Adding upstream version 1:115.7.0.upstream/1%115.7.0upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1957 insertions, 0 deletions

diff --git a/accessible/base/TextLeafRange.cpp b/accessible/base/TextLeafRange.cpp
new file mode 100644
index 0000000000..37840ce977
--- /dev/null
+++ b/accessible/base/TextLeafRange.cpp
@@ -0,0 +1,1957 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "TextLeafRange.h"
+
+#include "HyperTextAccessible-inl.h"
+#include "mozilla/a11y/Accessible.h"
+#include "mozilla/a11y/CacheConstants.h"
+#include "mozilla/a11y/DocAccessible.h"
+#include "mozilla/a11y/DocAccessibleParent.h"
+#include "mozilla/a11y/LocalAccessible.h"
+#include "mozilla/BinarySearch.h"
+#include "mozilla/Casting.h"
+#include "mozilla/dom/CharacterData.h"
+#include "mozilla/dom/Document.h"
+#include "mozilla/dom/HTMLInputElement.h"
+#include "mozilla/PresShell.h"
+#include "mozilla/intl/Segmenter.h"
+#include "mozilla/intl/WordBreaker.h"
+#include "mozilla/StaticPrefs_layout.h"
+#include "mozilla/TextEditor.h"
+#include "nsAccessibilityService.h"
+#include "nsAccUtils.h"
+#include "nsBlockFrame.h"
+#include "nsContentUtils.h"
+#include "nsFrameSelection.h"
+#include "nsIAccessiblePivot.h"
+#include "nsILineIterator.h"
+#include "nsINode.h"
+#include "nsRange.h"
+#include "nsStyleStructInlines.h"
+#include "nsTArray.h"
+#include "nsTextFrame.h"
+#include "nsUnicodeProperties.h"
+#include "Pivot.h"
+#include "TextAttrs.h"
+
+using mozilla::intl::WordBreaker;
+
+namespace mozilla::a11y {
+
+/*** Helpers ***/
+
+/**
+ * These two functions convert between rendered and content text offsets.
+ * When text DOM nodes are rendered, the rendered text often does not contain
+ * all the whitespace from the source. For example, by default, the text
+ * "a   b" will be rendered as "a b"; i.e. multiple spaces are compressed to
+ * one. TextLeafAccessibles contain rendered text, but when we query layout, we
+ * need to provide offsets into the original content text. Similarly, layout
+ * returns content offsets, but we need to convert them to rendered offsets to
+ * map them to TextLeafAccessibles.
+ */
+
+static int32_t RenderedToContentOffset(LocalAccessible* aAcc,
+                                       uint32_t aRenderedOffset) {
+  nsTextFrame* frame = do_QueryFrame(aAcc->GetFrame());
+  if (!frame) {
+    MOZ_ASSERT(!aAcc->HasOwnContent() || aAcc->IsHTMLBr(),
+               "No text frame because this is a XUL label[value] text leaf or "
+               "a BR element.");
+    return static_cast<int32_t>(aRenderedOffset);
+  }
+
+  if (frame->StyleText()->WhiteSpaceIsSignificant() &&
+      frame->StyleText()->NewlineIsSignificant(frame)) {
+    // Spaces and new lines aren't altered, so the content and rendered offsets
+    // are the same. This happens in pre-formatted text and text fields.
+    return static_cast<int32_t>(aRenderedOffset);
+  }
+
+  nsIFrame::RenderedText text =
+      frame->GetRenderedText(aRenderedOffset, aRenderedOffset + 1,
+                             nsIFrame::TextOffsetType::OffsetsInRenderedText,
+                             nsIFrame::TrailingWhitespace::DontTrim);
+  return text.mOffsetWithinNodeText;
+}
+
+static uint32_t ContentToRenderedOffset(LocalAccessible* aAcc,
+                                        int32_t aContentOffset) {
+  nsTextFrame* frame = do_QueryFrame(aAcc->GetFrame());
+  if (!frame) {
+    MOZ_ASSERT(!aAcc->HasOwnContent(),
+               "No text frame because this is a XUL label[value] text leaf.");
+    return aContentOffset;
+  }
+
+  if (frame->StyleText()->WhiteSpaceIsSignificant() &&
+      frame->StyleText()->NewlineIsSignificant(frame)) {
+    // Spaces and new lines aren't altered, so the content and rendered offsets
+    // are the same. This happens in pre-formatted text and text fields.
+    return aContentOffset;
+  }
+
+  nsIFrame::RenderedText text =
+      frame->GetRenderedText(aContentOffset, aContentOffset + 1,
+                             nsIFrame::TextOffsetType::OffsetsInContentText,
+                             nsIFrame::TrailingWhitespace::DontTrim);
+  return text.mOffsetWithinNodeRenderedText;
+}
+
+class LeafRule : public PivotRule {
+ public:
+  explicit LeafRule(bool aIgnoreListItemMarker)
+      : mIgnoreListItemMarker(aIgnoreListItemMarker) {}
+
+  virtual uint16_t Match(Accessible* aAcc) override {
+    if (aAcc->IsOuterDoc()) {
+      // Treat an embedded doc as a single character in this document, but do
+      // not descend inside it.
+      return nsIAccessibleTraversalRule::FILTER_MATCH |
+             nsIAccessibleTraversalRule::FILTER_IGNORE_SUBTREE;
+    }
+
+    if (mIgnoreListItemMarker && aAcc->Role() == roles::LISTITEM_MARKER) {
+      // Ignore list item markers if configured to do so.
+      return nsIAccessibleTraversalRule::FILTER_IGNORE;
+    }
+
+    // We deliberately include Accessibles such as empty input elements and
+    // empty containers, as these can be at the start of a line.
+    if (!aAcc->HasChildren()) {
+      return nsIAccessibleTraversalRule::FILTER_MATCH;
+    }
+    return nsIAccessibleTraversalRule::FILTER_IGNORE;
+  }
+
+ private:
+  bool mIgnoreListItemMarker;
+};
+
+static HyperTextAccessible* HyperTextFor(LocalAccessible* aAcc) {
+  for (LocalAccessible* acc = aAcc; acc; acc = acc->LocalParent()) {
+    if (HyperTextAccessible* ht = acc->AsHyperText()) {
+      return ht;
+    }
+  }
+  return nullptr;
+}
+
+static Accessible* NextLeaf(Accessible* aOrigin, bool aIsEditable = false,
+                            bool aIgnoreListItemMarker = false) {
+  MOZ_ASSERT(aOrigin);
+  Accessible* doc = nsAccUtils::DocumentFor(aOrigin);
+  Pivot pivot(doc);
+  auto rule = LeafRule(aIgnoreListItemMarker);
+  Accessible* leaf = pivot.Next(aOrigin, rule);
+  if (aIsEditable && leaf) {
+    return leaf->Parent() && (leaf->Parent()->State() & states::EDITABLE)
+               ? leaf
+               : nullptr;
+  }
+  return leaf;
+}
+
+static Accessible* PrevLeaf(Accessible* aOrigin, bool aIsEditable = false,
+                            bool aIgnoreListItemMarker = false) {
+  MOZ_ASSERT(aOrigin);
+  Accessible* doc = nsAccUtils::DocumentFor(aOrigin);
+  Pivot pivot(doc);
+  auto rule = LeafRule(aIgnoreListItemMarker);
+  Accessible* leaf = pivot.Prev(aOrigin, rule);
+  if (aIsEditable && leaf) {
+    return leaf->Parent() && (leaf->Parent()->State() & states::EDITABLE)
+               ? leaf
+               : nullptr;
+  }
+  return leaf;
+}
+
+static nsIFrame* GetFrameInBlock(const LocalAccessible* aAcc) {
+  dom::HTMLInputElement* input =
+      dom::HTMLInputElement::FromNodeOrNull(aAcc->GetContent());
+  if (!input) {
+    if (LocalAccessible* parent = aAcc->LocalParent()) {
+      input = dom::HTMLInputElement::FromNodeOrNull(parent->GetContent());
+    }
+  }
+
+  if (input) {
+    // If this is a single line input (or a leaf of an input) we want to return
+    // the top frame of the input element and not the text leaf's frame because
+    // the leaf may be inside of an embedded block frame in the input's shadow
+    // DOM that we aren't interested in.
+    return input->GetPrimaryFrame();
+  }
+
+  return aAcc->GetFrame();
+}
+
+static bool IsLocalAccAtLineStart(LocalAccessible* aAcc) {
+  if (aAcc->NativeRole() == roles::LISTITEM_MARKER) {
+    // A bullet always starts a line.
+    return true;
+  }
+  // Splitting of content across lines is handled by layout.
+  // nsIFrame::IsLogicallyAtLineEdge queries whether a frame is the first frame
+  // on its line. However, we can't use that because the first frame on a line
+  // might not be included in the a11y tree; e.g. an empty span, or space
+  // in the DOM after a line break which is stripped when rendered. Instead, we
+  // get the line number for this Accessible's frame and the line number for the
+  // previous leaf Accessible's frame and compare them.
+  Accessible* prev = PrevLeaf(aAcc);
+  LocalAccessible* prevLocal = prev ? prev->AsLocal() : nullptr;
+  if (!prevLocal) {
+    // There's nothing before us, so this is the start of the first line.
+    return true;
+  }
+  if (prevLocal->NativeRole() == roles::LISTITEM_MARKER) {
+    // If there is  a bullet immediately before us and we're inside the same
+    // list item, this is not the start of a line.
+    LocalAccessible* listItem = prevLocal->LocalParent();
+    MOZ_ASSERT(listItem);
+    LocalAccessible* doc = listItem->Document();
+    MOZ_ASSERT(doc);
+    for (LocalAccessible* parent = aAcc->LocalParent(); parent && parent != doc;
+         parent = parent->LocalParent()) {
+      if (parent == listItem) {
+        return false;
+      }
+    }
+  }
+
+  nsIFrame* thisFrame = GetFrameInBlock(aAcc);
+  if (!thisFrame) {
+    return false;
+  }
+
+  nsIFrame* prevFrame = GetFrameInBlock(prevLocal);
+  if (!prevFrame) {
+    return false;
+  }
+
+  auto [thisBlock, thisLineFrame] = thisFrame->GetContainingBlockForLine(
+      /* aLockScroll */ false);
+  if (!thisBlock) {
+    // We couldn't get the containing block for this frame. In that case, we
+    // play it safe and assume this is the beginning of a new line.
+    return true;
+  }
+
+  // The previous leaf might cross lines. We want to compare against the last
+  // line.
