Bug 29163 SafeRunnable needs to be accessible in JFace
We need to be able to access the SafeRunnable in JFace in order that some error protection can be added to preferences and properties dialogs.
bundles/org.eclipse.ui.workbench/extensions/org/eclipse/jface/action/StatusLine.java
if (fCancelButton != null)
			fCancelButton.setEnabled(!b);
	}
	/**
	 * Controls whether the ProgressIndication provides UI for canceling
	 * a long running operation.
	 * If the ProgressIndication is currently visible calling this method may have
	 * a direct effect on the layout because it will make a cancel button visible. 
	 */
	public void setCancelEnabled(boolean enabled) {
		fCancelEnabled= enabled; 
		if (fProgressIsVisible && !fCancelButtonIsVisible && enabled) {
			showButton();
			layout();
		}
		if (fCancelButton != null && !fCancelButton.isDisposed())
			fCancelButton.setEnabled(enabled);
	}
/**
 * Sets the error message text to be displayed on the status line.
 * The image on the status line is cleared.
 * 
 * @param message the error message, or <code>null</code> for no error message
 */
public void setErrorMessage(String message) {
	setErrorMessage(null, message);
}
/**
 * Sets an image and error message text to be displayed on the status line.
 *