[Lazarus] GTK2 EraseBackgound

[Paul Ishenin]

05.02.2010 19:57, JoshyFun wrote:
> Hello Lazarus-List,
>
> I wrote a little text induction feature to TCustomEdit, is is being
> done using LCL in Windows platform (without using Windows unit) where
> it works fine. The induction is the grayed text that appears in some
> textboxes like the attached one (taken from my windows code).
>
> To work in Windows it overrides the EraseBackground to paint the
> induction and the WMPaint message to not paint anything if no text
> available in the textbox.
>
> The problem is that in GTK2 this effect is not obtained as the
> EraseBackground is never called and message WMEraseBackground is never
> called also.
>
> GTK2 is almost new to me so I'm lost on how to solve this and if is in
> fact possible to solve it with the current LCL/GTK2 interaction.
>
> I hope somebody can give some hints or maybe simple says that
> "impossible with current LCL implementation".
EraseBackground message is only send for TCustomControl descendants. 
Therefore you get no message for TEdit.

Best regards,
Paul Ishenin.