Re: Re: gdk_draw_layout seems that it doesn't make damage event for offscreens.

[Alexander Larsson <alexl redhat com>]

On Tue, 2009-12-08 at 18:31 +0000, 박보람 wrote:
> Yes, the double buffering handling does generate damage events. 
> 
> Then, nomally widgets maybe doesn't have this kind of problem.
> 
>  
> 
> But "gtkperf" app draws layout to window directly in
> on_idle_gtkdrawingarea_text_test ( ). 
> 
> (I attached "test.c" of "gtkperf" which includes
> "on_idle_gtkdrawingarea_text_test ( )")
> 
> So, this problem happens.

Yes, any kind of direct drawing to the window via cairo or
gdk_draw_layout() will cause this problem. However, such operations are
not that common.
 
> To resolve this problem, isn't it good approach to add draw_layout,
> draw_layout_line_with_colors 
> 
> and draw_layout_with_colors to "struct _GdkDrawableClass" ?

Thats not really required. All these drawing operations will pass
through GdkPangoRenderer which could be modified to create damage events
when drawing directly to a window. I.E:

gdk_pango_renderer_draw_glyphs
gdk_pango_renderer_draw_rectangle
gdk_pango_renderer_draw_error_underline
gdk_pango_renderer_draw_shape

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 Alexander Larsson                                            Red Hat, Inc 
       alexl redhat com            alexander larsson gmail com 
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