[OpenJDK 2D-Dev] Review Request for bug (JDK-8039345) Strange behaviour of per-pixel translucency on linux

[prasanta sadhukhan]

I tried my fix on latest ubuntu14.04 and it seems to work for me, the 
checkbox and button gets painted without any trails and without any 
exception.
Also, regarding Clemens suggestion that "Transparency.OPAQUE is also 
passed to the super constructor of XRWindowSurfaceData" it is observed 
that the "transparancy" parameter is not used in the super constructor 
so it shouldn't have any effect on this particular bug, maybe we can 
remove the parameter from the super constructor for its lack of use.

Regards
Prasanta
On 2/10/2015 3:34 AM, Phil Race wrote:
> I tried this on Ubuntu (13.04) with the test case in the bug (BTW 
> there should be a regression test
> along with this fix) and I get a nasty exception (as below) and the 
> checkbox and button don't get painted.
>
> Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException
>     at sun.java2d.pipe.ValidatePipe.copyImage(ValidatePipe.java:196)
>     at sun.java2d.SunGraphics2D.copyImage(SunGraphics2D.java:3232)
>     at sun.java2d.SunGraphics2D.drawImage(SunGraphics2D.java:3396)
>     at sun.java2d.SunGraphics2D.drawImage(SunGraphics2D.java:3345)
>     at 
> java.awt.Component$BltBufferStrategy.showSubRegion(Component.java:4472)
>     at 
> java.awt.Component$BltSubRegionBufferStrategy.show(Component.java:4597)
>     at 
> javax.swing.BufferStrategyPaintManager.flushAccumulatedRegion(BufferStrategyPaintManager.java:371)
>     at 
> javax.swing.BufferStrategyPaintManager.endPaint(BufferStrategyPaintManager.java:333)
>     at javax.swing.RepaintManager.endPaint(RepaintManager.java:1387)
>     at javax.swing.JComponent.paint(JComponent.java:1041)
>     at 
> java.awt.GraphicsCallback$PaintCallback.run(GraphicsCallback.java:39)
>     at 
> sun.awt.SunGraphicsCallback.runOneComponent(SunGraphicsCallback.java:79)
>     at 
> sun.awt.SunGraphicsCallback.runComponents(SunGraphicsCallback.java:116)
>     at java.awt.Container.paint(Container.java:1997)
>     at java.awt.Window.paint(Window.java:3929)
>     at javax.swing.RepaintManager$4.run(RepaintManager.java:851)
>     at javax.swing.RepaintManager$4.run(RepaintManager.java:823)
>     at java.security.AccessController.doPrivileged(Native Method)
>     at 
> java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:76)
>     at 
> javax.swing.RepaintManager.paintDirtyRegions(RepaintManager.java:823)
>     at 
> javax.swing.RepaintManager.paintDirtyRegions(RepaintManager.java:798)
>     at 
> javax.swing.RepaintManager.prePaintDirtyRegions(RepaintManager.java:747)
>     at javax.swing.RepaintManager.access$1300(RepaintManager.java:65)
>     at 
> javax.swing.RepaintManager$ProcessingRunnable.run(RepaintManager.java:1751)
>     at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:311)
>     at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:759)
>     at java.awt.EventQueue.access$500(EventQueue.java:97)
>     at java.awt.EventQueue$3.run(EventQueue.java:712)
>     at java.awt.EventQueue$3.run(EventQueue.java:706)
>     at java.security.AccessController.doPrivileged(Native Method)
>     at 
> java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:76)
>     at java.awt.EventQueue.dispatchEvent(EventQueue.java:729)
>     at 
> java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:190)
>     at 
> java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:115)
>     at 
> java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:104)
>     at 
> java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:100)
>     at 
> java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:92)
>     at java.awt.EventDispatchThread.run(EventDispatchThread.java:81)
>
> -phil.
>
> On 02/05/2015 03:31 AM, prasanta sadhukhan wrote:
>> Hi,
>>
>> Please review a fix for this issue:
>> 8039345 Strange behaviour of per-pixel translucency on linux
>>
>> Bug description: https://bugs.openjdk.java.net/browse/JDK-8039345
>> webrev: http://cr.openjdk.java.net/~serb/prasanta/8039345/webrev.00/
>>
>> Note: A wrong (PictStandardRGB24) picture format was used for 
>> xrendering even for surface having alpha support thereby neglecting 
>> the alpha transparency. It should be using PictStandardARGB32 or 
>> TRANSLUCENT picture format for correct alpha support in xrendered 
>> surface.
>>
>> Regards
>> Prasanta
>