Re: [PATCH] Fixes to AWT PaintEvent handling

[Thomas Fitzsimmons <fitzsim at redhat dot com>]

On Fri, 2004-01-23 at 16:47, David Jee wrote:
> Hello all,
> 
> Here is a patch that reworks and fixes PaintEvent handling in Component
> and Container classes.  This patch eliminates redundant calls to
> paint()/update(), and will make sure that heavyweight components are
> repainted properly along with the lightweight peers.
> 
> Firstly, it consolidates the PaintEvent handling between the two classes
> so that only one paint()/update() method call results from a single
> PaintEvent.  This is done by relocating PaintEvent processing for both
> Component and Container objects to GtkComponentPeer's handleEvent().
> 
> Secondly, it adds a mechanism to explicitly repaint a heavyweight
> component by calling native GTK methods to invalidate and update the
> corresponding widget.
> 
> I originally had problems with repainting heavyweight peers, where
> invalidating a widget caused an expose event from GTK, which caused a
> PaintEvent in AWT, which then caused AWT to invalidate the same widget
> again, resulting in an infinite loop.  So I added mechanisms to filter
> out these unwanted expose events from GTK to break the loop.
> 
> Any comments and are welcome.
> 

This looks good to me with one change: GtkContainerPeer.handleEvent can
be removed completely since it just calls its parent's handleEvent
method.  We can address the FIXMEs later, if need be.

Thanks,
Tom

> -David Jee
> 
> 
> 2004-01-23  David Jee  <djee@redhat.com>
> 
>         * gnu/java/awt/peer/gtk/GtkComponentPeer.java
>         (handleEvent): Implemented. Handles PaintEvents.
>         (paint): Implemented. Use GTK native methods to queue updates
>         for this heavyweight peer.
>         * gnu/java/awt/peer/gtk/GtkContainerPeer.java
>         (handleEvent): Moved the code to GtkComponentPeer.handleEvent().
>         Just call super.handleEvent()
>         * java/awt/Component.java
>         (paint): Implemented. Explictly paint the heavyweight peer.
>         (update): Clear the background for heavyweight components.
>         (paintAll): No need to call peer.paint() anymore.
>         (processEvent): Don't process PaintEvents here. It's now done in
>         the peer's handleEvent().
>         (processPaintEvent): Removed.
>         * java/awt/Container.java
>         (paint): No need to call super.paint(). Visit heavyweight
>         children as well.
>         (update): Don't clear the background here.  It's done in
>         Component.update().
>         (visitChildren): Added check to not recurse into Containers.
>         * jni/gtk-peer/gnu_java_awt_peer_gtk_GtkComponentPeer.c
>         (filter_expose_event_handler): New method.  Filter unwanted
>         expose events while painting heavyweight peers.
>         (Java_gnu_java_awt_peer_gtk_GtkComponentPeer_addExposeFilter):
>         New method. Connect filter and block pre_event_handler.
>         (Java_gnu_java_awt_peer_gtk_GtkComponentPeer_removeExposeFilter):
>         New method. Disconnect filter and unblock pre_event_handler.
>         (Java_gnu_java_awt_peer_gtk_GtkComponentPeer_gtkWidgetQueueDrawArea):
>         New method. Invalidate and update given area.
>         * jni/gtk-peer/gnu_java_awt_peer_gtk_GtkEvents.c
>         (pre_event_handler): Add checks for unwanted expose events.
> 
>