Zoom out RangeSlider.Preview on double click

Author: rbu

src/js/Rickshaw.Graph.RangeSlider.Preview.js

@@ -380,6 +380,15 @@ Rickshaw.Graph.RangeSlider.Preview = Rickshaw.Class.create({
 			});
 		}
 
+		function zoomOut() {
+			self.graphs.forEach(function(graph) {
+				graph.window.xMin = undefined;
+				graph.window.xMax = undefined;
+
+				graph.update();
+			});
+		}
+
 		function onMousedown() {
 			drag.target = d3.event.target;
 			drag.start = self._getClientXFromEvent(d3.event, drag);
@@ -427,6 +436,7 @@ Rickshaw.Graph.RangeSlider.Preview = Rickshaw.Class.create({
 		element.select("rect.left_handle").on("touchstart", onMousedownLeftHandle);
 		element.select("rect.right_handle").on("touchstart", onMousedownRightHandle);
 		element.select("rect.middle_handle").on("touchstart", onMousedownMiddleHandle);
+		element.on("dblclick", zoomOut);
 	},
 
 	_getClientXFromEvent: function(event, drag) {