HTML and CSS Reference
Creating the Drag-and-Drop Application
When creating our drag-and-drop application, we need to accomplish the following:
▪ We will create objects that can be clicked on to decorate a Christmas tree and can be
dragged, dropped, and dragged again.
▪ We need to make the Canvas think it works in “retained mode” so that we can keep track
of multiple objects. To do this, we need to create a “display list” of objects.
▪ We need to add the ability for these Canvas objects to listen to “events,” and we need to
have a way for mouse events to be “broadcast” events to objects that need to “hear” them.
▪ We want to change the mouse pointer to a hand cursor when it is over objects that can be
clicked to make the application act like it might in Flash or Silverlight.
▪ The application will actually be a “click and stick” version of drag and drop. This means
that when you click on an item, it sticks to the mouse until you click the mouse again.