Widget is disposed exception when closing automatically opened diagram in Capella

[Kellindil]

• Download Capella 6.1 (or 7.0)
• Start on new workspace
• Create a new project
• Create a new diagram (e.g. PAB)
• Ensure properties view is shown
• Close Capella with this diagram open, do not save when prompted
• Restart Capella

The diagram is automatically opened with a message saying "This diagram was not saved. You can close the editor".

• Close the editor

One of the following exceptions is thrown:

org.eclipse.swt.SWTException: Widget is disposed
    at org.eclipse.swt.SWT.error(SWT.java:4893)
    at org.eclipse.swt.SWT.error(SWT.java:4808)
    at org.eclipse.swt.SWT.error(SWT.java:4779)
    at org.eclipse.swt.widgets.Widget.error(Widget.java:438)
    at org.eclipse.swt.widgets.Widget.checkWidget(Widget.java:357)
    at org.eclipse.swt.widgets.Button.getImage(Button.java:590)
    at org.eclipse.gmf.runtime.diagram.ui.properties.sections.grid.RulerGridPropertySection.dispose(RulerGridPropertySection.java:687)
    at org.eclipse.ui.views.properties.tabbed.TabContents$2.run(TabContents.java:130)
    at org.eclipse.core.runtime.SafeRunner.run(SafeRunner.java:45)
    at org.eclipse.jface.util.SafeRunnable.run(SafeRunnable.java:174)
    at org.eclipse.ui.views.properties.tabbed.TabContents.dispose(TabContents.java:133)
    at org.eclipse.ui.views.properties.tabbed.TabbedPropertySheetPage.disposeTabs(TabbedPropertySheetPage.java:623)
    at org.eclipse.ui.views.properties.tabbed.TabbedPropertySheetPage.disposeContributor(TabbedPropertySheetPage.java:468)
    at org.eclipse.ui.views.properties.tabbed.TabbedPropertySheetPage.dispose(TabbedPropertySheetPage.java:491)
    at org.eclipse.gmf.runtime.diagram.ui.properties.views.PropertiesBrowserPage.dispose(PropertiesBrowserPage.java:164)

or

org.eclipse.swt.SWTException: Widget is disposed
    at org.eclipse.swt.SWT.error(SWT.java:4893)
    at org.eclipse.swt.SWT.error(SWT.java:4808)
    at org.eclipse.swt.SWT.error(SWT.java:4779)
    at org.eclipse.swt.widgets.Widget.error(Widget.java:438)
    at org.eclipse.swt.widgets.Widget.checkWidget(Widget.java:357)
    at org.eclipse.swt.widgets.Button.getImage(Button.java:590)
    at org.eclipse.gmf.runtime.diagram.ui.properties.sections.grid.RulerGridPropertySection.dispose(RulerGridPropertySection.java:687)
    at org.eclipse.eef.properties.ui.legacy.internal.legacy2eef.EEFLegacySection.dispose(EEFLegacySection.java:71)
    at org.eclipse.eef.properties.ui.api.EEFTabContents$6.run(EEFTabContents.java:207)

[pcdavid]

Download Capella 6.1 (or 7.0)

For reference, Capella 6.1 uses GMF Runtime 1.15.3.

[pcdavid]

It seems to be caused by c453d15.

[pcdavid]

Testing if (lineColorButton != null) is not enough, we probably need to add if (lineColorButton != null && !lineColorButton.isDisposed()) {.

[pcdavid]

I see other similar exception on related (but different) scenarios:

