RFR: 8273743: KeyCharacterCombination for "+" does not work on US QWERTY keyboard layout [v2]

[Andy Goryachev]

On Tue, 14 May 2024 22:29:18 GMT, Martin Fox <mfox at openjdk.org> wrote:

>> On Linux getKeyCodeForChar does not consult the current keyboard layout. For example, it assumes the “+” character is on KeyCode.PLUS even on layouts which don’t generate KeyCode.PLUS. The result is that most KeyCharacterCombinations don’t work.
>> 
>> This PR fixes this using the same approach that Mac glass uses. When the user types a key we lookup all the characters that key might generate and put them in a map. getKeyCodeForChar then consults the map to find the Java key code. This ensures that we only pay attention to keys that are on the user’s physical keyboard.
>> 
>> (Some Linux layout maps are expansive and include entries for keys that may be on the user’s keyboard but probably aren’t, like “(“ and “)” on the numeric keypad. If we simply ask for all entries that generate a given character we can get multiple hits with no good way to determine which ones are physically present.)
>> 
>> This PR also contains fixes to the Robot to enable testing. When Glass consults the GdkKeymap to determine which keys might generate a keyval GDK returns a list covering every installed layout and shift level. The old Glass code simply picked the first entry in the list. This PR iterates through the list looking for one that works for the current layout and correct shift level.
>
> Martin Fox has updated the pull request with a new target base due to a merge or a rebase. The incremental webrev excludes the unrelated changes brought in by the merge/rebase. The pull request contains ten additional commits since the last revision:
> 
>  - Merge remote-tracking branch 'upstream/master' into linuxcharcombo
>  - Comment fixes
>  - Consistency in naming conventions and comment cleanup.
>  - Merge remote-tracking branch 'upstream/master' into linuxcharcombo
>  - Expanded robot lookup table, general cleanup
>  - Merge remote-tracking branch 'upstream/master' into linuxcharcombo
>  - Resolving duplicates for Robot, fallback for getKeyCodeForChar
>  - Merge remote-tracking branch 'upstream/master' into linuxcharcombo
>  - KeyCharacterCombination fixes on Linux

In the context of the recent discussion on the mailing list, would it be possible to actually detect the keyboard layout?  There is a limited number of layouts, so in theory that should be possible.

Another question - I recall on Windows there is a way to enter certain key using Alt codes.  Does this method exist on Linux?

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PR Comment: https://git.openjdk.org/jfx/pull/1373#issuecomment-2113454803