XWindows - how capture window ?

[guy keren]

Valery Reznic wrote:
> 
> --- On Sat, 3/13/10, guy keren <choo at actcom.co.il> wrote:
> 
>> From: guy keren <choo at actcom.co.il>
>> Subject: Re: XWindows - how capture window ?
>> To: "Valery Reznic" <valery_reznic at 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