Animating Motion Along a Curved Path

The YUI Animation Utility allows you to animate the motion of an HTMLElement along a curved path using control points.

For this example, we will animate the position of a <div> element named demo. The points attribute, introduced in the YAHOO.util.Motion subclass, accepts an optional control field of one or more control points

Add a little style so that we can see the animation in action:

<style type="text/css"> #demo { background:#ccc; height:30px; width:30px; } </style>

Create the demo element and a button to run the animation:

<div id="demo">Demo</div> <button id="demo-run">run</button>

Now we create an instance of YAHOO.util.Motion, passing it the element we wish to animate, and the points attribute (an array of [x, y] positions), with the point we are animating to, and the control points that will influence the path:

<script type="text/javascript"> var attributes = { points: { to: [600, 10], control: [ [100, 100], [800, 800] ] } }; var anim = new YAHOO.util.Motion('demo', attributes); </script> <p>The final step is to call the <code>animate</code> method on our instance to start the animation. The button will be the trigger that begins the animation sequence:</p> <textarea name="code" class="JScript" cols="60" rows="1"> <script type="text/javascript"> YAHOO.util.Event.on('demo-run', 'click', function() { anim.animate(); }); </script>

This is an example of animating the motion HTMLElement along a curved path.