From 88030dbce7137ccd99cfe1ff159c8551859a2061 Mon Sep 17 00:00:00 2001
From: Tim Schaub <tim.schaub@gmail.com>
Date: Tue, 21 Oct 2014 22:32:25 -0600
Subject: [PATCH] Allow layer source to be set

---
 src/ol/layer/layer.js            | 42 ++++++++++++++++++++----
 src/ol/layer/layerbase.js        |  3 +-
 test/spec/ol/layer/layer.test.js | 56 ++++++++++++++++++++++++++++++++
 3 files changed, 93 insertions(+), 8 deletions(-)

diff --git a/src/ol/layer/layer.js b/src/ol/layer/layer.js
index 3ce78653d9..cb172ac208 100644
--- a/src/ol/layer/layer.js
+++ b/src/ol/layer/layer.js
@@ -5,7 +5,7 @@ goog.require('goog.events');
 goog.require('goog.events.EventType');
 goog.require('goog.object');
 goog.require('ol.layer.Base');
-goog.require('ol.source.Source');
+goog.require('ol.layer.LayerProperty');
 
 
 
@@ -33,13 +33,11 @@ ol.layer.Layer = function(options) {
 
   /**
    * @private
-   * @type {ol.source.Source}
+   * @type {goog.events.Key}
    */
-  this.source_ = options.source;
-
-  goog.events.listen(this.source_, goog.events.EventType.CHANGE,
-      this.handleSourceChange_, false, this);
+  this.sourceChangeKey_ = null;
 
+  this.setSource(options.source);
 };
 goog.inherits(ol.layer.Layer, ol.layer.Base);
 
@@ -79,12 +77,20 @@ ol.layer.Layer.prototype.getLayerStatesArray = function(opt_states) {
 
 
 /**
+ * Get the layer source.
  * @return {ol.source.Source} Source.
+ * @observable
  * @api stable
  */
 ol.layer.Layer.prototype.getSource = function() {
-  return this.source_;
+  var source = this.get(ol.layer.LayerProperty.SOURCE);
+  return goog.isDef(source) ?
+      /** @type {ol.source.Source} */ (source) : null;
 };
+goog.exportProperty(
+    ol.layer.Layer.prototype,
+    'getSource',
+    ol.layer.Layer.prototype.getSource);
 
 
 /**
@@ -101,3 +107,25 @@ ol.layer.Layer.prototype.getSourceState = function() {
 ol.layer.Layer.prototype.handleSourceChange_ = function() {
   this.changed();
 };
+
+
+/**
+ * Set the layer source.
+ * @param {ol.source.Source} source The layer source.
+ * @observable
+ * @api stable
+ */
+ol.layer.Layer.prototype.setSource = function(source) {
+  if (!goog.isNull(this.sourceChangeKey_)) {
+    goog.events.unlistenByKey(this.sourceChangeKey_);
+    this.sourceChangeKey_ = null;
+  }
+  this.sourceChangeKey_ = goog.events.listen(source,
+      goog.events.EventType.CHANGE, this.handleSourceChange_, false, this);
+  this.set(ol.layer.LayerProperty.SOURCE, source);
+  this.changed();
+};
+goog.exportProperty(
+    ol.layer.Layer.prototype,
+    'setSource',
+    ol.layer.Layer.prototype.setSource);
diff --git a/src/ol/layer/layerbase.js b/src/ol/layer/layerbase.js
index 6df5c0d158..ac63c7dc80 100644
--- a/src/ol/layer/layerbase.js
+++ b/src/ol/layer/layerbase.js
@@ -21,7 +21,8 @@ ol.layer.LayerProperty = {
   VISIBLE: 'visible',
   EXTENT: 'extent',
   MAX_RESOLUTION: 'maxResolution',
-  MIN_RESOLUTION: 'minResolution'
+  MIN_RESOLUTION: 'minResolution',
+  SOURCE: 'source'
 };
 
 
diff --git a/test/spec/ol/layer/layer.test.js b/test/spec/ol/layer/layer.test.js
index 71bea3b08d..bf16e74942 100644
--- a/test/spec/ol/layer/layer.test.js
+++ b/test/spec/ol/layer/layer.test.js
@@ -243,6 +243,62 @@ describe('ol.layer.Layer', function() {
 
   });
 
+  describe('#getSource', function() {
+
+    it('gets the layer source', function() {
+      var source = new ol.source.Source({projection: ol.proj.get('EPSG:4326')});
+      var layer = new ol.layer.Layer({source: source});
+      expect(layer.getSource()).to.be(source);
+    });
+
+  });
+
+  describe('#setSource()', function() {
+    var projection = ol.proj.get('EPSG:4326');
+
+    it('sets the layer source', function() {
+      var layer = new ol.layer.Layer({
+        source: new ol.source.Source({projection: projection})
+      });
+
+      var source = new ol.source.Source({projection: projection});
+      layer.setSource(source);
+      expect(layer.getSource()).to.be(source);
+    });
+
+    it('calls changed', function() {
+      var layer = new ol.layer.Layer({
+        source: new ol.source.Source({projection: projection})
+      });
+      sinon.spy(layer, 'changed');
+
+      var source = new ol.source.Source({projection: projection});
+      layer.setSource(source);
+      expect(layer.changed.calledOnce).to.be(true);
+    });
+
+    it('sets up event listeners', function() {
+      sinon.spy(ol.layer.Layer.prototype, 'handleSourceChange_');
+
+      var first = new ol.source.Source({projection: projection});
+      var layer = new ol.layer.Layer({source: first});
+
+      first.setState(ol.source.State.READY);
+      expect(layer.handleSourceChange_.calledOnce).to.be(true);
+
+      var second = new ol.source.Source({projection: projection});
+      layer.setSource(second);
+
+      expect(layer.handleSourceChange_.calledOnce).to.be(true);
+      second.setState(ol.source.State.READY);
+      expect(layer.handleSourceChange_.callCount).to.be(2);
+
+      // remove spy
+      ol.layer.Layer.prototype.handleSourceChange_.restore();
+    });
+
+  });
+
   describe('#setBrightness', function() {
 
     var layer;