+  prevFrame = prevFrame->LastContinuation();
+  auto [prevBlock, prevLineFrame] = prevFrame->GetContainingBlockForLine(
+      /* aLockScroll */ false);
+  if (thisBlock != prevBlock) {
+    // If the blocks are different, that means there's nothing before us on the
+    // same line, so we're at the start.
+    return true;
+  }
+  if (nsBlockFrame* block = do_QueryFrame(thisBlock)) {
+    // If we have a block frame, it's faster for us to use
+    // BlockInFlowLineIterator because it uses the line cursor.
+    bool found = false;
+    block->SetupLineCursorForQuery();
+    nsBlockInFlowLineIterator prevIt(block, prevLineFrame, &found);
+    if (!found) {
+      // Error; play it safe.
+      return true;
+    }
+    found = false;
+    nsBlockInFlowLineIterator thisIt(block, thisLineFrame, &found);
+    // if the lines are different, that means there's nothing before us on the
+    // same line, so we're at the start.
+    return !found || prevIt.GetLine() != thisIt.GetLine();
+  }
+  AutoAssertNoDomMutations guard;
+  nsILineIterator* it = prevBlock->GetLineIterator();
+  MOZ_ASSERT(it, "GetLineIterator impl in line-container blocks is infallible");
+  int32_t prevLineNum = it->FindLineContaining(prevLineFrame);
+  if (prevLineNum < 0) {
+    // Error; play it safe.
+    return true;
+  }
+  int32_t thisLineNum = it->FindLineContaining(thisLineFrame, prevLineNum);
+  // if the blocks and line numbers are different, that means there's nothing
+  // before us on the same line, so we're at the start.
+  return thisLineNum != prevLineNum;
+}
+
+/**
+ * There are many kinds of word break, but we only need to treat punctuation and
+ * space specially.
+ */
+enum WordBreakClass { eWbcSpace = 0, eWbcPunct, eWbcOther };
+
+static WordBreakClass GetWordBreakClass(char16_t aChar) {
+  // Based on IsSelectionInlineWhitespace and IsSelectionNewline in
+  // layout/generic/nsTextFrame.cpp.
+  const char16_t kCharNbsp = 0xA0;
+  switch (aChar) {
+    case ' ':
+    case kCharNbsp:
+    case '\t':
+    case '\f':
+    case '\n':
+    case '\r':
+      return eWbcSpace;
+    default:
+      break;
+  }
+  // Based on ClusterIterator::IsPunctuation in
+  // layout/generic/nsTextFrame.cpp.
+  uint8_t cat = unicode::GetGeneralCategory(aChar);
+  switch (cat) {
+    case HB_UNICODE_GENERAL_CATEGORY_CONNECT_PUNCTUATION: /* Pc */
+      if (aChar == '_' &&
+          !StaticPrefs::layout_word_select_stop_at_underscore()) {
+        return eWbcOther;
+      }
+      [[fallthrough]];
+    case HB_UNICODE_GENERAL_CATEGORY_DASH_PUNCTUATION:    /* Pd */
+    case HB_UNICODE_GENERAL_CATEGORY_CLOSE_PUNCTUATION:   /* Pe */
+    case HB_UNICODE_GENERAL_CATEGORY_FINAL_PUNCTUATION:   /* Pf */
+    case HB_UNICODE_GENERAL_CATEGORY_INITIAL_PUNCTUATION: /* Pi */
+    case HB_UNICODE_GENERAL_CATEGORY_OTHER_PUNCTUATION:   /* Po */
+    case HB_UNICODE_GENERAL_CATEGORY_OPEN_PUNCTUATION:    /* Ps */
+    case HB_UNICODE_GENERAL_CATEGORY_CURRENCY_SYMBOL:     /* Sc */
+    case HB_UNICODE_GENERAL_CATEGORY_MATH_SYMBOL:         /* Sm */
+    case HB_UNICODE_GENERAL_CATEGORY_OTHER_SYMBOL:        /* So */
+      return eWbcPunct;
+    default:
+      break;
+  }
+  return eWbcOther;
+}
+
+/**
+ * Words can cross Accessibles. To work out whether we're at the start of a
+ * word, we might have to check the previous leaf. This class handles querying
+ * the previous WordBreakClass, crossing Accessibles if necessary.
+ */
+class PrevWordBreakClassWalker {
+ public:
+  PrevWordBreakClassWalker(Accessible* aAcc, const nsAString& aText,
+                           int32_t aOffset)
+      : mAcc(aAcc), mText(aText), mOffset(aOffset) {
+    mClass = GetWordBreakClass(mText.CharAt(mOffset));
+  }
+
+  WordBreakClass CurClass() { return mClass; }
+
+  Maybe<WordBreakClass> PrevClass() {
+    for (;;) {
+      if (!PrevChar()) {
+        return Nothing();
+      }
+      WordBreakClass curClass = GetWordBreakClass(mText.CharAt(mOffset));
+      if (curClass != mClass) {
+        mClass = curClass;
+        return Some(curClass);
+      }
+    }
+    MOZ_ASSERT_UNREACHABLE();
+    return Nothing();
+  }
+
+  bool IsStartOfGroup() {
+    if (!PrevChar()) {
+      // There are no characters before us.
+      return true;
+    }
+    WordBreakClass curClass = GetWordBreakClass(mText.CharAt(mOffset));
+    // We wanted to peek at the previous character, not really move to it.
+    ++mOffset;
+    return curClass != mClass;
+  }
+
+ private:
+  bool PrevChar() {
+    if (mOffset > 0) {
+      --mOffset;
+      return true;
+    }
+    if (!mAcc) {
+      // PrevChar was called already and failed.
+      return false;
+    }
+    mAcc = PrevLeaf(mAcc);
+    if (!mAcc) {
+      return false;
+    }
+    mText.Truncate();
+    mAcc->AppendTextTo(mText);
+    mOffset = static_cast<int32_t>(mText.Length()) - 1;
+    return true;
+  }
+
+  Accessible* mAcc;
+  nsAutoString mText;
+  int32_t mOffset;
+  WordBreakClass mClass;
+};
+
+/**
+ * WordBreaker breaks at all space, punctuation, etc. We want to emulate
+ * layout, so that's not what we want. This function determines whether this
+ * is acceptable as the start of a word for our purposes.
+ */
+static bool IsAcceptableWordStart(Accessible* aAcc, const nsAutoString& aText,
+                                  int32_t aOffset) {
+  PrevWordBreakClassWalker walker(aAcc, aText, aOffset);
+  if (!walker.IsStartOfGroup()) {
+    // If we're not at the start of a WordBreaker group, this can't be the
+    // start of a word.
+    return false;
+  }
+  WordBreakClass curClass = walker.CurClass();
+  if (curClass == eWbcSpace) {
+    // Space isn't the start of a word.
+    return false;
+  }
+  Maybe<WordBreakClass> prevClass = walker.PrevClass();
+  if (curClass == eWbcPunct && (!prevClass || prevClass.value() != eWbcSpace)) {
+    // Punctuation isn't the start of a word (unless it is after space).
+    return false;
+  }
+  if (!prevClass || prevClass.value() != eWbcPunct) {
+    // If there's nothing before this or the group before this isn't
+    // punctuation, this is the start of a word.
+    return true;
+  }
+  // At this point, we know the group before this is punctuation.
+  if (!StaticPrefs::layout_word_select_stop_at_punctuation()) {
+    // When layout.word_select.stop_at_punctuation is false (defaults to true),
+    // if there is punctuation before this, this is not the start of a word.
+    return false;
+  }
+  Maybe<WordBreakClass> prevPrevClass = walker.PrevClass();
+  if (!prevPrevClass || prevPrevClass.value() == eWbcSpace) {
+    // If there is punctuation before this and space (or nothing) before the
+    // punctuation, this is not the start of a word.
+    return false;
+  }
+  return true;
+}
+
+class BlockRule : public PivotRule {
+ public:
+  virtual uint16_t Match(Accessible* aAcc) override {
+    if (RefPtr<nsAtom>(aAcc->DisplayStyle()) == nsGkAtoms::block ||
+        aAcc->IsHTMLListItem() || aAcc->IsTableRow() || aAcc->IsTableCell()) {
+      return nsIAccessibleTraversalRule::FILTER_MATCH;
+    }
+    return nsIAccessibleTraversalRule::FILTER_IGNORE;
+  }
+};
+
+/**
+ * Find spelling error DOM ranges overlapping the requested LocalAccessible and
+ * offsets. This includes ranges that begin or end outside of the given
+ * LocalAccessible. Note that the offset arguments are rendered offsets, but
+ * because the returned ranges are DOM ranges, those offsets are content
+ * offsets. See the documentation for dom::Selection::GetRangesForIntervalArray
+ * for information about the aAllowAdjacent argument.
+ */
+static nsTArray<nsRange*> FindDOMSpellingErrors(LocalAccessible* aAcc,
+                                                int32_t aRenderedStart,
+                                                int32_t aRenderedEnd,
+                                                bool aAllowAdjacent = false) {
+  if (!aAcc->IsTextLeaf() || !aAcc->HasOwnContent()) {
+    return {};
+  }
+  nsIFrame* frame = aAcc->GetFrame();
+  RefPtr<nsFrameSelection> frameSel =
+      frame ? frame->GetFrameSelection() : nullptr;
+  dom::Selection* domSel =
+      frameSel ? frameSel->GetSelection(SelectionType::eSpellCheck) : nullptr;
+  if (!domSel) {
+    return {};
+  }
+  nsINode* node = aAcc->GetNode();
+  uint32_t contentStart = RenderedToContentOffset(aAcc, aRenderedStart);
+  uint32_t contentEnd =
+      aRenderedEnd == nsIAccessibleText::TEXT_OFFSET_END_OF_TEXT
+          ? dom::CharacterData::FromNode(node)->TextLength()
+          : RenderedToContentOffset(aAcc, aRenderedEnd);
+  nsTArray<nsRange*> domRanges;
+  domSel->GetDynamicRangesForIntervalArray(node, contentStart, node, contentEnd,
+                                           aAllowAdjacent, &domRanges);
+  return domRanges;
+}
+
+/**
+ * Given two DOM nodes get DOM Selection object that is common
+ * to both of them.
