Refactors STS node processing code into node_utils.js.

select_to_speak.js was getting too messy so this moves
automation node related logic into a separate class.

Bug: 803160
Cq-Include-Trybots: master.tryserver.chromium.linux:closure_compilation
Change-Id: I6867864f5ccefc14f4a5b98a31af5220d16f8259
Reviewed-on: https://chromium-review.googlesource.com/937802
Commit-Queue: Katie Dektar <katie@chromium.org>
Reviewed-by: Dominic Mazzoni <dmazzoni@chromium.org>
Cr-Commit-Position: refs/heads/master@{#539242}

chrome/browser/resources/chromeos/select_to_speak/BUILD.gn

@@ -33,6 +33,7 @@ run_jsbundler("select_to_speak_copied_files") {
     "checked.png",
     "closure_shim.js",
     "earcons/null_selection.ogg",
+    "node_utils.js",
     "options.css",
     "options.html",
     "paragraph_utils.js",

chrome/browser/resources/chromeos/select_to_speak/compiled_resources2.gyp

@@ -8,27 +8,28 @@
       'dependencies': [
         '../chromevox/cvox2/background/constants',
         '../chromevox/cvox2/background/automation_util',
-	'externs',
+        'externs',
         'rect_utils',
-	'paragraph_utils',
+        'paragraph_utils',
         'word_utils',
-	'<(EXTERNS_GYP):accessibility_private',
-	'<(EXTERNS_GYP):automation',
-	'<(EXTERNS_GYP):chrome_extensions',
-	'<(EXTERNS_GYP):clipboard',
-	'<(EXTERNS_GYP):command_line_private',
-	'<(EXTERNS_GYP):metrics_private',
+        'node_utils',
+        '<(EXTERNS_GYP):accessibility_private',
+        '<(EXTERNS_GYP):automation',
+        '<(EXTERNS_GYP):chrome_extensions',
+        '<(EXTERNS_GYP):clipboard',
+        '<(EXTERNS_GYP):command_line_private',
+        '<(EXTERNS_GYP):metrics_private',
        ],
       'includes': ['../../../../../third_party/closure_compiler/compile_js2.gypi'],
     },
     {
       'target_name': 'select_to_speak_options',
       'dependencies': [
-	'externs',
-	'<(EXTERNS_GYP):accessibility_private',
-	'<(EXTERNS_GYP):automation',
-	'<(EXTERNS_GYP):chrome_extensions',
-	'<(EXTERNS_GYP):metrics_private',
+        'externs',
+        '<(EXTERNS_GYP):accessibility_private',
+        '<(EXTERNS_GYP):automation',
+        '<(EXTERNS_GYP):chrome_extensions',
+        '<(EXTERNS_GYP):metrics_private',
        ],
       'includes': ['../../../../../third_party/closure_compiler/compile_js2.gypi'],
     },
@@ -36,22 +37,32 @@
       'target_name': 'externs',
       'includes': ['../../../../../third_party/closure_compiler/compile_js2.gypi'],
     },
+    {
+      'target_name': 'node_utils',
+      'dependencies': [
+        'externs',
+        'rect_utils',
+        'paragraph_utils',
+        '<(EXTERNS_GYP):automation',
+       ],
+       'includes': ['../../../../../third_party/closure_compiler/compile_js2.gypi'],
+    },
     {
       'target_name': 'word_utils',
       'dependencies': [
-	'externs',
+        'externs',
         'paragraph_utils',
-	'<(EXTERNS_GYP):automation',
+        '<(EXTERNS_GYP):automation',
        ],
        'includes': ['../../../../../third_party/closure_compiler/compile_js2.gypi'],
     },
     {
       'target_name': 'paragraph_utils',
       'dependencies': [
-	'externs',
-	'<(EXTERNS_GYP):accessibility_private',
-	'<(EXTERNS_GYP):automation',
-	'<(EXTERNS_GYP):chrome_extensions',
+        'externs',
+        '<(EXTERNS_GYP):accessibility_private',
+        '<(EXTERNS_GYP):automation',
+        '<(EXTERNS_GYP):chrome_extensions',
        ],
        'includes': ['../../../../../third_party/closure_compiler/compile_js2.gypi'],
     },
@@ -62,30 +73,30 @@
     {
       'target_name': '../chromevox/cvox2/background/automation_util',
       'dependencies': [
-	'../chromevox/cvox2/background/automation_predicate',
-	'../chromevox/cvox2/background/tree_walker',
-	'../chromevox/cvox2/background/constants',
-	'<(EXTERNS_GYP):automation',
-	'<(EXTERNS_GYP):chrome_extensions',
+        '../chromevox/cvox2/background/automation_predicate',
+        '../chromevox/cvox2/background/tree_walker',
+        '../chromevox/cvox2/background/constants',
+        '<(EXTERNS_GYP):automation',
+        '<(EXTERNS_GYP):chrome_extensions',
       ],
       'includes':  ['../../../../../third_party/closure_compiler/compile_js2.gypi'],
     },
     {
       'target_name': '../chromevox/cvox2/background/tree_walker',
       'dependencies': [
-	'../chromevox/cvox2/background/automation_predicate',
-	'../chromevox/cvox2/background/constants',
-	'<(EXTERNS_GYP):automation',
-	'<(EXTERNS_GYP):chrome_extensions',
+        '../chromevox/cvox2/background/automation_predicate',
+        '../chromevox/cvox2/background/constants',
+        '<(EXTERNS_GYP):automation',
+        '<(EXTERNS_GYP):chrome_extensions',
       ],
       'includes':  ['../../../../../third_party/closure_compiler/compile_js2.gypi'],
     },
     {
       'target_name': '../chromevox/cvox2/background/automation_predicate',
       'dependencies': [
-	'../chromevox/cvox2/background/constants',
-	'<(EXTERNS_GYP):automation',
-	'<(EXTERNS_GYP):chrome_extensions',
+        '../chromevox/cvox2/background/constants',
+        '<(EXTERNS_GYP):automation',
+        '<(EXTERNS_GYP):chrome_extensions',
       ],
       'includes':  ['../../../../../third_party/closure_compiler/compile_js2.gypi'],
     },

