[Gambas-user] Gambas2 Grab in Gambas3

[Richard Welch]

Fabien, thank you for your reply.

There are snags with each of these...

First approach:

Although the DrawingArea is often fully visible on screen, sometimes it 
will be too big.
I can think of a way round this but it is not very elegant!

Second approach:

The image is sometimes highly complex and can comprise hundreds of 
rectangles and lines as well as text.  I already do use generic 
functions as you describe, with variable-driven adjustments to cope with 
the differences between printing and screen display.  There are many 
places in the code which may build a display.

I found in G2 that there were times when the image in a DrawingArea was 
not restored if it was partially covered by a window from another 
application and then exposed once more.  This mechanism enabled it to be 
restored easily without having to rebuild it from scratch.  Maybe the 
DrawingArea in G3 is more robust?

Richard


On 08/11/16 17:31, Fabien Bodard wrote:
> Well... there is two answers.
>
> First :
>
> Use the Desktop.ScreenShot Function
> (http://gambaswiki.org/wiki/comp/gb.qt4/desktop/screenshot).
> But your widget must be visible on the screen... This is why it is a
> SCREEN shot.
>
>
> Second :
>
> When you are drawing something in a drawingarea you use a generic
> drawing function.
>
> Exemple :
>
>
> Public sub DrawingArea_Draw()
>
> DrawARect()
>
> End
>
>
> Private Sub DrawARect()
>
>    Paint.Brush = Brush.Color(Color.Yellow)
>    Paint.Rectangle(10,10,Paint.Width - 20, Paint.Height - 20)
>    Paint.Fill
>
> End
>
>
> Public Function MakeImage(iWidth as integer, iHeight as integer) as Image
>
>    Dim hImage a new Image(iWidth, iHeight, Color.White)
>
>    Paint.Begin(hImage)
>       DrawARect()
>    Paint.End
>
> End
>
>
> With that you have only one drawing function (DrawARect) able to draw
> every where ... even on a printer. This is the way used in most of the
> components too
>
> 2016-11-08 12:52 GMT+01:00 Richard Welch <richardpa608 at ...626...>:
>> I need a simple way to copy the current image in a visible DrawingArea
>> to a hidden PictureBox.
>>
>> The project was written in Gambas2, where a simple Grab method did the
>> trick, but in G3 this does something different so the converted code
>> does not function fully.
>>
>> FMain.pbxPicture.W = FMain.drwRep.W
>> FMain.pbxPicture.H = FMain.drwRep.H
>> FMain.pbxPicture.Background = FMain.drwRep.Background
>> FMain.pbxPicture.Picture = FMain.drwRep.Grab()
>>
>> With what do I replace the Grab method?
>>
>> (The DrawingArea is painted in many different pieces of code, depending
>> on context, so I want to make the change which will have the smallest
>> impact possible on the source code)
>>
>> There is a gambas-user thread started around 19 April 2012.
>> Is this fully relevant?
>> Is this the /simplest/ answer?
>> It would need some very tedious testing in my context.....
>>
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>