Implement support for chorded braille commands

chrome/browser/resources/chromeos/chromevox/cvox2/background/braille_command_handler.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 ChromeVox braille commands.
+ */
+
+goog.provide('BrailleCommandHandler');
+
+goog.require('ChromeVoxState');
+goog.require('CommandHandler');
+
+
+goog.scope(function() {
+/**
+ * Maps a dot pattern to a command.
+ * @type {!Object<number, string>}
+ */
+BrailleCommandHandler.DOT_PATTERN_TO_COMMAND = {
+};
+
+/**
+ * Makes a dot pattern given a list of dots numbered from 1 to 8 arranged in a
+ * braille cell (a 2 x 4 dot grid).
+ * @param {Array<number>} dots The dots to be set in the returned pattern.
+ * @return {number}
+ */
+BrailleCommandHandler.makeDotPattern = function(dots) {
+  return dots.reduce(function(p, c) {
+    return p | (1 << c - 1);
+  }, 0);
+};
+
+/**
+ * Perform a braille command based on a dot pattern from a chord.
+ * @param {number} dots Braille dot pattern
+ */
+BrailleCommandHandler.onBrailleCommand = function(dots) {
+  var command = BrailleCommandHandler.DOT_PATTERN_TO_COMMAND[dots];
+  if (command)
+    CommandHandler.onCommand(command);
+};
+
+/**
+ * @private
+ */
+BrailleCommandHandler.init_ = function() {
+  var map = function(dots, command) {
+    BrailleCommandHandler.DOT_PATTERN_TO_COMMAND[
+      BrailleCommandHandler.makeDotPattern(dots)] = command;
+  };
+
+  map([2, 3], 'previousGroup');

[dmazzoni, 2016/11/01 16:22:37]

Would it be possible to put this mapping into next_keymap.json instead?
I think it'd make more sense to put the keyboard and braille maps
together in one place to encourage mapping them together.

[David Tseng, 2016/11/01 20:11:59]

I would like to eventually move away from the way classic handles the keyboard.
To do what you suggest would mean touching KeyUtil, KeySequence, and probably
more. Much of the complexity comes from handling things like prefix key,
sequencing, etc. I think we want to have one keymap/braillemap, perhaps defined
in code.

+  map([5, 6], 'nextGroup');
+  map([1], 'previousObject');
+  map([4], 'nextObject');
+  map([2], 'previousWord');
+  map([5], 'nextWord');
+  map([3], 'previousCharacter');
+  map([6], 'nextCharacter');
+  map([1, 2, 3], 'jumpToTop');
+  map([4, 5, 6], 'jumpToBottom');
+
+  map([1, 4], 'fullyDescribe');
+  map([1, 3, 4], 'contextMenu');
+  map([1, 2, 3, 5], 'readFromHere');
+  map([2, 3, 4], 'toggleSelection');
+
+  // Forward jump.
+  map([1, 2], 'nextButton');
+  map([1, 5], 'nextEditText');
+  map([1, 2, 4], 'nextFormField');
+  map([1, 2, 5], 'nextHeading');
+  map([4, 5], 'nextLink');
+  map([2, 3, 4, 5], 'nextTable');
+
+  // Backward jump.
+  map([1, 2, 7], 'previousButton');
+  map([1, 5, 7], 'previousEditText');
+  map([1, 2, 4, 7], 'previousFormField');
+  map([1, 2, 5, 7], 'previousHeading');
+  map([4, 5, 7], 'previousLink');
+  map([2, 3, 4, 5, 7], 'previousTable');
+
+  map([8], 'forceClickOnCurrentItem');
+  map([3, 4], 'toggleSearchWidget');
+
+  // Question.
+  map([1, 4, 5, 6], 'toggleKeyboardHelp');
+};
+
+BrailleCommandHandler.init_();
+
+}); //  goog.scope