chrome/browser/resources/chromeos/select_to_speak/manifest.json.jinja2

@@ -16,6 +16,7 @@
       "automation_predicate.js",
       "tree_walker.js",
       "automation_util.js",
+      "node_utils.js",
       "paragraph_utils.js",
       "word_utils.js",
       "rect_utils.js",

chrome/browser/resources/chromeos/select_to_speak/node_utils.js

+// Copyright 2018 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.
+
+// Utility functions for automation nodes in Select-to-Speak.
+
+/**
+ * Node state. Nodes can be on-screen like normal, or they may
+ * be invisible if they are in a tab that is not in the foreground
+ * or similar, or they may be invalid if they were removed from their
+ * root, i.e. if they were in a window that was closed.
+ * @enum {number}
+ */
+const NodeState = {
+  NODE_STATE_INVALID: 0,
+  NODE_STATE_INVISIBLE: 1,
+  NODE_STATE_NORMAL: 2,
+};
+
+/**
+ * Gets the current visiblity state for a given node.
+ *
+ * @param {AutomationNode} node The starting node.
+ * @return {NodeState} the current node state.
+ */
+function getNodeState(node) {
+  if (node === undefined || node.root === null || node.root === undefined) {
+    // The node has been removed from the tree, perhaps because the
+    // window was closed.
+    return NodeState.NODE_STATE_INVALID;
+  }
+  // This might not be populated correctly on children nodes even if their
+  // parents or roots are now invisible.
+  // TODO: Update the C++ bindings to set 'invisible' automatically based
+  // on parents, rather than going through parents in JS below.
+  if (node.state.invisible) {
+    return NodeState.NODE_STATE_INVISIBLE;
+  }
+  // Walk up the tree to make sure the window it is in is not invisible.
+  var window = getNearestContainingWindow(node);
+  if (window != null && window.state[chrome.automation.StateType.INVISIBLE]) {
+    return NodeState.NODE_STATE_INVISIBLE;
+  }
+  // TODO: Also need a check for whether the window is minimized,
+  // which would also return NodeState.NODE_STATE_INVISIBLE.
+  return NodeState.NODE_STATE_NORMAL;
+}
+
+/**
+ * Returns true if a node should be ignored by Select-to-Speak.
+ * @param {AutomationNode} node The node to test
+ * @param {boolean} includeOffscreen Whether to include offscreen nodes.
+ * @return {boolean} whether this node should be ignored.
+ */
+function shouldIgnoreNode(node, includeOffscreen) {
+  return (
+      !node.name || isWhitespace(node.name) || !node.location ||
+      node.state.invisible || (node.state.offscreen && !includeOffscreen));
+}
+
+/**
+ * Gets the first window containing this node.
+ */
+function getNearestContainingWindow(node) {
+  // Go upwards to root nodes' parents until we find the first window.
+  if (node.root.role == RoleType.ROOT_WEB_AREA) {
+    var nextRootParent = node;
+    while (nextRootParent != null && nextRootParent.role != RoleType.WINDOW &&
+           nextRootParent.root != null &&
+           nextRootParent.root.role == RoleType.ROOT_WEB_AREA) {
+      nextRootParent = nextRootParent.root.parent;
+    }
+    return nextRootParent;
+  }
+  // If the parent isn't a root web area, just walk up the tree to find the
+  // nearest window.
+  var parent = node;
+  while (parent != null && parent.role != chrome.automation.RoleType.WINDOW) {
+    parent = parent.parent;
+  }
+  return parent;
+}
+
+/**
+ * Gets the length of a node's name. Returns 0 if the name is
+ * undefined.
+ * @param {AutomationNode} node The node for which to check the name.
+ * @return {number} The length of the node's name
+ */
+function nameLength(node) {
+  return node.name ? node.name.length : 0;
+}
+
+/**
+ * Gets the first (left-most) leaf node of a node. Returns undefined if
+ *  none is found.
+ * @param {AutomationNode} node The node to search for the first leaf.
+ * @return {AutomationNode|undefined} The leaf node.
+ */
+function getFirstLeafChild(node) {
+  let result = node.firstChild;
+  while (result && result.firstChild) {
+    result = result.firstChild;
+  }
+  return result;
+}
+
+/**
+ * Gets the first (left-most) leaf node of a node. Returns undefined
+ * if none is found.
+ * @param {AutomationNode} node The node to search for the first leaf.
+ * @return {AutomationNode|undefined} The leaf node.
+ */
+function getLastLeafChild(node) {
+  let result = node.lastChild;
+  while (result && result.lastChild) {
+    result = result.lastChild;
+  }
+  return result;
+}
+
+/**
+ * Finds all nodes within the subtree rooted at |node| that overlap
+ * a given rectangle.
+ * @param {AutomationNode} node The starting node.
+ * @param {{left: number, top: number, width: number, height: number}} rect
+ *     The bounding box to search.
+ * @param {Array<AutomationNode>} nodes The matching node array to be
+ *     populated.
+ * @return {boolean} True if any matches are found.
+ */
+function findAllMatching(node, rect, nodes) {
+  var found = false;
+  for (var c = node.firstChild; c; c = c.nextSibling) {
+    if (findAllMatching(c, rect, nodes))
+      found = true;
+  }
+
+  if (found)
+    return true;
+
+  // Closure needs node.location check here to allow the next few
+  // lines to compile.
+  if (shouldIgnoreNode(node, /* don't include offscreen */ false) ||
+      node.location === undefined)
+    return false;
+
+  if (overlaps(node.location, rect)) {
+    if (!node.children || node.children.length == 0 ||
+        node.children[0].role != RoleType.INLINE_TEXT_BOX) {
+      // Only add a node if it has no inlineTextBox children. If
+      // it has text children, they will be more precisely bounded
+      // and specific, so no need to add the parent node.
+      nodes.push(node);
+      return true;
+    }
+  }
+
+  return false;
+}
+
+/**
+ * Class representing a position on the accessibility, made of a
+ * selected node and the offset of that selection.
+ * @typedef {{node: (!AutomationNode),
+ *            offset: (number)}}
+ */
+var Position;
+
+/**
+ * Finds the deep equivalent node where a selection starts given a node
+ * object and selection offset. This is meant to be used in conjunction with
+ * the anchorObject/anchorOffset and focusObject/focusOffset of the
+ * automation API.
+ * @param {AutomationNode} parent The parent node of the selection,
+ * similar to chrome.automation.focusObject.
+ * @param {number} offset The integer offset of the selection. This is
+ * similar to chrome.automation.focusOffset.
+ * @return {!Position} The node matching the selected offset.
+ */
+function getDeepEquivalentForSelection(parent, offset) {
+  if (parent.children.length == 0)
+    return {node: parent, offset: offset};
+  // Create a stack of children nodes to search through.
+  let nodesToCheck = parent.children.slice().reverse();
+  let index = 0;
+  var node;
+  // Delve down into the children recursively to find the
+  // one at this offset.
+  while (nodesToCheck.length > 0) {
+    node = nodesToCheck.pop();
+    if (node.children.length > 0) {
+      nodesToCheck = nodesToCheck.concat(node.children.slice().reverse());
+    } else {
+      index += node.name ? node.name.length : 0;
+      if (index > offset) {
+        return {node: node, offset: offset - index + node.name.length};
+      }
+    }
+  }
+  // We are off the end of the last node.
+  return {node: node, offset: node.name ? node.name.length : 0};
+}

