Animation.js, a frame by frame animation lib

animation.js

/*
//	Animation CLASS
//	@author cav_dan<daniel@shinka.com.br>
//	@desc
//		Create a frame-by-frame animation that may use jQuery
//
//	@args
//		selector = $('#someid') || document.querySelector('#someid'),
//		
//		optionsObj = {
//			name: string || selector.id
//			rootFolder: string = 'path/to/images'
//			frames: objArray = ['first.png', 'second.png']
//		}
//
//	@example
//		var char01 = new Animation($('#char01'), {rootFolder: 'img/char01/', frames: ['0.png', '1.png', '2.png']});
//		char01.init() <-- creates the DOM elements
//		char01.animate(0, this.length)
*/
var Animation = function(selector, optionsObj) {
	this.selector = selector;
	this.optionsObj = optionsObj;
	this.frames = optionsObj.frames ? optionsObj.frames : [];
	this.stopLoop = false;

	this.onAnimationStart = function(){return true;};
	this.onAnimationEnd = 	function(){return true;};
}

//Creates the DOM elements needed for the animation
Animation.prototype.init = function() {
		var opts = this.optionsObj,
			selector = this.selector,
			framesDocFrag = document.createDocumentFragment(),
			frames = [],
			//Dentro de optionsObj definir uma array em frames
			numOfFrames = opts.frames.length,
			div, img, frameContainer;

		if ( Array.isArray(selector) ) {
			frameContainer = selector[0];
			this.el = selector[0];
		} else {
			frameContainer = selector;
			this.el = selector;
		}

		for (var i = 0; i <= opts.frames.length - 1; i++) {
			div = document.createElement('div'), 
			img = document.createElement('img');

			div.className = 'frame';
			//div.style.zIndex = 100;
			img.src = '';
			div.appendChild(img);

			img.src = opts.rootFolder + opts.frames[i];
			//console.log(img.src);
			opts.name = opts.name || 'animationFrame';
			div.id = new String(opts.name + i);
			framesDocFrag.appendChild(div);
			/*if (i !== 0) {
				div.style.display = 'none';
			}*/
			if (i !== 0) {
				div.style.display = 'none';
			}
			frames.push(div);
			frameContainer.appendChild(framesDocFrag);
		};

		frameContainer.style.width = opts.width || img.clientWidth + 'px';
		frameContainer.style.height = opts.height || img.clientHeight + 'px';
		frameContainer.style.overflow = 'hidden';
		//frameContainer.style.zIndex = 200;
		this.frames = frames;
}

/*
//	@method Animate
//	@args
//		firstFrame = number,
//		lastFrame = number,
//		duration = number,
//		isLoop = number || bool[false];
//		callback = func
*/
Animation.prototype.animate = function(firstFrame, lastFrame, duration, isLoop, callback) {
	var frames = this.frames,
		duration = duration || 500;

	//Verifica se passamos um callback antes do isLoop

	if (typeof isLoop === 'function' || typeof isLoop === 'object') {
		callback = isLoop;
		isLoop = false;
	}

	this.callback = callback || false;
	this.animating = true;
	this.isLoop = isLoop || false;

	if (this.callback && this.isLoop) {
		isLoop = false;
		console.warn("Callback can not be executed if you're looping: Loop has been turned off.");
	}

	this.onAnimationStart();
	this.inverse = false;

	if (lastFrame < firstFrame) {
		//console.error("Last frame can't be before the first!");
		//return false;
		this.inverse = true;
	} else if (lastFrame === firstFrame) {
		lastFrame = frames.length - 1;
	} else if (lastFrame > frames.length) {
		lastFrame = frames.length;
	}

	//console.log('first: ' + firstFrame, '\nlast: ' + lastFrame, '\ndur: ' + duration, '\nloop?: ' + isLoop);

	var betweenFrames;

	this.anim = function() {
		if (firstFrame !== 0 && lastFrame !== 0) {
			frames[0].style.display = 'none';
		}

		/*if (this.lastUsedFrame) {
			frames[this.lastUsedFrame].style.display = 'none';
		}*/
		//console.log(this.inverse);
		//Se for ao contrário
		if (this.inverse) {
			betweenFrames = Math.floor( duration / (firstFrame - lastFrame) );
			for (var i = firstFrame, animFrames = [], j = 0, _i = 0; i >= lastFrame; i--) {
				//console.log( betweenFrames * _i );
				// j foi declarado para que apenas seja alterado durante a execução 
				// da função anônima dentro do window.setTimeout.
				animFrames.push(frames[i]);
				setTimeout(function(){
					frame = animFrames[j];
					if (j !== 0) {
						animFrames[j - 1].style.display = 'none';
					}
					frame.style.display = 'block';

					//console.info(j, frame);
					j++;

				},  betweenFrames * _i);
				_i++;
			}
		}
		//Sentido normal
		else {
			betweenFrames = Math.floor( duration / (lastFrame - firstFrame) );
			for (var i = firstFrame, animFrames = [], j = 0, _i = 0; i <= lastFrame; i++) {
				//frames[i].style.display = 'none';
				// j foi declarado para que apenas seja alterado durante a execução 
				// da função anônima dentro do window.setTimeout.
				animFrames.push(frames[i]);
				setTimeout(function(){
					//console.log('animando');
					frame = animFrames[j];
					if (j !== 0) {
						animFrames[j - 1].style.display = 'none';
					}
					frame.style.display = 'block';

					//console.info(j, 'frame');
					j++;

				},  betweenFrames * _i);
				_i++;

			};
		}

		this.lastUsedFrame = lastFrame;

		if (this.callback) {
			this.callback();
		};
		
	}

	if (this.isLoop) {
		var that = this,
		animationLoop = window.setInterval(function(){
			if (that.stopLoop) {
				/*that.lastFrame.style.display = 'none';
				that.firstFrame.style.display = 'none';*/
				that.stopLoop = false;
				clearInterval(animationLoop);
			}
			that.anim();
			//console.log('looping');
		}, duration + isLoop);
	} else {
		this.anim();
	}

	for (var i = frames.length - 1; i >= 0; i--) {
		if (i !== this.lastUsedFrame) {
			frames[i].style.display = 'none';
		}
	};

	this.onAnimationEnd();
};