Merge branch 'master' of https://github.com/J-F-Liu/c3 into J-F-Liu-master

c3.js

@@ -584,9 +584,6 @@
             $$.subY2.domain($$.getYDomain(targetsToShow, 'y2'));
         }
 
-        // tooltip
-        $$.tooltip.style("display", "none");
-
         // xgrid focus
         $$.updateXgridFocus();
 
@@ -6374,9 +6371,7 @@
             scaleX = (diffDomain(orgDomain) / diffDomain(domain));
             transform = 'translate(' + translateX + ',0) scale(' + scaleX + ',1)';
 
-            // hide tooltip
             $$.hideXGridFocus();
-            $$.hideTooltip();
 
             d3.transition().ease('linear').duration(durationForFlow).each(function () {
                 wait.add($$.axes.x.transition().call($$.xAxis));

src/api.flow.js

@@ -214,9 +214,7 @@ c3_chart_internal_fn.generateFlow = function (args) {
         scaleX = (diffDomain(orgDomain) / diffDomain(domain));
         transform = 'translate(' + translateX + ',0) scale(' + scaleX + ',1)';
 
-        // hide tooltip
         $$.hideXGridFocus();
-        $$.hideTooltip();
 
         d3.transition().ease('linear').duration(durationForFlow).each(function () {
             wait.add($$.axes.x.transition().call($$.xAxis));

src/core.js

@@ -579,9 +579,6 @@ c3_chart_internal_fn.redraw = function (options, transitions) {
         $$.subY2.domain($$.getYDomain(targetsToShow, 'y2'));
     }
 
-    // tooltip
-    $$.tooltip.style("display", "none");
-
     // xgrid focus
     $$.updateXgridFocus();