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Subject: Re: GtkAda Scrollbars
To: "Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de>
Newsgroups: comp.lang.ada
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From: L Dries <bertus.dries@planet.nl>
Message-ID: <ed5bb971-7024-194e-8f0d-ef36dd0e27cc@planet.nl>
Date: Mon, 30 Dec 2019 11:09:07 +0100
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Date: 2019-12-30T11:09:07+01:00
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Op 25-12-2019 om 17:49 schreef Dmitry A. Kazakov:
> On 2019-12-24 08:36, L Dries wrote:
> 
>> I am trying to create a program using a "drawingarea". In some cases 
>> the drawing is to large for the window so I want to use scrollbars but 
>> I can get these correct.
> 
> Gtk_Drawing_Area must process the event "draw" in order to redraw itself 
> according to the allocation area and the current cairo context. Moving 
> sliders of the scrolled window would ultimately send "draw" down to its 
> drawing area child.
> 
> For an example of using Gtk_Drawing_Area for drawing various shapes see 
> AICWL:
> 
>     http://www.dmitry-kazakov.de/ada/aicwl.htm
> 
> The base type for all instruments is Gtk_Layered_Record derived from 
> Gtk_Drawing_Area_Record.
> 
> Merry Christmas!
> 
I cannot find any reference in this answer to the problem I have because 
for instance the scrollbars cannot move if even shown.
In the meantime I found on Internet references which suggest that the 
drawing area is in principle not a scrollable item so it should be 
inside a viewport. I have done so but my problem doesnot disappear. It 
looks to me now that the viewport or the drawingarea must have a size 
indication, so how to set initiate or even during runtime alter the size 
so that I get a scrollable drawing

-- 
L. Dries