chrome/browser/resources/chromeos/select_to_speak/node_utils_unittest.gtestjs

+// 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.
+
+/**
+ * Test fixture for node_utils.js.
+ * @constructor
+ * @extends {testing.Test}
+ */
+function SelectToSpeakNodeUtilsUnitTest () {
+  testing.Test.call(this);
+}
+
+SelectToSpeakNodeUtilsUnitTest.prototype = {
+  __proto__: testing.Test.prototype,
+
+  /** @override */
+  extraLibraries: [
+    'test_support.js',
+    'paragraph_utils.js',
+    'node_utils.js',
+    'word_utils.js',
+    'rect_utils.js',
+  ]
+};
+
+TEST_F('SelectToSpeakNodeUtilsUnitTest', 'GetNodeVisibilityState', function() {
+  let nodeWithoutRoot1 = {root: null};
+  let nodeWithoutRoot2 = {root: null, state: {invisible: true}};
+  assertEquals(getNodeState(nodeWithoutRoot1), NodeState.NODE_STATE_INVALID);
+  assertEquals(getNodeState(nodeWithoutRoot2), NodeState.NODE_STATE_INVALID);
+
+  let invisibleNode1 = {root: {}, parent: {role: ''}, state: {invisible: true}};
+  // Currently nodes aren't actually marked 'invisible', so we need to navigate
+  // up their tree.
+  let invisibleNode2 = {root: {}, parent: {role: 'window',
+                        state: {invisible: true}}, state: {}};
+  let invisibleNode3 = {root: {}, parent: invisibleNode2, state: {}};
+  let invisibleNode4 = {root: {}, parent: invisibleNode3, state: {}};
+  assertEquals(getNodeState(invisibleNode1), NodeState.NODE_STATE_INVISIBLE);
+  assertEquals(getNodeState(invisibleNode2), NodeState.NODE_STATE_INVISIBLE);
+  assertEquals(getNodeState(invisibleNode3), NodeState.NODE_STATE_INVISIBLE);
+
+  let normalNode1 = {root: {}, parent: {role: 'window', state: {}}, state: {}};
+  let normalNode2 = {root: {}, parent: {normalNode1}, state: {}};
+  assertEquals(getNodeState(normalNode1), NodeState.NODE_STATE_NORMAL);
+  assertEquals(getNodeState(normalNode2), NodeState.NODE_STATE_NORMAL);
+});
+
+TEST_F('SelectToSpeakNodeUtilsUnitTest',
+    'GetNodeVisibilityStateWithRootWebArea', function() {
+  // Currently nodes aren't actually marked 'invisible', so we need to navigate
+  // up their tree.
+  let window = {root: {}, role: 'window', state: {invisible: true}};
+  let rootNode = {root: {}, parent: window, state: {}, role: 'rootWebArea'};
+  let container = {root: rootNode, parent: rootNode, state: {}};
+  let node = {root: rootNode, parent: container, state: {}};
+  assertEquals(getNodeState(window), NodeState.NODE_STATE_INVISIBLE);
+  assertEquals(getNodeState(container), NodeState.NODE_STATE_INVISIBLE);
+  assertEquals(getNodeState(node), NodeState.NODE_STATE_INVISIBLE);
+
+  // Make a fake iframe in this invisible window by adding another RootWebArea.
+  // The iframe has no root but is parented to the container above.
+  let iframeRoot = {parent: container, state: {}, role: 'rootWebArea'};
+  let iframeContainer = {root: iframeRoot, parent: iframeRoot, state: {}};
+  let iframeNode = {root: iframeRoot, parent: iframeContainer, state: {}};
+  assertEquals(getNodeState(iframeContainer), NodeState.NODE_STATE_INVISIBLE);
+  assertEquals(getNodeState(iframeNode), NodeState.NODE_STATE_INVISIBLE);
+
+  // Make the window visible and try again.
+  window.state = {};
+  assertEquals(getNodeState(window), NodeState.NODE_STATE_NORMAL);
+  assertEquals(getNodeState(container), NodeState.NODE_STATE_NORMAL);
+  assertEquals(getNodeState(node), NodeState.NODE_STATE_NORMAL);
+  assertEquals(getNodeState(iframeContainer), NodeState.NODE_STATE_NORMAL);
+  assertEquals(getNodeState(iframeNode), NodeState.NODE_STATE_NORMAL);
+});
+
+TEST_F('SelectToSpeakNodeUtilsUnitTest', 'findAllMatching', function() {
+  let rect = {left: 0, top: 0, width: 100, height: 100};
+  let rootNode = {root: {}, state: {}, role: 'rootWebArea', state: {},
+      location: {left: 0, top: 0, width: 600, height: 600}};
+  let container1 = {root: rootNode, parent: rootNode, role: 'staticText',
+      name: 'one two', state: {},
+      location: {left: 0, top: 0, width: 200, height: 200}};
+  let container2 = {root: rootNode, parent: rootNode, state: {},
+      role: 'genericContainer',
+      location: {left: 0, top: 0, width: 200, height: 200}};
+  let node1 = {root: rootNode, parent: container1, name: 'one',
+      role: 'inlineTextBox', state: {},
+      location: {left: 50, top: 0, width: 50, height: 50}};
+  let node2 = {root: rootNode, parent: container1, name: 'two',
+      role: 'inlineTextBox', state: {},
+      location: {left: 0, top: 50, width: 50, height: 50}};
+
+  // Set up relationships between nodes.
+  rootNode.children = [container1, container2];
+  rootNode.firstChild = container1;
+  container1.nextSibling = container2;
+  container1.children = [node1, node2];
+  container1.firstChild = node1;
