add attribute 'display-legend' for area plot

Author: Andrey1024

src/idd/idd.area.js

@@ -7,6 +7,8 @@ InteractiveDataDisplay.Area = function (div, master) {
     // Initialization (#1)
     var initializer = InteractiveDataDisplay.Utils.getDataSourceFunction(div, InteractiveDataDisplay.readCsv);
     var initialData = initializer(div);
+    var displayInLegend = $(div).attr("data-idd-legend-visible") == "false" ? false : true;
+    
 
     this.base = InteractiveDataDisplay.CanvasPlot;
     this.base(div, master);
@@ -143,6 +145,8 @@ InteractiveDataDisplay.Area = function (div, master) {
     };
 
     this.getLegend = function () {
+        if (!displayInLegend)
+            return undefined;
         var that = this;
         var canvas = $("<canvas></canvas>");
         canvas[0].width = 40;