code: function documentOpened(doc) {
      docSize = doc.dimensions;
      mindmap = doc.mindmap;
  
      calculateCanvasSize();
      calculateDraggerPosition();
      calculateDraggerSize();
      calculateZoomLevel();
      calculateSliderValue();
      renderView();
  
      view.showActiveContent();
  
      // move dragger when container was scrolled
      $container.bind("scroll.navigator-view", function() {
        if (!viewDragging) {
          calculateDraggerPosition();
        }
      });
    }
docs: Initialize view when a document was opened.