+  node1.nextSibling = node2;
+
+  // Should get both children of the first container, without getting
+  // the first container itself or the empty container.
+  let result = [];
+  assertTrue(findAllMatching(rootNode, rect, result));
+  assertEquals(2, result.length);
+  assertEquals(node1, result[0]);
+  assertEquals(node2, result[1]);
+
+  // If a node doesn't have a name, it should not be included.
+  result = [];
+  node2.name = undefined;
+  assertTrue(findAllMatching(rootNode, rect, result));
+  assertEquals(1, result.length);
+  assertEquals(node1, result[0]);
+
+  // Try a rect that only overlaps one of the children.
+  result = [];
+  node2.name = 'two';
+  rect.height = 25;
+  assertTrue(findAllMatching(rootNode, rect, result));
+  assertEquals(1, result.length);
+  assertEquals(node1, result[0]);
+
+  // Now just overlap a different child.
+  result = [];
+  rect.top = 50;
+  assertTrue(findAllMatching(rootNode, rect, result));
+  assertEquals(1, result.length);
+  assertEquals(node2, result[0]);
+
+  // Offscreen should cause a node to be skipped.
+  result = [];
+  node2.state = {offscreen: true}
+  assertFalse(findAllMatching(rootNode, rect, result));
+  assertEquals(0, result.length);
+
+  // No location should cause a node to be skipped.
+  result = [];
+  node2.state = {};
+  node2.location = undefined;
+  assertFalse(findAllMatching(rootNode, rect, result));
+
+  // A non staticText container without a name should still have
+  // children found.
+  result = [];
+  let node3 = {root: rootNode, parent: container2, name: 'three',
+      state: {}, location: {left: 0, top: 50, width: 50, height: 50}};
+  container2.firstChild = node3;
+  assertTrue(findAllMatching(rootNode, rect, result));
+  assertEquals(1, result.length);
+  assertEquals(node3, result[0]);
+
+  // A non staticText container with a valid name should not be
+  // read if its children are read. Children take precidence.
+  result = [];
+  container2.name = 'container2';
+  assertTrue(findAllMatching(rootNode, rect, result));
+  assertEquals(1, result.length);
+  assertEquals(node3, result[0]);
+
+  // A non staticText container with a valid name which has only
+  // children without names should be read instead of its children.
+  result = [];
+  node3.name = undefined;
+  assertTrue(findAllMatching(rootNode, rect, result));
+  assertEquals(1, result.length);
+  assertEquals(container2, result[0]);
+});
+
+TEST_F('SelectToSpeakNodeUtilsUnitTest',
+    'getDeepEquivalentForSelectionNoChildren', function() {
+  let node = {name: 'Hello, world', children: []};
+  let result = getDeepEquivalentForSelection(node, 0);
+  assertEquals(node, result.node);
+  assertEquals(0, result.offset);
+
+  result = getDeepEquivalentForSelection(node, 6);
+  assertEquals(node, result.node);
+  assertEquals(6, result.offset);
+});
+
+TEST_F('SelectToSpeakNodeUtilsUnitTest', 'getDeepEquivalentForSelectionSimpleChildren',
+    function() {
+  let child1 = {name: 'Hello,', children: []};
+  let child2 = {name: ' world', children: []};
+  let root = {name: 'Hello, world', children: [child1, child2]};
+  let result = getDeepEquivalentForSelection(root, 0);
+  assertEquals(child1, result.node);
+  assertEquals(0, result.offset);
+
+  result = getDeepEquivalentForSelection(root, 5);
+  assertEquals(child1, result.node);
+  assertEquals(5, result.offset);
+
+  result = getDeepEquivalentForSelection(root, 6);
+  assertEquals(child2, result.node);
+  assertEquals(0, result.offset);
+
+  result = getDeepEquivalentForSelection(root, 9);
+  assertEquals(child2, result.node);
+  assertEquals(3, result.offset);
+});
+
+TEST_F('SelectToSpeakNodeUtilsUnitTest',
+    'getDeepEquivalentForSelectionComplexChildren', function() {
+  let child1 = {name: 'Hello', children: []};
+  let child2 = {name: undefined, children: []};  // Empty name
+  let child3 = {name: ',', children: []};
+  let child4 = {name: 'Hello,', children: [child1, child2, child3]};
+
+  let child5 = {name: ' ', children: []};
+  let child6 = {name: 'world', children: []};
+  let child7 = {name: ' world', children: [child5, child6]};
+
+  let root = {name: 'Hello, world', children: [child4, child7]};
+
+  let result = getDeepEquivalentForSelection(root, 0);
+  assertEquals(child1, result.node);
+  assertEquals(0, result.offset);
+
+  result = getDeepEquivalentForSelection(root, 5);
+  assertEquals(child3, result.node);
+  assertEquals(0, result.offset);
+
+  result = getDeepEquivalentForSelection(root, 6);
+  assertEquals(child5, result.node);
+  assertEquals(0, result.offset);
+
+  result = getDeepEquivalentForSelection(root, 9);
+  assertEquals(child6, result.node);
+  assertEquals(2, result.offset);
+});
\ No newline at end of file

