Bug 299731 [Progress] ProgressMonitorDialog should check for widget state in its async runnable
setOperationCancelButtonEnabled(boolean) should check whether the widget has been disposed or not before invoking setEnabled(boolean). Since this method is called in an asynchronous runnable, there is no guarantee that the widgets are still up when the display gets around to processing them. Display display = new Display(); Shell shell = new Shell(display); shell.setLayout(new GridLayout(1, false)); shell.pack(); shell.open(); ProgressMonitorDialog pmd = new ProgressMonitorDialog(shell); pmd.open(); pmd.run(false, true, new IRunnableWithProgress() { public void run(IProgressMonitor monitor) throws InvocationTargetException, InterruptedException { } }); while (!shell.isDisposed()) { if (!display.readAndDispatch()) display.sleep(); } display.dispose(); Exception in thread "main" org.eclipse.swt.SWTException: Failed to execute runnable (org.eclipse.swt.SWTException: Widget is disposed) at org.eclipse.swt.SWT.error(SWT.java:4068) at org.eclipse.swt.SWT.error(SWT.java:3983) at org.eclipse.swt.widgets.Synchronizer.runAsyncMessages(Synchronizer.java:137) at org.eclipse.swt.widgets.Display.runAsyncMessages(Display.java:3906) at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:3527) at org.eclipse.ui.Test.main(Test.java:45) Caused by: org.eclipse.swt.SWTException: Widget is disposed at org.eclipse.swt.SWT.error(SWT.java:4068) at org.eclipse.swt.SWT.error(SWT.java:3983) at org.eclipse.swt.SWT.error(SWT.java:3954) at org.eclipse.swt.widgets.Widget.error(Widget.java:467) at org.eclipse.swt.widgets.Widget.checkWidget(Widget.java:340) at org.eclipse.swt.widgets.Control.setEnabled(Control.java:2928) at org.eclipse.jface.dialogs.ProgressMonitorDialog.setOperationCancelButtonEnabled(ProgressMonitorDialog.java:622) at org.eclipse.jface.dialogs.ProgressMonitorDialog$1.run(ProgressMonitorDialog.java:329) at org.eclipse.swt.widgets.RunnableLock.run(RunnableLock.java:35) at org.eclipse.swt.widgets.Synchronizer.runAsyncMessages(Synchronizer.java:134) ... 3 more
bundles/org.eclipse.jface/src/org/eclipse/jface/dialogs/ProgressMonitorDialog.java
}
	/**
	 * Decrements the nesting depth of running operations.
	 * 
	 * @since 3.0
	 * 
	 */
	protected void decrementNestingDepth() {
		nestingDepth--;
	}
	/**
	 * Called just before the operation is run. Default behaviour is to open or
	 * create the dialog, based on the setting of <code>getOpenOnRun</code>,
	 * and increment the nesting depth.
	 * 
	 * @since 3.0
	 */
	protected void aboutToRun() {
		if (getOpenOnRun()) {
			open();
		} else {
			create();
		}
		incrementNestingDepth();
	}
	/**
	 * Called just after the operation is run. Default behaviour is to decrement
	 * the nesting depth, and close the dialog.
	 * 
	 * @since 3.0