Add data.selection.draggable and enable scrolling even if it's on the chart - #215 #798

c3.js

@@ -972,6 +972,7 @@
             data_selection_grouped: false,
             data_selection_isselectable: function () { return true; },
             data_selection_multiple: true,
+            data_selection_draggable: false,
             data_onclick: function () {},
             data_onmouseover: function () {},
             data_onmouseout: function () {},
@@ -2366,10 +2367,12 @@
                 });
             })
             .call(
+                config.data_selection_draggable && $$.drag ? (
                     d3.behavior.drag().origin(Object)
                         .on('drag', function () { $$.drag(d3.mouse(this)); })
                         .on('dragstart', function () { $$.dragstart(d3.mouse(this)); })
                         .on('dragend', function () { $$.dragend(); })
+                ) : function () {}
             );
     };
 

src/config.js

@@ -44,6 +44,7 @@ c3_chart_internal_fn.getDefaultConfig = function () {
         data_selection_grouped: false,
         data_selection_isselectable: function () { return true; },
         data_selection_multiple: true,
+        data_selection_draggable: false,
         data_onclick: function () {},
         data_onmouseover: function () {},
         data_onmouseout: function () {},

src/interaction.js

@@ -231,10 +231,12 @@ c3_chart_internal_fn.generateEventRectsForSingleX = function (eventRectEnter) {
             });
         })
         .call(
+            config.data_selection_draggable && $$.drag ? (
                 d3.behavior.drag().origin(Object)
                     .on('drag', function () { $$.drag(d3.mouse(this)); })
                     .on('dragstart', function () { $$.dragstart(d3.mouse(this)); })
                     .on('dragend', function () { $$.dragend(); })
+            ) : function () {}
         );
 };