// Copyright 2006 The Closure Library Authors. All Rights Reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS-IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
/**
* @fileoverview Basic animation controls.
*
* @author [email protected] (Erik Arvidsson)
*/
goog.provide('goog.fx.anim');
goog.provide('goog.fx.anim.Animated');
goog.require('goog.async.AnimationDelay');
goog.require('goog.async.Delay');
goog.require('goog.object');
/**
* An interface for programatically animated objects. I.e. rendered in
* javascript frame by frame.
*
* @interface
*/
goog.fx.anim.Animated = function() {};
/**
* Function called when a frame is requested for the animation.
*
* @param {number} now Current time in milliseconds.
*/
goog.fx.anim.Animated.prototype.onAnimationFrame;
/**
* Default wait timeout for animations (in milliseconds). Only used for timed
* animation, which uses a timer (setTimeout) to schedule animation.
*
* @type {number}
* @const
*/
goog.fx.anim.TIMEOUT = goog.async.AnimationDelay.TIMEOUT;
/**
* A map of animations which should be cycled on the global timer.
*
* @type {Object<number, goog.fx.anim.Animated>}
* @private
*/
goog.fx.anim.activeAnimations_ = {};
/**
* An optional animation window.
* @type {Window}
* @private
*/
goog.fx.anim.animationWindow_ = null;
/**
* An interval ID for the global timer or event handler uid.
* @type {goog.async.Delay|goog.async.AnimationDelay}
* @private
*/
goog.fx.anim.animationDelay_ = null;
/**
* Registers an animation to be cycled on the global timer.
* @param {goog.fx.anim.Animated} animation The animation to register.
*/
goog.fx.anim.registerAnimation = function(animation) {
var uid = goog.getUid(animation);
if (!(uid in goog.fx.anim.activeAnimations_)) {
goog.fx.anim.activeAnimations_[uid] = animation;
}
// If the timer is not already started, start it now.
goog.fx.anim.requestAnimationFrame_();
};
/**
* Removes an animation from the list of animations which are cycled on the
* global timer.
* @param {goog.fx.anim.Animated} animation The animation to unregister.
*/
goog.fx.anim.unregisterAnimation = function(animation) {
var uid = goog.getUid(animation);
delete goog.fx.anim.activeAnimations_[uid];
// If a timer is running and we no longer have any active timers we stop the
// timers.
if (goog.object.isEmpty(goog.fx.anim.activeAnimations_)) {
goog.fx.anim.cancelAnimationFrame_();
}
};
/**
* Tears down this module. Useful for testing.
*/
// TODO(nicksantos): Wow, this api is pretty broken. This should be fixed.
goog.fx.anim.tearDown = function() {
goog.fx.anim.animationWindow_ = null;
goog.dispose(goog.fx.anim.animationDelay_);
goog.fx.anim.animationDelay_ = null;
goog.fx.anim.activeAnimations_ = {};
};
/**
* Registers an animation window. This allows usage of the timing control API
* for animations. Note that this window must be visible, as non-visible
* windows can potentially stop animating. This window does not necessarily
* need to be the window inside which animation occurs, but must remain visible.
* See: https://developer.mozilla.org/en/DOM/window.mozRequestAnimationFrame.
*
* @param {Window} animationWindow The window in which to animate elements.
*/
goog.fx.anim.setAnimationWindow = function(animationWindow) {
// If a timer is currently running, reset it and restart with new functions
// after a timeout. This is to avoid mismatching timer UIDs if we change the
// animation window during a running animation.
//
// In practice this cannot happen before some animation window and timer
// control functions has already been set.
var hasTimer =
goog.fx.anim.animationDelay_ && goog.fx.anim.animationDelay_.isActive();
goog.dispose(goog.fx.anim.animationDelay_);
goog.fx.anim.animationDelay_ = null;
goog.fx.anim.animationWindow_ = animationWindow;
// If the timer was running, start it again.
if (hasTimer) {
goog.fx.anim.requestAnimationFrame_();
}
};
/**
* Requests an animation frame based on the requestAnimationFrame and
* cancelRequestAnimationFrame function pair.
* @private
*/
goog.fx.anim.requestAnimationFrame_ = function() {
if (!goog.fx.anim.animationDelay_) {
// We cannot guarantee that the global window will be one that fires
// requestAnimationFrame events (consider off-screen chrome extension
// windows). Default to use goog.async.Delay, unless
// the client has explicitly set an animation window.
if (goog.fx.anim.animationWindow_) {
// requestAnimationFrame will call cycleAnimations_ with the current
// time in ms, as returned from goog.now().
goog.fx.anim.animationDelay_ = new goog.async.AnimationDelay(
function(now) {
goog.fx.anim.cycleAnimations_(now);
}, goog.fx.anim.animationWindow_);
} else {
goog.fx.anim.animationDelay_ = new goog.async.Delay(function() {
goog.fx.anim.cycleAnimations_(goog.now());
}, goog.fx.anim.TIMEOUT);
}
}
var delay = goog.fx.anim.animationDelay_;
if (!delay.isActive()) {
delay.start();
}
};
/**
* Cancels an animation frame created by requestAnimationFrame_().
* @private
*/
goog.fx.anim.cancelAnimationFrame_ = function() {
if (goog.fx.anim.animationDelay_) {
goog.fx.anim.animationDelay_.stop();
}
};
/**
* Cycles through all registered animations.
* @param {number} now Current time in milliseconds.
* @private
*/
goog.fx.anim.cycleAnimations_ = function(now) {
goog.object.forEach(goog.fx.anim.activeAnimations_, function(anim) {
anim.onAnimationFrame(now);
});
if (!goog.object.isEmpty(goog.fx.anim.activeAnimations_)) {
goog.fx.anim.requestAnimationFrame_();
}
};
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