Re: XWindows - how capture window ?
OK, I found something interesting.
It's turn out that for some reason on-screen rendering is a problem too.
Greatly oversimplified description of my application:
There is a mai windows with 2 buttons ('A', and 'B')
When buttons 'A' pressed Windows 'W' (with a lot of child windows) created and
shown on the screen. It's done with function 'callback_A'
When I press button 'B' I want following to happened:
1. Window 'W created, like it was created, when button 'A' pressed
2. Window 'W content is captured.
So I have callback_B like this:
void callback_B()
{
callback_A(); // create Window 'W'
capture_window();
}
So far so good. The only trouble is that requests sent to XServer in the
function callback_A have no chance to be processed before call to
capture_window() function, because application does not retirned to it's main
application loop, which process events.
To get XServer chance to process events callback_B was modified as following:
void callback_B()
{
callback_A(); // create Window 'W'
handle_events();
capture_window();
}
Where handle_events looks like:
void handle_events()
{
XFlush(display);
XSync(display, False);
while (XtAppPending(appContext))
{
XtAppProcessEvent(appContext,Mask );
}
}
This functions used in this application in other cases when events should be
handled and it's works OK.
But in this case, Window 'W' was only partially drawn.
I found workaround modifie callback_B
void callback_B()
{
callback_A(); // create Window 'W'
handle_events();
usleep(10);
handle_events();
capture_window();
}
After some sleep and addition handle_events call Window 'W' rendered on screen
as expected.
But I don't why first approach didn't work.
From the XSync man page:
-
The XSync function flushes the output buffer and then waits until all
requests have been received and processed by the X server. Any errors
generated must be handled by the error handler. For each protocol
error received by Xlib, XSync calls the client application’s error han-
dling routine (see section 11.8.2). Any events generated by the server
are enqueued into the library’s event queue.
---
So it's looks like XSync alone should do the job.
Obviously it was not - and it was a reason, that event_handle function was
written.
What I did with sleep and two calls to even_handle is work, but it's ugly.
Anyone has idea why XSync alone is not enough and how I can wait to all
requests to be processed by XServer ?
Regards,
Valery.
--- On Sun, 3/7/10, Nadav Har'El n...@math.technion.ac.il wrote:
From: Nadav Har'El n...@math.technion.ac.il
Subject: Re: XWindows - how capture window ?
To: Erez D erez0...@gmail.com
Cc: Valery Reznic valery_rez...@yahoo.com, linux-il.
linux-il@cs.huji.ac.il
Date: Sunday, March 7, 2010, 10:38 AM
On Thu, Mar 04, 2010, Erez D wrote
about Re: XWindows - how capture window ?:
composite window managers (i.e. compiz, baryl) work by
drawing the original
window off screen, then read it as a 2D picture, and
render it back to the
screen with certain effects.
So i know it is possible to grab an off screen window.
I do not know however
how to make it off screen.
This is done using the Composite extension. See
http://www.freedesktop.org/wiki/Software/CompositeExt
But please note that all these extensions, as their title
implies, are
not available in every installation of X. The right way
to use them is
to use them when they're available, but fall back to some
slower or uglier
alternative when they aren't.
There is an X Extension called XDamage, which reports
changes on the window
so you do not have to poll it for changes. These
window managers use it.
Right. http://www.freedesktop.org/wiki/Software/XDamage
--
Nadav Har'El
|
Sunday, Mar 7 2010, 21 Adar 5770
n...@math.technion.ac.il
|-
Phone +972-523-790466, ICQ 13349191 |Business jargon is the
art of saying
http://nadav.harel.org.il
|nothing while appearing to say a lot.
___
Linux-il mailing list
Linux-il@cs.huji.ac.il
http://mailman.cs.huji.ac.il/mailman/listinfo/linux-il
Re: XWindows - how capture window ?
ב-13/03/2010, בשעה 13:03, Valery Reznic valery_rez...@yahoo.com
כתב/ה:
OK, I found something interesting.
It's turn out that for some reason on-screen rendering is a problem
too.
