8291908: VirtualFlow creates unneeded empty cells

[johanvos]

When calculating the viewportOffset, we now already take into account that cells will have to shift.

This prevents the creation of temporary empty cells in the layout phase.
One test needed to be fixed, since the number of invocations to updateItem() was hardcoded (and it
is decreased by this commit).

---

Progress

• Change must not contain extraneous whitespace
• Commit message must refer to an issue
• Change must be properly reviewed (2 reviews required, with at least 1 Reviewer, 1 Author)

Issue

• JDK-8291908: VirtualFlow creates unneeded empty cells

Reviewers

• Kevin Rushforth (@kevinrushforth - Reviewer)
• Ajit Ghaisas (@aghaisas - Reviewer)

Reviewing

Using git

Checkout this PR locally:
$ git fetch https://git.openjdk.org/jfx pull/863/head:pull/863
$ git checkout pull/863

Update a local copy of the PR:
$ git checkout pull/863
$ git pull https://git.openjdk.org/jfx pull/863/head

Using Skara CLI tools

Checkout this PR locally:
$ git pr checkout 863

View PR using the GUI difftool:
$ git pr show -t 863

Using diff file

Download this PR as a diff file:
https://git.openjdk.org/jfx/pull/863.diff

[bridgekeeper]

👋 Welcome back jvos! 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.

[mlbridge]

Webrevs

• 00: Full (767b4173)

[kevinrushforth]

/reviewers 2

[openjdk]

@kevinrushforth
The total number of required reviews for this PR (including the jcheck configuration and the last /reviewers command) is now set to 2 (with at least 1 Reviewer, 1 Author).

[kevinrushforth]

This fix looks good. I confirmed that the new test fails without the fix and passes with the fix. I also confirmed that this also fixes JDK-8291467.

[kevinrushforth]

@johanvos As noted in JBS, this PR also fixes JDK-8291467. Can you add that issue to this PR? Alternatively, you could change JDK-8291908 to a bug and close JDK-8291467 as a duplicate.

[aghaisas]

Fix looks good to me.

[openjdk]

@johanvos 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:

8291908: VirtualFlow creates unneeded empty cells

Reviewed-by: kcr, aghaisas

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 12 new commits pushed to the master branch:

• 33534cb: 8291630: Update attribution in webkit.md file
• 38324a7: 8291087: Wrong position of focus of screen reader on Windows with screen scale > 1
• b4d86bd: 8218826: TableRowSkinBase: horizontal layout broken if row has padding
• 4c1f4c2: Merge
• dd30402: 8291589: Update copyright header for files modified in 2022
• 779365f: Merge
• 5febaca: 8291502: Mouse or touch presses on a non-focusable region don't clear the focusVisible flag of the current focus owner
• 8fa8919: 8291588: Update boot JDK to 18.0.2
• 08ec9c8: 8289605: Robot capture tests fail intermittently on Mac M1
• 4b4deae: 8289397: Fix warnings: Possible accidental assignment in place of a comparison. A condition expression should not be reduced to an assignment
• ... and 2 more: https://git.openjdk.org/jfx/compare/7e48413eb0f9eb3dcbd9d3a1572fc311036092c8...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.

➡️ To integrate this PR with the above commit message to the master branch, type /integrate in a new comment.

[johanvos]

/integrate

[openjdk]

Going to push as commit eaddb0f.
Since your change was applied there have been 12 commits pushed to the master branch:

• 33534cb: 8291630: Update attribution in webkit.md file
• 38324a7: 8291087: Wrong position of focus of screen reader on Windows with screen scale > 1
• b4d86bd: 8218826: TableRowSkinBase: horizontal layout broken if row has padding
• 4c1f4c2: Merge
• dd30402: 8291589: Update copyright header for files modified in 2022
• 779365f: Merge
• 5febaca: 8291502: Mouse or touch presses on a non-focusable region don't clear the focusVisible flag of the current focus owner
• 8fa8919: 8291588: Update boot JDK to 18.0.2
• 08ec9c8: 8289605: Robot capture tests fail intermittently on Mac M1
• 4b4deae: 8289397: Fix warnings: Possible accidental assignment in place of a comparison. A condition expression should not be reduced to an assignment
• ... and 2 more: https://git.openjdk.org/jfx/compare/7e48413eb0f9eb3dcbd9d3a1572fc311036092c8...master

Your commit was automatically rebased without conflicts.

[openjdk]

@johanvos Pushed as commit eaddb0f.

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

[smith3390s]

@johanvos I encountered the bug initially described here: https://bugs.openjdk.org/browse/JDK-8291467 when I advanced from JavaFX 17 to 19.0.2.1. You had fixed it and it was released in JavaFX 20. In my application this tracks. The problem is indeed fixed in JavaFX 20. However, it seems broken again in JavaFX 21.0.3. Is there a regression test that could confirm what I am seeing?