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
*/
	protected Label taskLabel;
	/**
	 * The label control for the subtask.
	 */
	protected Label subTaskLabel;
	/**
	 * The Cancel button control.
	 */
	protected Button cancel;
	/**
	 * Indicates whether the Cancel button is to be shown.
	 */
	protected boolean operationCancelableState = false;
	/**
	 * Indicates whether the Cancel button is to be enabled.
	 */
	protected boolean enableCancelButton;
	/**
	 * The progress monitor.
	 */
	private ProgressMonitor progressMonitor = new ProgressMonitor();
	/**
	 * The name of the current task (used by ProgressMonitor).
	 */
	private String task;
	/**
	 * The nesting depth of currently running runnables.
	 */
	private int nestingDepth;