MD Settings: Display: Move event listeners to dialog open/close

chrome/browser/resources/settings/device_page/display_overscan_dialog.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
  * 'settings-display-overscan-dialog' is the dialog for display overscan
  * adjustments.
  */
 
@@ skipping 12 matching lines @@
     comitted_: Boolean,
   },
 
   /**
    * Keyboard event handler for overscan adjustments.
    * @type {?function(!Event)}
    * @private
    */
   keyHandler_: null,
 
-  /** @override */
-  attached: function() {
+  open: function() {
     this.keyHandler_ = this.handleKeyEvent_.bind(this);
-    window.addEventListener('keydown', this.keyHandler_);
-  },
-
-  /** @override */
-  detached: function() {
-    window.removeEventListener('keydown', this.keyHandler_);
-  },
-
-  open: function() {
+    this.addEventListener('keydown', this.keyHandler_);
     this.comitted_ = false;
     this.$.dialog.showModal();
   },
 
   close: function() {
+    this.removeEventListener('keydown', this.keyHandler_);
+
     this.displayId = '';  // Will trigger displayIdChanged_.
 
     if (this.$.dialog.open)
       this.$.dialog.close();
   },
 
   /** @private */
   displayIdChanged_: function(newValue, oldValue) {
     if (oldValue && !this.comitted_) {
       settings.display.systemDisplayApi.overscanCalibrationReset(oldValue);
@@ skipping 16 matching lines @@
         this.displayId);
     this.comitted_ = true;
     this.close();
   },
 
   /**
    * @param {Event} event
    * @private
    */
   handleKeyEvent_: function(event) {
-    switch (event.keyCode) {
-      case 37:  // left arrow
-        if (event.shiftKey)
-          this.move_(-1, 0);
-        else
-          this.resize_(1, 0);
-        break;
-      case 38:  // up arrow
-        if (event.shiftKey)
-          this.move_(0, -1);
-        else
-          this.resize_(0, -1);
-        break;
-      case 39:  // right arrow
-        if (event.shiftKey)
-          this.move_(1, 0);
-        else
-          this.resize_(-1, 0);
-        break;
-      case 40:  // down arrow
-        if (event.shiftKey)
-          this.move_(0, 1);
-        else
-          this.resize_(0, 1);
-        break;
-      default:

[Dan Beam, 2016/09/28 22:10:38]

// Only preventDefault() for keys that do something (i.e. arrow keys).

-        return;
+    if (event.altKey || event.ctrlKey || event.metaKey)
+      return;
+    if (this.handleKeyCode_(event.keyCode, event.shiftKey))
+      event.preventDefault();
+  },
+
+  /**
+   * @param {number} keyCode
+   * @param {boolean} shiftKey
+   * @return {boolean}
+   * @private
+   */
+  handleKeyCode_: function(keyCode, shiftKey) {
+    if (shiftKey) {
+      switch (keyCode) {
+        case 37:  // left arrow
+          return this.move_(-1, 0);
+        case 38:  // up arrow
+          return this.move_(0, -1);
+        case 39:  // right arrow
+          return this.move_(1, 0);
+        case 40:  // down arrow
+          return this.move_(0, 1);
+      }
+    } else {
+      switch (keyCode) {
+        case 37:  // left arrow
+          return this.resize_(1, 0);
+        case 38:  // up arrow
+          return this.resize_(0, -1);
+        case 39:  // right arrow
+          return this.resize_(-1, 0);
+        case 40:  // down arrow
+          return this.resize_(0, 1);
+      }
     }
-    event.preventDefault();
+    return false;
   },
 
   /**
    * @param {number} x
    * @param {number} y
+   * @return {boolean} Always returns true for simplifed switch handling.
    * @private
    */
   move_: function(x, y) {
     /** @type {!chrome.system.display.Insets} */ var delta = {
       left: x,
       top: y,
       right: x ? -x : 0,  // negating 0 will produce a double.
       bottom: y ? -y : 0,
     };
     settings.display.systemDisplayApi.overscanCalibrationAdjust(
         this.displayId, delta);
+    return true;
   },
 
   /**
    * @param {number} x
    * @param {number} y
+   * @return {boolean} Always returns true for simplifed switch handling.
    * @private
    */
   resize_: function(x, y) {
     /** @type {!chrome.system.display.Insets} */ var delta = {
       left: x,
       top: y,
       right: x,
       bottom: y,
     };
     settings.display.systemDisplayApi.overscanCalibrationAdjust(
         this.displayId, delta);
+    return true;
   }
 });