Merge pull request #2891 from ahocevar/imageloadfunction

Introduce a load function for image sources

externs/olx.js

@@ -3863,6 +3863,7 @@ olx.source.IGCOptions.prototype.urls;
  *     projection: ol.proj.ProjectionLike,
  *     ratio: (number|undefined),
  *     resolutions: (Array.<number>|undefined),
+ *     imageLoadFunction: (ol.ImageLoadFunctionType|undefined),
  *     params: (Object|undefined)}}
  * @api
  */
@@ -3935,6 +3936,15 @@ olx.source.ImageMapGuideOptions.prototype.ratio;
 olx.source.ImageMapGuideOptions.prototype.resolutions;
 
 
+
+/**
+ * Optional function to load an image given a URL.
+ * @type {ol.TileLoadFunctionType|undefined}
+ * @api
+ */
+olx.source.ImageMapGuideOptions.prototype.imageLoadFunction;
+
+
 /**
  * Additional parameters.
  * @type {Object|undefined}
@@ -4374,6 +4384,7 @@ olx.source.ImageVectorOptions.prototype.style;
  *     hidpi: (boolean|undefined),
  *     serverType: (ol.source.wms.ServerType|string|undefined),
  *     logo: (string|olx.LogoOptions|undefined),
+ *     imageLoadFunction: (ol.ImageLoadFunctionType|undefined),
  *     params: Object.<string,*>,
  *     projection: ol.proj.ProjectionLike,
  *     ratio: (number|undefined),
@@ -4418,6 +4429,14 @@ olx.source.ImageWMSOptions.prototype.hidpi;
 olx.source.ImageWMSOptions.prototype.serverType;
 
 
+/**
+ * Optional function to load an image given a URL.
+ * @type {ol.TileLoadFunctionType|undefined}
+ * @api
+ */
+olx.source.ImageWMSOptions.prototype.imageLoadFunction;
+
+
 /**
  * Logo.
  * @type {string|olx.LogoOptions|undefined}
@@ -4534,6 +4553,7 @@ olx.source.StamenOptions.prototype.url;
  *     crossOrigin: (null|string|undefined),
  *     imageExtent: (ol.Extent),
  *     imageSize: (ol.Size|undefined),
+ *     imageLoadFunction: (ol.ImageLoadFunctionType|undefined),
  *     logo: (string|olx.LogoOptions|undefined),
  *     projection: ol.proj.ProjectionLike,
  *     url: string}}
@@ -4574,6 +4594,14 @@ olx.source.ImageStaticOptions.prototype.imageExtent;
 olx.source.ImageStaticOptions.prototype.imageSize;
 
 
+/**
+ * Optional function to load an image given a URL.
+ * @type {ol.TileLoadFunctionType|undefined}
+ * @api
+ */
+olx.source.ImageStaticOptions.prototype.imageLoadFunction;
+
+
 /**
  * Logo.
  * @type {string|olx.LogoOptions|undefined}

src/ol/image.js

@@ -20,9 +20,10 @@ goog.require('ol.extent');
  * @param {Array.<ol.Attribution>} attributions Attributions.
  * @param {string} src Image source URI.
  * @param {?string} crossOrigin Cross origin.
+ * @param {ol.ImageLoadFunctionType} imageLoadFunction Image load function.
  */
-ol.Image =
-    function(extent, resolution, pixelRatio, attributions, src, crossOrigin) {
+ol.Image = function(extent, resolution, pixelRatio, attributions, src,
+    crossOrigin, imageLoadFunction) {
 
   goog.base(this, extent, resolution, pixelRatio, ol.ImageState.IDLE,
       attributions);
@@ -59,6 +60,13 @@ ol.Image =
    * @type {ol.ImageState}
    */
   this.state = ol.ImageState.IDLE;
+
+  /**
+   * @private
+   * @type {ol.ImageLoadFunctionType}
+   */
+  this.imageLoadFunction_ = imageLoadFunction;
+
 };
 goog.inherits(ol.Image, ol.ImageBase);
 
