Bug 15844 [Exception Handling] SelectionChange events and NPE
Build 20020508 Due to new global actions there are now more objects listening to selection changes send out by a JFace viewer. We now had the case that one of the listener generated a NPE. As a result all listeners registered after that one didn't receive the selection change event. StructuredViewers should be more fault tolorant to exceptions when informing listeners.
bundles/org.eclipse.jface/src/org/eclipse/jface/viewers/CheckboxTreeViewer.java
* no sorter, and no filters.
 *
 * @param parent the parent control
 */
public CheckboxTreeViewer(Composite parent) {
	this(parent, SWT.BORDER);
}
/**
 * Creates a tree viewer on a newly-created tree control under the given parent.
 * The tree control is created using the given SWT style bits, plus the <code>CHECK</code> style bit.
 * The viewer has no input, no content provider, a default label provider, 
 * no sorter, and no filters.
 *
 * @param parent the parent control
 * @param style the SWT style bits
 */
public CheckboxTreeViewer(Composite parent, int style) {
	this(new Tree(parent, SWT.CHECK | style));
}
/**
 * Creates a tree viewer on the given tree control.
 * The <code>SWT.CHECK</code> style bit must be set on the given tree control.
 * The viewer has no input, no content provider, a default label provider, 
 * no sorter, and no filters.
 *
 * @param tree the tree control
 */
public CheckboxTreeViewer(Tree tree) {
	super(tree);
}