RFR: 8298500: Create test to initially show stage with various attributes (iconified, maximized, full screen) [v2]

[Lukasz Kostyra]

On Fri, 15 Sep 2023 14:43:23 GMT, Lukasz Kostyra <lkostyra at openjdk.org> wrote:

>> PR adds tests mentioned in the title - a new `AttributesTest` class is added testing iconification, maximization and full-screen-ification of a Stage.
>> 
>> All variants are tested with decorated stage style.
>> 
>> Iconification is tested via overlaying two stages on top of one another, and then iconifying the top one - this is similar to already existing `IconifyTest.java` but it tests just the iconfication process and nothing more.
>> 
>> Maximization and FullScreen are both tested by creating two stages _not_ overlapping each other. After maximization/fullscreen top stage (being always on top as well) should cover the bottom stage. Moreover, FullScreen and Maximize are differentiated by checking if window decoration exists - maximized Stage will have its decoration taking space on top of the screen, whereas FullScreen one will not.
>> 
>> **NOTE:** on macOS I had issues with `getColor()` returning a valid color when called a second time. This only happened on macOS and with FullScreen test (others worked fine). Unfortunately I couldn't figure out why it returned (0, 0, 0, 255) or (255, 255, 255, 255). To mitigate that I moved color checks into separate `runAndWait()`-s with a small sleep between them, which seemed to help `getColor()` return proper values.
>> 
>> Verified to work on Windows 11, macOS and Linux.
>
> Lukasz Kostyra has updated the pull request incrementally with three additional commits since the last revision:
> 
>  - Add pre-stage-show tests
>  - Address review issues
>  - Rename AttributesTest -> StageAttributesTest

I addressed review remarks. I noticed following behaviors when testing the change:
- On Windows all tests pass
- On macOS `testMaximizedStageBeforeShow` and `testIconifiedStageBeforeShow` fail because stages are not shown already iconified/maximized. Rest of the tests work fine - I assume a bug in functionality that needs to be fixed.
- On Linux all tests fail, on my VM (Fedora 38 with X11) the stages are created without taking into account WIDTH/HEIGHT parameters provided to the Scene. They are created smaller than expected (I guess 100x100), so `getColor()` calls return background colors (terminal background/letters in my case). This could be cured in-test of course, but it also seems like a bug that should be ironed out (we do expect stages to be larger after all). After forcing proper width/height, testMaximizedStageBeforeShow/testFullScreenStageBeforeShow both fail - I noticed top stage is created maximized/fullscreen and immediately brought back to default dimensions, so I think it's another to-be-fixed bug.

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PR Comment: https://git.openjdk.org/jfx/pull/1240#issuecomment-1721404497