code: function addRenderController() {
      var modifier = new Modifier({
          size: [200, 200],
          transform: Transform.translate(400, 0)
      });
  
      var controller = new RenderController();
  
      var index = 0;
      var items = [];
  
      function getItem(i) {
          var surface = new Surface({
              content: 'View ' + i,
              properties: {
                  backgroundColor: getRandomColor(),
                  color: 'white',
                  lineHeight: '200px',
                  textAlign: 'center',
                  fontSize: '30px',
                  cursor: 'pointer'
              }
          });
  
          surface.on('click', function() {
              index = (index + 1) % items.length;
              controller.show(items[index]);
          });
  
          return surface;
      }
  
      for (var i = 0; i < 4; i++) {
          items.push(getItem(i));
      }
  
      controller.show(items[index]);
      ctx.add(modifier).add(controller);
  }
docs: /*
  RenderController