+ */
+static dom::Selection* GetDOMSelection(const nsIContent* aStartContent,
+                                       const nsIContent* aEndContent) {
+  nsIFrame* startFrame = aStartContent->GetPrimaryFrame();
+  const nsFrameSelection* startFrameSel =
+      startFrame ? startFrame->GetConstFrameSelection() : nullptr;
+  nsIFrame* endFrame = aEndContent->GetPrimaryFrame();
+  const nsFrameSelection* endFrameSel =
+      endFrame ? endFrame->GetConstFrameSelection() : nullptr;
+
+  if (startFrameSel != endFrameSel) {
+    // Start and end point don't share the same selection state.
+    // This could happen when both points aren't in the same editable.
+    return nullptr;
+  }
+
+  return startFrameSel ? startFrameSel->GetSelection(SelectionType::eNormal)
+                       : nullptr;
+}
+
+std::pair<nsIContent*, int32_t> TextLeafPoint::ToDOMPoint(
+    bool aIncludeGenerated) const {
+  if (!(*this) || !mAcc->IsLocal()) {
+    MOZ_ASSERT_UNREACHABLE("Invalid point");
+    return {nullptr, 0};
+  }
+
+  nsIContent* content = mAcc->AsLocal()->GetContent();
+  nsIFrame* frame = content ? content->GetPrimaryFrame() : nullptr;
+  MOZ_ASSERT(frame);
+
+  if (!aIncludeGenerated && frame && frame->IsGeneratedContentFrame()) {
+    // List markers accessibles represent the generated content element,
+    // before/after text accessibles represent the child text nodes.
+    auto generatedElement = content->IsGeneratedContentContainerForMarker()
+                                ? content
+                                : content->GetParentElement();
+    auto parent = generatedElement ? generatedElement->GetParent() : nullptr;
+    MOZ_ASSERT(parent);
+    if (parent) {
+      if (generatedElement->IsGeneratedContentContainerForAfter()) {
+        // Use the end offset of the parent element for trailing generated
+        // content.
+        return {parent, parent->GetChildCount()};
+      }
+
+      if (generatedElement->IsGeneratedContentContainerForBefore() ||
+          generatedElement->IsGeneratedContentContainerForMarker()) {
+        // Use the start offset of the parent element for leading generated
+        // content.
+        return {parent, 0};
+      }
+
+      MOZ_ASSERT_UNREACHABLE("Unknown generated content type!");
+    }
+  }
+
+  if (!mAcc->IsTextLeaf() && !mAcc->IsHTMLBr() && !mAcc->HasChildren()) {
+    // If this is not a text leaf it can be an empty editable container,
+    // whitespace, or an empty doc. In any case, the offset inside should be 0.
+    MOZ_ASSERT(mOffset == 0);
+
+    if (RefPtr<TextControlElement> textControlElement =
+            TextControlElement::FromNodeOrNull(content)) {
+      // This is an empty input, use the shadow root's element.
+      if (RefPtr<TextEditor> textEditor = textControlElement->GetTextEditor()) {
+        if (textEditor->IsEmpty()) {
+          MOZ_ASSERT(mOffset == 0);
+          return {textEditor->GetRoot(), 0};
+        }
+      }
+    }
+
+    return {content, 0};
+  }
+
+  return {content, RenderedToContentOffset(mAcc->AsLocal(), mOffset)};
+}
+
+/*** TextLeafPoint ***/
+
+TextLeafPoint::TextLeafPoint(Accessible* aAcc, int32_t aOffset) {
+  if (!aAcc) {
+    // Construct an invalid point.
+    mAcc = nullptr;
+    mOffset = 0;
+    return;
+  }
+
+  // Even though an OuterDoc contains a document, we treat it as a leaf because
+  // we don't want to move into another document.
+  if (aOffset != nsIAccessibleText::TEXT_OFFSET_CARET && !aAcc->IsOuterDoc() &&
+      aAcc->HasChildren()) {
+    // Find a leaf. This might not necessarily be a TextLeafAccessible; it
+    // could be an empty container.
+    auto GetChild = [&aOffset](Accessible* acc) -> Accessible* {
+      if (acc->IsOuterDoc()) {
+        return nullptr;
+      }
+      return aOffset != nsIAccessibleText::TEXT_OFFSET_END_OF_TEXT
+                 ? acc->FirstChild()
+                 : acc->LastChild();
+    };
+
+    for (Accessible* acc = GetChild(aAcc); acc; acc = GetChild(acc)) {
+      mAcc = acc;
+    }
+    mOffset = aOffset != nsIAccessibleText::TEXT_OFFSET_END_OF_TEXT
+                  ? 0
+                  : nsAccUtils::TextLength(mAcc);
+    return;
+  }
+  mAcc = aAcc;
+  mOffset = aOffset != nsIAccessibleText::TEXT_OFFSET_END_OF_TEXT
+                ? aOffset
+                : nsAccUtils::TextLength(mAcc);
+}
+
+bool TextLeafPoint::operator<(const TextLeafPoint& aPoint) const {
+  if (mAcc == aPoint.mAcc) {
+    return mOffset < aPoint.mOffset;
+  }
+  return mAcc->IsBefore(aPoint.mAcc);
+}
+
+bool TextLeafPoint::operator<=(const TextLeafPoint& aPoint) const {
+  return *this == aPoint || *this < aPoint;
+}
+
+bool TextLeafPoint::IsDocEdge(nsDirection aDirection) const {
+  if (aDirection == eDirPrevious) {
+    return mOffset == 0 && !PrevLeaf(mAcc);
+  }
+
+  return mOffset == static_cast<int32_t>(nsAccUtils::TextLength(mAcc)) &&
+         !NextLeaf(mAcc);
+}
+
+bool TextLeafPoint::IsLeafAfterListItemMarker() const {
+  Accessible* prev = PrevLeaf(mAcc);
+  return prev && prev->Role() == roles::LISTITEM_MARKER &&
+         prev->Parent()->IsAncestorOf(mAcc);
+}
+
+bool TextLeafPoint::IsEmptyLastLine() const {
+  if (mAcc->IsHTMLBr() && mOffset == 1) {
+    return true;
+  }
+  if (!mAcc->IsTextLeaf()) {
+    return false;
+  }
+  if (mOffset < static_cast<int32_t>(nsAccUtils::TextLength(mAcc))) {
+    return false;
+  }
+  nsAutoString text;
+  mAcc->AppendTextTo(text, mOffset - 1, 1);
+  return text.CharAt(0) == '\n';
+}
+
+char16_t TextLeafPoint::GetChar() const {
+  nsAutoString text;
+  mAcc->AppendTextTo(text, mOffset, 1);
+  return text.CharAt(0);
+}
+
+TextLeafPoint TextLeafPoint::FindPrevLineStartSameLocalAcc(
+    bool aIncludeOrigin) const {
+  LocalAccessible* acc = mAcc->AsLocal();
+  MOZ_ASSERT(acc);
+  if (mOffset == 0) {
+    if (aIncludeOrigin && IsLocalAccAtLineStart(acc)) {
+      return *this;
+    }
+    return TextLeafPoint();
+  }
+  nsIFrame* frame = acc->GetFrame();
+  if (!frame) {
+    // This can happen if this is an empty element with display: contents. In
+    // that case, this Accessible contains no lines.
+    return TextLeafPoint();
+  }
+  if (!frame->IsTextFrame()) {
+    if (IsLocalAccAtLineStart(acc)) {
+      return TextLeafPoint(acc, 0);
+    }
+    return TextLeafPoint();
+  }
+  // Each line of a text node is rendered as a continuation frame. Get the
+  // continuation containing the origin.
+  int32_t origOffset = mOffset;
+  origOffset = RenderedToContentOffset(acc, origOffset);
+  nsTextFrame* continuation = nullptr;
+  int32_t unusedOffsetInContinuation = 0;
+  frame->GetChildFrameContainingOffset(
+      origOffset, true, &unusedOffsetInContinuation, (nsIFrame**)&continuation);
+  MOZ_ASSERT(continuation);
+  int32_t lineStart = continuation->GetContentOffset();
+  if (!aIncludeOrigin && lineStart > 0 && lineStart == origOffset) {
+    // A line starts at the origin, but the caller doesn't want this included.
+    // Go back one more.
+    continuation = continuation->GetPrevContinuation();
+    MOZ_ASSERT(continuation);
+    lineStart = continuation->GetContentOffset();
+  }
+  MOZ_ASSERT(lineStart >= 0);
+  if (lineStart == 0 && !IsLocalAccAtLineStart(acc)) {
+    // This is the first line of this text node, but there is something else
+    // on the same line before this text node, so don't return this as a line
+    // start.
+    return TextLeafPoint();
+  }
+  lineStart = static_cast<int32_t>(ContentToRenderedOffset(acc, lineStart));
+  return TextLeafPoint(acc, lineStart);
+}
+
+TextLeafPoint TextLeafPoint::FindNextLineStartSameLocalAcc(
+    bool aIncludeOrigin) const {
+  LocalAccessible* acc = mAcc->AsLocal();
+  MOZ_ASSERT(acc);
+  if (aIncludeOrigin && mOffset == 0 && IsLocalAccAtLineStart(acc)) {
+    return *this;
+  }
+  nsIFrame* frame = acc->GetFrame();
+  if (!frame) {
+    // This can happen if this is an empty element with display: contents. In
+    // that case, this Accessible contains no lines.
+    return TextLeafPoint();
+  }
+  if (!frame->IsTextFrame()) {
+    // There can't be multiple lines in a non-text leaf.
+    return TextLeafPoint();
+  }
+  // Each line of a text node is rendered as a continuation frame. Get the
+  // continuation containing the origin.
+  int32_t origOffset = mOffset;
+  origOffset = RenderedToContentOffset(acc, origOffset);
+  nsTextFrame* continuation = nullptr;
+  int32_t unusedOffsetInContinuation = 0;
+  frame->GetChildFrameContainingOffset(
+      origOffset, true, &unusedOffsetInContinuation, (nsIFrame**)&continuation);
+  MOZ_ASSERT(continuation);
+  if (
+      // A line starts at the origin and the caller wants this included.
+      aIncludeOrigin && continuation->GetContentOffset() == origOffset &&
+      // If this is the first line of this text node (offset 0), don't treat it
+      // as a line start if there's something else on the line before this text
+      // node.
