8280482: Window transparency bug on Linux

[rm-gh-8]

Backporting JDK-8280482: Window transparency bug on Linux.

Problem:
• Windows on screen 0 (default screen) incorrectly lose transparency
• Only windows on screen 1 should lose transparency
• Root cause: toGlobal() call in checkIfOnNewScreen() doubles the X position, causing wrong screen detection

Solution:
• Remove unnecessary toGlobal() call when passing window bounds to screen detection
• toGlobal() is not required for monitor number checking and causes coordinate miscalculation

Ran GHA Sanity Checks (passed) and related test (passed).

---

Progress

• Change must not contain extraneous whitespace
• Commit message must refer to an issue
• JDK-8280482 needs maintainer approval

Issue

• JDK-8280482: Window transparency bug on Linux (Bug - P4 - Approved)

Reviewing

Using git

Checkout this PR locally:
$ git fetch https://git.openjdk.org/jdk21u-dev.git pull/2482/head:pull/2482
$ git checkout pull/2482

Update a local copy of the PR:
$ git checkout pull/2482
$ git pull https://git.openjdk.org/jdk21u-dev.git pull/2482/head

Using Skara CLI tools

Checkout this PR locally:
$ git pr checkout 2482

View PR using the GUI difftool:
$ git pr show -t 2482

Using diff file

Download this PR as a diff file:
https://git.openjdk.org/jdk21u-dev/pull/2482.diff

Using Webrev

Link to Webrev Comment

[bridgekeeper]

👋 Welcome back rm-gh-8! A progress list of the required criteria for merging this PR into master will be added to the body of your pull request. There are additional pull request commands available for use with this pull request.

[openjdk]

@rm-gh-8 This change now passes all automated pre-integration checks.

ℹ️ This project also has non-automated pre-integration requirements. Please see the file CONTRIBUTING.md for details.

After integration, the commit message for the final commit will be:

8280482: Window transparency bug on Linux

You can use pull request commands such as /summary, /contributor and /issue to adjust it as needed.

At the time when this comment was updated there had been 66 new commits pushed to the master branch:

• 46687d3: 8366844: Update and automate MouseDraggedOriginatedByScrollBarTest.java
• 569d08b: 8365790: Shutdown hook for application image does not work on Windows
• 1302534: 8366229: runtime/Thread/TooSmallStackSize.java runs with all collectors
• ... and 63 more: https://git.openjdk.org/jdk21u-dev/compare/21fcec033c6e47947b4230e339bc59f49ed53602...master

As there are no conflicts, your changes will automatically be rebased on top of these commits when integrating. If you prefer to avoid this automatic rebasing, please check the documentation for the /integrate command for further details.

As you do not have Committer status in this project an existing Committer must agree to sponsor your change.

➡️ To flag this PR as ready for integration with the above commit message, type /integrate in a new comment. (Afterwards, your sponsor types /sponsor in a new comment to perform the integration).

[openjdk]

This backport pull request has now been updated with issue from the original commit.

[openjdk]

⚠️ @rm-gh-8 This change is now ready for you to apply for maintainer approval. This can be done directly in each associated issue or by using the /approval command.

[mlbridge]

Webrevs

• 00: Full (fb34b978)

[rm-gh-8]

/approval request for backport of JDK-8280482: Window transparency bug on Linux.

Ran the related tests on linux-x64:

(Passed) - make test TEST=test/jdk/java/awt/Multiscreen/MultiScreenCheckScreenIDTest.java

Results are attached.
linux-x64-specific-test.log

[openjdk]

@rm-gh-8
8280482: The approval request has been created successfully.

[rm-gh-8]

/integrate

[openjdk]

@rm-gh-8
Your change (at version fb34b97) is now ready to be sponsored by a Committer.

[phohensee]

/sponsor

[openjdk]

Going to push as commit c578eb2.
Since your change was applied there have been 66 commits pushed to the master branch:

• 46687d3: 8366844: Update and automate MouseDraggedOriginatedByScrollBarTest.java
• 569d08b: 8365790: Shutdown hook for application image does not work on Windows
• 1302534: 8366229: runtime/Thread/TooSmallStackSize.java runs with all collectors
• ... and 63 more: https://git.openjdk.org/jdk21u-dev/compare/21fcec033c6e47947b4230e339bc59f49ed53602...master

Your commit was automatically rebased without conflicts.

[openjdk]

@phohensee @rm-gh-8 Pushed as commit c578eb2.

💡 You may see a message that your pull request was closed with unmerged commits. This can be safely ignored.