Flash 8 Cookbook

11.12. Creating Simple Drag-and-Drop Functionality

Problem

You want to be able to create a draggable movie clip.

Solution

Use the startDrag( ) and stopDrag( ) methods.

Discussion

You can cause a movie clip to follow the mouse pointer using the startDrag( ) method, and you can tell the movie clip to stop following the mouse pointer using the stopDrag( ) method. Depending on the effect you want to create, you can use these methods in several different ways.

First of all, you can place the startDrag( ) method call on a frame to cause the movie clip to begin following the mouse pointer as soon as the playhead enters that frame. For example, if you place the action on the first frame of the movie, the specified movie clip will follow the pointer from the very beginning of playback:

	mClip.startDrag();

When you use the startDrag( ) method in this way, you’ll usually specify a value for the first, optional parameter of the method. The first parameter is a Boolean value indicating whether the movie clip should snap to the pointer. The default value is false, which means that the movie clip will follow the mouse pointer at the same distance that existed between them at the time the method was invoked. For example, if the movie clip instance was on stage at 0,0 and the mouse pointer was at 300,300 when the method was invoked, wherever the user moves the pointer, the movie clip will be offset by 300 pixels up and to the left. However, if you specify the value true when you invoke the startDrag( ) ...