+      !(origOffset == 0 && !IsLocalAccAtLineStart(acc))) {
+    return *this;
+  }
+  continuation = continuation->GetNextContinuation();
+  if (!continuation) {
+    return TextLeafPoint();
+  }
+  int32_t lineStart = continuation->GetContentOffset();
+  lineStart = static_cast<int32_t>(ContentToRenderedOffset(acc, lineStart));
+  return TextLeafPoint(acc, lineStart);
+}
+
+TextLeafPoint TextLeafPoint::FindLineStartSameRemoteAcc(
+    nsDirection aDirection, bool aIncludeOrigin) const {
+  RemoteAccessible* acc = mAcc->AsRemote();
+  MOZ_ASSERT(acc);
+  auto lines = acc->GetCachedTextLines();
+  if (!lines) {
+    return TextLeafPoint();
+  }
+  size_t index;
+  // If BinarySearch returns true, mOffset is in the array and index points at
+  // it. If BinarySearch returns false, mOffset is not in the array and index
+  // points at the next line start after mOffset.
+  if (BinarySearch(*lines, 0, lines->Length(), mOffset, &index)) {
+    if (aIncludeOrigin) {
+      return *this;
+    }
+    if (aDirection == eDirNext) {
+      // We don't want to include the origin. Get the next line start.
+      ++index;
+    }
+  }
+  MOZ_ASSERT(index <= lines->Length());
+  if ((aDirection == eDirNext && index == lines->Length()) ||
+      (aDirection == eDirPrevious && index == 0)) {
+    return TextLeafPoint();
+  }
+  // index points at the line start after mOffset.
+  if (aDirection == eDirPrevious) {
+    --index;
+  }
+  return TextLeafPoint(mAcc, lines->ElementAt(index));
+}
+
+TextLeafPoint TextLeafPoint::FindLineStartSameAcc(
+    nsDirection aDirection, bool aIncludeOrigin,
+    bool aIgnoreListItemMarker) const {
+  TextLeafPoint boundary;
+  if (aIgnoreListItemMarker && aIncludeOrigin && mOffset == 0 &&
+      IsLeafAfterListItemMarker()) {
+    // If:
+    // (1) we are ignoring list markers
+    // (2) we should include origin
+    // (3) we are at the start of a leaf that follows a list item marker
+    // ...then return this point.
+    return *this;
+  }
+
+  if (mAcc->IsLocal()) {
+    boundary = aDirection == eDirNext
+                   ? FindNextLineStartSameLocalAcc(aIncludeOrigin)
+                   : FindPrevLineStartSameLocalAcc(aIncludeOrigin);
+  } else {
+    boundary = FindLineStartSameRemoteAcc(aDirection, aIncludeOrigin);
+  }
+
+  if (aIgnoreListItemMarker && aDirection == eDirPrevious && !boundary &&
+      mOffset != 0 && IsLeafAfterListItemMarker()) {
+    // If:
+    // (1) we are ignoring list markers
+    // (2) we are searching backwards in accessible
+    // (3) we did not find a line start before this point
+    // (4) we are in a leaf that follows a list item marker
+    // ...then return the first point in this accessible.
+    boundary = TextLeafPoint(mAcc, 0);
+  }
+
+  return boundary;
+}
+
+TextLeafPoint TextLeafPoint::FindPrevWordStartSameAcc(
+    bool aIncludeOrigin) const {
+  if (mOffset == 0 && !aIncludeOrigin) {
+    // We can't go back any further and the caller doesn't want the origin
+    // included, so there's nothing more to do.
+    return TextLeafPoint();
+  }
+  nsAutoString text;
+  mAcc->AppendTextTo(text);
+  TextLeafPoint lineStart = *this;
+  if (!aIncludeOrigin || (lineStart.mOffset == 1 && text.Length() == 1 &&
+                          text.CharAt(0) == '\n')) {
+    // We're not interested in a line that starts here, either because
+    // aIncludeOrigin is false or because we're at the end of a line break
+    // node.
+    --lineStart.mOffset;
+  }
+  // A word never starts with a line feed character. If there are multiple
+  // consecutive line feed characters and we're after the first of them, the
+  // previous line start will be a line feed character. Skip this and any prior
+  // consecutive line feed first.
+  for (; lineStart.mOffset >= 0 && text.CharAt(lineStart.mOffset) == '\n';
+       --lineStart.mOffset) {
+  }
+  if (lineStart.mOffset < 0) {
+    // There's no line start for our purposes.
+    lineStart = TextLeafPoint();
+  } else {
+    lineStart =
+        lineStart.FindLineStartSameAcc(eDirPrevious, /* aIncludeOrigin */ true);
+  }
+  // Keep walking backward until we find an acceptable word start.
+  intl::WordRange word;
+  if (mOffset == 0) {
+    word.mBegin = 0;
+  } else if (mOffset == static_cast<int32_t>(text.Length())) {
+    word = WordBreaker::FindWord(text.get(), text.Length(), mOffset - 1);
+  } else {
+    word = WordBreaker::FindWord(text.get(), text.Length(), mOffset);
+  }
+  for (;; word = WordBreaker::FindWord(text.get(), text.Length(),
+                                       word.mBegin - 1)) {
+    if (!aIncludeOrigin && static_cast<int32_t>(word.mBegin) == mOffset) {
+      // A word possibly starts at the origin, but the caller doesn't want this
+      // included.
+      MOZ_ASSERT(word.mBegin != 0);
+      continue;
+    }
+    if (lineStart && static_cast<int32_t>(word.mBegin) < lineStart.mOffset) {
+      // A line start always starts a new word.
+      return lineStart;
+    }
+    if (IsAcceptableWordStart(mAcc, text, static_cast<int32_t>(word.mBegin))) {
+      break;
+    }
+    if (word.mBegin == 0) {
+      // We can't go back any further.
+      if (lineStart) {
+        // A line start always starts a new word.
+        return lineStart;
+      }
+      return TextLeafPoint();
+    }
+  }
+  return TextLeafPoint(mAcc, static_cast<int32_t>(word.mBegin));
+}
+
+TextLeafPoint TextLeafPoint::FindNextWordStartSameAcc(
+    bool aIncludeOrigin) const {
+  nsAutoString text;
+  mAcc->AppendTextTo(text);
+  int32_t wordStart = mOffset;
+  if (aIncludeOrigin) {
+    if (wordStart == 0) {
+      if (IsAcceptableWordStart(mAcc, text, 0)) {
+        return *this;
+      }
+    } else {
+      // The origin might start a word, so search from just before it.
+      --wordStart;
+    }
+  }
+  TextLeafPoint lineStart = FindLineStartSameAcc(eDirNext, aIncludeOrigin);
+  if (lineStart) {
+    // A word never starts with a line feed character. If there are multiple
+    // consecutive line feed characters, lineStart will point at the second of
+    // them. Skip this and any subsequent consecutive line feed.
+    for (; lineStart.mOffset < static_cast<int32_t>(text.Length()) &&
+           text.CharAt(lineStart.mOffset) == '\n';
+         ++lineStart.mOffset) {
+    }
+    if (lineStart.mOffset == static_cast<int32_t>(text.Length())) {
+      // There's no line start for our purposes.
+      lineStart = TextLeafPoint();
+    }
+  }
+  // Keep walking forward until we find an acceptable word start.
+  intl::WordBreakIteratorUtf16 wordBreakIter(text);
+  Maybe<uint32_t> nextBreak = wordBreakIter.Seek(wordStart);
+  for (;;) {
+    if (!nextBreak || *nextBreak == text.Length()) {
+      if (lineStart) {
+        // A line start always starts a new word.
+        return lineStart;
+      }
+      return TextLeafPoint();
+    }
+    wordStart = AssertedCast<int32_t>(*nextBreak);
+    if (lineStart && wordStart > lineStart.mOffset) {
+      // A line start always starts a new word.
+      return lineStart;
+    }
+    if (IsAcceptableWordStart(mAcc, text, wordStart)) {
+      break;
+    }
+    nextBreak = wordBreakIter.Next();
+  }
+  return TextLeafPoint(mAcc, wordStart);
+}
+
+bool TextLeafPoint::IsCaretAtEndOfLine() const {
+  MOZ_ASSERT(IsCaret());
+  if (LocalAccessible* acc = mAcc->AsLocal()) {
+    HyperTextAccessible* ht = HyperTextFor(acc);
+    if (!ht) {
+      return false;
+    }
+    // Use HyperTextAccessible::IsCaretAtEndOfLine. Eventually, we'll want to
+    // move that code into TextLeafPoint, but existing code depends on it living
+    // in HyperTextAccessible (including caret events).
+    return ht->IsCaretAtEndOfLine();
+  }
+  return mAcc->AsRemote()->Document()->IsCaretAtEndOfLine();
+}
+
+TextLeafPoint TextLeafPoint::ActualizeCaret(bool aAdjustAtEndOfLine) const {
+  MOZ_ASSERT(IsCaret());
+  HyperTextAccessibleBase* ht;
+  int32_t htOffset;
+  if (LocalAccessible* acc = mAcc->AsLocal()) {
+    // Use HyperTextAccessible::CaretOffset. Eventually, we'll want to move
+    // that code into TextLeafPoint, but existing code depends on it living in
+    // HyperTextAccessible (including caret events).
+    ht = HyperTextFor(acc);
+    if (!ht) {
+      return TextLeafPoint();
+    }
+    htOffset = ht->CaretOffset();
+    if (htOffset == -1) {
+      return TextLeafPoint();
+    }
+  } else {
+    // Ideally, we'd cache the caret as a leaf, but our events are based on
+    // HyperText for now.
+    std::tie(ht, htOffset) = mAcc->AsRemote()->Document()->GetCaret();
+    if (!ht) {
+      return TextLeafPoint();
+    }
+  }
+  if (aAdjustAtEndOfLine && htOffset > 0 && IsCaretAtEndOfLine()) {
+    // It is the same character offset when the caret is visually at the very
+    // end of a line or the start of a new line (soft line break). Getting text
+    // at the line should provide the line with the visual caret. Otherwise,
+    // screen readers will announce the wrong line as the user presses up or
+    // down arrow and land at the end of a line.
+    --htOffset;
+  }
+  return ht->ToTextLeafPoint(htOffset);
+}
+
+TextLeafPoint TextLeafPoint::FindBoundary(AccessibleTextBoundary aBoundaryType,
+                                          nsDirection aDirection,
+                                          BoundaryFlags aFlags) const {
+  if (IsCaret()) {
+    if (aBoundaryType == nsIAccessibleText::BOUNDARY_CHAR) {
+      if (IsCaretAtEndOfLine()) {
+        // The caret is at the end of the line. Return no character.
