Make touch accessibility gestures work with ChromeVox Next

chrome/browser/resources/chromeos/chromevox/cvox2/background/background.js

 // Copyright 2014 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 The entry point for all ChromeVox2 related code for the
  * background page.
  */
 
 goog.provide('Background');
@@ skipping 122 matching lines @@
   this.liveRegions_ = new LiveRegions(this);
 
   /** @type {number} @private */
   this.passThroughKeyUpCount_ = 0;
 
   /** @type {boolean} @private */
   this.inExcursion_ = false;
 
   if (!chrome.accessibilityPrivate.setKeyboardListener)
     chrome.accessibilityPrivate.setKeyboardListener = function() {};
+
+  if (cvox.ChromeVox.isChromeOS) {
+    chrome.accessibilityPrivate.onAccessibilityGesture.addListener(
+        this.onAccessibilityGesture_);
+  }
 };
 
 /**
  * @const {string}
  */
 Background.ISSUE_URL = 'https://code.google.com/p/chromium/issues/entry?' +
     'labels=Type-Bug,Pri-2,cvox2,OS-Chrome&' +
     'components=UI>accessibility&' +
     'description=';
 
@@ skipping 832 matching lines @@
     this.restoreCurrentRange_();
   },
 
   /**
    * Move ChromeVox back to the last saved range.
    */
   saveExcursion: function() {
     this.savedRange_ =
         new cursors.Range(this.currentRange_.start, this.currentRange_.end);
   },
+
+  /**
+   * Handles accessibility gestures from the touch screen.
+   * @param {string} gesture The gesture to handle, based on the AXGesture enum
+   *     defined in ui/accessibility/ax_enums.idl
+   * @private
+   */
+  onAccessibilityGesture_: function(gesture) {
+    console.error('Gesture: ' + gesture);

[David Tseng, 2016/05/05 22:30:39]

nit: remove

[dmazzoni, 2016/05/06 19:06:09]

Done.

+
+    if (this.mode_ == ChromeVoxMode.CLASSIC) {
+      if (this.handleClassicGesture_(gesture))
+        return;

[David Tseng, 2016/05/05 22:30:39]

Are you going to allow for unhandled gestures?

[dmazzoni, 2016/05/06 19:06:09]

Yes, it should return true if it shouldn't continue processing just like an
event.

+    }

[David Tseng, 2016/05/05 22:30:39]

Is this meant to fall through?

[dmazzoni, 2016/05/06 19:06:09]

Yes, my thought was that some gestures might be universal for both classic and
next, like if there was a gesture to go home or speak the date and time. I added
a comment.

+
+    var command;
+    switch (gesture) {
+      case 'swipeUp1': command = 'previousLine'; break;
+      case 'swipeDown1': command = 'nextLine'; break;
+      case 'swipeLeft1': command = 'previousObject'; break;
+      case 'swipeRight1': command = 'nextObject'; break;
+      case 'swipeUp2': command = 'jumpToTop'; break;
+      case 'swipeDown2': command = 'jumpToBottom'; break;

[David Tseng, 2016/05/05 22:30:39]

This should be readFromHere

[David Tseng, 2016/05/05 22:30:39]

Maybe just put these into an object dictionary?

[dmazzoni, 2016/05/06 19:06:08]

Done.

[dmazzoni, 2016/05/06 19:06:08]

Done.

+    }

[David Tseng, 2016/05/05 22:30:39]

default?

[dmazzoni, 2016/05/06 19:06:09]

What do you want the default handler to do? I think it's okay if not every
possible gesture maps to something, especially as we increase our gesture
vocabulary

+
+    console.error('Gesture command: ' + command);

[David Tseng, 2016/05/05 22:30:39]

nit: remove

[dmazzoni, 2016/05/06 19:06:09]

Done.

+
+    if (command)
+      this.onGotCommand(command);
+  },
+
+  /**
+   * Handles accessibility gestures from the touch screen when in CLASSIC
+   * mode, by forwarding a command to the content script.
+   * @param {string} gesture The gesture to handle, based on the AXGesture enum
+   *     defined in ui/accessibility/ax_enums.idl
+   * @return {boolean} True if this gesture was handled.
+   * @private
+   */
+  handleClassicGesture_: function(gesture) {
+    var command;
+    switch (gesture) {
+      case 'swipeUp1': command = 'backward'; break;
+      case 'swipeDown1': command = 'forward'; break;
+      case 'swipeLeft1': command = 'left'; break;
+      case 'swipeRight1': command = 'right'; break;
+      case 'swipeUp2': command = 'jumpToTop'; break;
+      case 'swipeDown2': command = 'jumpToBottom'; break;

[David Tseng, 2016/05/05 22:30:39]

Ditto; readFromHere.

[dmazzoni, 2016/05/06 19:06:08]

Done.

+    }
+
+    if (!command)
+      return false;
+
+

[David Tseng, 2016/05/05 22:30:39]

nit: extra line

[dmazzoni, 2016/05/06 19:06:09]

Done.

+    var msg = {
+      'message': 'USER_COMMAND',
+      'command': command
+    };
+    cvox.ExtensionBridge.send(msg);
+    return true;
+  },
 };
 
 /**
  * Converts a list of globs, as used in the extension manifest, to a regular
  * expression that matches if and only if any of the globs in the list matches.
  * @param {!Array<string>} globs
  * @return {!RegExp}
  * @private
  */
 Background.globsToRegExp_ = function(globs) {
   return new RegExp('^(' + globs.map(function(glob) {
     return glob.replace(/[.+^$(){}|[\]\\]/g, '\\$&')
         .replace(/\*/g, '.*')
         .replace(/\?/g, '.');
   }).join('|') + ')$');
 };
 
 /** @type {Background} */
 global.backgroundObj = new Background();
 
 });  // goog.scope