example, we have a photo gallery page. All photos come from the
> internet.
> Once transition to the page is done, Qt 5.6 already has a number of photos
> to show.
> 5.8 only shows first picture after a while.
>
> I know that my problem is not concrete enough, but maybe you know smth
> that
> was changed between 5.6 and 5.8 that is very important to check or modify
> to get better performance.
>
> We use QtQuickCompiler if it's matter.
>
>
> ___
> Interest mailing list
> Interest@qt-project.org
> http://lists.qt-project.org/mailman/listinfo/interest
>
>


-- 
Tomas Konir
Czech Republic
___
Interest mailing list
Interest@qt-project.org
http://lists.qt-project.org/mailman/listinfo/interest

Re: [Interest] [android] How to avoid deploying extra styles

[Лагнер , Сергей]

Bump.

Is it really impossible to avoid extra themes(material, universal) for
quick controls 2.0?



2017-05-05 12:16 GMT+07:00 Лагнер, Сергей :

> Hello all.
>
> We are going to use Qt Quick Controls 2.0 for our Android application.
> I have built android apk and I see it contains
> libqml_QtQuick_Controls.2_Material_libqtquickcontrols2materialsty
> leplugin.so
> libqml_QtQuick_Controls.2_Universal_libqtquickcontrols2universalst
> yleplugin.so
>
> The problem is that all our controls have a custom style and we do not
> want to deploy extra libs.
> Neither Material nor Universal styles are needed. Thereby a number of
> questions here.
>
> Is there any option to configure and build qt without universal, material
> styles?
> Is there any option to say androiddeployqt do not deploy this libs?
>
___
Interest mailing list
Interest@qt-project.org
http://lists.qt-project.org/mailman/listinfo/interest

[Interest] Qt 5.8 performance regression in android application

[Лагнер , Сергей]

Hello all.

We are going to upgrade Qt from 5.6 to 5.8 for our android application.
I've got the build with Qt 5.8 and it much slower.

First of all I mean animations.
We use Qml StackView and we animate transitions between pages.
With 5.6 this animations are smooth, but with 5.8 they are laggy.
It freezes 3 or 4 times each transition.

One more example, we have a photo gallery page. All photos come from the
internet.
Once transition to the page is done, Qt 5.6 already has a number of photos
to show.
5.8 only shows first picture after a while.

I know that my problem is not concrete enough, but maybe you know smth that
was changed between 5.6 and 5.8 that is very important to check or modify
to get better performance.

We use QtQuickCompiler if it's matter.
___
Interest mailing list
Interest@qt-project.org
http://lists.qt-project.org/mailman/listinfo/interest