+        return ActualizeCaret(/* aAdjustAtEndOfLine */ false);
+      }
+    }
+    return ActualizeCaret().FindBoundary(
+        aBoundaryType, aDirection, aFlags & BoundaryFlags::eIncludeOrigin);
+  }
+
+  bool inEditableAndStopInIt = (aFlags & BoundaryFlags::eStopInEditable) &&
+                               mAcc->Parent() &&
+                               (mAcc->Parent()->State() & states::EDITABLE);
+  if (aBoundaryType == nsIAccessibleText::BOUNDARY_LINE_END) {
+    return FindLineEnd(aDirection,
+                       inEditableAndStopInIt
+                           ? aFlags
+                           : (aFlags & ~BoundaryFlags::eStopInEditable));
+  }
+  if (aBoundaryType == nsIAccessibleText::BOUNDARY_WORD_END) {
+    return FindWordEnd(aDirection,
+                       inEditableAndStopInIt
+                           ? aFlags
+                           : (aFlags & ~BoundaryFlags::eStopInEditable));
+  }
+  if ((aBoundaryType == nsIAccessibleText::BOUNDARY_LINE_START ||
+       aBoundaryType == nsIAccessibleText::BOUNDARY_PARAGRAPH) &&
+      (aFlags & BoundaryFlags::eIncludeOrigin) && aDirection == eDirPrevious &&
+      IsEmptyLastLine()) {
+    // If we're at an empty line at the end of an Accessible,  we don't want to
+    // walk into the previous line. For example, this can happen if the caret
+    // is positioned on an empty line at the end of a textarea.
+    return *this;
+  }
+  bool includeOrigin = !!(aFlags & BoundaryFlags::eIncludeOrigin);
+  bool ignoreListItemMarker = !!(aFlags & BoundaryFlags::eIgnoreListItemMarker);
+  Accessible* lastAcc = nullptr;
+  for (TextLeafPoint searchFrom = *this; searchFrom;
+       searchFrom = searchFrom.NeighborLeafPoint(
+           aDirection, inEditableAndStopInIt, ignoreListItemMarker)) {
+    lastAcc = searchFrom.mAcc;
+    if (ignoreListItemMarker && searchFrom == *this &&
+        searchFrom.mAcc->Role() == roles::LISTITEM_MARKER) {
+      continue;
+    }
+    TextLeafPoint boundary;
+    // Search for the boundary within the current Accessible.
+    switch (aBoundaryType) {
+      case nsIAccessibleText::BOUNDARY_CHAR:
+        if (includeOrigin) {
+          boundary = searchFrom;
+        } else if (aDirection == eDirPrevious && searchFrom.mOffset > 0) {
+          boundary.mAcc = searchFrom.mAcc;
+          boundary.mOffset = searchFrom.mOffset - 1;
+        } else if (aDirection == eDirNext &&
+                   searchFrom.mOffset + 1 <
+                       static_cast<int32_t>(
+                           nsAccUtils::TextLength(searchFrom.mAcc))) {
+          boundary.mAcc = searchFrom.mAcc;
+          boundary.mOffset = searchFrom.mOffset + 1;
+        }
+        break;
+      case nsIAccessibleText::BOUNDARY_WORD_START:
+        if (aDirection == eDirPrevious) {
+          boundary = searchFrom.FindPrevWordStartSameAcc(includeOrigin);
+        } else {
+          boundary = searchFrom.FindNextWordStartSameAcc(includeOrigin);
+        }
+        break;
+      case nsIAccessibleText::BOUNDARY_LINE_START:
+        boundary = searchFrom.FindLineStartSameAcc(aDirection, includeOrigin,
+                                                   ignoreListItemMarker);
+        break;
+      case nsIAccessibleText::BOUNDARY_PARAGRAPH:
+        boundary = searchFrom.FindParagraphSameAcc(aDirection, includeOrigin,
+                                                   ignoreListItemMarker);
+        break;
+      default:
+        MOZ_ASSERT_UNREACHABLE();
+        break;
+    }
+    if (boundary) {
+      return boundary;
+    }
+
+    // The start/end of the Accessible might be a boundary. If so, we must stop
+    // on it.
+    includeOrigin = true;
+  }
+
+  MOZ_ASSERT(lastAcc);
+  // No further leaf was found. Use the start/end of the first/last leaf.
+  return TextLeafPoint(
+      lastAcc, aDirection == eDirPrevious
+                   ? 0
+                   : static_cast<int32_t>(nsAccUtils::TextLength(lastAcc)));
+}
+
+TextLeafPoint TextLeafPoint::FindLineEnd(nsDirection aDirection,
+                                         BoundaryFlags aFlags) const {
+  if (aDirection == eDirPrevious && IsEmptyLastLine()) {
+    // If we're at an empty line at the end of an Accessible,  we don't want to
+    // walk into the previous line. For example, this can happen if the caret
+    // is positioned on an empty line at the end of a textarea.
+    // Because we want the line end, we must walk back to the line feed
+    // character.
+    return FindBoundary(nsIAccessibleText::BOUNDARY_CHAR, eDirPrevious,
+                        aFlags & ~BoundaryFlags::eIncludeOrigin);
+  }
+  if ((aFlags & BoundaryFlags::eIncludeOrigin) && IsLineFeedChar()) {
+    return *this;
+  }
+  if (aDirection == eDirPrevious && !(aFlags & BoundaryFlags::eIncludeOrigin)) {
+    // If there is a line feed immediately before us, return that.
+    TextLeafPoint prevChar =
+        FindBoundary(nsIAccessibleText::BOUNDARY_CHAR, eDirPrevious,
+                     aFlags & ~BoundaryFlags::eIncludeOrigin);
+    if (prevChar.IsLineFeedChar()) {
+      return prevChar;
+    }
+  }
+  TextLeafPoint searchFrom = *this;
+  if (aDirection == eDirNext && IsLineFeedChar()) {
+    // If we search for the next line start from a line feed, we'll get the
+    // character immediately following the line feed. We actually want the
+    // next line start after that. Skip the line feed.
+    searchFrom = FindBoundary(nsIAccessibleText::BOUNDARY_CHAR, eDirNext,
+                              aFlags & ~BoundaryFlags::eIncludeOrigin);
+  }
+  TextLeafPoint lineStart = searchFrom.FindBoundary(
+      nsIAccessibleText::BOUNDARY_LINE_START, aDirection, aFlags);
+  if (aDirection == eDirNext && IsEmptyLastLine()) {
+    // There is a line feed immediately before us, but that's actually the end
+    // of the previous line, not the end of our empty line. Don't walk back.
+    return lineStart;
+  }
+  // If there is a line feed before this line start (at the end of the previous
+  // line), we must return that.
+  TextLeafPoint prevChar =
+      lineStart.FindBoundary(nsIAccessibleText::BOUNDARY_CHAR, eDirPrevious,
+                             aFlags & ~BoundaryFlags::eIncludeOrigin);
+  if (prevChar && prevChar.IsLineFeedChar()) {
+    return prevChar;
+  }
+  return lineStart;
+}
+
+bool TextLeafPoint::IsSpace() const {
+  return GetWordBreakClass(GetChar()) == eWbcSpace;
+}
+
+TextLeafPoint TextLeafPoint::FindWordEnd(nsDirection aDirection,
+                                         BoundaryFlags aFlags) const {
+  char16_t origChar = GetChar();
+  const bool origIsSpace = GetWordBreakClass(origChar) == eWbcSpace;
+  bool prevIsSpace = false;
+  if (aDirection == eDirPrevious ||
+      ((aFlags & BoundaryFlags::eIncludeOrigin) && origIsSpace) || !origChar) {
+    TextLeafPoint prev =
+        FindBoundary(nsIAccessibleText::BOUNDARY_CHAR, eDirPrevious,
+                     aFlags & ~BoundaryFlags::eIncludeOrigin);
+    if (aDirection == eDirPrevious && prev == *this) {
+      return *this;  // Can't go any further.
+    }
+    prevIsSpace = prev.IsSpace();
+    if ((aFlags & BoundaryFlags::eIncludeOrigin) &&
+        (origIsSpace || IsDocEdge(eDirNext)) && !prevIsSpace) {
+      // The origin is space or end of document, but the previous
+      // character is not. This means we're at the end of a word.
+      return *this;
+    }
+  }
+  TextLeafPoint boundary = *this;
+  if (aDirection == eDirPrevious && !prevIsSpace) {
+    // If there isn't space immediately before us, first find the start of the
+    // previous word.
+    boundary = FindBoundary(nsIAccessibleText::BOUNDARY_WORD_START,
+                            eDirPrevious, aFlags);
+  } else if (aDirection == eDirNext &&
+             (origIsSpace || (!origChar && prevIsSpace))) {
+    // We're within the space at the end of the word. Skip over the space. We
+    // can do that by searching for the next word start.
+    boundary = FindBoundary(nsIAccessibleText::BOUNDARY_WORD_START, eDirNext,
+                            aFlags & ~BoundaryFlags::eIncludeOrigin);
+    if (boundary.IsSpace()) {
+      // The next word starts with a space. This can happen if there is a space
+      // after or at the start of a block element.
+      return boundary;
+    }
+  }
+  if (aDirection == eDirNext) {
+    BoundaryFlags flags = aFlags;
+    if (IsDocEdge(eDirPrevious)) {
+      // If this is the start of the doc don't be inclusive in the word-start
+      // search because there is no preceding block where this could be a
+      // word-end for.
+      flags &= ~BoundaryFlags::eIncludeOrigin;
+    }
+    boundary = boundary.FindBoundary(nsIAccessibleText::BOUNDARY_WORD_START,
+                                     eDirNext, flags);
+  }
+  // At this point, boundary is either the start of a word or at a space. A
+  // word ends at the beginning of consecutive space. Therefore, skip back to
+  // the start of any space before us.
+  TextLeafPoint prev = boundary;
+  for (;;) {
+    prev = prev.FindBoundary(nsIAccessibleText::BOUNDARY_CHAR, eDirPrevious,
+                             aFlags & ~BoundaryFlags::eIncludeOrigin);
+    if (prev == boundary) {
+      break;  // Can't go any further.
+    }
+    if (!prev.IsSpace()) {
+      break;
+    }
+    boundary = prev;
+  }
+  return boundary;
+}
+
+TextLeafPoint TextLeafPoint::FindParagraphSameAcc(
+    nsDirection aDirection, bool aIncludeOrigin,
+    bool aIgnoreListItemMarker) const {
+  if (aIncludeOrigin && IsDocEdge(eDirPrevious)) {
+    // The top of the document is a paragraph boundary.
+    return *this;
+  }
+
+  if (aIgnoreListItemMarker && aIncludeOrigin && mOffset == 0 &&
+      IsLeafAfterListItemMarker()) {
+    // If we are in a list item and the previous sibling is
+    // a bullet, the 0 offset in this leaf is a line start.
