[Switch Access] Make TextNavigationManager a singleton

This is the first step in incorporating Sophie and Rose's code from last
summer into the new navigation paradigm.

Bug: 982004
Change-Id: I247fa82ec58560505c64f92993108ec7b5687d74
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2076000Reviewed-by: Akihiro Ota <akihiroota@chromium.org>
Commit-Queue: Anastasia Helfinstein <anastasi@google.com>
Cr-Commit-Position: refs/heads/master@{#745600}

chrome/browser/resources/chromeos/accessibility/switch_access/menu_manager.js

@@ -25,12 +25,6 @@ class MenuManager {
      */
     this.navigationManager_ = navigationManager;
 
-    /**
-     * The text navigation manager.
-     * @private {!TextNavigationManager}
-     */
-    this.textNavigationManager_ = new TextNavigationManager();
-
     /**
      * The root node of the screen.
      * @private {!chrome.automation.AutomationNode}
@@ -503,8 +497,7 @@ class MenuManager {
     const newSelectionState = this.nodeHasSelection_();
     if (this.selectionExists_ != newSelectionState) {
       this.selectionExists_ = newSelectionState;
-      if (this.menuOriginNode_ &&
-          !this.textNavigationManager_.currentlySelecting()) {
+      if (this.menuOriginNode_ && !TextNavigationManager.currentlySelecting()) {
         const currentMenuId = this.menuPanel_.currentMenuId();
         if (currentMenuId) {
           this.openMenu_(this.menuOriginNode_, currentMenuId);
@@ -535,7 +528,7 @@ class MenuManager {
         autoNode.state[StateType.FOCUSED]) {
       actions.push(SAConstants.MenuAction.MOVE_CURSOR);
       actions.push(SAConstants.MenuAction.SELECT_START);
-      if (this.textNavigationManager_.currentlySelecting()) {
+      if (TextNavigationManager.currentlySelecting()) {
         actions.push(SAConstants.MenuAction.SELECT_END);
       }
       if (this.selectionExists_) {
@@ -591,28 +584,28 @@ class MenuManager {
         }
         return;
       case SAConstants.MenuAction.JUMP_TO_BEGINNING_OF_TEXT:
-        this.textNavigationManager_.jumpToBeginning();
+        TextNavigationManager.jumpToBeginning();
         return;
       case SAConstants.MenuAction.JUMP_TO_END_OF_TEXT:
-        this.textNavigationManager_.jumpToEnd();
+        TextNavigationManager.jumpToEnd();
         return;
       case SAConstants.MenuAction.MOVE_BACKWARD_ONE_CHAR_OF_TEXT:
-        this.textNavigationManager_.moveBackwardOneChar();
+        TextNavigationManager.moveBackwardOneChar();
         return;
       case SAConstants.MenuAction.MOVE_BACKWARD_ONE_WORD_OF_TEXT:
-        this.textNavigationManager_.moveBackwardOneWord();
+        TextNavigationManager.moveBackwardOneWord();
         return;
       case SAConstants.MenuAction.MOVE_DOWN_ONE_LINE_OF_TEXT:
-        this.textNavigationManager_.moveDownOneLine();
+        TextNavigationManager.moveDownOneLine();
         return;
       case SAConstants.MenuAction.MOVE_FORWARD_ONE_CHAR_OF_TEXT:
-        this.textNavigationManager_.moveForwardOneChar();
+        TextNavigationManager.moveForwardOneChar();
         return;
       case SAConstants.MenuAction.MOVE_FORWARD_ONE_WORD_OF_TEXT:
-        this.textNavigationManager_.moveForwardOneWord();
+        TextNavigationManager.moveForwardOneWord();
         return;
       case SAConstants.MenuAction.MOVE_UP_ONE_LINE_OF_TEXT:
-        this.textNavigationManager_.moveUpOneLine();
+        TextNavigationManager.moveUpOneLine();
         return;
       case SAConstants.MenuAction.CUT:
         EventHelper.simulateKeyPress(EventHelper.KeyCode.X, {ctrl: true});
@@ -624,13 +617,13 @@ class MenuManager {
         EventHelper.simulateKeyPress(EventHelper.KeyCode.V, {ctrl: true});
         return;
       case SAConstants.MenuAction.SELECT_START:
-        this.textNavigationManager_.saveSelectStart();
+        TextNavigationManager.saveSelectStart();
         if (this.menuOriginNode_) {
           this.openMenu_(this.menuOriginNode_, SAConstants.MenuId.MAIN);
         }
         return;
       case SAConstants.MenuAction.SELECT_END:
-        this.textNavigationManager_.resetCurrentlySelecting();
+        TextNavigationManager.resetCurrentlySelecting();
         if (this.menuOriginNode_) {
           this.openMenu_(this.menuOriginNode_, SAConstants.MenuId.MAIN);
         }

