onMouseWheel (Mouse.onMouseWheel event listener)

onMouseWheel = function([delta:Number], [scrollTarget:Object]) {}

Notified when the user rolls the mouse wheel. To use the onMouseWheel listener, you must create a listener object. You can then define a function for onMouseWheel and use addListener() to register the listener with the Mouse object.

Note: Mouse wheel event listeners are available only in Windows versions of Flash Player.

A Flash application can only monitor mouse events that occur within its focus. A Flash application cannot detect mouse events in another application.

Parameters

delta:Number [optional] - A number indicating how many lines should be scrolled for each notch the user rolls the mouse wheel. A positive delta value indicates an upward scroll; a negative value indicates a downward scroll. Typical values are from 1 to 3; faster scrolling can produce larger values.

scrollTarget:Object [optional] - A parameter that indicates the topmost movie clip or object instance under the mouse pointer when the mouse wheel is rolled. If you want to specify a value for scrollTarget but don't want to specify a value for delta, pass null for delta.

Example

The following example shows how to create a listener object that responds to mouse wheel events. In this example, the x coordinate of a movie clip object named clip_mc changes each time the user rotates the mouse wheel:

var mouseListener:Object = new Object();
mouseListener.onMouseWheel = function(delta) {
    clip_mc._x += delta;
}
Mouse.addListener(mouseListener);

The following example draws a line that rotates when you rotate the mouse wheel. Click the SWF file at runtime and then rotate your mouse wheel to see the movie clip in action.

this.createEmptyMovieClip("line_mc", this.getNextHighestDepth());
line_mc.lineStyle(2, 0xFF0000, 100);
line_mc.moveTo(0, 100);
line_mc.lineTo(0, 0);
line_mc._x = 200;
line_mc._y = 200;

var mouseListener:Object = new Object();
mouseListener.onMouseWheel = function(delta:Number) {
    line_mc._rotation += delta;
};
mouseListener.onMouseDown = function() {
    trace("Down");
};
Mouse.addListener(mouseListener);

The MovieClip.getNextHighestDepth() method used in this example requires Flash Player 7 or later. If your SWF file includes a version 2 component, use the version 2 components' DepthManager class instead of the MovieClip.getNextHighestDepth() method.

onMouseWheel (Mouse.onMouseWheel event listener)

Parameters

Example

See also