[icedtea-web] RFC: Patch to double-buffer applets

[Deepak Bhole]

* Dr Andrew John Hughes <ahughes at redhat.com> [2010-11-02 19:04]:
> On 17:37 Tue 02 Nov     , Deepak Bhole wrote:
> > * Deepak Bhole <dbhole at redhat.com> [2010-11-02 17:31]:
> > > Hi,
> > > 
> > > IcedTea plugin currently does not double-buffer the applet panel. As a
> > > result, some applets may flicker depending on the machine.
> > > 
> > > Attached patch buffers the frame offscreen and then draws it, thereby
> > > addressing the issue.
> > > 
> > > ChangeLog:
> > > 2010-11-02  Deepak Bhole <dbhole at redhat.com>
> > > 
> > >    * plugin/icedteanp/java/sun/applet/PluginAppletViewer.java (update):
> > >    Override method and implement double-buffering.
> > > 
> > > Cheers,
> > > Deepak
> > 
> > 
> > Doh! There shouldn't be a println in there. New patch attached. I also
> > fixed the variable names for the image and its graphics.
> > 
> > Cheers,
> > Deepak
> > 
> 
> Looks good to me.  Maybe the variable names could be shorter, while still
> conveying the same meaning e.g. bufPanelImage.
> 

Done and pushed:
http://icedtea.classpath.org/hg/icedtea-web/rev/8e66d9386273

Thanks for reviewing!

Cheers,
Deepak


> > > diff -r 6c2527d42900 ChangeLog
> > > --- a/ChangeLog	Mon Nov 01 11:44:15 2010 -0400
> > > +++ b/ChangeLog	Tue Nov 02 17:29:03 2010 -0700
> > > @@ -1,3 +1,8 @@
> > > +2010-11-02  Deepak Bhole <dbhole at redhat.com>
> > > +
> > > +	* plugin/icedteanp/java/sun/applet/PluginAppletViewer.java (update):
> > > +	Override method and implement double-buffering.
> > > +
> > >  2010-11-01  Omair Majid  <omajid at redhat.com>
> > >  
> > >  	* Makefile.am (clean-IcedTeaPlugin): Only delete launcher directory if it
> > > diff -r 6c2527d42900 NEWS
> > > --- a/NEWS	Mon Nov 01 11:44:15 2010 -0400
> > > +++ b/NEWS	Tue Nov 02 17:29:03 2010 -0700
> > > @@ -12,3 +12,4 @@
> > >  
> > >  * Initial release of IcedTea-Web
> > >  * PR542: Plugin fails with NPE on http://www.openprocessing.org/visuals/iframe.php?visualID=2615
> > > +* Applets are now double-buffered to eliminate flicker in ones that do heavy drawing
> > > diff -r 6c2527d42900 plugin/icedteanp/java/sun/applet/PluginAppletViewer.java
> > > --- a/plugin/icedteanp/java/sun/applet/PluginAppletViewer.java	Mon Nov 01 11:44:15 2010 -0400
> > > +++ b/plugin/icedteanp/java/sun/applet/PluginAppletViewer.java	Tue Nov 02 17:29:03 2010 -0700
> > > @@ -359,6 +366,9 @@
> > >  
> > >       private static Long requestIdentityCounter = 0L;
> > >       
> > > +     private Image bufferedPanelImage;
> > > +     private Graphics bufferedImageGraphics;
> > > +     
> > >       /**
> > >        * Null constructor to allow instantiation via newInstance()
> > >        */
> > > @@ -2163,4 +2178,24 @@
> > >          }
> > >      }
> > >       }
> > > +
> > > +     /**
> > > +      * {@inheritDoc}
> > > +      */
> > > +     public void update(Graphics g) {
> > > +
> > > +    	 System.err.println("Buffering and drawing");
> > > +    	 
> > > +    	 // If the image or the graphics don't exist, create new ones
> > > +    	 if (bufferedPanelImage == null || bufferedImageGraphics == null) {
> > > +    		 bufferedPanelImage = createImage(getWidth(), getHeight());
> > > +    		 bufferedImageGraphics = bufferedPanelImage.getGraphics ();
> > > +    	 }
> > > +
> > > +    	 // Paint off-screen
> > > +    	 paint(bufferedImageGraphics);
> > > +
> > > +    	 // Draw the painted image
> > > +    	 g.drawImage(bufferedPanelImage, 0, 0, this);
> > > +     }
> > >   }
> > 
> 
> > diff -r 6c2527d42900 ChangeLog
> > --- a/ChangeLog	Mon Nov 01 11:44:15 2010 -0400
> > +++ b/ChangeLog	Tue Nov 02 17:37:09 2010 -0700
> > @@ -1,3 +1,8 @@
> > +2010-11-02  Deepak Bhole <dbhole at redhat.com>
> > +
> > +	* plugin/icedteanp/java/sun/applet/PluginAppletViewer.java (update):
> > +	Override method and implement double-buffering.
> > +
> >  2010-11-01  Omair Majid  <omajid at redhat.com>
> >  
> >  	* Makefile.am (clean-IcedTeaPlugin): Only delete launcher directory if it
> > diff -r 6c2527d42900 NEWS
> > --- a/NEWS	Mon Nov 01 11:44:15 2010 -0400
> > +++ b/NEWS	Tue Nov 02 17:37:09 2010 -0700
> > @@ -12,3 +12,4 @@
> >  
> >  * Initial release of IcedTea-Web
> >  * PR542: Plugin fails with NPE on http://www.openprocessing.org/visuals/iframe.php?visualID=2615
> > +* Applets are now double-buffered to eliminate flicker in ones that do heavy drawing
> > diff -r 6c2527d42900 plugin/icedteanp/java/sun/applet/PluginAppletViewer.java
> > --- a/plugin/icedteanp/java/sun/applet/PluginAppletViewer.java	Mon Nov 01 11:44:15 2010 -0400
> > +++ b/plugin/icedteanp/java/sun/applet/PluginAppletViewer.java	Tue Nov 02 17:37:09 2010 -0700
> > @@ -359,6 +366,9 @@
> >  
> >       private static Long requestIdentityCounter = 0L;
> >       
> > +     private Image bufferedFrameImage;
> > +     private Graphics bufferedFrameImageGraphics;
> > +     
> >       /**
> >        * Null constructor to allow instantiation via newInstance()
> >        */
> > @@ -2163,4 +2178,22 @@
> >          }
> >      }
> >       }
> > +
> > +     /**
> > +      * {@inheritDoc}
> > +      */
> > +     public void update(Graphics g) {
> > +
> > +    	 // If the image or the graphics don't exist, create new ones
> > +    	 if (bufferedFrameImage == null || bufferedFrameImageGraphics == null) {
> > +    		 bufferedFrameImage = createImage(getWidth(), getHeight());
> > +    		 bufferedFrameImageGraphics = bufferedFrameImage.getGraphics ();
> > +    	 }
> > +
> > +    	 // Paint off-screen
> > +    	 paint(bufferedFrameImageGraphics);
> > +
> > +    	 // Draw the painted image
> > +    	 g.drawImage(bufferedFrameImage, 0, 0, this);
> > +     }
> >   }
> 
> 
> -- 
> Andrew :)
> 
> Free Java Software Engineer
> Red Hat, Inc. (http://www.redhat.com)
> 
> Support Free Java!
> Contribute to GNU Classpath and the OpenJDK
> http://www.gnu.org/software/classpath
> http://openjdk.java.net
> PGP Key: 94EFD9D8 (http://subkeys.pgp.net)
> Fingerprint = F8EF F1EA 401E 2E60 15FA  7927 142C 2591 94EF D9D8