[jdk8u-dev] RFR: 8189687: Swing: Invalid position of candidate pop-up of InputMethod in Hi-DPI on Windows [v2]

[Simon Tooke]

On Fri, 1 Nov 2024 07:21:13 GMT, Kazuhisa Takakuri <ktakakuri at openjdk.org> wrote:

>> This is a backport of JDK-8189687: Swing: Invalid position of candidate pop-up of InputMethod in Hi-DPI on Windows.
>> JDK-8189687 contains two fixes to AwtComponent:.OpenCandidateWindow, one of which is backported in this pull request.
>> The other fix is an enhancement to JEP 263 (JDK-8055212) and is not needed since JDK8 does not implement JEP 263.
>> 
>> 1. Fix to make OpenCandidateWindow reference the correct Window
>> Fix OpenCandidateWindow to reference the proxy window that has focus when getting "HWND."
>> 
>> 
>> --- a/src/java.desktop/windows/native/libawt/windows/awt_Component.cpp
>> +++ b/src/java.desktop/windows/native/libawt/windows/awt_Component.cpp
>> @@ -3880,19 +3880,21 @@ void AwtComponent::OpenCandidateWindow(int x, int y)
>>  {
>>      UINT bits = 1;
>>      POINT p = {0, 0}; // upper left corner of the client area
>> -    HWND hWnd = GetHWnd();
>> +    HWND hWnd = ImmGetHWnd();
>>      if (!::IsWindowVisible(hWnd)) {
>>          return;
>>      }
>> 
>> 
>> 
>> 2. Scaling fixes to enhance JDK-8073320
>> OpenJDK9 has supported HiDPI Graphics since JEP 263 (JDK-8055212). This fix is one of its enhancements: when OpenCandidateWindow opens an IME conversion candidate, it corrects the coordinates for the device.
>> 
>> 
>> In the attached test that reproduces the issue problem, the Panel containing the TextField is a child component, so it refers to the wrong window to get the position coordinate of the candidate window.
>> Therefore, the candidate window will appear in the correct position with the "1" fix.
>> Note that OpenJDK8 does not implement JEP 263, so the "2" fix is not included in this pull request.
>
> Kazuhisa Takakuri 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 three additional commits since the last revision:
> 
>  - Merge branch 'master' into 8189687
>  - Fix the Copyright year
>  - Backport 489e5ae3349370825b7faa1d7514796a2b1ac1c7

(Disclaimer: I am not an official reviewer)
I have reproduced the issue, reviewed and tested this change and the tier1 Windows failures which are all certificate failures (unrelated), and my opinion is that this is good to go.

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PR Comment: https://git.openjdk.org/jdk8u-dev/pull/564#issuecomment-2451762538