Qt Reference Documentation

itemCreation.js Example File

declarative/toys/dynamicscene/qml/dynamicscene/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.x + draggedItem.width > toolbox.x) { //Don't drop it in the toolbox
         draggedItem.destroy();
         draggedItem = null;
     } else {
         draggedItem.created = true;
         draggedItem = null;
     }
 }