From 249449df3b533b797aae785444b05d1ab1127b15 Mon Sep 17 00:00:00 2001
From: Tom Payne <twpayne@gmail.com>
Date: Sun, 15 Jul 2012 20:45:39 +0200
Subject: [PATCH] Listen for changes in layer renderers

---
 src/ol/webgl/map.js | 47 +++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 47 insertions(+)

diff --git a/src/ol/webgl/map.js b/src/ol/webgl/map.js
index 421b0ea09d..6e03016af2 100644
--- a/src/ol/webgl/map.js
+++ b/src/ol/webgl/map.js
@@ -3,6 +3,9 @@ goog.provide('ol.webgl.Map');
 goog.require('goog.dispose');
 goog.require('goog.dom');
 goog.require('goog.dom.TagName');
+goog.require('goog.events');
+goog.require('goog.events.Event');
+goog.require('goog.events.EventType');
 goog.require('goog.style');
 goog.require('goog.webgl');
 goog.require('ol.Layer');
@@ -96,6 +99,12 @@ ol.webgl.Map = function(target, opt_values) {
    */
   this.vertexShader_ = ol.webgl.Map.createVertexShader_();
 
+  /**
+   * @private
+   * @type {Object.<number, null|number>}
+   */
+  this.layerRendererChangeListenKeys_ = {};
+
   if (goog.isDef(opt_values)) {
     this.setValues(opt_values);
   }
@@ -262,6 +271,18 @@ ol.webgl.Map.prototype.handleLayerAdd = function(layer) {
 };
 
 
+/**
+ * @param {goog.events.Event} event Event.
+ * @protected
+ */
+ol.webgl.Map.prototype.handleLayerRendererChange = function(event) {
+  var layerRenderer = /** @type {ol.LayerRenderer} */ (event.target);
+  if (layerRenderer.getLayer().getVisible()) {
+    this.redraw();
+  }
+};
+
+
 /**
  * @inheritDoc
  */
@@ -363,3 +384,29 @@ ol.webgl.Map.prototype.redrawInternal = function() {
   return animate;
 
 };
+
+
+/**
+ * @inheritDoc
+ */
+ol.webgl.Map.prototype.removeLayerRenderer = function(layer) {
+  var layerRenderer = goog.base(this, 'removeLayerRenderer', layer);
+  if (!goog.isNull(layerRenderer)) {
+    var key = goog.getUid(layer);
+    goog.events.unlistenByKey(this.layerRendererChangeListenKeys_[key]);
+    delete this.layerRendererChangeListenKeys_[key];
+  }
+  return layerRenderer;
+};
+
+
+/**
+ * @inheritDoc
+ */
+ol.webgl.Map.prototype.setLayerRenderer = function(layer, layerRenderer) {
+  goog.base(this, 'setLayerRenderer', layer, layerRenderer);
+  var key = goog.getUid(layer);
+  this.layerRendererChangeListenKeys_[key] = goog.events.listen(layerRenderer,
+      goog.events.EventType.CHANGE, this.handleLayerRendererChange, false,
+      this);
+};