openlayers
Version:
Build tools and sources for developing OpenLayers based mapping applications
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JavaScript
goog.provide('ol.style.IconImage');
goog.require('ol');
goog.require('ol.dom');
goog.require('ol.events');
goog.require('ol.events.EventTarget');
goog.require('ol.events.EventType');
goog.require('ol.Image');
goog.require('ol.style');
/**
* @constructor
* @param {Image|HTMLCanvasElement} image Image.
* @param {string|undefined} src Src.
* @param {ol.Size} size Size.
* @param {?string} crossOrigin Cross origin.
* @param {ol.Image.State} imageState Image state.
* @param {ol.Color} color Color.
* @extends {ol.events.EventTarget}
*/
ol.style.IconImage = function(image, src, size, crossOrigin, imageState,
color) {
ol.events.EventTarget.call(this);
/**
* @private
* @type {Image|HTMLCanvasElement}
*/
this.hitDetectionImage_ = null;
/**
* @private
* @type {Image|HTMLCanvasElement}
*/
this.image_ = !image ? new Image() : image;
if (crossOrigin !== null) {
this.image_.crossOrigin = crossOrigin;
}
/**
* @private
* @type {HTMLCanvasElement}
*/
this.canvas_ = color ?
/** @type {HTMLCanvasElement} */ (document.createElement('CANVAS')) :
null;
/**
* @private
* @type {ol.Color}
*/
this.color_ = color;
/**
* @private
* @type {Array.<ol.EventsKey>}
*/
this.imageListenerKeys_ = null;
/**
* @private
* @type {ol.Image.State}
*/
this.imageState_ = imageState;
/**
* @private
* @type {ol.Size}
*/
this.size_ = size;
/**
* @private
* @type {string|undefined}
*/
this.src_ = src;
/**
* @private
* @type {boolean}
*/
this.tainting_ = false;
if (this.imageState_ == ol.Image.State.LOADED) {
this.determineTainting_();
}
};
ol.inherits(ol.style.IconImage, ol.events.EventTarget);
/**
* @param {Image|HTMLCanvasElement} image Image.
* @param {string} src Src.
* @param {ol.Size} size Size.
* @param {?string} crossOrigin Cross origin.
* @param {ol.Image.State} imageState Image state.
* @param {ol.Color} color Color.
* @return {ol.style.IconImage} Icon image.
*/
ol.style.IconImage.get = function(image, src, size, crossOrigin, imageState,
color) {
var iconImageCache = ol.style.iconImageCache;
var iconImage = iconImageCache.get(src, crossOrigin, color);
if (!iconImage) {
iconImage = new ol.style.IconImage(
image, src, size, crossOrigin, imageState, color);
iconImageCache.set(src, crossOrigin, color, iconImage);
}
return iconImage;
};
/**
* @private
*/
ol.style.IconImage.prototype.determineTainting_ = function() {
var context = ol.dom.createCanvasContext2D(1, 1);
try {
context.drawImage(this.image_, 0, 0);
context.getImageData(0, 0, 1, 1);
} catch (e) {
this.tainting_ = true;
}
};
/**
* @private
*/
ol.style.IconImage.prototype.dispatchChangeEvent_ = function() {
this.dispatchEvent(ol.events.EventType.CHANGE);
};
/**
* @private
*/
ol.style.IconImage.prototype.handleImageError_ = function() {
this.imageState_ = ol.Image.State.ERROR;
this.unlistenImage_();
this.dispatchChangeEvent_();
};
/**
* @private
*/
ol.style.IconImage.prototype.handleImageLoad_ = function() {
this.imageState_ = ol.Image.State.LOADED;
if (this.size_) {
this.image_.width = this.size_[0];
this.image_.height = this.size_[1];
}
this.size_ = [this.image_.width, this.image_.height];
this.unlistenImage_();
this.determineTainting_();
this.replaceColor_();
this.dispatchChangeEvent_();
};
/**
* @param {number} pixelRatio Pixel ratio.
* @return {Image|HTMLCanvasElement} Image or Canvas element.
*/
ol.style.IconImage.prototype.getImage = function(pixelRatio) {
return this.canvas_ ? this.canvas_ : this.image_;
};
/**
* @return {ol.Image.State} Image state.
*/
ol.style.IconImage.prototype.getImageState = function() {
return this.imageState_;
};
/**
* @param {number} pixelRatio Pixel ratio.
* @return {Image|HTMLCanvasElement} Image element.
*/
ol.style.IconImage.prototype.getHitDetectionImage = function(pixelRatio) {
if (!this.hitDetectionImage_) {
if (this.tainting_) {
var width = this.size_[0];
var height = this.size_[1];
var context = ol.dom.createCanvasContext2D(width, height);
context.fillRect(0, 0, width, height);
this.hitDetectionImage_ = context.canvas;
} else {
this.hitDetectionImage_ = this.image_;
}
}
return this.hitDetectionImage_;
};
/**
* @return {ol.Size} Image size.
*/
ol.style.IconImage.prototype.getSize = function() {
return this.size_;
};
/**
* @return {string|undefined} Image src.
*/
ol.style.IconImage.prototype.getSrc = function() {
return this.src_;
};
/**
* Load not yet loaded URI.
*/
ol.style.IconImage.prototype.load = function() {
if (this.imageState_ == ol.Image.State.IDLE) {
ol.DEBUG && console.assert(this.src_ !== undefined,
'this.src_ must not be undefined');
ol.DEBUG && console.assert(!this.imageListenerKeys_,
'no listener keys existing');
this.imageState_ = ol.Image.State.LOADING;
this.imageListenerKeys_ = [
ol.events.listenOnce(this.image_, ol.events.EventType.ERROR,
this.handleImageError_, this),
ol.events.listenOnce(this.image_, ol.events.EventType.LOAD,
this.handleImageLoad_, this)
];
try {
this.image_.src = this.src_;
} catch (e) {
this.handleImageError_();
}
}
};
/**
* @private
*/
ol.style.IconImage.prototype.replaceColor_ = function() {
if (this.tainting_ || this.color_ === null) {
return;
}
this.canvas_.width = this.image_.width;
this.canvas_.height = this.image_.height;
var ctx = this.canvas_.getContext('2d');
ctx.drawImage(this.image_, 0, 0);
var imgData = ctx.getImageData(0, 0, this.image_.width, this.image_.height);
var data = imgData.data;
var r = this.color_[0] / 255.0;
var g = this.color_[1] / 255.0;
var b = this.color_[2] / 255.0;
for (var i = 0, ii = data.length; i < ii; i += 4) {
data[i] *= r;
data[i + 1] *= g;
data[i + 2] *= b;
}
ctx.putImageData(imgData, 0, 0);
};
/**
* Discards event handlers which listen for load completion or errors.
*
* @private
*/
ol.style.IconImage.prototype.unlistenImage_ = function() {
this.imageListenerKeys_.forEach(ol.events.unlistenByKey);
this.imageListenerKeys_ = null;
};