#

API Documentation for: NEXT
Show: Inherited Protected Private Deprecated

# File:easeljs\display\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 {HTMLImageElement | 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.
    	 **/
    	function Bitmap(imageOrUri) {
    		this.DisplayObject_constructor();

    	// public properties:
    		/**
    		 * The image to render. This can be an Image, a Canvas, or a Video. Not all browsers (especially
    		 * mobile browsers) support drawing video to a canvas.
    		 * @property image
    		 * @type HTMLImageElement | HTMLCanvasElement | HTMLVideoElement
    		 **/
    		if (typeof imageOrUri == "string") {
    			this.image = document.createElement("img");
    			this.image.src = imageOrUri;
    		} else {
    			this.image = imageOrUri;
    		}

    		/**
    		 * Specifies an area of the source image to draw. If omitted, the whole image will be drawn.
    		 * Note that video sources must have a width / height set to work correctly with `sourceRect`.
    		 * @property sourceRect
    		 * @type Rectangle
    		 * @default null
    		 */
    		this.sourceRect = null;
    	}
    	var p = createjs.extend(Bitmap, createjs.DisplayObject);

    // public methods:
    	/**
    	 * Constructor alias for backwards compatibility. This method will be removed in future versions.
    	 * Subclasses should be updated to use {{#crossLink "Utility Methods/extends"}}{{/crossLink}}.
    	 * @method initialize
    	 * @deprecated in favour of `createjs.promote()`
    	 **/
    	p.initialize = Bitmap; // TODO: deprecated.

    	/**
    	 * 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 image = this.image;
    		var hasContent = this.cacheCanvas || (image && (image.naturalWidth || image.getContext || image.readyState >= 2));
    		return !!(this.visible && this.alpha > 0 && this.scaleX != 0 && this.scaleY != 0 && hasContent);
    	};

    	/**
    	 * 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) || !this.image) { return true; }
    		var img = this.image, rect = this.sourceRect;
    		if (rect) {
    			// some browsers choke on out of bound values, so we'll fix them:
    			var x1 = rect.x, y1 = rect.y, x2 = x1 + rect.width, y2 = y1 + rect.height, x = 0, y = 0, w = img.width, h = img.height;
    			if (x1 < 0) { x -= x1; x1 = 0; }
    			if (x2 > w) { x2 = w; }
    			if (y1 < 0) { y -= y1; y1 = 0; }
    			if (y2 > h) { y2 = h; }
    			ctx.drawImage(img, x1, y1, x2-x1, y2-y1, x, y, x2-x1, y2-y1);
    		} else {
    			ctx.drawImage(img, 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
    	 **/

    	/**
    	 * Docced in superclass.
    	 */
    	p.getBounds = function() {
    		var rect = this.DisplayObject_getBounds();
    		if (rect) { return rect; }
    		var image = this.image, o = this.sourceRect || image;
    		var hasContent = (image && (image.naturalWidth || image.getContext || image.readyState >= 2));
    		return hasContent ? this._rectangle.setValues(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 +")]";
    	};

    	createjs.Bitmap = createjs.promote(Bitmap, "DisplayObject");
    }());