chrome/browser/resources/chromeos/accessibility/switch_access/switch_access.js

@@ -19,6 +19,7 @@ class SwitchAccess {
       Commands.initialize();
       KeyboardRootNode.startWatchingVisibility();
       SwitchAccessPreferences.initialize();
+      TextNavigationManager.initialize();
     });
   }
 

chrome/browser/resources/chromeos/accessibility/switch_access/text_navigation_manager.js

@@ -2,20 +2,18 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// Constant to indicate selection index is not set.
-const NO_SELECT_INDEX = -1;
-
 /**
  * Class to handle navigating text. Currently, only
  * navigation and selection in editable text fields is supported.
  */
 class TextNavigationManager {
+  /** @private */
   constructor() {
     /** @private {number} */
-    this.selectionStartIndex_ = NO_SELECT_INDEX;
+    this.selectionStartIndex_ = TextNavigationManager.NO_SELECT_INDEX;
 
     /** @private {number} */
-    this.selectionEndIndex_ = NO_SELECT_INDEX;
+    this.selectionEndIndex_ = TextNavigationManager.NO_SELECT_INDEX;
 
     /** @private {chrome.automation.AutomationNode} */
     this.selectionStartObject_;
@@ -30,13 +28,18 @@ class TextNavigationManager {
     this.selectionListener_ = this.onNavChange_.bind(this);
   }
 
