Bug 100565 [Viewers] Tree viewer selection not revealed if unchanged
[RC3] Steps: 1. Check out org.eclipse.ui.workbench 2. Open Workbench.java 3. Ctrl-O to open Quick Outline 4. Type "r", note that the field "runEventLoop" is the first match 5. Type "u", note that the field is not shown anymore 6. Type arrow-down key, note that you cannot see the selected entry
bundles/org.eclipse.jface/src/org/eclipse/jface/viewers/AbstractTreeViewer.java
}
    /**
     * Returns the SWT child items for the given SWT widget.
     * 
     * @param widget
     *           the widget
     * @return the child items
     */
    protected abstract Item[] getChildren(Widget widget);
	
	/**
	 * Get the child for the widget at index. Note that the default
	 * implementation is not very effecient and should be overridden
	 * if this class is implemented.
	 * @param widget the widget to check
	 * @param index the index of the widget
	 * @return Item or <code>null</code> if widget is not a type
	 * that can contain items.
     *
	 * @throws ArrayIndexOutOfBoundsException if the index is not valid.
     * @since 3.1
	 */
    protected Item getChild (Widget widget, int index) {
		return getChildren(widget)[index];
    }
    /**
     * Returns whether the given SWT item is expanded or collapsed.
     * 
     * @param item
     *           the item