+    return *this;
+  }
+
+  if (mAcc->IsTextLeaf() &&
+      // We don't want to copy strings unnecessarily. See below for the context
+      // of these individual conditions.
+      ((aIncludeOrigin && mOffset > 0) || aDirection == eDirNext ||
+       mOffset >= 2)) {
+    // If there is a line feed, a new paragraph begins after it.
+    nsAutoString text;
+    mAcc->AppendTextTo(text);
+    if (aIncludeOrigin && mOffset > 0 && text.CharAt(mOffset - 1) == '\n') {
+      return TextLeafPoint(mAcc, mOffset);
+    }
+    int32_t lfOffset = -1;
+    if (aDirection == eDirNext) {
+      lfOffset = text.FindChar('\n', mOffset);
+    } else if (mOffset >= 2) {
+      // A line feed at mOffset - 1 means the origin begins a new paragraph,
+      // but we already handled aIncludeOrigin above. Therefore, we search from
+      // mOffset - 2.
+      lfOffset = text.RFindChar('\n', mOffset - 2);
+    }
+    if (lfOffset != -1 && lfOffset + 1 < static_cast<int32_t>(text.Length())) {
+      return TextLeafPoint(mAcc, lfOffset + 1);
+    }
+  }
+
+  if (aIgnoreListItemMarker && mOffset > 0 && aDirection == eDirPrevious &&
+      IsLeafAfterListItemMarker()) {
+    // No line breaks were found in the preceding text to this offset.
+    // If we are in a list item and the previous sibling is
+    // a bullet, the 0 offset in this leaf is a line start.
+    return TextLeafPoint(mAcc, 0);
+  }
+
+  // Check whether this Accessible begins a paragraph.
+  if ((!aIncludeOrigin && mOffset == 0) ||
+      (aDirection == eDirNext && mOffset > 0)) {
+    // The caller isn't interested in whether this Accessible begins a
+    // paragraph.
+    return TextLeafPoint();
+  }
+  Accessible* prevLeaf = PrevLeaf(mAcc);
+  BlockRule blockRule;
+  Pivot pivot(nsAccUtils::DocumentFor(mAcc));
+  Accessible* prevBlock = pivot.Prev(mAcc, blockRule);
+  // Check if we're the first leaf after a block element.
+  if (prevBlock) {
+    if (
+        // If there's no previous leaf, we must be the first leaf after the
+        // block.
+        !prevLeaf ||
+        // A block can be a leaf; e.g. an empty div or paragraph.
+        prevBlock == prevLeaf) {
+      return TextLeafPoint(mAcc, 0);
+    }
+    if (prevBlock->IsAncestorOf(mAcc)) {
+      // We're inside the block.
+      if (!prevBlock->IsAncestorOf(prevLeaf)) {
+        // The previous leaf isn't inside the block. That means we're the first
+        // leaf in the block.
+        return TextLeafPoint(mAcc, 0);
+      }
+    } else {
+      // We aren't inside the block, so the block ends before us.
+      if (prevBlock->IsAncestorOf(prevLeaf)) {
+        // The previous leaf is inside the block. That means we're the first
+        // leaf after the block. This case is necessary because a block causes a
+        // paragraph break both before and after it.
+        return TextLeafPoint(mAcc, 0);
+      }
+    }
+  }
+  if (!prevLeaf || prevLeaf->IsHTMLBr()) {
+    // We're the first leaf after a line break or the start of the document.
+    return TextLeafPoint(mAcc, 0);
+  }
+  if (prevLeaf->IsTextLeaf()) {
+    // There's a text leaf before us. Check if it ends with a line feed.
+    nsAutoString text;
+    prevLeaf->AppendTextTo(text, nsAccUtils::TextLength(prevLeaf) - 1, 1);
+    if (text.CharAt(0) == '\n') {
+      return TextLeafPoint(mAcc, 0);
+    }
+  }
+  return TextLeafPoint();
+}
+
+bool TextLeafPoint::IsInSpellingError() const {
+  if (LocalAccessible* acc = mAcc->AsLocal()) {
+    auto domRanges = FindDOMSpellingErrors(acc, mOffset, mOffset + 1);
+    // If there is a spelling error overlapping this character, we're in a
+    // spelling error.
+    return !domRanges.IsEmpty();
+  }
+
+  RemoteAccessible* acc = mAcc->AsRemote();
+  MOZ_ASSERT(acc);
+  if (!acc->mCachedFields) {
+    return false;
+  }
+  auto spellingErrors =
+      acc->mCachedFields->GetAttribute<nsTArray<int32_t>>(nsGkAtoms::spelling);
+  if (!spellingErrors) {
+    return false;
+  }
+  size_t index;
+  const bool foundOrigin = BinarySearch(
+      *spellingErrors, 0, spellingErrors->Length(), mOffset, &index);
+  // In spellingErrors, even indices are start offsets, odd indices are end
+  // offsets.
+  const bool foundStart = index % 2 == 0;
+  if (foundOrigin) {
+    // mOffset is a spelling error boundary. If it's a start offset, we're in a
+    // spelling error.
+    return foundStart;
+  }
+  // index points at the next spelling error boundary after mOffset.
+  if (index == 0) {
+    return false;  // No spelling errors before mOffset.
+  }
+  if (foundStart) {
+    // We're not in a spelling error because it starts after mOffset.
+    return false;
+  }
+  // A spelling error ends after mOffset.
+  return true;
+}
+
+TextLeafPoint TextLeafPoint::FindSpellingErrorSameAcc(
+    nsDirection aDirection, bool aIncludeOrigin) const {
+  if (!aIncludeOrigin && mOffset == 0 && aDirection == eDirPrevious) {
+    return TextLeafPoint();
+  }
+  if (LocalAccessible* acc = mAcc->AsLocal()) {
+    // We want to find both start and end points, so we pass true for
+    // aAllowAdjacent.
+    auto domRanges =
+        aDirection == eDirNext
+            ? FindDOMSpellingErrors(acc, mOffset,
+                                    nsIAccessibleText::TEXT_OFFSET_END_OF_TEXT,
+                                    /* aAllowAdjacent */ true)
+            : FindDOMSpellingErrors(acc, 0, mOffset,
+                                    /* aAllowAdjacent */ true);
+    nsINode* node = acc->GetNode();
+    if (aDirection == eDirNext) {
+      for (nsRange* domRange : domRanges) {
+        if (domRange->GetStartContainer() == node) {
+          int32_t matchOffset = static_cast<int32_t>(ContentToRenderedOffset(
+              acc, static_cast<int32_t>(domRange->StartOffset())));
+          if ((aIncludeOrigin && matchOffset == mOffset) ||
+              matchOffset > mOffset) {
+            return TextLeafPoint(mAcc, matchOffset);
+          }
+        }
+        if (domRange->GetEndContainer() == node) {
+          int32_t matchOffset = static_cast<int32_t>(ContentToRenderedOffset(
+              acc, static_cast<int32_t>(domRange->EndOffset())));
+          if ((aIncludeOrigin && matchOffset == mOffset) ||
+              matchOffset > mOffset) {
+            return TextLeafPoint(mAcc, matchOffset);
+          }
+        }
+      }
+    } else {
+      for (nsRange* domRange : Reversed(domRanges)) {
+        if (domRange->GetEndContainer() == node) {
+          int32_t matchOffset = static_cast<int32_t>(ContentToRenderedOffset(
+              acc, static_cast<int32_t>(domRange->EndOffset())));
+          if ((aIncludeOrigin && matchOffset == mOffset) ||
+              matchOffset < mOffset) {
+            return TextLeafPoint(mAcc, matchOffset);
+          }
+        }
+        if (domRange->GetStartContainer() == node) {
+          int32_t matchOffset = static_cast<int32_t>(ContentToRenderedOffset(
+              acc, static_cast<int32_t>(domRange->StartOffset())));
+          if ((aIncludeOrigin && matchOffset == mOffset) ||
+              matchOffset < mOffset) {
+            return TextLeafPoint(mAcc, matchOffset);
+          }
+        }
+      }
+    }
+    return TextLeafPoint();
+  }
+
+  RemoteAccessible* acc = mAcc->AsRemote();
+  MOZ_ASSERT(acc);
+  if (!acc->mCachedFields) {
+    return TextLeafPoint();
+  }
+  auto spellingErrors =
+      acc->mCachedFields->GetAttribute<nsTArray<int32_t>>(nsGkAtoms::spelling);
+  if (!spellingErrors) {
+    return TextLeafPoint();
+  }
+  size_t index;
+  if (BinarySearch(*spellingErrors, 0, spellingErrors->Length(), mOffset,
+                   &index)) {
+    // mOffset is in spellingErrors.
+    if (aIncludeOrigin) {
+      return *this;
+    }
+    if (aDirection == eDirNext) {
+      // We don't want the origin, so move to the next spelling error boundary
+      // after mOffset.
+      ++index;
+    }
+  }
+  // index points at the next spelling error boundary after mOffset.
+  if (aDirection == eDirNext) {
+    if (spellingErrors->Length() == index) {
+      return TextLeafPoint();  // No spelling error boundary after us.
+    }
+    return TextLeafPoint(mAcc, (*spellingErrors)[index]);
+  }
+  if (index == 0) {
+    return TextLeafPoint();  // No spelling error boundary before us.
+  }
+  // Decrement index so it points at a spelling error boundary before mOffset.
+  --index;
+  if ((*spellingErrors)[index] == -1) {
+    MOZ_ASSERT(index == 0);
+    // A spelling error starts before mAcc.
+    return TextLeafPoint();
+  }
+  return TextLeafPoint(mAcc, (*spellingErrors)[index]);
+}
+
+TextLeafPoint TextLeafPoint::NeighborLeafPoint(
+    nsDirection aDirection, bool aIsEditable,
+    bool aIgnoreListItemMarker) const {
+  Accessible* acc = aDirection == eDirPrevious
+                        ? PrevLeaf(mAcc, aIsEditable, aIgnoreListItemMarker)
+                        : NextLeaf(mAcc, aIsEditable, aIgnoreListItemMarker);
+  if (!acc) {
+    return TextLeafPoint();
+  }
+
+  return TextLeafPoint(
+      acc, aDirection == eDirPrevious
+               ? static_cast<int32_t>(nsAccUtils::TextLength(acc)) - 1
+               : 0);
+}
+
+LayoutDeviceIntRect TextLeafPoint::ComputeBoundsFromFrame() const {
+  LocalAccessible* local = mAcc->AsLocal();
+  MOZ_ASSERT(local, "Can't compute bounds in frame from non-local acc");
+  nsIFrame* frame = local->GetFrame();
+  MOZ_ASSERT(frame, "No frame found for acc!");
+
+  if (!frame || !frame->IsTextFrame()) {
+    return local->Bounds();
+  }
+
+  // Substring must be entirely within the same text node.
