Make Backpack open in Firefox

Change-Id: If360e42e1fc497b7cdd5ffdc0756513ade51af14

appinventor/blocklyeditor/src/backpack.js

@@ -2,7 +2,7 @@
 * Visual Blocks Editor
 *
 * Copyright © 2011 Google Inc.
 * Copyright © 2011-2016 Massachusetts Institute of Technology
 * Copyright © 2011-2018 Massachusetts Institute of Technology
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
@@ -215,6 +215,8 @@ Blockly.Backpack.prototype.init = function() {
  this.position_();
  // If the document resizes, reposition the backpack.
  Blockly.bindEvent_(window, 'resize', this, this.position_);
  // Fixes a bug in Firefox where the backpack cannot be opened.
  Blockly.bindEvent_(this.svgBody_, 'mousedown', this, function(e) { e.stopPropagation(); e.preventDefault(); });
  Blockly.bindEvent_(this.svgBody_, 'click', this, this.openBackpack);
  Blockly.bindEvent_(this.svgBody_, 'contextmenu', this, this.openBackpackDoc);
  this.flyout_.init(this.workspace_);
@@ -450,8 +452,14 @@ Blockly.Backpack.prototype.openBackpackDoc = function(e) {

/**
 * On left click, open backpack and view flyout
 *
 * @param {?MouseEvent} e Click event if the backpack is being opened in
 * response to a user action.
 */
Blockly.Backpack.prototype.openBackpack = function() {
Blockly.Backpack.prototype.openBackpack = function(e) {
  if (e) {
    e.stopPropagation();
  }
  if (!this.isAdded && this.flyout_.isVisible()) {
    this.flyout_.hide();
  } else {