[PATCH] 8088147: FXCanvas: implement custom cursors

[Alexander Nyssen]

Hi Kevin,

> Am 30.06.2016 um 01:20 schrieb Kevin Rushforth <kevin.rushforth at oracle.com>:
> 
> Hi Alexander,
> 
> I attached the patch to the bug:
> 
> https://bugs.openjdk.java.net/browse/JDK-8088147
> 
> If I build it and run the manual test in "legacy" mode, meaning run everything with 9+109 and the legacy jfxrt.jar file, then it runs and the cursor now changes. So this looks like a good starting point for a fix.

Fine.

> 
> I tried building and running this in Jigsaw mode (building with jdk-9+109, but running the tests with a more recent JDK that includes modularization support), and noticed two problems right away that must be addressed:
> 
> 1. The unit tests for SWT are missing some of the jigsaw test tasks so the build fails right away with an exception from gradle:
> 
>   > Task with name 'jigsawTestsLinux' not found in project ':swt'.
> 
> Wiring up SWT-based tests to our unit test harness will take a bit more work than what you have provided (not even counting the Mac issue, which could be handled by excluding the test on Mac). In the short term, relying on manual tests for this fix might be best.
> 

I did not execute the tests in jigsaw mode yet, because other tests failed in this mode, too (as indicated in an earlier discussion). I will try to set things up in a virtual machine with Windows and/or Linux so I can work on the Gradle tests without having to deal with the Mac issue. The test harness will IMHO also be required for other contributions, and it would of course be fine if the automated test, I included in this patch, could be executed as well.

> 
> 2. You have introduced a dependency on a new internal package, com.sun.javafx.tk. If this is required in order to implement the fix, then you will need to add this package to the list of packages exports to javafx.swt in PlatformImpl; otherwise the following exception is thrown at runtime:
> 
> Exception in thread "JavaFX Application Thread" java.lang.IllegalAccessError: class javafx.embed.swt.SWTCursors (in module javafx.swt) cannot access class com.sun.javafx.tk.Toolkit (in module javafx.graphics) because module javafx.graphics does not export com.sun.javafx.tk to module javafx.swt

This dependency is required unless there is public API to convert a platform image (which is provided by the image cursor frame) to an image. To me, 
  Image image = Toolkit.getImageAccessor().fromPlatformImage(cursorFrame.getPlatformImage());
seemed to be the way to go. I will thus add the respective export in a revised patch.

> 
> 
> I won't have time to sponsor this change until the second half of July, but if others have time, the review can proceed and I'll pick it back up then if it is in good enough shape to run.

Especially setting up the SWT test harness will be kind of a blocker for succeeding contributions, so it would be nice if somebody could step in.

Regards,
Alexander

> 
> -- Kevin
> 
> 
> Kevin Rushforth wrote:
>> Hi Alexander,
>> 
>> It looks like your patch was stripped out by the mailing list server.
>> 
>> Can you please send me the patch offline, as a zip file (so line endings are preserved across different systems), and I will unzip it and attach it to the bug report.
>> 
>> -- Kevin
>> 
>> 
>> Alexander Nyssen wrote:
>>> Hi,
>>> 
>>> I have worked on a first contribution related to JDK-8088147. Attached please find a patch (created in extended Git format) that comprises the related changes. I have augmented the implementation of javafx.embed.swt.SWTCursors to handle the image cursor case. I further adjusted javafx.scene.Scene to update the cursor frame (in addition to the cursor) within synchronizeSceneProperties, so the cursor is not cleared in the first pulse succeeding the cursor property change.
>>> I have added an automated JUnit test (SWTCursorsTest) to the swt module, as well as a manual test (SWTImageCursorTest) to the systemTests module, with which the proper behavior can be verified. As no tests for SWT existed so far, I updated the build.gradle and gradle.properties files to support an SWT_TEST option, which allows to handle them similar to Swing tests. I also added the respective SWT dependency to the systemTests module. Please note that the JUnit test can currently not be executed using Gradle on the Mac (where the manual test currently is the single option; the automated tests are disabled), because there SWT-based tests require the -XstartOnFirstThread option that is currently not supported by the Gradle test runner (see https://issues.gradle.org/browse/GRADLE-3290 for details). We would have to use an ant task as a workaround.
>>> 
>>> Regards,
>>> Alexander
>>> 
>>> 
>>>