+  MOZ_ASSERT(frame->IsPrimaryFrame(),
+             "Cannot compute content offset on non-primary frame");
+  nsIFrame::RenderedText text = frame->GetRenderedText(
+      mOffset, mOffset + 1, nsIFrame::TextOffsetType::OffsetsInRenderedText,
+      nsIFrame::TrailingWhitespace::DontTrim);
+  int32_t contentOffset = text.mOffsetWithinNodeText;
+  int32_t contentOffsetInFrame;
+  // Get the right frame continuation -- not really a child, but a sibling of
+  // the primary frame passed in
+  nsresult rv = frame->GetChildFrameContainingOffset(
+      contentOffset, true, &contentOffsetInFrame, &frame);
+  NS_ENSURE_SUCCESS(rv, LayoutDeviceIntRect());
+
+  // Start with this frame's screen rect, which we will shrink based on
+  // the char we care about within it.
+  nsRect frameScreenRect = frame->GetScreenRectInAppUnits();
+
+  // Add the point where the char starts to the frameScreenRect
+  nsPoint frameTextStartPoint;
+  rv = frame->GetPointFromOffset(contentOffset, &frameTextStartPoint);
+  NS_ENSURE_SUCCESS(rv, LayoutDeviceIntRect());
+
+  // Use the next offset to calculate the width
+  // XXX(morgan) does this work for vertical text?
+  nsPoint frameTextEndPoint;
+  rv = frame->GetPointFromOffset(contentOffset + 1, &frameTextEndPoint);
+  NS_ENSURE_SUCCESS(rv, LayoutDeviceIntRect());
+
+  frameScreenRect.SetRectX(
+      frameScreenRect.X() +
+          std::min(frameTextStartPoint.x, frameTextEndPoint.x),
+      mozilla::Abs(frameTextStartPoint.x - frameTextEndPoint.x));
+
+  nsPresContext* presContext = local->Document()->PresContext();
+  return LayoutDeviceIntRect::FromAppUnitsToNearest(
+      frameScreenRect, presContext->AppUnitsPerDevPixel());
+}
+
+/* static */
+nsTArray<int32_t> TextLeafPoint::GetSpellingErrorOffsets(
+    LocalAccessible* aAcc) {
+  nsINode* node = aAcc->GetNode();
+  auto domRanges = FindDOMSpellingErrors(
+      aAcc, 0, nsIAccessibleText::TEXT_OFFSET_END_OF_TEXT);
+  // Our offsets array will contain two offsets for each range: one for the
+  // start, one for the end. That is, the array is of the form:
+  // [r1start, r1end, r2start, r2end, ...]
+  nsTArray<int32_t> offsets(domRanges.Length() * 2);
+  for (nsRange* domRange : domRanges) {
+    if (domRange->GetStartContainer() == node) {
+      offsets.AppendElement(static_cast<int32_t>(ContentToRenderedOffset(
+          aAcc, static_cast<int32_t>(domRange->StartOffset()))));
+    } else {
+      // This range overlaps aAcc, but starts before it.
+      // This can only happen for the first range.
+      MOZ_ASSERT(domRange == *domRanges.begin() && offsets.IsEmpty());
+      // Using -1 here means this won't be treated as the start of a spelling
+      // error range, while still indicating that we're within a spelling error.
+      offsets.AppendElement(-1);
+    }
+    if (domRange->GetEndContainer() == node) {
+      offsets.AppendElement(static_cast<int32_t>(ContentToRenderedOffset(
+          aAcc, static_cast<int32_t>(domRange->EndOffset()))));
+    } else {
+      // This range overlaps aAcc, but ends after it.
+      // This can only happen for the last range.
+      MOZ_ASSERT(domRange == *domRanges.rbegin());
+      // We don't append -1 here because this would just make things harder for
+      // a binary search.
+    }
+  }
+  return offsets;
+}
+
+/* static */
+void TextLeafPoint::UpdateCachedSpellingError(dom::Document* aDocument,
+                                              const nsRange& aRange) {
+  DocAccessible* docAcc = GetExistingDocAccessible(aDocument);
+  if (!docAcc) {
+    return;
+  }
+  LocalAccessible* startAcc = docAcc->GetAccessible(aRange.GetStartContainer());
+  LocalAccessible* endAcc = docAcc->GetAccessible(aRange.GetEndContainer());
+  if (!startAcc || !endAcc) {
+    return;
+  }
+  for (Accessible* acc = startAcc; acc; acc = NextLeaf(acc)) {
+    if (acc->IsTextLeaf()) {
+      docAcc->QueueCacheUpdate(acc->AsLocal(), CacheDomain::Spelling);
+    }
+    if (acc == endAcc) {
+      // Subtle: We check this here rather than in the loop condition because
+      // we want to include endAcc but stop once we reach it. Putting it in the
+      // loop condition would mean we stop at endAcc, but we would also exclude
+      // it; i.e. we wouldn't push the cache for it.
+      break;
+    }
+  }
+}
+
+already_AddRefed<AccAttributes> TextLeafPoint::GetTextAttributesLocalAcc(
+    bool aIncludeDefaults) const {
+  LocalAccessible* acc = mAcc->AsLocal();
+  MOZ_ASSERT(acc);
+  MOZ_ASSERT(acc->IsText());
+  // TextAttrsMgr wants a HyperTextAccessible.
+  LocalAccessible* parent = acc->LocalParent();
+  HyperTextAccessible* hyperAcc = parent->AsHyperText();
+  MOZ_ASSERT(hyperAcc);
+  RefPtr<AccAttributes> attributes = new AccAttributes();
+  if (hyperAcc) {
+    TextAttrsMgr mgr(hyperAcc, aIncludeDefaults, acc,
+                     acc ? acc->IndexInParent() : -1);
+    mgr.GetAttributes(attributes, nullptr, nullptr);
+  }
+  return attributes.forget();
+}
+
+already_AddRefed<AccAttributes> TextLeafPoint::GetTextAttributes(
+    bool aIncludeDefaults) const {
+  if (!mAcc->IsText()) {
+    return nullptr;
+  }
+  RefPtr<AccAttributes> attrs;
+  if (mAcc->IsLocal()) {
+    attrs = GetTextAttributesLocalAcc(aIncludeDefaults);
+  } else {
+    attrs = new AccAttributes();
+    if (aIncludeDefaults) {
+      Accessible* parent = mAcc->Parent();
+      if (parent && parent->IsRemote() && parent->IsHyperText()) {
+        if (auto defAttrs = parent->AsRemote()->GetCachedTextAttributes()) {
+          defAttrs->CopyTo(attrs);
+        }
+      }
+    }
+    if (auto thisAttrs = mAcc->AsRemote()->GetCachedTextAttributes()) {
+      thisAttrs->CopyTo(attrs);
+    }
+  }
+  if (IsInSpellingError()) {
+    attrs->SetAttribute(nsGkAtoms::invalid, nsGkAtoms::spelling);
+  }
+  return attrs.forget();
+}
+
+TextLeafPoint TextLeafPoint::FindTextAttrsStart(nsDirection aDirection,
+                                                bool aIncludeOrigin) const {
+  if (IsCaret()) {
+    return ActualizeCaret().FindTextAttrsStart(aDirection, aIncludeOrigin);
+  }
+  const bool isRemote = mAcc->IsRemote();
+  RefPtr<const AccAttributes> lastAttrs =
+      isRemote ? mAcc->AsRemote()->GetCachedTextAttributes()
+               : GetTextAttributesLocalAcc();
+  if (aIncludeOrigin && aDirection == eDirNext && mOffset == 0) {
+    // Even when searching forward, the only way to know whether the origin is
+    // the start of a text attrs run is to compare with the previous sibling.
+    // Anything other than text breaks an attrs run.
+    TextLeafPoint point;
+    point.mAcc = mAcc->PrevSibling();
+    if (!point.mAcc || !point.mAcc->IsText()) {
+      return *this;
+    }
+    // For RemoteAccessible, we can get attributes from the cache without any
+    // calculation or copying.
+    RefPtr<const AccAttributes> attrs =
+        isRemote ? point.mAcc->AsRemote()->GetCachedTextAttributes()
+                 : point.GetTextAttributesLocalAcc();
+    if (attrs && lastAttrs && !attrs->Equal(lastAttrs)) {
+      return *this;
+    }
+  }
+  TextLeafPoint lastPoint = *this;
+  for (;;) {
+    if (TextLeafPoint spelling = lastPoint.FindSpellingErrorSameAcc(
+            aDirection, aIncludeOrigin && lastPoint.mAcc == mAcc)) {
+      // A spelling error starts or ends somewhere in the Accessible we're
+      // considering. This causes an attribute change, so return that point.
+      return spelling;
+    }
+    TextLeafPoint point;
+    point.mAcc = aDirection == eDirNext ? lastPoint.mAcc->NextSibling()
+                                        : lastPoint.mAcc->PrevSibling();
+    if (!point.mAcc || !point.mAcc->IsText()) {
+      break;
+    }
+    RefPtr<const AccAttributes> attrs =
+        isRemote ? point.mAcc->AsRemote()->GetCachedTextAttributes()
+                 : point.GetTextAttributesLocalAcc();
+    if (attrs && lastAttrs && !attrs->Equal(lastAttrs)) {
+      // The attributes change here. If we're moving forward, we want to
+      // return this point. If we're moving backward, we've now moved before
+      // the start of the attrs run containing the origin, so return that start
+      // point; i.e. the start of the last Accessible we hit.
+      if (aDirection == eDirPrevious) {
+        point = lastPoint;
+        point.mOffset = 0;
+      }
+      if (!aIncludeOrigin && point == *this) {
+        MOZ_ASSERT(aDirection == eDirPrevious);
+        // The origin is the start of an attrs run, but the caller doesn't want
+        // the origin included.
+        continue;
+      }
+      return point;
+    }
+    lastPoint = point;
+    if (aDirection == eDirPrevious) {
+      // On the next iteration, we want to search for spelling errors from the
+      // end of this Accessible.
+      lastPoint.mOffset =
+          static_cast<int32_t>(nsAccUtils::TextLength(point.mAcc));
+    }
+    lastAttrs = attrs;
+  }
+  // We couldn't move any further. Use the start/end.