+  static initialize() {
+    TextNavigationManager.instance = new TextNavigationManager();
+  }
+
   /**
    * Jumps to the beginning of the text field (does nothing
    * if already at the beginning).
    */
-  jumpToBeginning() {
-    if (this.currentlySelecting_) {
-      this.setupDynamicSelection_(false /* resetCursor */);
+  static jumpToBeginning() {
+    const manager = TextNavigationManager.instance;
+    if (manager.currentlySelecting_) {
+      manager.setupDynamicSelection_(false /* resetCursor */);
     }
     EventHelper.simulateKeyPress(EventHelper.KeyCode.HOME, {ctrl: true});
   }
@@ -45,9 +48,10 @@ class TextNavigationManager {
    * Jumps to the end of the text field (does nothing if
    * already at the end).
    */
-  jumpToEnd() {
-    if (this.currentlySelecting_) {
-      this.setupDynamicSelection_(false /* resetCursor */);
+  static jumpToEnd() {
+    const manager = TextNavigationManager.instance;
+    if (manager.currentlySelecting_) {
+      manager.setupDynamicSelection_(false /* resetCursor */);
     }
     EventHelper.simulateKeyPress(EventHelper.KeyCode.END, {ctrl: true});
   }
@@ -57,9 +61,10 @@ class TextNavigationManager {
    * if there are no more characters preceding the current
    * location of the caret).
    */
-  moveBackwardOneChar() {
-    if (this.currentlySelecting_) {
-      this.setupDynamicSelection_(true /* resetCursor */);
+  static moveBackwardOneChar() {
+    const manager = TextNavigationManager.instance;
+    if (manager.currentlySelecting_) {
+      manager.setupDynamicSelection_(true /* resetCursor */);
     }
     EventHelper.simulateKeyPress(EventHelper.KeyCode.LEFT_ARROW);
   }
@@ -69,9 +74,10 @@ class TextNavigationManager {
    * if there are no more characters following the current
    * location of the caret).
    */
-  moveForwardOneChar() {
-    if (this.currentlySelecting_) {
-      this.setupDynamicSelection_(true /* resetCursor */);
+  static moveForwardOneChar() {
+    const manager = TextNavigationManager.instance;
+    if (manager.currentlySelecting_) {
+      manager.setupDynamicSelection_(true /* resetCursor */);
     }
     EventHelper.simulateKeyPress(EventHelper.KeyCode.RIGHT_ARROW);
   }
@@ -82,9 +88,10 @@ class TextNavigationManager {
    * text caret is in the middle of a word, moves the caret
    * to the beginning of that word.
    */
-  moveBackwardOneWord() {
-    if (this.currentlySelecting_) {
-      this.setupDynamicSelection_(false /* resetCursor */);
+  static moveBackwardOneWord() {
+    const manager = TextNavigationManager.instance;
+    if (manager.currentlySelecting_) {
+      manager.setupDynamicSelection_(false /* resetCursor */);
     }
     EventHelper.simulateKeyPress(EventHelper.KeyCode.LEFT_ARROW, {ctrl: true});
   }
@@ -95,9 +102,10 @@ class TextNavigationManager {
    * in the middle of a word, moves the caret to the end of
    * that word.
    */
-  moveForwardOneWord() {
-    if (this.currentlySelecting_) {
-      this.setupDynamicSelection_(false /* resetCursor */);
+  static moveForwardOneWord() {
+    const manager = TextNavigationManager.instance;
+    if (manager.currentlySelecting_) {
+      manager.setupDynamicSelection_(false /* resetCursor */);
     }
     EventHelper.simulateKeyPress(EventHelper.KeyCode.RIGHT_ARROW, {ctrl: true});
   }
@@ -107,9 +115,10 @@ class TextNavigationManager {
    * if there are no lines above the current location of
    * the caret).
    */
-  moveUpOneLine() {
-    if (this.currentlySelecting_) {
-      this.setupDynamicSelection_(true /* resetCursor */);
+  static moveUpOneLine() {
+    const manager = TextNavigationManager.instance;
+    if (manager.currentlySelecting_) {
+      manager.setupDynamicSelection_(true /* resetCursor */);
     }
     EventHelper.simulateKeyPress(EventHelper.KeyCode.UP_ARROW);
   }
@@ -119,9 +128,10 @@ class TextNavigationManager {
    * if there are no lines below the current location of
    * the caret).
    */
-  moveDownOneLine() {
-    if (this.currentlySelecting_) {
-      this.setupDynamicSelection_(true /* resetCursor */);
+  static moveDownOneLine() {
+    const manager = TextNavigationManager.instance;
+    if (manager.currentlySelecting_) {
+      manager.setupDynamicSelection_(true /* resetCursor */);
     }
     EventHelper.simulateKeyPress(EventHelper.KeyCode.DOWN_ARROW);
   }
@@ -141,8 +151,8 @@ class TextNavigationManager {
    */
   setupDynamicSelection_(needToResetCursor) {
     if (needToResetCursor) {
-      if (this.currentlySelecting() &&
-          this.selectionEndIndex_ != NO_SELECT_INDEX) {
+      if (TextNavigationManager.currentlySelecting() &&
+          this.selectionEndIndex_ != TextNavigationManager.NO_SELECT_INDEX) {
         // Move the cursor to the end of the existing selection.
         chrome.automation.setDocumentSelection({
           anchorObject: this.selectionEndObject_,
@@ -162,8 +172,8 @@ class TextNavigationManager {
    * @private
    */
   saveSelection_() {
-    if (this.selectionStartIndex_ == NO_SELECT_INDEX ||
-        this.selectionEndIndex_ == NO_SELECT_INDEX) {
+    if (this.selectionStartIndex_ == TextNavigationManager.NO_SELECT_INDEX ||
+        this.selectionEndIndex_ == TextNavigationManager.NO_SELECT_INDEX) {
       console.log(
           'Selection bounds are not set properly:', this.selectionStartIndex_,
           this.selectionEndIndex_);
@@ -189,7 +199,7 @@ class TextNavigationManager {
    * Reset the selectionStartIndex to NO_SELECT_INDEX.
    */
   resetSelStartIndex() {
-    this.selectionStartIndex_ = NO_SELECT_INDEX;
+    this.selectionStartIndex_ = TextNavigationManager.NO_SELECT_INDEX;
   }
 
