RFR: 8351357: Add canary system test checking if Stage receives focus on show [v7]

[Kevin Rushforth]

On Wed, 23 Jul 2025 19:40:20 GMT, Martin Fox <mfox at openjdk.org> wrote:

>> Lukasz Kostyra has updated the pull request incrementally with one additional commit since the last revision:
>> 
>>   Adjust error message for window-on-top check
>
> tests/system/src/test/java/test/robot/javafx/stage/StageFocusTest.java line 208:
> 
>> 206:                 for (int y = 0; y < STAGE_SIZE; ++y) {
>> 207:                     Color color = captureReader.getColor(x, y);
>> 208:                     assertTrue(checkColorEquals(SCENE_COLOR, color, TOLERANCE),
> 
> It looks like this assertion is executed in the JavaFX thread instead of the JUnit testing thread. Is this officially supported? Seems to be working in my testing.

Yes, this is supported. The `Util.runAndWait` method catches all Throwables and re-throws them to the calling thread.

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PR Review Comment: https://git.openjdk.org/jfx/pull/1804#discussion_r2228300644