Add ol.source.ImageSource

src/ol/source/imagesource.js

@@ -0,0 +1,111 @@
+goog.provide('ol.source.ImageSource');
+
+goog.require('goog.array');
+goog.require('ol.Attribution');
+goog.require('ol.Extent');
+goog.require('ol.Image');
+goog.require('ol.ImageUrlFunction');
+goog.require('ol.ImageUrlFunctionType');
+goog.require('ol.Projection');
+goog.require('ol.Size');
+goog.require('ol.array');
+goog.require('ol.source.Source');
+
+
+/**
+ * @typedef {{attributions: (Array.<ol.Attribution>|undefined),
+ *            crossOrigin: (null|string|undefined),
+ *            extent: (null|ol.Extent|undefined),
+ *            projection: (ol.Projection|undefined),
+ *            resolutions: (Array.<number>|undefined),
+ *            imageUrlFunction: (ol.ImageUrlFunctionType|
+ *                undefined)}}
+ */
+ol.source.ImageSourceOptions;
+
+
+
+/**
+ * @constructor
+ * @extends {ol.source.Source}
+ * @param {ol.source.ImageSourceOptions} options Single
+ *     image source options.
+ */
+ol.source.ImageSource = function(options) {
+
+  goog.base(this, {
+    attributions: options.attributions,
+    extent: options.extent,
+    projection: options.projection
+  });
+
+  /**
+   * @protected
+   * @type {ol.ImageUrlFunctionType}
+   */
+  this.imageUrlFunction =
+      goog.isDef(options.imageUrlFunction) ?
+          options.imageUrlFunction :
+          ol.ImageUrlFunction.nullImageUrlFunction;
+
+  /**
+   * @private
+   * @type {?string}
+   */
+  this.crossOrigin_ =
+      goog.isDef(options.crossOrigin) ? options.crossOrigin : 'anonymous';
+
+  /**
+   * @private
+   * @type {Array.<number>}
+   */
+  this.resolutions_ = goog.isDef(options.resolutions) ?
+      options.resolutions : null;
+  if (!goog.isNull(this.resolutions_)) {
+    goog.array.sort(this.resolutions_, function(a, b) {return b - a; });
+  }
+
+};
+goog.inherits(ol.source.ImageSource, ol.source.Source);
+
+
+/**
+ * @protected
+ * @param {ol.Extent} extent Extent.
+ * @param {number} resolution Resolution.
+ * @param {ol.Size} size Size.
+ * @return {ol.Image} Single image.
+ */
+ol.source.ImageSource.prototype.createImage =
+    function(extent, resolution, size) {
+  var image = null;
+  var imageUrl = this.imageUrlFunction(extent, size);
+  if (goog.isDef(imageUrl)) {
+    image = new ol.Image(
+        extent, resolution, imageUrl, this.crossOrigin_);
+  }
+  return image;
+};
+
+
+/**
+ * @protected
+ * @param {number} resolution Resolution.
+ * @return {number} Resolution.
+ */
+ol.source.ImageSource.prototype.findNearestResolution =
+    function(resolution) {
+  if (!goog.isNull(this.resolutions_)) {
+    var idx = ol.array.linearFindNearest(this.resolutions_, resolution);
+    resolution = this.resolutions_[idx];
+  }
+  return resolution;
+};
+
+
+/**
+ * @param {ol.Extent} extent Extent.
+ * @param {number} resolution Resolution.
+ * @return {ol.Image} Single image.
+ */
+ol.source.ImageSource.prototype.getImage = goog.abstractMethod;