Controlling Flash Animation Frame, Direction and Speed with Mouse Scroll

Most animations just play, you set their frame rate, your press play, and away they go. But I have an interactive item that I want users to be able to play forwards, or backwards, at the speed they scroll their mouse.

I am using ActionScript 2 for this, and the code is blissfully simple:
var mouseListener:Object = new Object();
mouseListener.onMouseWheel = function(delta) {
     frame = (clip_mc._currentframe + delta);
     clip_mc.gotoAndStop(frame);
}
Mouse.addListener(mouseListener);

As you can see you just create a mouseListener object and then build a function that acts on the onMouseWheel event.

When the mouse is rolled the 'delta' (or the value of the mouse scroll, forward or backwards) is used to calculate a new position in a MovieClip's timeline based on the current frame. The function then moves the play head using gotoAndStop to that new position in the timeline.

And you're done... This can be used to control the speed and direction of animation play within a MovieClip. I have a few creative applications of this technique in mind for the future - I hope you find it helpful. Happy scrolling.