RFR: 8006421: GraphicsConfiguration of a frame is changed when the frame is moved to another screen [v5]

[Alexander Zvegintsev]

On Wed, 14 Jun 2023 07:32:51 GMT, Tejesh R <tr at openjdk.org> wrote:

>> When a frame is dragged from one screen to another screen, the `GraphicsConfigurations` may vary depending on screen/monitor. However, transparency has to be maintained since it is expected as it is set. So the fix addresses in maintaining the translucency capability when frame is moved from one screen to another screen. For main screen, translucency is set when `setBackground` is called, but for second screen the same is not taken care. Hence setting of Translucency Capable `GC` is taken care when screen switch happens. The fix handles only for non-opaque windows alone retaining the behavior for opaque windows. 
>> The fix is verified in CI for regression check, which is Green.
>
> Tejesh R has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Updated based on review comments

src/java.desktop/macosx/classes/sun/lwawt/macosx/CFileDialog.java line 205:

> 203:     public GraphicsConfiguration getAppropriateGraphicsConfiguration(
> 204:             GraphicsConfiguration gc)
> 205:     {

Could you please move the brace to the line 204 to match the overall style of the file?

src/java.desktop/share/classes/java/awt/Window.java line 3223:

> 3221:                     getDefaultScreenDevice().
> 3222:                     getDefaultConfiguration();
> 3223:         }

It looks like `gc` was always not null before the fix, which is no longer true after the fix.
We need to double check that we didn't break anything in this regard.

src/java.desktop/unix/classes/sun/awt/X11/XWindowPeer.java line 240:

> 238:             XToolkit.awtUnlock();
> 239:         }
> 240:     }

The same code is already in XCanvasPeer.

XWindowPeer is a descendant of XCanvasPeer, there is no need to repeat the code here.

src/java.desktop/windows/classes/sun/awt/windows/WWindowPeer.java line 671:

> 669:         return gc;
> 670:     }
> 671: 

Same here, WWindowPeer is a WCanvasPeer descendant.

-------------

PR Review Comment: https://git.openjdk.org/jdk/pull/14246#discussion_r1231559438
PR Review Comment: https://git.openjdk.org/jdk/pull/14246#discussion_r1231650769
PR Review Comment: https://git.openjdk.org/jdk/pull/14246#discussion_r1231640268
PR Review Comment: https://git.openjdk.org/jdk/pull/14246#discussion_r1231640811