itemCreation.js Example File

  var itemComponent = null;
  var draggedItem = null;
  var startingMouse;
  var posnInWindow;

  function startDrag(mouse)
  {
      posnInWindow = paletteItem.mapToItem(window, 0, 0);
      startingMouse = { x: mouse.x, y: mouse.y }
      loadComponent();
  }

  //Creation is split into two functions due to an asynchronous wait while
  //possible external files are loaded.

  function loadComponent() {
      if (itemComponent != null) { // component has been previously loaded
          createItem();
          return;
      }

      itemComponent = Qt.createComponent(paletteItem.componentFile);
      if (itemComponent.status == Component.Loading)  //Depending on the content, it can be ready or error immediately
          component.statusChanged.connect(createItem);
      else
          createItem();
  }

  function createItem() {
      if (itemComponent.status == Component.Ready && draggedItem == null) {
          draggedItem = itemComponent.createObject(window, {"image": paletteItem.image, "x": posnInWindow.x, "y": posnInWindow.y, "z": 3});
          // make sure created item is above the ground layer
      } else if (itemComponent.status == Component.Error) {
          draggedItem = null;
          console.log("error creating component");
          console.log(itemComponent.errorString());
      }
  }

  function continueDrag(mouse)
  {
      if (draggedItem == null)
          return;

      draggedItem.x = mouse.x + posnInWindow.x - startingMouse.x;
      draggedItem.y = mouse.y + posnInWindow.y - startingMouse.y;
  }

  function endDrag(mouse)
  {
      if (draggedItem == null)
          return;

      if (draggedItem.y < toolbox.height) { //Don't drop it in the toolbox
          draggedItem.destroy();
          draggedItem = null;
      } else {
          draggedItem.created = true;
          draggedItem = null;
      }
  }