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

[Dr Andrew John Hughes]

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.

> > 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)

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