#

API Documentation for: NEXT
Show: Inherited Protected Private Deprecated

# File:Bitmap.js

    /*
    * Bitmap
    * Visit http://createjs.com/ for documentation, updates and examples.
    *
    * Copyright (c) 2010 gskinner.com, inc.
    *
    * Permission is hereby granted, free of charge, to any person
    * obtaining a copy of this software and associated documentation
    * files (the "Software"), to deal in the Software without
    * restriction, including without limitation the rights to use,
    * copy, modify, merge, publish, distribute, sublicense, and/or sell
    * copies of the Software, and to permit persons to whom the
    * Software is furnished to do so, subject to the following
    * conditions:
    *
    * The above copyright notice and this permission notice shall be
    * included in all copies or substantial portions of the Software.
    *
    * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
    * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
    * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
    * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
    * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
    * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
    * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
    * OTHER DEALINGS IN THE SOFTWARE.
    */

    /**
    * @module EaselJS
    */

    // namespace:
    this.createjs = this.createjs||{};

    (function() {

    /**
     * A Bitmap represents an Image, Canvas, or Video in the display list. A Bitmap can be instantiated using an existing
     * HTML element, or a string.
     *
     * <h4>Example</h4>
     *
     *      var bitmap = new createjs.Bitmap("imagePath.jpg");
     *
     * <strong>Notes:</strong>
     * <ol>
     *     <li>When a string path or image tag that is not yet loaded is used, the stage may need to be redrawn before it
     *      will be displayed.</li>
     *     <li>Bitmaps with an SVG source currently will not respect an alpha value other than 0 or 1. To get around this,
     *     the Bitmap can be cached.</li>
     *     <li>Bitmaps with an SVG source will taint the canvas with cross-origin data, which prevents interactivity. This
     *     happens in all browsers except recent Firefox builds.</li>
     *     <li>Images loaded cross-origin will throw cross-origin security errors when interacted with using a mouse, using
     *     methods such as `getObjectUnderPoint`, or using filters, or caching. You can get around this by setting
     *     `crossOrigin` flags on your images before passing them to EaselJS, eg: `img.crossOrigin="Anonymous";`</li>
     * </ol>
     *
     * @class Bitmap
     * @extends DisplayObject
     * @constructor
     * @param {Image | HTMLCanvasElement | HTMLVideoElement | String} imageOrUri The source object or URI to an image to
     * display. This can be either an Image, Canvas, or Video object, or a string URI to an image file to load and use.
     * If it is a URI, a new Image object will be constructed and assigned to the .image property.
     **/
    var Bitmap = function(imageOrUri) {
      this.initialize(imageOrUri);
    };
    var p = Bitmap.prototype = new createjs.DisplayObject();

    // public properties:
    	/**
    	 * The image to render. This can be an Image, a Canvas, or a Video.
    	 * @property image
    	 * @type Image | HTMLCanvasElement | HTMLVideoElement
    	 **/
    	p.image = null;

    	/**
    	 * Specifies an area of the source image to draw. If omitted, the whole image will be drawn.
    	 * @property sourceRect
    	 * @type Rectangle
    	 * @default null
    	 */
    	p.sourceRect = null;

    	// constructor:

    	/**
    	 * @property DisplayObject_initialize
    	 * @type Function
    	 * @private
    	 **/
    	p.DisplayObject_initialize = p.initialize;

    	/**
    	 * Initialization method.
    	 * @method initialize
    	 * @param {Image | HTMLCanvasElement | HTMLVideoElement | String} imageOrUri The source object or URI to an image to
    	 * display. This can be either an Image, Canvas, or Video object, or a string URI to an image file to load and use.
    	 * If it is a URI, a new Image object will be constructed and assigned to the `.image` property.
    	 * @protected
    	 **/
    	p.initialize = function(imageOrUri) {
    		this.DisplayObject_initialize();
    		if (typeof imageOrUri == "string") {
    			this.image = document.createElement("img");
    			this.image.src = imageOrUri;
    		} else {
    			this.image = imageOrUri;
    		}
    	};

    // public methods:

    	/**
    	 * Returns true or false indicating whether the display object would be visible if drawn to a canvas.
    	 * This does not account for whether it would be visible within the boundaries of the stage.
    	 *
    	 * NOTE: This method is mainly for internal use, though it may be useful for advanced uses.
    	 * @method isVisible
    	 * @return {Boolean} Boolean indicating whether the display object would be visible if drawn to a canvas
    	 **/
    	p.isVisible = function() {
    		var hasContent = this.cacheCanvas || (this.image && (this.image.complete || this.image.getContext || this.image.readyState >= 2));
    		return !!(this.visible && this.alpha > 0 && this.scaleX != 0 && this.scaleY != 0 && hasContent);
    	};

