163 lines
3.7 KiB
JavaScript
163 lines
3.7 KiB
JavaScript
goog.provide('ol.Image');
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goog.require('goog.asserts');
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goog.require('ol.ImageBase');
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goog.require('ol.ImageState');
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goog.require('ol.events');
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goog.require('ol.events.EventType');
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goog.require('ol.extent');
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goog.require('ol.object');
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/**
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* @constructor
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* @extends {ol.ImageBase}
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* @param {ol.Extent} extent Extent.
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* @param {number|undefined} resolution Resolution.
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* @param {number} pixelRatio Pixel ratio.
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* @param {Array.<ol.Attribution>} attributions Attributions.
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* @param {string} src Image source URI.
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* @param {?string} crossOrigin Cross origin.
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* @param {ol.ImageLoadFunctionType} imageLoadFunction Image load function.
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*/
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ol.Image = function(extent, resolution, pixelRatio, attributions, src,
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crossOrigin, imageLoadFunction) {
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goog.base(this, extent, resolution, pixelRatio, ol.ImageState.IDLE,
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attributions);
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/**
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* @private
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* @type {string}
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*/
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this.src_ = src;
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/**
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* @private
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* @type {HTMLCanvasElement|Image|HTMLVideoElement}
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*/
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this.image_ = new Image();
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if (crossOrigin !== null) {
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this.image_.crossOrigin = crossOrigin;
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}
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/**
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* @private
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* @type {Object.<number, (HTMLCanvasElement|Image|HTMLVideoElement)>}
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*/
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this.imageByContext_ = {};
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/**
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* @private
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* @type {Array.<ol.events.Key>}
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*/
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this.imageListenerKeys_ = null;
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/**
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* @protected
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* @type {ol.ImageState}
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*/
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this.state = ol.ImageState.IDLE;
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/**
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* @private
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* @type {ol.ImageLoadFunctionType}
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*/
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this.imageLoadFunction_ = imageLoadFunction;
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};
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goog.inherits(ol.Image, ol.ImageBase);
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/**
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* Get the HTML image element (may be a Canvas, Image, or Video).
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* @param {Object=} opt_context Object.
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* @return {HTMLCanvasElement|Image|HTMLVideoElement} Image.
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* @api
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*/
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ol.Image.prototype.getImage = function(opt_context) {
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if (opt_context !== undefined) {
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var image;
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var key = goog.getUid(opt_context);
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if (key in this.imageByContext_) {
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return this.imageByContext_[key];
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} else if (ol.object.isEmpty(this.imageByContext_)) {
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image = this.image_;
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} else {
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image = /** @type {Image} */ (this.image_.cloneNode(false));
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}
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this.imageByContext_[key] = image;
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return image;
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} else {
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return this.image_;
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}
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};
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/**
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* Tracks loading or read errors.
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*
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* @private
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*/
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ol.Image.prototype.handleImageError_ = function() {
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this.state = ol.ImageState.ERROR;
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this.unlistenImage_();
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this.changed();
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};
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/**
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* Tracks successful image load.
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*
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* @private
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*/
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ol.Image.prototype.handleImageLoad_ = function() {
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if (this.resolution === undefined) {
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this.resolution = ol.extent.getHeight(this.extent) / this.image_.height;
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}
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this.state = ol.ImageState.LOADED;
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this.unlistenImage_();
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this.changed();
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};
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/**
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* Load not yet loaded URI.
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*/
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ol.Image.prototype.load = function() {
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if (this.state == ol.ImageState.IDLE) {
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this.state = ol.ImageState.LOADING;
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this.changed();
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goog.asserts.assert(!this.imageListenerKeys_,
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'this.imageListenerKeys_ should be null');
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this.imageListenerKeys_ = [
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ol.events.listenOnce(this.image_, ol.events.EventType.ERROR,
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this.handleImageError_, this),
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ol.events.listenOnce(this.image_, ol.events.EventType.LOAD,
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this.handleImageLoad_, this)
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];
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this.imageLoadFunction_(this, this.src_);
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}
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};
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/**
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* @param {HTMLCanvasElement|Image|HTMLVideoElement} image Image.
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*/
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ol.Image.prototype.setImage = function(image) {
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this.image_ = image;
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};
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/**
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* Discards event handlers which listen for load completion or errors.
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*
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* @private
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*/
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ol.Image.prototype.unlistenImage_ = function() {
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goog.asserts.assert(this.imageListenerKeys_,
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'this.imageListenerKeys_ should not be null');
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this.imageListenerKeys_.forEach(ol.events.unlistenByKey);
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this.imageListenerKeys_ = null;
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};
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