[Lazarus] Weird GTK TGroupBox bug

[Mattias Gaertner]

On Thu, 07 Mar 2013 17:44:02 +0100
Giuliano Colla <giuliano.colla at fastwebnet.it> wrote:

> I've stumbled against a rather weird bug in TGroupBox with GTK2 WS.
> 
> If a TGroupBox gets partly covered by another window (as it may happen 
> with the drop-down of a TComboBox, or simply by moving another window 
> over it), and then uncovered, not all the widgets inside the TGroupBox 
> are properly repainted.

I see no such problems on Ubuntu.
Can you reproduce the problem in a small example?
It sounds like a problem with clipping area (gtk expose events).
 
> It turns out that:
> 
> 1) All widgets which were fully hidden are properly repainted.
> 
> 3) Not all widgets which were partly hidden are repainted properly. 
> TButton and TBitButton are repainted properly, while TLabel and 
> TSpeedButton are not.

TButton and TBitBtn are painted solely by the gtk, while TLabel and
TSpeedButton are painted by the LCL. 
Maybe there is something wrong with clipping or MoveWindowOrgEx.

 
> 4) Depending on GTK style, also the TGroupBox caption is not properly 
> repainted, when partly hidden.

TGroupBox is painted solely by the gtk.

 
> See attached screenshots of the same form, before and after sliding 
> another window over it.
> 
> Verified with different Window Managers (KDE 3.x, KDE 4.x, GNOME 2.x, 
> XFCE4), Lazarus Trunk, Lazarus 1.0.2, Lazarus 1.0.4., under RHEL5, and 
> FC14.
> 
> Using QT WS, all widgets are properly repainted.
> 
> As an additional information, this bug wasn't present in Lazarus 
> 0.9.26.2. (I don't have at hand a Lazarus 0.9.30 to test).
> 
> I didn't find a mention in the BugTracker. Should I file a new bug, or I 
> just missed an entry?

Please create a bug report with an example.

Mattias