chrome/browser/resources/chromeos/select_to_speak/select_to_speak.js

@@ -24,166 +24,6 @@ const CLIPBOARD_READ_MAX_DELAY_MS = 1000;
 const DRIVE_APP_REGEXP =
     /^https:\/\/docs\.(?:sandbox\.)?google\.com\/(?:(?:presentation)|(?:document)|(?:spreadsheets)|(?:drawings)){1}\//;
 
-/**
- * Node state. Nodes can be on-screen like normal, or they may
- * be invisible if they are in a tab that is not in the foreground
- * or similar, or they may be invalid if they were removed from their
- * root, i.e. if they were in a window that was closed.
- * @enum {number}
- */
-const NodeState = {
-  NODE_STATE_INVALID: 0,
-  NODE_STATE_INVISIBLE: 1,
-  NODE_STATE_NORMAL: 2,
-};
-
-/**
- * Gets the first window containing this node.
- */
-function getNearestContainingWindow(node) {
-  // Go upwards to root nodes' parents until we find the first window.
-  if (node.root.role == RoleType.ROOT_WEB_AREA) {
-    var nextRootParent = node;
-    while (nextRootParent != null && nextRootParent.role != RoleType.WINDOW &&
-           nextRootParent.root != null &&
-           nextRootParent.root.role == RoleType.ROOT_WEB_AREA) {
-      nextRootParent = nextRootParent.root.parent;
-    }
-    return nextRootParent;
-  }
-  // If the parent isn't a root web area, just walk up the tree to find the
-  // nearest window.
-  var parent = node;
-  while (parent != null && parent.role != chrome.automation.RoleType.WINDOW) {
-    parent = parent.parent;
-  }
-  return parent;
-}
-
-/**
- * Gets the current visiblity state for a given node.
- *
- * @param {AutomationNode} node The starting node.
- * @return {NodeState} the current node state.
- */
-function getNodeState(node) {
-  if (node === undefined || node.root === null || node.root === undefined) {
-    // The node has been removed from the tree, perhaps because the
-    // window was closed.
-    return NodeState.NODE_STATE_INVALID;
-  }
-  // This might not be populated correctly on children nodes even if their
-  // parents or roots are now invisible.
-  // TODO: Update the C++ bindings to set 'invisible' automatically based
-  // on parents, rather than going through parents in JS below.
-  if (node.state.invisible) {
-    return NodeState.NODE_STATE_INVISIBLE;
-  }
-  // Walk up the tree to make sure the window it is in is not invisible.
-  var window = getNearestContainingWindow(node);
-  if (window != null && window.state[chrome.automation.StateType.INVISIBLE]) {
-    return NodeState.NODE_STATE_INVISIBLE;
-  }
-  // TODO: Also need a check for whether the window is minimized,
-  // which would also return NodeState.NODE_STATE_INVISIBLE.
-  return NodeState.NODE_STATE_NORMAL;
-}
-
-/**
- * Returns true if a node should be ignored by Select-to-Speak.
- * @param {AutomationNode} node The node to test
- * @param {boolean} includeOffscreen Whether to include offscreen nodes.
- * @return {boolean} whether this node should be ignored.
- */
-function shouldIgnoreNode(node, includeOffscreen) {
-  return (
-      !node.name || isWhitespace(node.name) || !node.location ||
-      node.state.invisible || (node.state.offscreen && !includeOffscreen));
-}
-
-/**
- * Finds all nodes within the subtree rooted at |node| that overlap
- * a given rectangle.
- * @param {AutomationNode} node The starting node.
- * @param {{left: number, top: number, width: number, height: number}} rect
- *     The bounding box to search.
- * @param {Array<AutomationNode>} nodes The matching node array to be
- *     populated.
- * @return {boolean} True if any matches are found.
- */
-function findAllMatching(node, rect, nodes) {
-  var found = false;
-  for (var c = node.firstChild; c; c = c.nextSibling) {
-    if (findAllMatching(c, rect, nodes))
-      found = true;
-  }
-
-  if (found)
-    return true;
-
-  // Closure needs node.location check here to allow the next few
-  // lines to compile.
-  if (shouldIgnoreNode(node, /* don't include offscreen */ false) ||
-      node.location === undefined)
-    return false;
-
-  if (overlaps(node.location, rect)) {
-    if (!node.children || node.children.length == 0 ||
-        node.children[0].role != RoleType.INLINE_TEXT_BOX) {
-      // Only add a node if it has no inlineTextBox children. If
-      // it has text children, they will be more precisely bounded
-      // and specific, so no need to add the parent node.
-      nodes.push(node);
-      return true;
-    }
-  }
-
-  return false;
-}
-
-/**
- * Class representing a position on the accessibility, made of a
- * selected node and the offset of that selection.
- * @typedef {{node: (!AutomationNode),
- *            offset: (number)}}
- */
-var Position;
-
-/**
- * Finds the deep equivalent node where a selection starts given a node
- * object and selection offset. This is meant to be used in conjunction with
- * the anchorObject/anchorOffset and focusObject/focusOffset of the
- * automation API.
- * @param {AutomationNode} parent The parent node of the selection,
- * similar to chrome.automation.focusObject.
- * @param {number} offset The integer offset of the selection. This is
- * similar to chrome.automation.focusOffset.
- * @return {!Position} The node matching the selected offset.
- */
-function getDeepEquivalentForSelection(parent, offset) {
-  if (parent.children.length == 0)
-    return {node: parent, offset: offset};
-  // Create a stack of children nodes to search through.
-  let nodesToCheck = parent.children.slice().reverse();
-  let index = 0;
-  var node;
-  // Delve down into the children recursively to find the
-  // one at this offset.
-  while (nodesToCheck.length > 0) {
-    node = nodesToCheck.pop();
-    if (node.children.length > 0) {
-      nodesToCheck = nodesToCheck.concat(node.children.slice().reverse());
-    } else {
-      index += node.name ? node.name.length : 0;
-      if (index > offset) {
-        return {node: node, offset: offset - index + node.name.length};
-      }
-    }
-  }
-  // We are off the end of the last node.
-  return {node: node, offset: node.name ? node.name.length : 0};
-}
-
 /**
  * Determines if a node is in one of the known Google Drive apps that needs
  * special case treatment for speaking selected text. Not all Google Drive pages
@@ -535,7 +375,8 @@ SelectToSpeak.prototype = {
   },
 