Greatly oversimplified description of my application:
There is a mai windows with 2 buttons ('A', and 'B')
When buttons 'A' pressed Windows 'W' (with a lot of child windows)
created and shown on the screen. It's done with function 'callback_A'
When I press button 'B' I want following to happened:
1. Window 'W created, like it was created, when button 'A' pressed
2. Window 'W content is captured.
So I have callback_B like this:
void callback_B()
{
callback_A(); // create Window 'W'
capture_window();
}
Problem is, like you stated that you to wait for all the drawing
callbacks to finish
The best approach for such a thing is to post and event to do the
capture that will go on the queue after the draw events and then
process the capture in that callback
So far so good. The only trouble is that requests sent to XServer in
the function callback_A have no chance to be processed before call
to capture_window() function, because application does not retirned
to it's main application loop, which process events.
To get XServer chance to process events callback_B was modified as
following:
void callback_B()
{
callback_A(); // create Window 'W'
handle_events();
capture_window();
}
Where handle_events looks like:
void handle_events()
{
XFlush(display);
XSync(display, False);
while (XtAppPending(appContext))
{
XtAppProcessEvent(appContext,Mask );
}
}
This functions used in this application in other cases when events
should be handled and it's works OK.
But in this case, Window 'W' was only partially drawn.
I found workaround modifie callback_B
void callback_B()
{
callback_A(); // create Window 'W'
handle_events();
usleep(10);
handle_events();
capture_window();
}
After some sleep and addition handle_events call Window 'W' rendered
on screen as expected.
But I don't why first approach didn't work.
From the XSync man page:
---
--
The XSync function flushes the output buffer and then waits
until all
requests have been received and processed by the X server.
Any errors
generated must be handled by the error handler. For each
protocol
error received by Xlib, XSync calls the client application’s e
rror han-
dling routine (see section 11.8.2). Any events generated by
the server
are enqueued into the library’s event queue.
---
So it's looks like XSync alone should do the job.
Obviously it was not - and it was a reason, that event_handle
function was written.
What I did with sleep and two calls to even_handle is work, but it's
ugly.
Anyone has idea why XSync alone is not enough and how I can wait to
all requests to be processed by XServer ?
Regards,
Valery.
--- On Sun, 3/7/10, Nadav Har'El n...@math.technion.ac.il wrote:
From: Nadav Har'El n...@math.technion.ac.il
Subject: Re: XWindows - how capture window ?
To: Erez D erez0...@gmail.com
Cc: Valery Reznic valery_rez...@yahoo.com, linux-il. linux-il@cs.huji.ac.il
Date: Sunday, March 7, 2010, 10:38 AM
On Thu, Mar 04, 2010, Erez D wrote
about Re: XWindows - how capture window ?:
composite window managers (i.e. compiz, baryl) work by
drawing the original
window off screen, then read it as a 2D picture, and
render it back to the
screen with certain effects.
So i know it is possible to grab an off screen window.
I do not know however
how to make it off screen.
This is done using the Composite extension. See
http://www.freedesktop.org/wiki/Software/CompositeExt
But please note that all these extensions, as their title
implies, are
not available in every installation of X. The right way
to use them is
to use them when they're available, but fall back to some
slower or uglier
alternative when they aren't.
There is an X Extension called XDamage, which reports
changes on the window
so you do not have to poll it for changes. These
window managers use it.
Right. http://www.freedesktop.org/wiki/Software/XDamage
--
Nadav Har'El
|
Sunday, Mar 7 2010, 21 Adar 5770
n...@math.technion.ac.il
|-
Phone +972-523-790466, ICQ 13349191 |Business jargon is the
art of saying
http://nadav.harel.org.il
|nothing while appearing to say a lot.
___
Linux-il mailing list
Linux-il@cs.huji.ac.il
http://mailman.cs.huji.ac.il/mailman/listinfo/linux-il
___
Linux-il mailing list
Linux-il@cs.huji.ac.il
http://mailman.cs.huji.ac.il/mailman/listinfo/linux-il
Re: XWindows - how capture window ?