    	/**
    	 * @property DisplayObject_draw
    	 * @type Function
    	 * @protected
    	 **/
    	p.DisplayObject_draw = p.draw;

    	/**
    	 * Draws the display object into the specified context ignoring its visible, alpha, shadow, and transform.
    	 * Returns true if the draw was handled (useful for overriding functionality).
    	 *
    	 * NOTE: This method is mainly for internal use, though it may be useful for advanced uses.
    	 * @method draw
    	 * @param {CanvasRenderingContext2D} ctx The canvas 2D context object to draw into.
    	 * @param {Boolean} [ignoreCache=false] Indicates whether the draw operation should ignore any current cache.
    	 * For example, used for drawing the cache (to prevent it from simply drawing an existing cache back
    	 * into itself).
    	 * @return {Boolean}
    	 **/
    	p.draw = function(ctx, ignoreCache) {
    		if (this.DisplayObject_draw(ctx, ignoreCache)) { return true; }
    		var rect = this.sourceRect;
    		if (rect) {
    			ctx.drawImage(this.image, rect.x, rect.y, rect.width, rect.height, 0, 0, rect.width, rect.height);
    		} else {
    			ctx.drawImage(this.image, 0, 0);
    		}
    		return true;
    	};

    	//Note, the doc sections below document using the specified APIs (from DisplayObject)  from
    	//Bitmap. This is why they have no method implementations.

    	/**
    	 * Because the content of a Bitmap is already in a simple format, cache is unnecessary for Bitmap instances.
    	 * You should <b>not</b> cache Bitmap instances as it can degrade performance.
    	 *
    	 * <strong>However: If you want to use a filter on a Bitmap, you <em>MUST</em> cache it, or it will not work.</strong>
    	 * To see the API for caching, please visit the DisplayObject {{#crossLink "DisplayObject/cache"}}{{/crossLink}}
    	 * method.
    	 * @method cache
    	 **/

    	/**
    	 * Because the content of a Bitmap is already in a simple format, cache is unnecessary for Bitmap instances.
    	 * You should <b>not</b> cache Bitmap instances as it can degrade performance.
    	 *
    	 * <strong>However: If you want to use a filter on a Bitmap, you <em>MUST</em> cache it, or it will not work.</strong>
    	 * To see the API for caching, please visit the DisplayObject {{#crossLink "DisplayObject/cache"}}{{/crossLink}}
    	 * method.
    	 * @method updateCache
    	 **/

    	/**
    	 * Because the content of a Bitmap is already in a simple format, cache is unnecessary for Bitmap instances.
    	 * You should <b>not</b> cache Bitmap instances as it can degrade performance.
    	 *
    	 * <strong>However: If you want to use a filter on a Bitmap, you <em>MUST</em> cache it, or it will not work.</strong>
    	 * To see the API for caching, please visit the DisplayObject {{#crossLink "DisplayObject/cache"}}{{/crossLink}}
    	 * method.
    	 * @method uncache
    	 **/

    	/**
    	 * @property DisplayObject_getBounds
    	 * @type Function
    	 * @protected
    	 **/
    	p.DisplayObject_getBounds = p.getBounds;

    	/**
    	 * Docced in superclass.
    	 */
    	p.getBounds = function() {
    		var rect = this.DisplayObject_getBounds();
    		if (rect) { return rect; }
    		var o = this.sourceRect || this.image;
    		var hasContent = (this.image && (this.image.complete || this.image.getContext || this.image.readyState >= 2));
    		return hasContent ? this._rectangle.initialize(0, 0, o.width, o.height) : null;
    	};

    	/**
    	 * Returns a clone of the Bitmap instance.
    	 * @method clone
    	 * @return {Bitmap} a clone of the Bitmap instance.
    	 **/
    	p.clone = function() {
    		var o = new Bitmap(this.image);
    		if (this.sourceRect) { o.sourceRect = this.sourceRect.clone(); }
    		this.cloneProps(o);
    		return o;
    	};

    	/**
    	 * Returns a string representation of this object.
    	 * @method toString
    	 * @return {String} a string representation of the instance.
    	 **/
    	p.toString = function() {
    		return "[Bitmap (name="+  this.name +")]";
    	};

    // private methods:

    createjs.Bitmap = Bitmap;
    }());