MD Settings: Display: Add mirroring and other fixes

chrome/browser/resources/settings/device_page/layout_behavior.js

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 /**
  * @fileoverview Behavior for handling display layout, specifically
  *     edge snapping and collisions.
  */
 
 /** @polymerBehavior */
 var LayoutBehavior = {
   properties: {
     /**
      * Array of display layouts.
      * @type {!Array<!chrome.system.display.DisplayLayout>}
      */
     layouts: Array,
+
+    /**
+     * Whether or not mirroring is enabled.
+     * @type {boolean}
+     */
+    mirroring: false,
   },
 
   /** @private {!Map<string, chrome.system.display.Bounds>} */
   displayBoundsMap_: new Map(),
 
   /** @private {!Map<string, chrome.system.display.DisplayLayout>} */
   displayLayoutMap_: new Map(),
 
   /**
    * The calculated bounds used for generating the div bounds.
@@ skipping 14 matching lines @@
   dragLayoutPosition_: undefined,
 
   /**
    * @param {!Array<!chrome.system.display.DisplayUnitInfo>} displays
    * @param {!Array<!chrome.system.display.DisplayLayout>} layouts
    */
   initializeDisplayLayout: function(displays, layouts) {
     this.dragLayoutId = '';
     this.dragParentId_ = '';
 
+    this.mirroring = displays.length > 0 && !!displays[0].mirroringSourceId;
+
     this.displayBoundsMap_.clear();
     for (let display of displays)
       this.displayBoundsMap_.set(display.id, display.bounds);
 
     this.displayLayoutMap_.clear();
     for (let layout of layouts)
       this.displayLayoutMap_.set(layout.id, layout);
 
     this.calculatedBoundsMap_.clear();
     for (let display of displays) {
@@ skipping 113 matching lines @@
     chrome.system.display.setDisplayLayout(this.layouts, function() {
       if (chrome.runtime.lastError) {
         console.error(
             'setDisplayLayout Error: ' + chrome.runtime.lastError.message);
       }
     });
   },
 
   /**
    * @param {string} displayId
+   * @param {boolean=} opt_test

[michaelpg, 2016/07/11 20:41:56]

i'd prefer optional params default to false, e.g. opt_allowMissingBounds

if you insist on opt_test, comment that it asserts by default

[stevenjb, 2016/07/11 21:56:23]

I inverted the variable to be notest instead. We call this about 20 times so I
don't want to pass true explicitly in all of them.

    * @return {!chrome.system.display.Bounds} bounds
    */
-  getCalculatedDisplayBounds: function(displayId) {
+  getCalculatedDisplayBounds: function(displayId, opt_test) {
     var bounds = this.calculatedBoundsMap_.get(displayId);
-    assert(bounds);
+    assert(opt_test === false || bounds);
     return bounds;
   },
 
   /**
    * @param {string} displayId
    * @param {!chrome.system.display.Bounds|undefined} bounds
    * @private
    */
   setCalculatedDisplayBounds_: function(displayId, bounds) {
     assert(bounds);
@@ skipping 101 matching lines @@
    * Recursively calculates the absolute bounds of a display.
    * Caches the display bounds so that parent bounds are only calculated once.
    * @param {string} id
    * @param {number} width
    * @param {number} height
    * @private
    */
   calculateBounds_: function(id, width, height) {
     var left, top;
     var layout = this.displayLayoutMap_.get(id);
-    if (!layout || !layout.parentId) {
+    if (this.mirroring || !layout || !layout.parentId) {
       left = -width / 2;
       top = -height / 2;
     } else {
       if (!this.calculatedBoundsMap_.has(layout.parentId)) {
         var pbounds = this.displayBoundsMap_.get(layout.parentId);
         this.calculateBounds_(layout.parentId, pbounds.width, pbounds.height);
       }
       var parentBounds = this.getCalculatedDisplayBounds(layout.parentId);
       left = parentBounds.left;
       top = parentBounds.top;
@@ skipping 367 matching lines @@
           highlight == chrome.system.display.LayoutPosition.LEFT);
       div.classList.toggle(
           'highlight-top',
           highlight == chrome.system.display.LayoutPosition.TOP);
       div.classList.toggle(
           'highlight-bottom',
           highlight == chrome.system.display.LayoutPosition.BOTTOM);
     }
   },
 };