openlayers
Version:
Build tools and sources for developing OpenLayers based mapping applications
149 lines (125 loc) • 3.17 kB
JavaScript
goog.provide('ol.ImageTile');
goog.require('ol');
goog.require('ol.Tile');
goog.require('ol.events');
goog.require('ol.events.EventType');
/**
* @constructor
* @extends {ol.Tile}
* @param {ol.TileCoord} tileCoord Tile coordinate.
* @param {ol.Tile.State} state State.
* @param {string} src Image source URI.
* @param {?string} crossOrigin Cross origin.
* @param {ol.TileLoadFunctionType} tileLoadFunction Tile load function.
*/
ol.ImageTile = function(tileCoord, state, src, crossOrigin, tileLoadFunction) {
ol.Tile.call(this, tileCoord, state);
/**
* Image URI
*
* @private
* @type {string}
*/
this.src_ = src;
/**
* @private
* @type {Image}
*/
this.image_ = new Image();
if (crossOrigin !== null) {
this.image_.crossOrigin = crossOrigin;
}
/**
* @private
* @type {Array.<ol.EventsKey>}
*/
this.imageListenerKeys_ = null;
/**
* @private
* @type {ol.TileLoadFunctionType}
*/
this.tileLoadFunction_ = tileLoadFunction;
};
ol.inherits(ol.ImageTile, ol.Tile);
/**
* @inheritDoc
*/
ol.ImageTile.prototype.disposeInternal = function() {
if (this.state == ol.Tile.State.LOADING) {
this.unlistenImage_();
}
if (this.interimTile) {
this.interimTile.dispose();
}
this.state = ol.Tile.State.ABORT;
this.changed();
ol.Tile.prototype.disposeInternal.call(this);
};
/**
* Get the image element for this tile.
* @inheritDoc
* @api
*/
ol.ImageTile.prototype.getImage = function() {
return this.image_;
};
/**
* @inheritDoc
*/
ol.ImageTile.prototype.getKey = function() {
return this.src_;
};
/**
* Tracks loading or read errors.
*
* @private
*/
ol.ImageTile.prototype.handleImageError_ = function() {
this.state = ol.Tile.State.ERROR;
this.unlistenImage_();
this.changed();
};
/**
* Tracks successful image load.
*
* @private
*/
ol.ImageTile.prototype.handleImageLoad_ = function() {
if (this.image_.naturalWidth && this.image_.naturalHeight) {
this.state = ol.Tile.State.LOADED;
} else {
this.state = ol.Tile.State.EMPTY;
}
this.unlistenImage_();
this.changed();
};
/**
* Load the image or retry if loading previously failed.
* Loading is taken care of by the tile queue, and calling this method is
* only needed for preloading or for reloading in case of an error.
* @api
*/
ol.ImageTile.prototype.load = function() {
if (this.state == ol.Tile.State.IDLE || this.state == ol.Tile.State.ERROR) {
this.state = ol.Tile.State.LOADING;
this.changed();
ol.DEBUG && console.assert(!this.imageListenerKeys_,
'this.imageListenerKeys_ should be null');
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)
];
this.tileLoadFunction_(this, this.src_);
}
};
/**
* Discards event handlers which listen for load completion or errors.
*
* @private
*/
ol.ImageTile.prototype.unlistenImage_ = function() {
this.imageListenerKeys_.forEach(ol.events.unlistenByKey);
this.imageListenerKeys_ = null;
};