gistfile1.js

var mainContainer = new qx.ui.window.Window("Toolbar").set({
  layout : new qx.ui.layout.VBox(20),
  contentPadding: 0,
  width: 400,
  height: 300
});
this.getRoot().add(mainContainer, {left:20, top:20});

mainContainer.open();
      ///////////////////////////////////////////////////////////////
      // Toolbar stuff
      ///////////////////////////////////////////////////////////////

      // create the toolbar
      toolbar = new qx.ui.toolbar.ToolBar();
      toolbar.setSpacing(5);
      mainContainer.add(toolbar);
      var overflowMenu = new qx.ui.menu.Menu();
      var overflow = new qx.ui.toolbar.MenuButton("More ...",null,overflowMenu);
      for (var i = 0; i < 20;i++){
          var tbBtn = new qx.ui.toolbar.Button('Button '+i);
          toolbar.add(tbBtn);
          toolbar.setRemovePriority(tbBtn,i);
          var mnBtn = new qx.ui.menu.Button('Button '+i);
          mnBtn.exclude();
          overflowMenu.add(mnBtn);
          tbBtn.setUserData('mnBtn',mnBtn);
      }
      toolbar.addSpacer();
      toolbar.add(overflow);
      toolbar.set({
        spacing: 5,
        overflowHandling: true,
        overflowIndicator: overflow
      });
      var showHideHandler = function(item, visibility) {
        item.getUserData('mnBtn').setVisibility(visibility);
      };

      // handler for showind and hiding toobar items
      toolbar.addListener("showItem", function(e) {
        showHideHandler(e.getData(), "excluded");
      }, this);

      toolbar.addListener("hideItem", function(e) {
        showHideHandler(e.getData(), "visible");
      }, this);   
      // naive me would expect this not to be neccessary
      tbBtn.addListenerOnce('appear',function(){    
        var pane = this.getLayoutParent();
        this.fireDataEvent('resize', pane.getBounds());
      },toolbar);  
      // nor this
      toolbar.getOverflowIndicator().addListener('appear',function(){    
        var pane = this.getLayoutParent();
        this.fireDataEvent('resize', pane.getBounds());
      },toolbar);