@@ -66,8 +74,9 @@ goog.inherits(ol.Image, ol.ImageBase);
 /**
  * @param {Object=} opt_context Object.
  * @return {HTMLCanvasElement|Image|HTMLVideoElement} Image.
+ * @api
  */
-ol.Image.prototype.getImageElement = function(opt_context) {
+ol.Image.prototype.getImage = function(opt_context) {
   if (goog.isDef(opt_context)) {
     var image;
     var key = goog.getUid(opt_context);
@@ -126,7 +135,7 @@ ol.Image.prototype.load = function() {
       goog.events.listenOnce(this.image_, goog.events.EventType.LOAD,
           this.handleImageLoad_, false, this)
     ];
-    this.image_.src = this.src_;
+    this.imageLoadFunction_(this, this.src_);
   }
 };
 

src/ol/imagebase.js

@@ -95,7 +95,7 @@ ol.ImageBase.prototype.getExtent = function() {
  * @param {Object=} opt_context Object.
  * @return {HTMLCanvasElement|Image|HTMLVideoElement} Image.
  */
-ol.ImageBase.prototype.getImageElement = goog.abstractMethod;
+ol.ImageBase.prototype.getImage = goog.abstractMethod;
 
 
 /**

src/ol/imagecanvas.js

@@ -33,6 +33,6 @@ goog.inherits(ol.ImageCanvas, ol.ImageBase);
 /**
  * @inheritDoc
  */
-ol.ImageCanvas.prototype.getImageElement = function(opt_context) {
+ol.ImageCanvas.prototype.getImage = function(opt_context) {
   return this.canvas_;
 };

src/ol/imageloadfunction.js

@@ -0,0 +1,21 @@
+goog.provide('ol.ImageLoadFunctionType');
+
+
+/**
+ * A function that takes an {@link ol.Image} for the image and a `{string}` for
+ * the src as arguments. It is supposed to make it so the underlying image
+ * {@link ol.Image#getImage} is assigned the content specified by the src. If
+ * not specified, the default is
+ *
+ *     function(image, src) {
+ *       image.getImage().src = src;
+ *     }
+ *
+ * Providing a custom `imageLoadFunction` can be useful to load images with
+ * post requests or - in general - through XHR requests, where the src of the
+ * image element would be set to a data URI when the content is loaded.
+ *
+ * @typedef {function(ol.Image, string)}
+ * @api
+ */
+ol.ImageLoadFunctionType;

src/ol/renderer/canvas/canvasimagelayerrenderer.js

@@ -69,7 +69,7 @@ ol.renderer.canvas.ImageLayer.prototype.forEachFeatureAtPixel =
  */
 ol.renderer.canvas.ImageLayer.prototype.getImage = function() {
   return goog.isNull(this.image_) ?
-      null : this.image_.getImageElement();
+      null : this.image_.getImage();
 };
 
 

src/ol/renderer/dom/domimagelayerrenderer.js

@@ -129,7 +129,7 @@ ol.renderer.dom.ImageLayer.prototype.prepareFrame =
         (imageExtent[0] - viewCenter[0]) / imageResolution,
         (viewCenter[1] - imageExtent[3]) / imageResolution);
     if (image != this.image_) {
-      var imageElement = image.getImageElement(this);
+      var imageElement = image.getImage(this);
       // Bootstrap sets the style max-width: 100% for all images, which breaks
       // prevents the image from being displayed in FireFox.  Workaround by
       // overriding the max-width style.

src/ol/renderer/webgl/webglimagelayerrenderer.js

@@ -48,7 +48,7 @@ ol.renderer.webgl.ImageLayer.prototype.createTexture_ = function(image) {
   // http://www.khronos.org/webgl/wiki/WebGL_and_OpenGL_Differences#Non-Power_of_Two_Texture_Support
   // http://learningwebgl.com/blog/?p=2101
 
-  var imageElement = image.getImageElement();
+  var imageElement = image.getImage();
   var gl = this.getWebGLMapRenderer().getGL();
 
   var texture = gl.createTexture();

src/ol/source/imagemapguidesource.js

@@ -3,6 +3,7 @@ goog.provide('ol.source.ImageMapGuide');
 goog.require('goog.object');
 goog.require('goog.uri.utils');
 goog.require('ol.Image');
+goog.require('ol.ImageLoadFunctionType');
 goog.require('ol.ImageUrlFunction');
 goog.require('ol.extent');
 goog.require('ol.source.Image');
@@ -59,6 +60,13 @@ ol.source.ImageMapGuide = function(options) {
    */
   this.imageUrlFunction_ = imageUrlFunction;
 
