JDK-8302846: IGV: Zoom stuck when zooming out on large graphs

[tobiasholenstein]

Problem

In the IdealGraphVisualizer (IGV) the user can zoom in and out using either the mouse-wheel or by entering/selecting a value in the zoom combo-box. The zoom combo-box is implemented in ZoomLevelAction.java:

• ZoomLevelAction has a listener on scene.getZoomChangedEvent() which calls changed(..) each time the zoom level of the diagramScene changes, e.g. when the user zooms in/out with the mouse-wheel.
• actionPerformed(..) is called when the user enters/selects a zoom level in the combo-box, in which case it calls setZoomLevel(..) -> diagramScene.setZoomPercentage(zoomLevel) to update the zooming of the scene.
• changed(..) calls setSelectedItem(..) which updates the content of the combo-box and triggers a also a call to actionPerformed(..). Unfortunately, in this case we should not call diagramScene.setZoomPercentage(zoomLevel) because the diagramScene is updating the ZoomLevelAction and not vice versa. The problem only reveals for small zooming level because ZoomLevelAction uses an integer for the zooming level (1-100%) while the diagramScene uses a float (1.0f is 100%). In the example where the bug occurs, mouse wheel zooming changed zoom level in diagramScene from 0.01 to 0.012 - then diagramScene updates the ZoomLevelAction which rounds 1.2% to 1% : and now the BUG: ZoomLevelAction sets diagramScene zooming again to 0.01. The zooming is stuck at 0.01

Solution

When diagramScene updates the ZoomLevelAction, actionPerformed(..) should not call diagramScene.setZoomPercentage(zoomLevel). So we introduce a boolean updateZoomInScene that is set to false when a change of zoom in diagramScene triggered the actionPerformed(..)

---

Progress

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Issue

• JDK-8302846: IGV: Zoom stuck when zooming out on large graphs

Reviewers

• Roberto Castañeda Lozano (@robcasloz - Reviewer) ⚠️ Review applies to 9f97bf39
• Tobias Hartmann (@TobiHartmann - Reviewer) ⚠️ Review applies to 9f97bf39

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[mlbridge]

Webrevs

• 01: Full - Incremental (913386be)
• 00: Full (9f97bf39)

[robcasloz]

Thanks for fixing this, Toby! Please update the copyright header.

[openjdk]

@tobiasholenstein 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:

8302846: IGV: Zoom stuck when zooming out on large graphs

Reviewed-by: rcastanedalo, thartmann

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 75 new commits pushed to the master branch:

• 92dfa11: 8302863: Speed up String::encodeASCII using countPositives
• 8b20aa9: 8302981: Fix a typo in the doc comment for java.lang.Record.equals
• 644fe0a: 8302837: Kernel32.cpp array memory release invokes undefined behaviour
• 60e6378: 8302977: ZGC: Doesn't support gc/TestVerifySubSet.java
• fef1910: 8299777: Test runtime/NMT/BaselineWithParameter.java timed out
• 622f560: 8302886: Parallel: Remove unimplemented methods in ParCompactionManager
• 9fd77c7: 8302868: Serial: Remove CardTableRS::initialize
• f35cf79: 8302867: G1: Removing unused variable in G1CardTable::initialize
• 63a3501: 8302741: ZGC: Remove Universe::verify calls
• 9145670: 8301661: Enhance os::pd_print_cpu_info on macOS and Windows
• ... and 65 more: https://git.openjdk.org/jdk/compare/2e3cea01daca594dfa4477439a9849eea19b249e...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.

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[TobiHartmann]

Looks good to me.

[tobiasholenstein]

thanks @robcasloz and

Thanks for fixing this, Toby! Please update the copyright header.

done

[tobiasholenstein]

Thanks @robcasloz and @TobiHartmann for the reviews!

/integrate

[openjdk]

Going to push as commit 02eb240.
Since your change was applied there have been 75 commits pushed to the master branch:

• 92dfa11: 8302863: Speed up String::encodeASCII using countPositives
• 8b20aa9: 8302981: Fix a typo in the doc comment for java.lang.Record.equals
• 644fe0a: 8302837: Kernel32.cpp array memory release invokes undefined behaviour
• 60e6378: 8302977: ZGC: Doesn't support gc/TestVerifySubSet.java
• fef1910: 8299777: Test runtime/NMT/BaselineWithParameter.java timed out
• 622f560: 8302886: Parallel: Remove unimplemented methods in ParCompactionManager
• 9fd77c7: 8302868: Serial: Remove CardTableRS::initialize
• f35cf79: 8302867: G1: Removing unused variable in G1CardTable::initialize
• 63a3501: 8302741: ZGC: Remove Universe::verify calls
• 9145670: 8301661: Enhance os::pd_print_cpu_info on macOS and Windows
• ... and 65 more: https://git.openjdk.org/jdk/compare/2e3cea01daca594dfa4477439a9849eea19b249e...master

Your commit was automatically rebased without conflicts.

[openjdk]

@tobiasholenstein Pushed as commit 02eb240.

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