Add custom hide plugin

Adds a simple plugin to hide/show time series of a graph.
The plugin simply adds checkboxes above the graph to hide/show a series.

Author: Matthias K

inst/plugins/hide.js

@@ -0,0 +1,65 @@
+/**
+ * @fileoverview Plug-in for hiding/showing time-series.
+ */
+Dygraph.Plugins.Hide = (function() {
+
+  "use strict";
+
+  /**
+   * Create a new instance.
+   *
+   * @constructor
+   */
+  var hide = function() {
+    this.showSeriesArray = [];
+  };
+
+  hide.prototype.toString = function() {
+    return 'hide Plugin';
+  };
+
+/**
+ * This is called during the dygraph constructor, after options have been set
+ * but before the data is available.
+ * @param {Dygraph} g Graph instance.
+ * @return {object.<string, function(ev)>} Mapping of event names to callbacks.
+ */
+  hide.prototype.activate = function(g) {
+    return {
+      willDrawChart: this.willDrawChart
+    };
+  };
+
+  hide.prototype.willDrawChart = function(e) {
+    var g = e.dygraph;
+    var area = g.plotter_.area;
+    var parent = g.graphDiv;
+
+    var visibility = g.visibility();
+    for (var i = 0; i < visibility.length; i++) {
+      var offset = 20*i+4;
+      var cb = document.createElement('input');
+      cb.type = 'checkbox';
+      cb.checked = true;
+      cb.id = i;
+      cb.style.position = 'absolute';
+      cb.style.top = (area.y + 4) + 'px';
+      cb.style.left = (area.x + offset) + 'px';
+      cb.style.zIndex = 11;
+      this.showSeriesArray.push(true);
+
+      var self = this;
+
+      g.addAndTrackEvent(cb, 'click', function(e) {
+        var targetId = e.target.id;
+        self.showSeriesArray[targetId] = !self.showSeriesArray[targetId];
+        g.setVisibility(targetId, self.showSeriesArray[targetId]);
+      });
+      
+      parent.insertBefore(cb, parent.firstChild);
+    }
+  };
+
+  return hide;
+
+})();