Support programmatic edit key commands

- introduce a scoped setter which enables the keyboard during spoken
feedback's lifetime
- remove restriction/message from ChromeVox disclaimer asking user to
enable a11y vk
- re-map some Search-like-function keys
1. Search+Left/Right -> Home/End
2. Search+Shift+Left/Right -> Shift Home/End
3. Search+Ctrl+Left/Right -> Ctrl+Home/End
4. Search+Shift+Ctrl+Left/Right -> Shift+Ctrl+Home/End
- re-map braille commands to edit key commands as follows:
1. dot 3/6 chord -> previous/nextCharacter -> Left/Right
2. dot 2/5 chord -> previous/nextWord -> Ctrl+Left/Right
3. dot 1/4 chord -> previous/nextObject -> Up/Down
4. dot 2-3/5-6 chord -> previous/nextGroup -> Ctrl+Up/Down

(jumpToTop/Bottom remain dots 1-2-3/4-5-6 and trigger ordinary edit key command
mappings).

notes:
we use the vk codepath because it handles compatibility down the stack
for us and potentially triggers other side effects such as auto
complete/IME

Test: with a braille display, ensure a11y vk off. Press incrementally
Ctrl + t; verify new tab shows up.  In Google Docs, press
Search+Left/Right (and all other combos enumerated above). Verify proper
caret/selection afterwards. Turn on sticky mode. Verify Search nav
performs ChromeVox commands rather than send keys.

Do all of the same with a braille display inside of Docs. Verify ability
to edit and navigate directly from display.

Bug: 
Cq-Include-Trybots: master.tryserver.chromium.linux:closure_compilation
Change-Id: I4878c8a930cd643c406294b7f302c9ad2c07ee9f
Reviewed-on: https://chromium-review.googlesource.com/823578
Commit-Queue: David Tseng <dtseng@chromium.org>
Reviewed-by: Dominic Mazzoni <dmazzoni@chromium.org>
Cr-Commit-Position: refs/heads/master@{#524545}

chrome/browser/chromeos/accessibility/accessibility_manager.cc

@@ -149,6 +149,23 @@ class ChromeVoxPanelWidgetObserver : public views::WidgetObserver {
   DISALLOW_COPY_AND_ASSIGN(ChromeVoxPanelWidgetObserver);
 };
 
+class ScopedKeyboardStateSetter {
+ public:
+  ScopedKeyboardStateSetter() : is_enabled_(keyboard::IsKeyboardEnabled()) {
+    keyboard::SetRequestedKeyboardState(keyboard::KEYBOARD_STATE_ENABLED);
+  }
+
+  ~ScopedKeyboardStateSetter() {
+    if (!is_enabled_)
+      keyboard::SetRequestedKeyboardState(keyboard::KEYBOARD_STATE_DISABLED);
+  }
+
+ private:
+  bool is_enabled_;
+
+  DISALLOW_COPY_AND_ASSIGN(ScopedKeyboardStateSetter);
+};
+
 ///////////////////////////////////////////////////////////////////////////////
 // AccessibilityStatusEventDetails
 
@@ -1459,6 +1476,8 @@ void AccessibilityManager::PostLoadChromeVox() {
     base::CommandLine::ForCurrentProcess()->AppendSwitch(
         ::switches::kEnableAudioFocus);
   }
+
+  keyboard_state_setter_.reset(new ScopedKeyboardStateSetter());
 }
 
 void AccessibilityManager::PostUnloadChromeVox() {
@@ -1477,6 +1496,8 @@ void AccessibilityManager::PostUnloadChromeVox() {
 
   // In case the user darkened the screen, undarken it now.
   scoped_backlights_forced_off_.reset();
+
+  keyboard_state_setter_.reset();
 }
 
 void AccessibilityManager::PostSwitchChromeVoxProfile() {

chrome/browser/chromeos/accessibility/accessibility_manager.h

@@ -41,6 +41,7 @@ namespace chromeos {
 
 class AccessibilityExtensionLoader;
 class AccessibilityHighlightManager;
+class ScopedKeyboardStateSetter;
 class SelectToSpeakEventHandler;
 class SwitchAccessEventHandler;
 
@@ -449,6 +450,8 @@ class AccessibilityManager
   // Used to force the backlights off to darken the screen.
   std::unique_ptr<ash::ScopedBacklightsForcedOff> scoped_backlights_forced_off_;
 
