Bug 166015 Refactor designer actions to eclipse command framework
Eclipse command framework provide a more explicit way to manage UI actions contributions, we can take it's advantage to make our actions code more clean and maintainable.
UI/org.eclipse.birt.report.designer.ui/src/org/eclipse/birt/report/designer/internal/ui/editors/schematic/actions/ApplyStyleAction.java
{
		List handles = getElementHandles( );
		if ( handles.isEmpty( ) )
			return false;
		for ( int i = 0; i < handles.size( ); i++ )
		{
			if ( !( handles.get( i ) instanceof DesignElementHandle ) )
			{
				return false;
			}
			DesignElementHandle handle = (DesignElementHandle) handles.get( i );
			if ( handle != null && handle.getDefn( ).hasStyle( ) == false )
			{
				return false;
			}
		}
		return true;
	}
	/**
	 * @see org.eclipse.jface.action.Action#run()
	 */
	public void run( )
	{
		if ( Policy.TRACING_ACTIONS )
		{
			System.out.println( "Apply style rule action >> Run ..." ); 
		}
		CommandStack stack = SessionHandleAdapter.getInstance( )
				.getCommandStack( );
		stack.startTrans( STACK_MSG_APPLY_STYLE );