Show modebar if no hover available

Author: dy

package.json

@@ -83,6 +83,7 @@
     "gl-shader": "4.2.0",
     "gl-spikes2d": "^1.0.1",
     "gl-surface3d": "^1.3.0",
+    "has-hover": "^1.0.0",
     "mapbox-gl": "^0.22.0",
     "matrix-camera-controller": "^2.1.3",
     "mouse-change": "^1.4.0",

src/plot_api/plot_api.js

@@ -12,6 +12,7 @@
 
 var d3 = require('d3');
 var isNumeric = require('fast-isnumeric');
+var hasHover = require('has-hover');
 
 var Plotly = require('../plotly');
 var Lib = require('../lib');
@@ -423,6 +424,11 @@ function setPlotContext(gd, config) {
         context.showLink = false;
         context.displayModeBar = false;
     }
+
+    // make sure hover-only devices have mode bar visible
+    if(context.displayModeBar === 'hover' && !hasHover) {
+        context.displayModeBar = true;
+    }
 }
 
 function plotPolar(gd, data, layout) {