+  return TextLeafPoint(
+      lastPoint.mAcc,
+      aDirection == eDirPrevious
+          ? 0
+          : static_cast<int32_t>(nsAccUtils::TextLength(lastPoint.mAcc)));
+}
+
+LayoutDeviceIntRect TextLeafPoint::CharBounds() {
+  if (mAcc && !mAcc->IsText()) {
+    // If we're dealing with an empty container, return the
+    // accessible's non-text bounds.
+    return mAcc->Bounds();
+  }
+
+  if (!mAcc || (mAcc->IsRemote() && !mAcc->AsRemote()->mCachedFields)) {
+    return LayoutDeviceIntRect();
+  }
+
+  if (LocalAccessible* local = mAcc->AsLocal()) {
+    if (!local->IsTextLeaf() || nsAccUtils::TextLength(local) == 0) {
+      // Empty content, use our own bounds to at least get x,y coordinates
+      return local->Bounds();
+    }
+
+    if (mOffset >= 0 &&
+        static_cast<uint32_t>(mOffset) >= nsAccUtils::TextLength(local)) {
+      // It's valid for a caller to query the length because the caret might be
+      // at the end of editable text. In that case, we should just silently
+      // return. However, we assert that the offset isn't greater than the
+      // length.
+      NS_ASSERTION(
+          static_cast<uint32_t>(mOffset) <= nsAccUtils::TextLength(local),
+          "Wrong in offset");
+      return LayoutDeviceIntRect();
+    }
+
+    LayoutDeviceIntRect bounds = ComputeBoundsFromFrame();
+
+    // This document may have a resolution set, we will need to multiply
+    // the document-relative coordinates by that value and re-apply the doc's
+    // screen coordinates.
+    nsPresContext* presContext = local->Document()->PresContext();
+    nsIFrame* rootFrame = presContext->PresShell()->GetRootFrame();
+    LayoutDeviceIntRect orgRectPixels =
+        LayoutDeviceIntRect::FromAppUnitsToNearest(
+            rootFrame->GetScreenRectInAppUnits(),
+            presContext->AppUnitsPerDevPixel());
+    bounds.MoveBy(-orgRectPixels.X(), -orgRectPixels.Y());
+    bounds.ScaleRoundOut(presContext->PresShell()->GetResolution());
+    bounds.MoveBy(orgRectPixels.X(), orgRectPixels.Y());
+    return bounds;
+  }
+
+  RemoteAccessible* remote = mAcc->AsRemote();
+  nsRect charBounds = remote->GetCachedCharRect(mOffset);
+  if (!charBounds.IsEmpty()) {
+    return remote->BoundsWithOffset(Some(charBounds));
+  }
+
+  return LayoutDeviceIntRect();
+}
+
+bool TextLeafPoint::ContainsPoint(int32_t aX, int32_t aY) {
+  if (mAcc && !mAcc->IsText()) {
+    // If we're dealing with an empty embedded object, use the
+    // accessible's non-text bounds.
+    return mAcc->Bounds().Contains(aX, aY);
+  }
+
+  return CharBounds().Contains(aX, aY);
+}
+
+LayoutDeviceIntRect TextLeafRange::Bounds() const {
+  if (mEnd == mStart || mEnd < mStart) {
+    return LayoutDeviceIntRect();
+  }
+
+  bool locatedFinalLine = false;
+  TextLeafPoint currPoint = mStart;
+  LayoutDeviceIntRect result = currPoint.CharBounds();
+
+  // Union the first and last chars of each line to create a line rect. Then,
+  // union the lines together.
+  while (!locatedFinalLine) {
+    // Fetch the last point in the current line by getting the
+    // start of the next line and going back one char. We don't
+    // use BOUNDARY_LINE_END here because it is equivalent to LINE_START when
+    // the line doesn't end with a line feed character.
+    TextLeafPoint lineStartPoint = currPoint.FindBoundary(
+        nsIAccessibleText::BOUNDARY_LINE_START, eDirNext);
+    TextLeafPoint lastPointInLine = lineStartPoint.FindBoundary(
+        nsIAccessibleText::BOUNDARY_CHAR, eDirPrevious);
+    // If currPoint is the end of the document, lineStartPoint will be equal
+    // to currPoint and we would be in an endless loop.
+    if (lineStartPoint == currPoint || mEnd <= lastPointInLine) {
+      lastPointInLine = mEnd;
+      locatedFinalLine = true;
+    }
+
+    LayoutDeviceIntRect currLine = currPoint.CharBounds();
+    currLine.UnionRect(currLine, lastPointInLine.CharBounds());
+    result.UnionRect(result, currLine);
+
+    currPoint = lineStartPoint;
+  }
+
+  return result;
+}
+
+bool TextLeafRange::SetSelection(int32_t aSelectionNum) const {
+  if (!mStart || !mEnd || mStart.mAcc->IsLocal() != mEnd.mAcc->IsLocal()) {
+    return false;
+  }
+
+  if (mStart.mAcc->IsRemote()) {
+    DocAccessibleParent* doc = mStart.mAcc->AsRemote()->Document();
+    if (doc != mEnd.mAcc->AsRemote()->Document()) {
+      return false;
+    }
+
+    Unused << doc->SendSetTextSelection(mStart.mAcc->ID(), mStart.mOffset,
+                                        mEnd.mAcc->ID(), mEnd.mOffset,
+                                        aSelectionNum);
+    return true;
+  }
+
+  bool reversed = mEnd < mStart;
+  auto [startContent, startContentOffset] =
+      !reversed ? mStart.ToDOMPoint(false) : mEnd.ToDOMPoint(false);
+  auto [endContent, endContentOffset] =
+      !reversed ? mEnd.ToDOMPoint(false) : mStart.ToDOMPoint(false);
+
+  if (!startContent || !endContent) {
+    return false;
+  }
+
+  RefPtr<dom::Selection> domSel = GetDOMSelection(startContent, endContent);
+  if (!domSel) {
+    return false;
+  }
+
+  uint32_t rangeCount = domSel->RangeCount();
+  RefPtr<nsRange> domRange = nullptr;
+  if (aSelectionNum == static_cast<int32_t>(rangeCount) || aSelectionNum < 0) {
+    domRange = nsRange::Create(startContent);
+  } else {
+    domRange = domSel->GetRangeAt(AssertedCast<uint32_t>(aSelectionNum));
+  }
+  if (!domRange) {
+    return false;
+  }
+
+  domRange->SetStart(startContent, startContentOffset);
+  domRange->SetEnd(endContent, endContentOffset);
+
+  // If this is not a new range, notify selection listeners that the existing
+  // selection range has changed. Otherwise, just add the new range.
+  if (aSelectionNum != static_cast<int32_t>(rangeCount)) {
+    domSel->RemoveRangeAndUnselectFramesAndNotifyListeners(*domRange,
+                                                           IgnoreErrors());
+  }
+
+  IgnoredErrorResult err;
+  domSel->AddRangeAndSelectFramesAndNotifyListeners(*domRange, err);
+  if (!err.Failed()) {
+    // Changing the direction of the selection assures that the caret
+    // will be at the logical end of the selection.
+    domSel->SetDirection(reversed ? eDirPrevious : eDirNext);
+    return true;
+  }
+
+  return false;
+}
+
+void TextLeafRange::ScrollIntoView(uint32_t aScrollType) const {
+  if (!mStart || !mEnd || mStart.mAcc->IsLocal() != mEnd.mAcc->IsLocal()) {
+    return;
+  }
+
+  if (mStart.mAcc->IsRemote()) {
+    DocAccessibleParent* doc = mStart.mAcc->AsRemote()->Document();
+    if (doc != mEnd.mAcc->AsRemote()->Document()) {
+      // Can't scroll range that spans docs.
+      return;
+    }
+
+    Unused << doc->SendScrollTextLeafRangeIntoView(
+        mStart.mAcc->ID(), mStart.mOffset, mEnd.mAcc->ID(), mEnd.mOffset,
+        aScrollType);
+    return;
+  }
+
+  auto [startContent, startContentOffset] = mStart.ToDOMPoint();
+  auto [endContent, endContentOffset] = mEnd.ToDOMPoint();
+
+  if (!startContent || !endContent) {
+    return;
+  }
+
+  ErrorResult er;
+  RefPtr<nsRange> domRange = nsRange::Create(startContent, startContentOffset,
+                                             endContent, endContentOffset, er);
+  if (er.Failed()) {
+    return;
+  }
+
+  nsCoreUtils::ScrollSubstringTo(mStart.mAcc->AsLocal()->GetFrame(), domRange,
+                                 aScrollType);
+}
+
+TextLeafRange::Iterator TextLeafRange::Iterator::BeginIterator(
+    const TextLeafRange& aRange) {
+  Iterator result(aRange);
+
+  result.mSegmentStart = aRange.mStart;
+  if (aRange.mStart.mAcc == aRange.mEnd.mAcc) {
+    result.mSegmentEnd = aRange.mEnd;
+  } else {
+    result.mSegmentEnd = TextLeafPoint(
+        aRange.mStart.mAcc, nsIAccessibleText::TEXT_OFFSET_END_OF_TEXT);
+  }
+
+  return result;
+}
+
+TextLeafRange::Iterator TextLeafRange::Iterator::EndIterator(
+    const TextLeafRange& aRange) {
+  Iterator result(aRange);
+
+  result.mSegmentEnd = TextLeafPoint();
+  result.mSegmentStart = TextLeafPoint();
+
+  return result;
+}
+
+TextLeafRange::Iterator& TextLeafRange::Iterator::operator++() {
+  if (mSegmentEnd.mAcc == mRange.mEnd.mAcc) {
+    mSegmentEnd = TextLeafPoint();
+    mSegmentStart = TextLeafPoint();
+    return *this;
+  }
+
+  if (Accessible* nextLeaf = NextLeaf(mSegmentEnd.mAcc)) {
+    mSegmentStart = TextLeafPoint(nextLeaf, 0);
+    if (nextLeaf == mRange.mEnd.mAcc) {
+      mSegmentEnd = TextLeafPoint(nextLeaf, mRange.mEnd.mOffset);
+    } else {
+      mSegmentEnd =
+          TextLeafPoint(nextLeaf, nsIAccessibleText::TEXT_OFFSET_END_OF_TEXT);
+    }
+  } else {
+    mSegmentEnd = TextLeafPoint();
+    mSegmentStart = TextLeafPoint();
+  }
+
+  return *this;
+}
+
+}  // namespace mozilla::a11y