java.lang.Error: SWT Resource was not properly disposed
	at org.eclipse.swt.graphics.Resource.initNonDisposeTracking(Resource.java:172)
	at org.eclipse.swt.graphics.Resource.<init>(Resource.java:120)
	at org.eclipse.swt.graphics.Image.<init>(Image.java:655)
	at org.eclipse.jface.resource.ImageDescriptor.createImage(ImageDescriptor.java:341)
	at org.eclipse.jface.resource.ImageDescriptor.createImage(ImageDescriptor.java:290)
	at org.eclipse.jface.resource.ImageDescriptor.createImage(ImageDescriptor.java:268)
	at org.eclipse.gmf.runtime.diagram.ui.properties.sections.appearance.ColorsAndFontsPropertySection.refresh(ColorsAndFontsPropertySection.java:577)
	at org.eclipse.gmf.runtime.diagram.ui.properties.sections.appearance.ColoursAndFontsAndLineStylesPropertySection.refresh(ColoursAndFontsAndLineStylesPropertySection.java:312)
	at org.eclipse.gmf.runtime.diagram.ui.properties.sections.appearance.ShapeColorsAndFontsPropertySection.refresh(ShapeColorsAndFontsPropertySection.java:96)

java.lang.Error: SWT Resource was not properly disposed
	at org.eclipse.swt.graphics.Resource.initNonDisposeTracking(Resource.java:172)
	at org.eclipse.swt.graphics.Resource.<init>(Resource.java:120)
	at org.eclipse.swt.graphics.Image.<init>(Image.java:655)
	at org.eclipse.jface.resource.ImageDescriptor.createImage(ImageDescriptor.java:341)
	at org.eclipse.jface.resource.ImageDescriptor.createImage(ImageDescriptor.java:290)
	at org.eclipse.jface.resource.ImageDescriptor.createImage(ImageDescriptor.java:268)
	at org.eclipse.gmf.runtime.diagram.ui.properties.sections.appearance.ShapeColorsAndFontsPropertySection.refresh(ShapeColorsAndFontsPropertySection.java:100)
	at org.eclipse.ui.views.properties.tabbed.TabContents$6.run(TabContents.java:220)
	at org.eclipse.core.runtime.SafeRunner.run(SafeRunner.java:47)
	at org.eclipse.jface.util.SafeRunnable.run(SafeRunnable.java:174)
	at org.eclipse.ui.views.properties.tabbed.TabContents.refresh(TabContents.java:223)
	at org.eclipse.ui.views.properties.tabbed.TabbedPropertySheetPage.handlePartActivated(TabbedPropertySheetPage.java:349)
	at org.eclipse.ui.views.properties.tabbed.TabbedPropertySheetPage$1.partActivated(TabbedPropertySheetPage.java:121)

java.lang.Error: SWT Resource was not properly disposed
	at org.eclipse.swt.graphics.Resource.initNonDisposeTracking(Resource.java:172)
	at org.eclipse.swt.graphics.Resource.<init>(Resource.java:120)
	at org.eclipse.swt.graphics.Image.<init>(Image.java:655)
	at org.eclipse.jface.resource.ImageDescriptor.createImage(ImageDescriptor.java:341)
	at org.eclipse.jface.resource.ImageDescriptor.createImage(ImageDescriptor.java:290)
	at org.eclipse.jface.resource.ImageDescriptor.createImage(ImageDescriptor.java:268)
	at org.eclipse.gmf.runtime.diagram.ui.properties.sections.appearance.ColorsAndFontsPropertySection.refresh(ColorsAndFontsPropertySection.java:571)
	at org.eclipse.gmf.runtime.diagram.ui.properties.sections.appearance.ColoursAndFontsAndLineStylesPropertySection.refresh(ColoursAndFontsAndLineStylesPropertySection.java:312)
	at org.eclipse.gmf.runtime.diagram.ui.properties.sections.appearance.ShapeColorsAndFontsPropertySection.refresh(ShapeColorsAndFontsPropertySection.java:96)
	at org.eclipse.ui.views.properties.tabbed.TabContents$6.run(TabContents.java:220)
	at org.eclipse.core.runtime.SafeRunner.run(SafeRunner.java:47)
	at org.eclipse.jface.util.SafeRunnable.run(SafeRunnable.java:174)
	at org.eclipse.ui.views.properties.tabbed.TabContents.refresh(TabContents.java:223)
	at org.eclipse.ui.views.properties.tabbed.TabbedPropertySheetPage.handlePartActivated(TabbedPropertySheetPage.java:349)
	at org.eclipse.ui.views.properties.tabbed.TabbedPropertySheetPage$1.partActivated(TabbedPropertySheetPage.java:121)