Qt 5.9 | Qt QML | QML Example - Dynamic Scene | itemCreation.js Example File

Qt 5.9.9 Reference Documentation

# itemCreation.js Example File

dynamicscene/content/itemCreation.js

      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;
          }
      }