+  std::unique_ptr<ScopedKeyboardStateSetter> keyboard_state_setter_;
+
   base::WeakPtrFactory<AccessibilityManager> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(AccessibilityManager);

chrome/browser/resources/chromeos/chromevox/braille/braille_input_handler.js

@@ -421,14 +421,6 @@ cvox.BrailleInputHandler.prototype = {
     chrome.virtualKeyboardPrivate.getKeyboardConfig(function(config) {
       // Use the virtual keyboard API instead of the IME key event API
       // so that these keys work even if the Braille IME is not active.
-
-      // The virtual keyboard private api fails silently if the a11y keyboard
-      // isn't enabled in settings. Let the user know.
-      if (!config.a11ymode) {
-        new Output().format('@enable_virtual_keyboard').go();
-        return;
-      }
-
       var keyName = /** @type {string} */ (event.standardKeyCode);
       var numericCode = cvox.BrailleKeyEvent.keyCodeToLegacyCode(keyName);
       if (!goog.isDef(numericCode))

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

@@ -348,8 +348,13 @@ Background.prototype = {
           return false;
 
         var command = BrailleCommandHandler.getCommand(evt.brailleDots);
-        if (command)
-          CommandHandler.onCommand(command);
+        if (command) {
+          if (!ChromeVoxState.instance.currentRange ||
+              !ChromeVoxState.instance.currentRange.start.node
+                   .state[StateType.EDITABLE] ||
+              BrailleCommandHandler.onEditCommand(command))
+            CommandHandler.onCommand(command);
+        }
         break;
       default:
         return false;

chrome/browser/resources/chromeos/chromevox/cvox2/background/background_test.extjs

@@ -449,6 +449,10 @@ TEST_F('BackgroundTest', 'EarconsForControls', function() {
           .call(doCmd('nextObject'))
           .expectSpeech('Edit text')
           .expectEarcon(cvox.Earcon.EDITABLE_TEXT)
+
+      // Editable text Search re-mappings are in effect.
+          .call(doCmd('toggleStickyMode'))
+          .expectSpeech('Sticky mode enabled')
           .call(doCmd('nextObject'))
           .expectSpeech('List box')
           .expectEarcon(cvox.Earcon.LISTBOX)

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

@@ -8,7 +8,11 @@
 
 goog.provide('BrailleCommandHandler');
 
+goog.require('BackgroundKeyboardHandler');
+
 goog.scope(function() {
+var Mod = constants.ModifierFlag;
+
 /**
  * Maps a dot pattern to a command.
  * @type {!Object<number, string>}
@@ -87,6 +91,46 @@ BrailleCommandHandler.getDots = function(command) {
   return 0;
 };
 
+/**
+ * Customizes ChromeVox commands when issued from a braille display while within
+ * editable text.
+ * @param {string} command
+ * @return {boolean} True if the command should propagate.
+ */
+BrailleCommandHandler.onEditCommand = function(command) {
+  switch (command) {
+    case 'previousCharacter':
+      BackgroundKeyboardHandler.sendKeyPress(37, 'ArrowLeft');
+      break;
+    case 'nextCharacter':
+      BackgroundKeyboardHandler.sendKeyPress(39, 'ArrowRight');
+      break;
+    case 'previousWord':
+      BackgroundKeyboardHandler.sendKeyPress(37, 'ArrowLeft', Mod.CONTROL);
+      break;
+    case 'nextWord':
+      BackgroundKeyboardHandler.sendKeyPress(39, 'ArrowRight', Mod.CONTROL);
+      break;
+    case 'previousObject':
+    case 'previousLine':
+      BackgroundKeyboardHandler.sendKeyPress(38, 'ArrowUp');
+      break;
+    case 'nextObject':
+    case 'nextLine':
+      BackgroundKeyboardHandler.sendKeyPress(40, 'ArrowDown');
+      break;
+    case 'previousGroup':
+      BackgroundKeyboardHandler.sendKeyPress(38, 'ArrowUp', Mod.CONTROL);
+      break;
+    case 'nextGroup':
+      BackgroundKeyboardHandler.sendKeyPress(40, 'ArrowDown', Mod.CONTROL);
+      break;
+    default:
+      return true;
+  }
+  return false;
+};
+
 /**
  * @private
  */

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

@@ -18,8 +18,10 @@ goog.scope(function() {
 var AutomationEvent = chrome.automation.AutomationEvent;
 var AutomationNode = chrome.automation.AutomationNode;
 var Dir = constants.Dir;
+var Mod = constants.ModifierFlag;
 var EventType = chrome.automation.EventType;
 var RoleType = chrome.automation.RoleType;
+var StateType = chrome.automation.StateType;
 