--- On Sat, 3/13/10, Micha mi...@post.tau.ac.il wrote:
From: Micha mi...@post.tau.ac.il
Subject: Re: XWindows - how capture window ?
To:
Cc: linux-il. linux-il@cs.huji.ac.il
Date: Saturday, March 13, 2010, 4:00 PM
ב-13/03/2010, בשעה 13:03, Valery Reznic valery_rez...@yahoo.com כתב/ה:
OK, I found something interesting.
It's turn out that for some reason on-screen rendering is a problem too.
Greatly oversimplified description of my application:
There is a mai windows with 2 buttons ('A', and 'B')
When buttons 'A' pressed Windows 'W' (with a lot of child windows) created and
shown on the screen. It's done with function 'callback_A'
When I press button 'B' I want following to happened:
1. Window 'W created, like it was created, when button 'A' pressed
2. Window 'W content is captured.
So I have callback_B like this:
void callback_B()
{
callback_A(); // create Window 'W'
capture_window();
}
Problem is, like you stated that you to wait for all the drawing callbacks to
finish
The best approach for such a thing is to post and event to do the capture that
will go on the queue after the draw events and then process the capture in that
callback
I though about this but it's looks like events reported to be processed, while
them still not - or I misunderstood meaning of XSync function.
Valery.
So far so good. The only trouble is that requests sent to XServer in the
function callback_A have no chance to be processed before call to
capture_window() function, because application does not retirned to it's main
application loop, which process events.
To get XServer chance to process events callback_B was modified as following:
void callback_B()
{
callback_A(); // create Window 'W'
handle_events();
capture_window();
}
Where handle_events looks like:
void handle_events()
{
XFlush(display);
XSync(display, False);
while (XtAppPending(appContext))
{
XtAppProcessEvent(appContext,Mask );
}
}
This functions used in this application in other cases when events should be
handled and it's works OK.
But in this case, Window 'W' was only partially drawn.
I found workaround modifie callback_B
void callback_B()
{
callback_A(); // create Window 'W'
handle_events();
usleep(10);
handle_events();
capture_window();
}
After some sleep and addition handle_events call Window 'W' rendered on screen
as expected.
But I don't why first approach didn't work.
From the XSync man page:
-
The XSync function flushes the output buffer and then waits until all
requests have been received and processed by the X server. Any errors
generated must be handled by the error handler. For each protocol
error received by Xlib, XSync calls the client application’s error han-
dling routine (see section 11.8.2). Any events generated by the server
are enqueued into the library’s event queue.
---
So it's looks like XSync alone should do the job.
Obviously it was not - and it was a reason, that event_handle function was
written.
What I did with sleep and two calls to even_handle is work, but it's ugly.
Anyone has idea why XSync alone is not enough and how I can wait to all
requests to be processed by XServer ?
Regards,
Valery.
--- On Sun, 3/7/10, Nadav Har'El n...@math.technion.ac.il wrote:
From: Nadav Har'El n...@math.technion.ac.il
Subject: Re: XWindows - how capture window ?
To: Erez D erez0...@gmail.com
Cc: Valery Reznic valery_rez...@yahoo.com, linux-il.
linux-il@cs.huji.ac.il
Date: Sunday, March 7, 2010, 10:38 AM
On Thu, Mar 04, 2010, Erez D wrote
about Re: XWindows - how capture window ?:
composite window managers (i.e. compiz, baryl) work by
drawing the original
window off screen, then read it as a 2D picture, and
render it back to the
screen with certain effects.
So i know it is possible to grab an off screen window.
I do not know however
how to make it off screen.
This is done using the Composite extension. See
http://www.freedesktop.org/wiki/Software/CompositeExt
But please note that all these extensions, as their title
implies, are
not available in every installation of X. The right way
to use them is
to use them when they're available, but fall back to some
slower or uglier
alternative when they aren't.
There is an X Extension called XDamage, which reports
changes on the window
so you do not have to poll it for changes. These
window managers use it.
