Tommi,
Excellent hint. With matchbox (or no window manager at all), just doing
gtk_widget_realize (win);
gdk_window_set_back_pixmap (win->window, NULL, FALSE);
does the trick.
Thanks
On 10/11/06, Tommi Komulainen <tommi.komulainen@xxxxxx> wrote:
> On 10/11/06, Matt Hoosier <mwhoosier@xxxxxxxxx> wrote:
> > When a GtkWindow first appears after gtk_widget_show() is called on
> > it, there is a moment during which it isn't yet rendered, and the X11
> > window's space is filled with all white background.
> >
> > I understand that this is an artifact of the normal allocate -> map ->
> > expose progression. Is there a way to force that the window already
> > has a rendered copy of itself available for the first refresh cycle,
> > so that applications don't flicker to/from white at startup?
>
> As I recall, windows can not be drawn on until they're mapped. But
> once they're mapped, they're also visible, usually.
>
> Hack that comes to mind, it may or may not help, could be to render
> the window to an offscreen pixmap prior to showing it. Currently it's
> a hack, there's better offscreen support in bugzilla, I think.
> Possibly something like the following:
>
> (On second thought gtk_widget_realize (window);
> gdk_window_set_back_pixmap (window->window, NULL, FALSE); alone might
> work, if I'm understanding the API docs correctly. Depends on window
> manager.)
>
> gtk_window_iconify (window);
> gtk_widget_show (window);
>
> /* now the widgets should be in "visible enough" state, namely
> mapped, to be drawn correctly but hopefully not visible to the user */
>
> /* render the widgets to an offsceen pixmap and set it as background pixmap */
> pixmap = gdk_pixmap_new (..., window->allocation.width,
> window->allocation.height, ...);
> fake_expose_event (window, pixmap);
> gdk_window_set_back_pixmap (window->window, pixmap, FALSE);
> g_object_unref (pixmap);
>
> /* show the window and let it be drawn normally */
> gtk_window_deiconify (window);
> /* the following should probably be done after expose event */
> gdk_window_set_back_pixmap (window->window, NULL, FALSE);
>
> /* found from gnome-control-center */
> static void
> fake_expose_event (GtkWidget *widget, GdkPixmap *pixmap)
> {
> GdkWindow *tmp_window;
> GdkEventExpose event;
>
> tmp_window = widget->window;
> widget->window = pixmap;
>
> event.type = GDK_EXPOSE;
> event.window = widget->window;
> event.send_event = FALSE;
> event.area = widget->allocation;
> event.region = NULL;
> event.count = 0;
>
> gtk_widget_send_expose (widget, (GdkEvent *) &event);
>
> widget->window = tmp_window;
> }
>
> --
> Tommi Komulainen tommi.komulainen@xxxxxx
> _______________________________________________
> gtk-list mailing list
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> http://mail.gnome.org/mailman/listinfo/gtk-list
>
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