Re: draw line in gtk

[Peter Krueger <pkrueger appss de>]

On Thu, 6 May 2004, Utpal Shasane wrote:
> I drawn line using
>                                         gdk_draw_line
> (draw->window,draw->style->fg_gc[GTK_WIDGET_STATE(draw)],23,20,23,450);
> on drawing area widget. But, it comes once and vanishes. When i called
> gtk_timeout_add() function it
> is contineous. Can somebody tell me, how i can draw a line without using
> gtk_timeout_add().
Hi Utpal!
The drawing area widget can't remember your drawing calls, that's why your
line disappears when the drawing area was covered by some other window and
then exposed again. You have to connect the "expose-event" signal to your
drawing area and then draw your contents from the signal handler.
Drawing outside an expose-event can also be dangerous, since the
underlying window resources could be invalid when the widget is
currently not shown on the screen.

Regards,
                     Peter
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Peter Krüger

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