From 7f180331718ba8bcc31b6daf6e763e196b209a7f Mon Sep 17 00:00:00 2001
From: Tim Schaub <tim.schaub@gmail.com>
Date: Sat, 7 Feb 2015 16:42:36 -0700
Subject: [PATCH] Make layer renderers observable and re-render on change

---
 src/ol/renderer/layerrenderer.js |  5 +++--
 src/ol/renderer/maprenderer.js   | 26 ++++++++++++++++++++++++++
 2 files changed, 29 insertions(+), 2 deletions(-)

diff --git a/src/ol/renderer/layerrenderer.js b/src/ol/renderer/layerrenderer.js
index 08b7f4e03b..796384ce5e 100644
--- a/src/ol/renderer/layerrenderer.js
+++ b/src/ol/renderer/layerrenderer.js
@@ -6,6 +6,7 @@ goog.require('goog.events');
 goog.require('goog.events.EventType');
 goog.require('goog.functions');
 goog.require('ol.ImageState');
+goog.require('ol.Observable');
 goog.require('ol.TileRange');
 goog.require('ol.TileState');
 goog.require('ol.layer.Layer');
@@ -19,7 +20,7 @@ goog.require('ol.vec.Mat4');
 
 /**
  * @constructor
- * @extends {goog.Disposable}
+ * @extends {ol.Observable}
  * @param {ol.renderer.Map} mapRenderer Map renderer.
  * @param {ol.layer.Layer} layer Layer.
  * @suppress {checkStructDictInheritance}
@@ -43,7 +44,7 @@ ol.renderer.Layer = function(mapRenderer, layer) {
 
 
 };
-goog.inherits(ol.renderer.Layer, goog.Disposable);
+goog.inherits(ol.renderer.Layer, ol.Observable);
 
 
 /**
diff --git a/src/ol/renderer/maprenderer.js b/src/ol/renderer/maprenderer.js
index 5fa707a00b..c1c7748e67 100644
--- a/src/ol/renderer/maprenderer.js
+++ b/src/ol/renderer/maprenderer.js
@@ -4,6 +4,8 @@ goog.provide('ol.renderer.Map');
 goog.require('goog.Disposable');
 goog.require('goog.asserts');
 goog.require('goog.dispose');
+goog.require('goog.events');
+goog.require('goog.events.EventType');
 goog.require('goog.functions');
 goog.require('goog.object');
 goog.require('goog.vec.Mat4');
@@ -56,6 +58,12 @@ ol.renderer.Map = function(container, map) {
    */
   this.layerRenderers_ = {};
 
+  /**
+   * @private
+   * @type {Object.<string, goog.events.Key>}
+   */
+  this.layerRendererListeners_ = {};
+
 };
 goog.inherits(ol.renderer.Map, goog.Disposable);
 
@@ -254,6 +262,10 @@ ol.renderer.Map.prototype.getLayerRenderer = function(layer) {
   } else {
     var layerRenderer = this.createLayerRenderer(layer);
     this.layerRenderers_[layerKey] = layerRenderer;
+    this.layerRendererListeners_[layerKey] = goog.events.listen(layerRenderer,
+        goog.events.EventType.CHANGE, this.handleLayerRendererChange_,
+        false, this);
+
     return layerRenderer;
   }
 };
@@ -293,6 +305,15 @@ ol.renderer.Map.prototype.getMap = function() {
 ol.renderer.Map.prototype.getType = goog.abstractMethod;
 
 
+/**
+ * Handle changes in a layer renderer.
+ * @private
+ */
+ol.renderer.Map.prototype.handleLayerRendererChange_ = function() {
+  this.map_.render();
+};
+
+
 /**
  * @param {string} layerKey Layer key.
  * @return {ol.renderer.Layer} Layer renderer.
@@ -302,6 +323,11 @@ ol.renderer.Map.prototype.removeLayerRendererByKey_ = function(layerKey) {
   goog.asserts.assert(layerKey in this.layerRenderers_);
   var layerRenderer = this.layerRenderers_[layerKey];
   delete this.layerRenderers_[layerKey];
+
+  goog.asserts.assert(layerKey in this.layerRendererListeners_);
+  goog.events.unlistenByKey(this.layerRendererListeners_[layerKey]);
+  delete this.layerRendererListeners_[layerKey];
+
   return layerRenderer;
 };