   /**
-   * Queues up selected text for reading.
+   * Queues up selected text for reading by finding the Position objects
+   * representing the selection.
    */
   requestSpeakSelectedText_: function(focusedNode) {
     // If nothing is selected, return early.
@@ -552,6 +393,16 @@ SelectToSpeak.prototype = {
       this.onNullSelection_();
       return;
     }
+    // First calculate the equivalant position for this selection.
+    // Sometimes the automation selection returns a offset into a root
+    // node rather than a child node, which may be a bug. This allows us to
+    // work around that bug until it is fixed or redefined.
+    // Note that this calculation is imperfect: it uses node name length
+    // to index into child nodes. However, not all node names are
+    // user-visible text, so this does not always work. Instead, we must
+    // fix the Blink bug where focus offset is not specific enough to
+    // say which node is selected and at what charOffset. See
+    // https://crbug.com/803160 for more.
     let anchorPosition =
         getDeepEquivalentForSelection(anchorObject, anchorOffset);
     let focusPosition = getDeepEquivalentForSelection(focusObject, focusOffset);
@@ -589,7 +440,17 @@ SelectToSpeak.prototype = {
       lastPosition.offset =
           lastPosition.node.name ? lastPosition.node.name.length : 0;
     }
+    this.readNodesInSelection_(firstPosition, lastPosition, focusedNode);
+  },
 
+  /**
+   * Reads nodes between the first and last position selected by the user.
+   * @param {Position} firstPosition The first position at which to start
+   *     reading.
+   * @param {Position} lastPosition The last position at which to stop reading.
+   * @param {AutomationNode} focusedNode The node with user focus.
+   */
+  readNodesInSelection_: function(firstPosition, lastPosition, focusedNode) {
     let nodes = [];
     let selectedNode = firstPosition.node;
     if (selectedNode.name && firstPosition.offset < selectedNode.name.length &&
@@ -653,6 +514,11 @@ SelectToSpeak.prototype = {
     this.recordStartEvent_(START_SPEECH_METHOD_KEYSTROKE);
   },
 
+  /**
+   * Gets ready to cancel future scrolling to offscreen nodes as soon as
+   * a user-initiated scroll is done.
+   * @param {AutomationNode=} root The root node to listen for events on.
+   */
   initializeScrollingToOffscreenNodes_: function(root) {
     this.scrollToSpokenNode_ = true;
     let listener = (event) => {

chrome/browser/resources/chromeos/select_to_speak/select_to_speak_keystroke_selection_test.extjs

@@ -196,4 +196,4 @@ TEST_F('SelectToSpeakKeystrokeSelectionTest',
             focusObject: lastNode, focusOffset: 5
         });
       }, 'This is some bold text');
-});
\ No newline at end of file
+});

chrome/browser/resources/chromeos/select_to_speak/select_to_speak_unittest.gtestjs

@@ -17,223 +17,10 @@ SelectToSpeakUnitTest.prototype = {
   /** @override */
   extraLibraries: [
     'test_support.js',
-    'paragraph_utils.js',
-    'word_utils.js',
-    'rect_utils.js',
     'select_to_speak.js'
   ]
 };
 