Right. http://www.freedesktop.org/wiki/Software/XDamage
--
Nadav Har'El
|
Sunday, Mar 7 2010, 21 Adar 5770
n...@math.technion.ac.il
|-
Phone +972-523-790466, ICQ 13349191 |Business jargon is the
art of saying
http://nadav.harel.org.il
|nothing while appearing to say a lot.
___
Re: XWindows - how capture window ?
--- On Sat, 3/13/10, guy keren c...@actcom.co.il wrote:
From: guy keren c...@actcom.co.il
Subject: Re: XWindows - how capture window ?
To: Valery Reznic valery_rez...@yahoo.com
Date: Saturday, March 13, 2010, 3:56 PM
the reason is: background jobs.
the application does not necessarily do everything in one
shot. some of its widgets leave some processing to be done
during idle periods - which, i imagine, are triggered by
timers. for this, they need the main loop to be executed for
some (non-zero) duration.
At least application itself do nothing with timers.
And widgets are the standard ones - labels, buttons, text and draw areas.
So I don't sure what's background jobs is.
Valery.
i had a similar problem in an application, and i did
something similar to what you did (only that as long sa
there were events handled in the 'handle events' loop - i
retried to sleep and do the handle events loop).
if you want it done differently, - you'll have to know
which is the last object to become visible, and synchronize
with it. i think this is not any better then the
sleepy-event-loop method you chose.
--guy
Valery Reznic wrote:
OK, I found something interesting.
It's turn out that for some reason on-screen rendering
is a problem too.
Greatly oversimplified description of my application:
There is a mai windows with 2 buttons ('A', and 'B')
When buttons 'A' pressed Windows 'W' (with a lot of
child windows) created and shown on the screen. It's done
with function 'callback_A'
When I press button 'B' I want following to happened:
1. Window 'W created, like it was created, when
button 'A' pressed
2. Window 'W content is captured.
So I have callback_B like this:
void callback_B()
{
callback_A(); // create Window
'W'
capture_window();
}
So far so good. The only trouble is that requests sent
to XServer in the function callback_A have no chance to be
processed before call to capture_window() function, because
application does not retirned to it's main application loop,
which process events.
To get XServer chance to process events callback_B was
modified as following:
void callback_B()
{
callback_A(); // create Window
'W'
handle_events();
capture_window();
}
Where handle_events looks like:
void handle_events()
{
XFlush(display);
XSync(display, False);
while (XtAppPending(appContext))
{
XtAppProcessEvent(appContext,Mask );
}
}
This functions used in this application in other cases
when events should be handled and it's works OK.
But in this case, Window 'W' was only partially
drawn.
I found workaround modifie callback_B
void callback_B()
{
callback_A(); // create Window
'W'
handle_events();
usleep(10);
handle_events();
capture_window();
}
After some sleep and addition handle_events call
Window 'W' rendered on screen as expected.
But I don't why first approach didn't work.
From the XSync man page:
-
The XSync function flushes
the output buffer and then waits until all
requests have been received
and processed by the X server. Any errors
generated must be handled
by the error handler. For each protocol
error received by Xlib,
XSync calls the client application’s error han-
dling routine (see section
11.8.2). Any events generated by the server
are enqueued into the
library’s event queue.
---
So it's looks like XSync alone should do the job.
Obviously it was not - and it was a reason, that
event_handle function was written.
What I did with sleep and two calls to even_handle is
work, but it's ugly.
Anyone has idea why XSync alone is not enough and how
I can wait to all requests to be processed by XServer ?
Regards,
Valery.
--- On Sun, 3/7/10, Nadav Har'El n...@math.technion.ac.il
wrote:
From: Nadav Har'El n...@math.technion.ac.il
Subject: Re: XWindows - how capture window ?
To: Erez D erez0...@gmail.com
Cc: Valery Reznic valery_rez...@yahoo.com,
linux-il. linux-il@cs.huji.ac.il
Date: Sunday, March 7, 2010, 10:38 AM
On Thu, Mar 04, 2010, Erez D wrote
about Re: XWindows - how capture window ?:
composite window managers (i.e. compiz, baryl)
work by
drawing the original
window off screen, then read it as a 2D
picture, and
render it back to the
screen with certain effects.