 /**
  * Handles ChromeVox Next commands.
@@ -238,6 +240,11 @@ CommandHandler.onCommand = function(command) {
     return true;
 
   var current = ChromeVoxState.instance.currentRange_;
+
+  // Allow edit commands first.
+  if (!CommandHandler.onEditCommand_(current, command))
+    return false;
+
   var dir = Dir.FORWARD;
   var pred = null;
   var predErrorMsg = undefined;
@@ -903,6 +910,58 @@ CommandHandler.viewGraphicAsBraille_ = function(current) {
   }
 };
 
+/**
+ * Provides a partial mapping from ChromeVox key combinations to
+ * Search-as-a-function key as seen in Chrome OS documentation.
+ * @param {cursors.Range} current
+ * @param {string} command
+ * @return {boolean} True if the command should propagate.
+ * @private
+ */
+CommandHandler.onEditCommand_ = function(current, command) {
+  if (cvox.ChromeVox.isStickyModeOn() || !current || !current.start ||
+      !current.start.node || !current.start.node.state[StateType.EDITABLE])
+    return true;
+
+  switch (command) {
+    case 'previousCharacter':
+      BackgroundKeyboardHandler.sendKeyPress(36, 'Home', Mod.SHIFT);
+      break;
+    case 'nextCharacter':
+      BackgroundKeyboardHandler.sendKeyPress(35, 'End', Mod.SHIFT);
+      break;
+    case 'previousWord':
+      BackgroundKeyboardHandler.sendKeyPress(
+          36, 'Home', Mod.SHIFT | Mod.CONTROL);
+      break;
+    case 'nextWord':
+      BackgroundKeyboardHandler.sendKeyPress(
+          35, 'End', Mod.SHIFT | Mod.CONTROL);
+      break;
+    case 'previousObject':
+      BackgroundKeyboardHandler.sendKeyPress(36, 'Home');
+      break;
+    case 'nextObject':
+      BackgroundKeyboardHandler.sendKeyPress(35, 'End');
+      break;
+    case 'previousLine':
+      BackgroundKeyboardHandler.sendKeyPress(33, 'PageUp');
+      break;
+    case 'nextLine':
+      BackgroundKeyboardHandler.sendKeyPress(34, 'PageDown');
+      break;
+    case 'jumpToTop':
+      BackgroundKeyboardHandler.sendKeyPress(36, 'Home', Mod.CONTROL);
+      break;
+    case 'jumpToBottom':
+      BackgroundKeyboardHandler.sendKeyPress(35, 'End', Mod.CONTROL);
+      break;
+    default:
+      return true;
+  }
+  return false;
+};
+
 /**
  * Performs global initialization.
  */

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

@@ -30,3 +30,14 @@ constants.Dir = {
  * @const
  */
 constants.OBJECT_MAX_CHARCOUNT = 1500;
+
+/**
+ * Modifier values used by Chrome.
+ * See ui/events/event_constants.h
+ */
+constants.ModifierFlag = {
+  SHIFT: 2,
+  CONTROL: 4,
+  ALT: 8,
+  SEARCH: 16
+};

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

@@ -8,7 +8,10 @@
 
 goog.provide('BackgroundKeyboardHandler');
 
+goog.require('ChromeVoxState');
+goog.require('Output');
 goog.require('cvox.ChromeVoxKbHandler');
+goog.require('cvox.ChromeVoxPrefs');
 
 /** @constructor */
 BackgroundKeyboardHandler = function() {
@@ -72,3 +75,24 @@ BackgroundKeyboardHandler.prototype = {
     return false;
   }
 };
+
+/**
+ * @param {number} keyCode
+ * @param {string} keyName
+ * @param {number=} modifiers
+ * @return {boolean}
+ */
+BackgroundKeyboardHandler.sendKeyPress = function(keyCode, keyName, modifiers) {
+  modifiers = modifiers || 0;
+  var key = {
+    type: 'keydown',
+    keyCode: keyCode,
+    keyName: keyName,
+    charValue: keyCode,
+    modifiers: modifiers
+  };
+  chrome.virtualKeyboardPrivate.sendKeyEvent(key);
+  key['type'] = 'keyup';
+  chrome.virtualKeyboardPrivate.sendKeyEvent(key);
+  return true;
+};