Fix missing cursor for ternary plot

draftlogs/7057_fix.md

@@ -0,0 +1,2 @@
+ - Fix missing cursor for Ternary Plot[[#7057](https://github.com/plotly/plotly.js/pull/7057)],
+   with thanks to @Lexachoc for the contribution!

src/plots/ternary/index.js

@@ -75,3 +75,10 @@ exports.clean = function(newFullData, newFullLayout, oldFullData, oldFullLayout)
         }
     }
 };
+
+exports.updateFx = function(gd) {
+    var fullLayout = gd._fullLayout;
+    fullLayout._ternarylayer
+        .selectAll('g.toplevel')
+        .style('cursor', fullLayout.dragmode === 'pan' ? 'move' : 'crosshair');
+};

src/plots/ternary/ternary.js

@@ -30,6 +30,7 @@ function Ternary(options, fullLayout) {
     this.graphDiv = options.graphDiv;
     this.init(fullLayout);
     this.makeFramework(fullLayout);
+    this.updateFx(fullLayout);
 
     // unfortunately, we have to keep track of some axis tick settings
     // as ternary subplots do not implement the 'ticks' editType
@@ -97,6 +98,12 @@ proto.makeFramework = function(fullLayout) {
     Drawing.setClipUrl(_this.layers.grids, clipId, gd);
 };
 
+proto.updateFx = function(fullLayout) {
+    fullLayout._ternarylayer
+        .selectAll('g.toplevel')
+        .style('cursor', fullLayout.dragmode === 'pan' ? 'move' : 'crosshair');
+};
+
 proto.updateLayers = function(ternaryLayout) {
     var _this = this;
     var layers = _this.layers;