Occassional 'Widget is disposed' error when hovering

[FlorianKroiss]

When hovering over a location which has markers but no hover content, I get the following error

org.eclipse.swt.SWTException: Widget is disposed
	at org.eclipse.swt.SWT.error(SWT.java:4946)
	at org.eclipse.swt.SWT.error(SWT.java:4861)
	at org.eclipse.swt.SWT.error(SWT.java:4832)
	at org.eclipse.swt.widgets.Widget.error(Widget.java:507)
	at org.eclipse.swt.widgets.Widget.checkWidget(Widget.java:426)
	at org.eclipse.swt.widgets.Scrollable.computeTrim(Scrollable.java:122)
	at org.eclipse.jface.text.AbstractInformationControl.computeTrim(AbstractInformationControl.java:577)
	at org.eclipse.jface.internal.text.html.BrowserInformationControl.computeTrim(BrowserInformationControl.java:485)
	at org.eclipse.jface.internal.text.html.BrowserInformationControl.computeSizeHint(BrowserInformationControl.java:424)
	at org.eclipse.lsp4e.operations.hover.FocusableBrowserInformationControl.updateBrowserSize(FocusableBrowserInformationControl.java:101)
	at org.eclipse.lsp4e.operations.hover.FocusableBrowserInformationControl.lambda$0(FocusableBrowserInformationControl.java:91)
	at org.eclipse.swt.browser.ProgressListener$2.completed(ProgressListener.java:97)
	at org.eclipse.swt.browser.Edge.lambda$43(Edge.java:1178)
	at org.eclipse.swt.widgets.RunnableLock.run(RunnableLock.java:40)
	at org.eclipse.swt.widgets.Synchronizer.runAsyncMessages(Synchronizer.java:132)
	at org.eclipse.swt.widgets.Display.runAsyncMessages(Display.java:4135)
	at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:3751)
	at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine$5.run(PartRenderingEngine.java:1151)
	at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:339)
	at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine.run(PartRenderingEngine.java:1042)
	at org.eclipse.e4.ui.internal.workbench.E4Workbench.createAndRunUI(E4Workbench.java:153)
	at org.eclipse.ui.internal.Workbench.lambda$3(Workbench.java:678)
	at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:339)
	at org.eclipse.ui.internal.Workbench.createAndRunWorkbench(Workbench.java:583)
	at org.eclipse.ui.PlatformUI.createAndRunWorkbench(PlatformUI.java:173)
        [...]

The popup also seems to be stuck at "Loading..."

This might be a regression of #1375

[sebthom]

@FlorianKroiss Can you please test the snapshot release from http://download.eclipse.org/lsp4e/snapshots/ to see if the issue is solved.

[FlorianKroiss]

@sebthom Thanks for the quick fix :)
I tested it directly with e2029dd and the 'Widget is disposed' no longer occurs in this situation. However, the popup is still stuck at "Loading..." but that is probably a separate problem.

[sebthom]

Loading... means LSP4E waits for up to 5 seconds for a response. So it looks like the LSP is not responding.

[FlorianKroiss]

The LS responds with an empty hover list and we end up in this branch:

lsp4e/org.eclipse.lsp4e/src/org/eclipse/lsp4e/operations/hover/FocusableBrowserInformationControl.java

Lines 180 to 183 in e2029dd

	} else {
	// No content from LS; hide placeholder
	dispose();
	}

Is this maybe the initial cause for the 'Widget is disposed' error?

[sebthom]

Since FocusableBrowserInformationControl.updateBrowserSize is re-executed async I think adding the getShell().isDisposed() check was valid