   /**
@@ -214,10 +224,12 @@ class TextNavigationManager {
    * Returns if the selection start index is set in the current node.
    * @return {boolean}
    */
-  currentlySelecting() {
+  static currentlySelecting() {
+    const manager = TextNavigationManager.instance;
     return (
-        this.selectionStartIndex_ !== NO_SELECT_INDEX &&
-        this.currentlySelecting_);
+        manager.selectionStartIndex_ !==
+            TextNavigationManager.NO_SELECT_INDEX &&
+        manager.currentlySelecting_);
   }
 
   /**
@@ -230,14 +242,14 @@ class TextNavigationManager {
    * @private
    */
   getSelectionIndexFromNode_(node, getStart) {
-    let indexFromNode = NO_SELECT_INDEX;
+    let indexFromNode = TextNavigationManager.NO_SELECT_INDEX;
     if (getStart) {
       indexFromNode = node.textSelStart;
     } else {
       indexFromNode = node.textSelEnd;
     }
     if (indexFromNode === undefined) {
-      return NO_SELECT_INDEX;
+      return TextNavigationManager.NO_SELECT_INDEX;
     }
     return indexFromNode;
   }
@@ -246,13 +258,14 @@ class TextNavigationManager {
    * Sets the selectionStart variable based on the selection of the current
    * node. Also sets the currently selecting boolean to true.
    */
-  saveSelectStart() {
+  static saveSelectStart() {
+    const manager = TextNavigationManager.instance;
     chrome.automation.getFocus((focusedNode) => {
-      this.selectionStartObject_ = focusedNode;
-      this.selectionStartIndex_ = this.getSelectionIndexFromNode_(
-          this.selectionStartObject_,
+      manager.selectionStartObject_ = focusedNode;
+      manager.selectionStartIndex_ = manager.getSelectionIndexFromNode_(
+          manager.selectionStartObject_,
           true /* We are getting the start index.*/);
-      this.currentlySelecting_ = true;
+      manager.currentlySelecting_ = true;
     });
   }
 
@@ -264,7 +277,7 @@ class TextNavigationManager {
    */
   onNavChange_() {
     this.manageNavigationListener_(false);
-    if (this.currentlySelecting) {
+    if (this.currentlySelecting_) {
       this.saveSelectEnd();
     }
   }
@@ -290,11 +303,12 @@ class TextNavigationManager {
    * Reset the currentlySelecting variable to false, reset the selection
    * indices, and remove the listener on navigation.
    */
-  resetCurrentlySelecting() {
-    this.currentlySelecting_ = false;
-    this.manageNavigationListener_(false /** Removing listener */);
-    this.selectionStartIndex_ = NO_SELECT_INDEX;
-    this.selectionEndIndex_ = NO_SELECT_INDEX;
+  static resetCurrentlySelecting() {
+    const manager = TextNavigationManager.instance;
+    manager.currentlySelecting_ = false;
+    manager.manageNavigationListener_(false /** Removing listener */);
+    manager.selectionStartIndex_ = TextNavigationManager.NO_SELECT_INDEX;
+    manager.selectionEndIndex_ = TextNavigationManager.NO_SELECT_INDEX;
   }
 
