Add auto-resizing of figures in JupyterLab when no width/heigh explicitly set

Author: jonmmease

js/src/Figure.js

@@ -793,10 +793,22 @@ var FigureView = widgets.DOMWidgetView.extend({
      */
     processPhosphorMessage: function(msg) {
         FigureView.__super__.processPhosphorMessage.apply(this, arguments);
+        var that = this;
         switch (msg.type) {
             case 'after-attach':
                 this.perform_render();
                 break;
+            case 'resize':
+                var layout = this.model.get('_layout');
+                if (_.isNil(layout) ||
+                    (_.isNil(layout.width) && _.isNil(layout.height))) {
+                    Plotly.Plots.resize(this.el).then(function(){
+                        var layout_edit_id = that.model.get(
+                            "_last_layout_edit_id");
+                        that._sendLayoutDelta(layout_edit_id);
+                    });
+                }
+                break
         }
     },