+  /**
+   * @private
+   * @type {ol.ImageLoadFunctionType}
+   */
+  this.imageLoadFunction_ = goog.isDef(options.imageLoadFunction) ?
+      options.imageLoadFunction : ol.source.Image.defaultImageLoadFunction;
+
   /**
    * @private
    * @type {boolean}
@@ -140,7 +148,8 @@ ol.source.ImageMapGuide.prototype.getImage =
   var imageUrl = this.imageUrlFunction_(extent, size, projection);
   if (goog.isDef(imageUrl)) {
     image = new ol.Image(extent, resolution, pixelRatio,
-        this.getAttributions(), imageUrl, this.crossOrigin_);
+        this.getAttributions(), imageUrl, this.crossOrigin_,
+        this.imageLoadFunction_);
   } else {
     image = null;
   }

src/ol/source/imagesource.js

@@ -88,3 +88,14 @@ ol.source.Image.prototype.findNearestResolution =
  * @return {ol.ImageBase} Single image.
  */
 ol.source.Image.prototype.getImage = goog.abstractMethod;
+
+
+/**
+ * Default image load function for image sources that use ol.Image image
+ * instances.
+ * @param {ol.Image} image Image.
+ * @param {string} src Source.
+ */
+ol.source.Image.defaultImageLoadFunction = function(image, src) {
+  image.getImage().src = src;
+};

src/ol/source/imagestaticsource.js

@@ -34,6 +34,9 @@ ol.source.ImageStatic = function(options) {
   var crossOrigin = goog.isDef(options.crossOrigin) ?
       options.crossOrigin : null;
 
+  var imageLoadFunction = goog.isDef(options.imageLoadFunction) ?
+      options.imageLoadFunction : ol.source.Image.defaultImageLoadFunction;
+
   goog.base(this, {
     attributions: attributions,
     logo: options.logo,
@@ -46,7 +49,7 @@ ol.source.ImageStatic = function(options) {
    * @type {ol.Image}
    */
   this.image_ = new ol.Image(imageExtent, resolution, 1, attributions,
-      options.url, crossOrigin);
+      options.url, crossOrigin, imageLoadFunction);
 
 };
 goog.inherits(ol.source.ImageStatic, ol.source.Image);

src/ol/source/imagewmssource.js

@@ -8,6 +8,7 @@ goog.require('goog.string');
 goog.require('goog.uri.utils');
 goog.require('ol');
 goog.require('ol.Image');
+goog.require('ol.ImageLoadFunctionType');
 goog.require('ol.extent');
 goog.require('ol.proj');
 goog.require('ol.source.Image');
@@ -49,6 +50,13 @@ ol.source.ImageWMS = function(opt_options) {
    */
   this.url_ = options.url;
 
+  /**
+   * @private
+   * @type {ol.ImageLoadFunctionType}
+   */
+  this.imageLoadFunction_ = goog.isDef(options.imageLoadFunction) ?
+      options.imageLoadFunction : ol.source.Image.defaultImageLoadFunction;
+
   /**
    * @private
    * @type {Object}
@@ -235,7 +243,7 @@ ol.source.ImageWMS.prototype.getImage =
       projection, params);
 
   this.image_ = new ol.Image(extent, resolution, pixelRatio,
-      this.getAttributions(), url, this.crossOrigin_);
+      this.getAttributions(), url, this.crossOrigin_, this.imageLoadFunction_);
 
   this.renderedRevision_ = this.getRevision();
 

test/spec/ol/source/imagewmssource.test.js

@@ -134,6 +134,16 @@ describe('ol.source.ImageWMS', function() {
       expect(queryData.get('DPI')).to.be('180');
     });
 
+    it('creates an image with a custom imageLoadFunction', function() {
+      var imageLoadFunction = sinon.spy();
+      options.imageLoadFunction = imageLoadFunction;
+      var source = new ol.source.ImageWMS(options);
+      var image = source.getImage(extent, resolution, pixelRatio, projection);
+      image.load();
+      expect(imageLoadFunction).to.be.called();
+      expect(imageLoadFunction.calledWith(image, image.src_)).to.be(true);
+    });
+
   });
 
   describe('#getGetFeatureInfo', function() {