code: private void canvasClick(int x, int y)
      {
          //always called listeners
          for (CanvasClickListener listener : canvasClickAlwaysListeners)
              listener.canvasClicked(x, y);
          //selected listener by toggle buttons
          for (JToggleButton button : canvasClickToggleListeners.keySet())
          {
              if (button.isSelected())
                  canvasClickToggleListeners.get(button).canvasClicked(x, y);
          }
          
          /*if (lookupButton.isSelected())
          {
              if (proc.getAreaTree() != null)
              {
                  Area node = proc.getAreaTree().getAreaAt(x, y);
                  if (node != null)
                  {
                      showAreaInTree(node);
                      showAreaInLogicalTree(node);
                  }
              }
              //lookupButton.setSelected(false);
          }
          if (boxLookupButton.isSelected())
          {
              Box node = proc.getPage().getBoxAt(x, y);
              if (node != null)
                  showBoxInTree(node);
              //boxLookupButton.setSelected(false);
          }
          if (sepLookupButton.isSelected())
          {
              showSeparatorAt(x, y);
          }
          if (extractButton.isSelected())
          {
              AreaNode node = proc.getAreaTree().getAreaAt(x, y);
              if (node != null)
              {
                  proc.getExtractor().findArticleBounds(node);
                  try {
                      PrintStream exs = new PrintStream(new FileOutputStream("test/extract.html"));
                      proc.getExtractor().dumpTo(exs);
                      exs.close();
                  } catch (java.io.IOException e) {
                      System.err.println("Output failed: " + e.getMessage());
                  }
                  
                  //String s = ex.getDescriptionX(node, 2);
                  //System.out.println("Extracted: " + s);
              }
              extractButton.setSelected(false);
          }*/
      }
docs: This is called when the browser canvas is clicked