-TEST_F('SelectToSpeakUnitTest', 'GetNodeVisibilityState', function() {
-  let nodeWithoutRoot1 = {root: null};
-  let nodeWithoutRoot2 = {root: null, state: {invisible: true}};
-  assertEquals(getNodeState(nodeWithoutRoot1), NodeState.NODE_STATE_INVALID);
-  assertEquals(getNodeState(nodeWithoutRoot2), NodeState.NODE_STATE_INVALID);
-
-  let invisibleNode1 = {root: {}, parent: {role: ''}, state: {invisible: true}};
-  // Currently nodes aren't actually marked 'invisible', so we need to navigate
-  // up their tree.
-  let invisibleNode2 = {root: {}, parent: {role: 'window',
-                        state: {invisible: true}}, state: {}};
-  let invisibleNode3 = {root: {}, parent: invisibleNode2, state: {}};
-  let invisibleNode4 = {root: {}, parent: invisibleNode3, state: {}};
-  assertEquals(getNodeState(invisibleNode1), NodeState.NODE_STATE_INVISIBLE);
-  assertEquals(getNodeState(invisibleNode2), NodeState.NODE_STATE_INVISIBLE);
-  assertEquals(getNodeState(invisibleNode3), NodeState.NODE_STATE_INVISIBLE);
-
-  let normalNode1 = {root: {}, parent: {role: 'window', state: {}}, state: {}};
-  let normalNode2 = {root: {}, parent: {normalNode1}, state: {}};
-  assertEquals(getNodeState(normalNode1), NodeState.NODE_STATE_NORMAL);
-  assertEquals(getNodeState(normalNode2), NodeState.NODE_STATE_NORMAL);
-});
-
-TEST_F('SelectToSpeakUnitTest', 'GetNodeVisibilityStateWithRootWebArea',
-    function() {
-  // Currently nodes aren't actually marked 'invisible', so we need to navigate
-  // up their tree.
-  let window = {root: {}, role: 'window', state: {invisible: true}};
-  let rootNode = {root: {}, parent: window, state: {}, role: 'rootWebArea'};
-  let container = {root: rootNode, parent: rootNode, state: {}};
-  let node = {root: rootNode, parent: container, state: {}};
-  assertEquals(getNodeState(window), NodeState.NODE_STATE_INVISIBLE);
-  assertEquals(getNodeState(container), NodeState.NODE_STATE_INVISIBLE);
-  assertEquals(getNodeState(node), NodeState.NODE_STATE_INVISIBLE);
-
-  // Make a fake iframe in this invisible window by adding another RootWebArea.
-  // The iframe has no root but is parented to the container above.
-  let iframeRoot = {parent: container, state: {}, role: 'rootWebArea'};
-  let iframeContainer = {root: iframeRoot, parent: iframeRoot, state: {}};
-  let iframeNode = {root: iframeRoot, parent: iframeContainer, state: {}};
-  assertEquals(getNodeState(iframeContainer), NodeState.NODE_STATE_INVISIBLE);
-  assertEquals(getNodeState(iframeNode), NodeState.NODE_STATE_INVISIBLE);
-
-  // Make the window visible and try again.
-  window.state = {};
-  assertEquals(getNodeState(window), NodeState.NODE_STATE_NORMAL);
-  assertEquals(getNodeState(container), NodeState.NODE_STATE_NORMAL);
-  assertEquals(getNodeState(node), NodeState.NODE_STATE_NORMAL);
-  assertEquals(getNodeState(iframeContainer), NodeState.NODE_STATE_NORMAL);
-  assertEquals(getNodeState(iframeNode), NodeState.NODE_STATE_NORMAL);
-});
-
-TEST_F('SelectToSpeakUnitTest', 'findAllMatching', function() {
-  let rect = {left: 0, top: 0, width: 100, height: 100};
-  let rootNode = {root: {}, state: {}, role: 'rootWebArea', state: {},
-      location: {left: 0, top: 0, width: 600, height: 600}};
-  let container1 = {root: rootNode, parent: rootNode, role: 'staticText',
-      name: 'one two', state: {},
-      location: {left: 0, top: 0, width: 200, height: 200}};
-  let container2 = {root: rootNode, parent: rootNode, state: {},
-      role: 'genericContainer',
-      location: {left: 0, top: 0, width: 200, height: 200}};
-  let node1 = {root: rootNode, parent: container1, name: 'one',
-      role: 'inlineTextBox', state: {},
-      location: {left: 50, top: 0, width: 50, height: 50}};
-  let node2 = {root: rootNode, parent: container1, name: 'two',
-      role: 'inlineTextBox', state: {},
-      location: {left: 0, top: 50, width: 50, height: 50}};
-
-  // Set up relationships between nodes.
-  rootNode.children = [container1, container2];
-  rootNode.firstChild = container1;
-  container1.nextSibling = container2;
-  container1.children = [node1, node2];
-  container1.firstChild = node1;
-  node1.nextSibling = node2;
-
-  // Should get both children of the first container, without getting
-  // the first container itself or the empty container.
-  let result = [];
-  assertTrue(findAllMatching(rootNode, rect, result));
-  assertEquals(2, result.length);
-  assertEquals(node1, result[0]);
-  assertEquals(node2, result[1]);
-
-  // If a node doesn't have a name, it should not be included.
-  result = [];
-  node2.name = undefined;
-  assertTrue(findAllMatching(rootNode, rect, result));
-  assertEquals(1, result.length);
-  assertEquals(node1, result[0]);
-
-  // Try a rect that only overlaps one of the children.
-  result = [];
-  node2.name = 'two';
-  rect.height = 25;
-  assertTrue(findAllMatching(rootNode, rect, result));
-  assertEquals(1, result.length);
-  assertEquals(node1, result[0]);
-
