Framework for creating CSS-based animations : Animation « GUI Components « JavaScript DHTML

Framework for creating CSS-based animations

Examples From
JavaScript: The Definitive Guide, Fourth Edition

Legal matters: these files were created by David Flanagan, and are
Copyright (c) 2001 by David Flanagan.  You may use, study, modify, and
distribute them for any purpose.  Please note that these examples are
provided "as-is" and come with no warranty of any kind.

David Flanagan

 * AnimateCSS.js:
 * This file defines a function named animateCSS(), which serves as a framework
 * for creating CSS-based animations.  The arguments to this function are:
 *     element: The HTML element that is to be animated.
 *     numFrames: The total number of frames in the animation.
 *     timePerFrame: The number of milliseconds to display each frame.
 *     animation: An object that defines the animation; described below.
 *     whendone: An optional function to call when the animation finishes.
 *               If specified, this function is passed element as its argument.
 * The animateCSS() function simply defines an animation framework.  It is the
 * properties of the animation object that specify the animation to be
 * done. Each property should have the same name as a CSS style property.  The
 * value of each property must be a function that returns values for that
 * style property.  Each function is passed the frame number and the total
 * amount of elapsed time, and it can use these to compute the style value it
 * should return for that frame.  For example, to animate an image so that it
 * slides in from the upperleft, you might invoke animateCSS as follows:
 *  animateCSS(image, 25, 50,  // Animate image for 25 frames of 50ms each
 *             { // Set top and left attributes for each frame as follows
 *               top: function(frame,time) { return frame*8 + "px"; },
 *               left: function(frame,time) { return frame*8 + "px"; }
 *             });
function animateCSS(element, numFrames, timePerFrame, animation, whendone) {
    var frame = 0;   // Store current frame number
    var time = 0;    // Store total elapsed time

    // Arrange to call displayNextFrame() every timePerFrame milliseconds.
    // This will display each of the frames of the animation.
    var intervalId = setInterval(displayNextFrame, timePerFrame);

    // The call to animateCSS() returns now, but the line above ensures that
    // the nested function defined below will be invoked once for each frame
    // of the animation.  Because this function is defined inside 
    // animateCSS(), it has access to the arguments and local variables of
    // animateCSS() even though it is invoked after that function has returned!
    function displayNextFrame() {
        if (frame >= numFrames) {             // First, see if we're done
            clearInterval(intervalId);        // If so, stop calling ourselves
            if (whendone) whendone(element);  // Invoke whendone function
            return;                           // And we're finished

        // Now loop through all properties defined in the animation object
        for(var cssprop in animation) {
            // For each property, call its animation function, passing the
            // frame number and the elapsed time.  Use the return value of the
            // function as the new value of the corresponding style property
            // of the specified element.  Use try/catch to ignore any
            // exceptions caused by bad return values.
            try {
      [cssprop] = animation[cssprop](frame, time);
            } catch(e) {}

        frame++;               // Increment the frame number
        time += timePerFrame;  // Increment the elapsed time

animateCSS(image, 25, 50,  // Animate image for 25 frames of 50ms each
             { // Set top and left attributes for each frame as follows
               top: function(frame,time) { return frame*8 + "px"; },
               left: function(frame,time) { return frame*8 + "px"; }

Related examples in the same category

1.Attack animation
2.Circle Animation
3.Right to left animation
4.Flash animation in Javascript
5.Flash animation in JavaScript: Changing style Properties
6.Animation along Straight Line
7.Animation along a Circle
8.Dancing Text (IE)
9.Type Writer effect (IE)
10.Type Writer Effect 1.1 (IE)
11.JavaScript Ticker 1.2 (IE)
12.Animation: Lottery Number Picker and Statistics
13.Animation: wriggly
14.Animation: welcome message
15.Animation: trio
16.Auto lotto dip
17.Animation: snow
18.Animation: star
19.Animation: mouse doodle
20.Animation: fireworks
21.Animation: pretty
22.Animation: Random Movement
23.Lotto number draw
24.Following eyes
25.Animation: three eyes
26.Animation: eyes
27.Spot light
28.Big static eyes
29.Animation based on DIV with color flash
30.Animate dynamic element h1 tag
31.Popup window animation (fly across screen)
32.Animation on several images
33.Using the onFilterChange Event Handler
34.JavaScript Animation
35.Periodically Updating the Text Displayed by an HTML Element
36.Moving an Airplane Across a Web Page
37.Link Hint Scroller 2.0 (IE)
38.Snow animation
39.Animation with JSTween