[Lazarus] 'WARNING: TGtk2WidgetSet.InvalidateRect refused invalidating during paint message:

[Mattias Gaertner]

On Thu, 3 May 2018 17:15:42 -0400
Donald Ziesig via Lazarus <lazarus at lists.lazarus-ide.org> wrote:

> Hi All!
> 
> I have written a control that works fine except that it produces the 
> subject WARNING twice for every time it is painted.  The problem comes 
> from a single line:
> 
>          Canvas.Draw(0, 0, Bitmap);
> 
> I do much drawing to the Bitmap's Canvas (behind the scenes to avoid 
> flicker) before calling the Draw method.
> 
> I have stepped through this call and sure enough, it calls 
> InvalidateRect twice before returning.  Otherwise it does exactly what 
> it is supposed to do.

If there is an InvalidateRect during OnPaint there is a bug.
Please create a bug report with an example.

Mattias