-  // Now just overlap a different child.
-  result = [];
-  rect.top = 50;
-  assertTrue(findAllMatching(rootNode, rect, result));
-  assertEquals(1, result.length);
-  assertEquals(node2, result[0]);
-
-  // Offscreen should cause a node to be skipped.
-  result = [];
-  node2.state = {offscreen: true}
-  assertFalse(findAllMatching(rootNode, rect, result));
-  assertEquals(0, result.length);
-
-  // No location should cause a node to be skipped.
-  result = [];
-  node2.state = {};
-  node2.location = undefined;
-  assertFalse(findAllMatching(rootNode, rect, result));
-
-  // A non staticText container without a name should still have
-  // children found.
-  result = [];
-  let node3 = {root: rootNode, parent: container2, name: 'three',
-      state: {}, location: {left: 0, top: 50, width: 50, height: 50}};
-  container2.firstChild = node3;
-  assertTrue(findAllMatching(rootNode, rect, result));
-  assertEquals(1, result.length);
-  assertEquals(node3, result[0]);
-
-  // A non staticText container with a valid name should not be
-  // read if its children are read. Children take precidence.
-  result = [];
-  container2.name = 'container2';
-  assertTrue(findAllMatching(rootNode, rect, result));
-  assertEquals(1, result.length);
-  assertEquals(node3, result[0]);
-
-  // A non staticText container with a valid name which has only
-  // children without names should be read instead of its children.
-  result = [];
-  node3.name = undefined;
-  assertTrue(findAllMatching(rootNode, rect, result));
-  assertEquals(1, result.length);
-  assertEquals(container2, result[0]);
-});
-
-TEST_F('SelectToSpeakUnitTest', 'getDeepEquivalentForSelectionNoChildren',
-    function() {
-  let node = {name: 'Hello, world', children: []};
-  let result = getDeepEquivalentForSelection(node, 0);
-  assertEquals(node, result.node);
-  assertEquals(0, result.offset);
-
-  result = getDeepEquivalentForSelection(node, 6);
-  assertEquals(node, result.node);
-  assertEquals(6, result.offset);
-});
-
-TEST_F('SelectToSpeakUnitTest', 'getDeepEquivalentForSelectionSimpleChildren',
-    function() {
-  let child1 = {name: 'Hello,', children: []};
-  let child2 = {name: ' world', children: []};
-  let root = {name: 'Hello, world', children: [child1, child2]};
-  let result = getDeepEquivalentForSelection(root, 0);
-  assertEquals(child1, result.node);
-  assertEquals(0, result.offset);
-
-  result = getDeepEquivalentForSelection(root, 5);
-  assertEquals(child1, result.node);
-  assertEquals(5, result.offset);
-
-  result = getDeepEquivalentForSelection(root, 6);
-  assertEquals(child2, result.node);
-  assertEquals(0, result.offset);
-
-  result = getDeepEquivalentForSelection(root, 9);
-  assertEquals(child2, result.node);
-  assertEquals(3, result.offset);
-});
-
-TEST_F('SelectToSpeakUnitTest', 'getDeepEquivalentForSelectionComplexChildren',
-    function() {
-  let child1 = {name: 'Hello', children: []};
-  let child2 = {name: undefined, children: []};  // Empty name
-  let child3 = {name: ',', children: []};
-  let child4 = {name: 'Hello,', children: [child1, child2, child3]};
-
-  let child5 = {name: ' ', children: []};
-  let child6 = {name: 'world', children: []};
-  let child7 = {name: ' world', children: [child5, child6]};
-
-  let root = {name: 'Hello, world', children: [child4, child7]};
-
-  let result = getDeepEquivalentForSelection(root, 0);
-  assertEquals(child1, result.node);
-  assertEquals(0, result.offset);
-
-  result = getDeepEquivalentForSelection(root, 5);
-  assertEquals(child3, result.node);
-  assertEquals(0, result.offset);
-
-  result = getDeepEquivalentForSelection(root, 6);
-  assertEquals(child5, result.node);
-  assertEquals(0, result.offset);
-
-  result = getDeepEquivalentForSelection(root, 9);
-  assertEquals(child6, result.node);
-  assertEquals(2, result.offset);
-});
-
 TEST_F('SelectToSpeakUnitTest', 'getDriveAppRoot', function() {
   let root = {url: 'https://docs.google.com/presentation/p/cats_r_awesome'};
   let div1 = {root: root};

chrome/test/data/webui/BUILD.gn

@@ -165,6 +165,7 @@ js2gtest("unit_tests_js") {
   if (is_chromeos) {
     sources += [
       "../../../browser/resources/chromeos/braille_ime/braille_ime_unittest.gtestjs",
+      "../../../browser/resources/chromeos/select_to_speak/node_utils_unittest.gtestjs",
       "../../../browser/resources/chromeos/select_to_speak/paragraph_utils_unittest.gtestjs",
       "../../../browser/resources/chromeos/select_to_speak/rect_utils_unittest.gtestjs",
       "../../../browser/resources/chromeos/select_to_speak/select_to_speak_unittest.gtestjs",
@@ -177,6 +178,7 @@ js2gtest("unit_tests_js") {
       "../../../browser/resources/chromeos/select_to_speak/select_to_speak.js",
       "../../../browser/resources/chromeos/select_to_speak/test_support.js",
       "../../../browser/resources/chromeos/select_to_speak/word_utils.js",
+      "../../../browser/resources/chromeos/select_to_speak/node_utils.js",
     ]
   }
 }