Bug 152412 [Smoke]Insert,delete a master page, can not take effect
Insert,delete a master page, can not take effect Steps: 1.new a report 2.open outline view, insert a master page or delete a master page Actual Results 1.Can not take effect.
UI/org.eclipse.birt.report.designer.ui/src/org/eclipse/birt/report/designer/internal/ui/editors/parts/event/ModelEventManager.java
/**Hook the root.
	 * @param obj
	 */
	public void hookRoot( Object obj )
	{
		if ( root == obj )
		{
			return;
		}
		unhookRoot( root );
		
		listenerList.clear( );
		if ( obj instanceof DesignElementHandle )
		{
			getListenerElementVisitor( ).addListener( (DesignElementHandle) obj );
		}
		this.root = obj;
	}
	/**Unhook the rootz
	 * @param obj
	 */
	public void unhookRoot( Object obj )
	{
		if ( obj instanceof DesignElementHandle )
		{
			getListenerElementVisitor( ).removeListener( (DesignElementHandle) obj );
		}
	}
}