From 6a4457b403f78ba559550f97330ac25ee4d9629f Mon Sep 17 00:00:00 2001
From: Klaus Weidner <klausw@google.com>
Date: Tue, 10 Apr 2012 16:01:55 -0700
Subject: [PATCH] Update plugin registry

- use legend.prototype consistently for method calls, remove .call() hack

- replace the registerer with returning an event map object
---
 dygraph.js        | 14 ++++----------
 plugins/legend.js | 30 ++++++++++++++++--------------
 2 files changed, 20 insertions(+), 24 deletions(-)

diff --git a/dygraph.js b/dygraph.js
index 1ebe261..3867b29 100644
--- a/dygraph.js
+++ b/dygraph.js
@@ -422,16 +422,10 @@ Dygraph.prototype.__init__ = function(div, file, attrs) {
       pluginOptions: {}
     };
 
-    var registerer = (function(pluginDict) {
-      return {
-        addEventListener: function(eventName, callback) {
-          // TODO(danvk): validate eventName.
-          pluginDict.events[eventName] = callback;
-        }
-      };
-    })(pluginDict);
-    pluginInstance.activate(this, registerer);
-    // TODO(danvk): prevent activate() from holding a reference to registerer.
+    var handlers = pluginInstance.activate(this);
+    for (var eventName in handlers) {
+      pluginDict.events[eventName] = handlers[eventName];
+    }
 
     this.plugins_.push(pluginDict);
   }
diff --git a/plugins/legend.js b/plugins/legend.js
index 9e4650e..6e2e555 100644
--- a/plugins/legend.js
+++ b/plugins/legend.js
@@ -8,7 +8,6 @@ Current bits of jankiness:
     2. dygraph.plotter_.area
 - Registers for a "predraw" event, which should be renamed.
 - I call calculateEmWidthInDiv more often than needed.
-- Why can't I call "this.deselect(e)" instead of "legend.deselect.call(this, e)"?
 
 */
 
@@ -38,8 +37,11 @@ legend.prototype.toString = function() {
  * - Reading your own options
  * - DOM manipulation
  * - Registering event listeners
+ *
+ * @param {Dygraph} g Graph instance.
+ * @return {object.<string, function(ev)>} Mapping of event names to callbacks.
  */
-legend.prototype.activate = function(g, r) {
+legend.prototype.activate = function(g) {
   var div;
   var divWidth = g.getOption('labelsDivWidth');
 
@@ -87,12 +89,13 @@ legend.prototype.activate = function(g, r) {
 
   this.legend_div_ = div;
 
-  r.addEventListener('select', legend.select);
-  r.addEventListener('deselect', legend.deselect);
-
-  // TODO(danvk): rethink the name "predraw" before we commit to it in any API.
-  r.addEventListener('predraw', legend.predraw);
-  r.addEventListener('drawChart', legend.drawChart);
+  return {
+    select: this.select,
+    deselect: this.deselect,
+    // TODO(danvk): rethink the name "predraw" before we commit to it in any API.
+    predraw: this.predraw,
+    drawChart: this.drawChart
+  };
 };
 
 // Needed for dashed lines.
@@ -105,7 +108,7 @@ var calculateEmWidthInDiv = function(div) {
   return oneEmWidth;
 };
 
-legend.select = function(e) {
+legend.prototype.select = function(e) {
   var xValue = e.selectedX;
   var points = e.selectedPoints;
 
@@ -117,15 +120,14 @@ legend.select = function(e) {
   this.legend_div_.innerHTML = html;
 };
 
-legend.deselect = function(e) {
+legend.prototype.deselect = function(e) {
   var oneEmWidth = calculateEmWidthInDiv(this.legend_div_);
   var html = generateLegendHTML(e.dygraph, undefined, undefined, oneEmWidth);
   this.legend_div_.innerHTML = html;
 };
 
-legend.drawChart = function(e) {
-  // TODO(danvk): why doesn't this.deselect(e) work here?
-  legend.deselect.call(this, e);
+legend.prototype.drawChart = function(e) {
+  this.deselect(e);
 }
 
 // Right edge should be flush with the right edge of the charting area (which
@@ -137,7 +139,7 @@ legend.drawChart = function(e) {
  * - its top edge is flush with the top edge of the charting area
  * @private
  */
-legend.predraw = function(e) {
+legend.prototype.predraw = function(e) {
   // Don't touch a user-specified labelsDiv.
   if (!this.is_generated_div_) return;
 
-- 
2.7.4