   /**
@@ -310,3 +324,6 @@ class TextNavigationManager {
     });
   }
 }
+
+// Constant to indicate selection index is not set.
+TextNavigationManager.NO_SELECT_INDEX = -1;

chrome/browser/resources/chromeos/accessibility/switch_access/text_navigation_manager_test.js

@@ -17,8 +17,8 @@ SwitchAccessTextNavigationManagerTest.prototype = {
 
   /** @override */
   setUp() {
-    this.textNavigationManager =
-        NavigationManager.instance.menuManager_.textNavigationManager_;
+    TextNavigationManager.initialize();
+    this.textNavigationManager = TextNavigationManager.instance;
     this.navigationManager = NavigationManager.instance;
   }
 };
@@ -242,7 +242,7 @@ TEST_F('SwitchAccessTextNavigationManagerTest', 'JumpToBeginning', function() {
     initialIndex: 6,
     targetIndex: 0,
     navigationAction: () => {
-      this.textNavigationManager.jumpToBeginning();
+      TextNavigationManager.jumpToBeginning();
     }
   });
 });
@@ -253,7 +253,7 @@ TEST_F('SwitchAccessTextNavigationManagerTest', 'JumpToEnd', function() {
     initialIndex: 3,
     targetIndex: 8,
     navigationAction: () => {
-      this.textNavigationManager.jumpToEnd();
+      TextNavigationManager.jumpToEnd();
     }
   });
 });
@@ -265,7 +265,7 @@ TEST_F(
         initialIndex: 7,
         targetIndex: 6,
         navigationAction: () => {
-          this.textNavigationManager.moveBackwardOneChar();
+          TextNavigationManager.moveBackwardOneChar();
         }
       });
     });
@@ -277,7 +277,7 @@ TEST_F(
         initialIndex: 5,
         targetIndex: 0,
         navigationAction: () => {
-          this.textNavigationManager.moveBackwardOneWord();
+          TextNavigationManager.moveBackwardOneWord();
         }
       });
     });
@@ -289,7 +289,7 @@ TEST_F(
         initialIndex: 0,
         targetIndex: 1,
         navigationAction: () => {
-          this.textNavigationManager.moveForwardOneChar();
+          TextNavigationManager.moveForwardOneChar();
         }
       });
     });
@@ -301,7 +301,7 @@ TEST_F(
         initialIndex: 4,
         targetIndex: 12,
         navigationAction: () => {
-          this.textNavigationManager.moveForwardOneWord();
+          TextNavigationManager.moveForwardOneWord();
         }
       });
     });
@@ -314,7 +314,7 @@ TEST_F('SwitchAccessTextNavigationManagerTest', 'MoveUpOneLine', function() {
     cols: 8,
     wrap: 'hard',
     navigationAction: () => {
-      this.textNavigationManager.moveUpOneLine();
+      TextNavigationManager.moveUpOneLine();
     }
   });
 });
@@ -327,7 +327,7 @@ TEST_F('SwitchAccessTextNavigationManagerTest', 'MoveDownOneLine', function() {
     cols: 8,
     wrap: 'hard',
     navigationAction: () => {
-      this.textNavigationManager.moveDownOneLine();
+      TextNavigationManager.moveDownOneLine();
     }
   });
 });
@@ -394,7 +394,7 @@ TEST_F(
         cols: 8,
         wrap: 'hard',
         navigationAction: () => {
-          this.textNavigationManager.moveForwardOneChar();
+          TextNavigationManager.moveForwardOneChar();
         }
       });
     });
@@ -414,7 +414,7 @@ TEST_F(
         cols: 8,
         wrap: 'hard',
         navigationAction: () => {
-          this.textNavigationManager.moveBackwardOneWord();
+          TextNavigationManager.moveBackwardOneWord();
         },
         backward: true
       });