Re: expose event & pixmap question

[Havoc Pennington <hp redhat com>]

Christian Seberino <seberino spawar navy mil> writes:
> gint exposeEventHandler(GtkWidget* widget, GdkEventExpose* event) {
>    gdk_draw_pixmap(widget->window, widget->style->fg_gc[GTK_WIDGET_STATE(widget)],
>       Pixmaps::myPicture, event->area.x, event->area.y,
>       event->area.x, event->area.y, event->area.width, event->area.height);
> 
>    return FALSE;
> };
> 
> 
> Pixmaps make expose event handlers easy I think because you can just
> redraw uncovered portion with a single function call as in function above.
> 
> WHY CAN'T WE REDRAW A PORTION OF THE DRAWING AREA THE SAME
> WAY AND AVOID NEED FOR PIXMAP?

Because the user will see each individual drawing operation, causing
flicker. Try it.

This is what GTK 2 fixes - it automatically double buffers, so you can
redraw directly to the drawing area and do not need the pixmap.

Havoc