So i know it is possible to grab an off screen
window.
I do not know however
how to make it off screen.
This is done using the Composite extension. See
http://www.freedesktop.org/wiki/Software/CompositeExt
But please note that all these extensions, as
their title
implies, are
not available in every installation of X. The
right way
to use
Re: XWindows - how capture window ?
Valery Reznic wrote: --- On Sat, 3/13/10, guy keren c...@actcom.co.il wrote: From: guy keren c...@actcom.co.il Subject: Re: XWindows - how capture window ? To: Valery Reznic valery_rez...@yahoo.com Date: Saturday, March 13, 2010, 3:56 PM the reason is: background jobs. the application does not necessarily do everything in one shot. some of its widgets leave some processing to be done during idle periods - which, i imagine, are triggered by timers. for this, they need the main loop to be executed for some (non-zero) duration. At least application itself do nothing with timers. And widgets are the standard ones - labels, buttons, text and draw areas. So I don't sure what's background jobs is. in my program, i used the gtk+ toolkit, and specifically the TextView widget. in this widget, when you populate it with a large amount of text, it calculates the size of lines in the background (as an idle task), in order to be able to draw the window withthe first lines of text as soon as possible. i needed to be able to show the text and immediately jump to some line - this failed because the widget didn't yet know exactly where to draw each line. there was no method for the widget to tell me it finished calculating its background tasks, so i had to use this kind of sleep-and-wait as a work-around. --guy ___ Linux-il mailing list Linux-il@cs.huji.ac.il http://mailman.cs.huji.ac.il/mailman/listinfo/linux-il
[HAIFUX Lecture] Scientific programming with modern Fortran - Shimon Panfil, Ph.D.
Next Monday, March 15th at 18:30, Haifux will gather to hear Shimon Panfil, Ph.D., talk about: Scientific programming with modern Fortran Abstract Fortran is the most known language for scientific and engineering problems. However growth of popularity of C/C++,Java, Matlab etc has shadowed the development and mere existence of Fortran from wider community. Situation may change know. Fortran 2003 standard provides all language features, one expects from modern programming language and gfortran which replaced g77 in gcc starting from version 4.0 implements this standard. === Please note that this meeting is going to be held in Taub 8 (!). For instructions how to get to Taub 6 (which is very close to Taub 8): http://www.haifux.org/where.html Attendance is free, and you are all invited! == Future lectures: 12/4/10 Genetic Algorithms - Omer Boehm == We are always interested in hearing your talks and ideas. If you wish to give a talk, hold a discussion, or just plan some event haifux might be interested in, please contact us at webmas...@haifux.org -- Orr Dunkelman, orr.dunkel...@gmail.com GPG fingerprint: C2D5 C6D6 9A24 9A95 C5B3 2023 6CAB 4A7C B73F D0AA (This key will never sign Emails, only other PGP keys. The key corresponds to o...@vipe.technion.ac.il) ___ Linux-il mailing list Linux-il@cs.huji.ac.il http://mailman.cs.huji.ac.il/mailman/listinfo/linux-il
INOVA USB DVB receiver??
Home Center has the Inova USB DVB receiver dongles on sale for 99 NIS this week. Anyone have one? Does it work with Linux? From what I can see on the various forums, the GeniaTech (sold here as APEX) is not (yet?) supported by Linux. The old version (never sold here AFAIK), works, but the one sold here uses a different tuner chip. Thanks in advance, Geoff. -- geoffrey mendelson N3OWJ/4X1GM Jerusalem Israel geoffreymendel...@gmail.com New word I coined 12/13/09, Sub-Wikipedia adj, describing knowledge or understanding, as in he has a sub-wikipedia understanding of the situation. i.e possessing less facts or information than can be found in the Wikipedia. ___ Linux-il mailing list Linux-il@cs.huji.ac.il http://mailman.cs.huji.ac.il/mailman/listinfo/linux-il
