Adding upstream version 115.8.0esr.upstream/115.8.0esr

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

1 files changed, 817 insertions, 0 deletions

diff --git a/editor/libeditor/TextEditSubActionHandler.cpp b/editor/libeditor/TextEditSubActionHandler.cpp
new file mode 100644
index 0000000000..17fae74f2a
--- /dev/null
+++ b/editor/libeditor/TextEditSubActionHandler.cpp
@@ -0,0 +1,817 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* 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 "ErrorList.h"
+#include "TextEditor.h"
+
+#include "AutoRangeArray.h"
+#include "EditAction.h"
+#include "EditorDOMPoint.h"
+#include "EditorUtils.h"
+#include "HTMLEditor.h"
+
+#include "mozilla/Assertions.h"
+#include "mozilla/LookAndFeel.h"
+#include "mozilla/Preferences.h"
+#include "mozilla/StaticPrefs_editor.h"
+#include "mozilla/TextComposition.h"
+#include "mozilla/dom/Element.h"
+#include "mozilla/dom/HTMLBRElement.h"
+#include "mozilla/dom/NodeFilterBinding.h"
+#include "mozilla/dom/NodeIterator.h"
+#include "mozilla/dom/Selection.h"
+
+#include "nsAString.h"
+#include "nsCOMPtr.h"
+#include "nsCRT.h"
+#include "nsCRTGlue.h"
+#include "nsComponentManagerUtils.h"
+#include "nsContentUtils.h"
+#include "nsDebug.h"
+#include "nsError.h"
+#include "nsGkAtoms.h"
+#include "nsIContent.h"
+#include "nsIHTMLCollection.h"
+#include "nsINode.h"
+#include "nsISupports.h"
+#include "nsLiteralString.h"
+#include "nsNameSpaceManager.h"
+#include "nsPrintfCString.h"
+#include "nsTextNode.h"
+#include "nsUnicharUtils.h"
+
+namespace mozilla {
+
+using namespace dom;
+
+#define CANCEL_OPERATION_AND_RETURN_EDIT_ACTION_RESULT_IF_READONLY \
+  if (IsReadonly()) {                                              \
+    return EditActionResult::CanceledResult();                     \
+  }
+
+void TextEditor::OnStartToHandleTopLevelEditSubAction(
+    EditSubAction aTopLevelEditSubAction,
+    nsIEditor::EDirection aDirectionOfTopLevelEditSubAction, ErrorResult& aRv) {
+  MOZ_ASSERT(IsEditActionDataAvailable());
+  MOZ_ASSERT(!aRv.Failed());
+
+  EditorBase::OnStartToHandleTopLevelEditSubAction(
+      aTopLevelEditSubAction, aDirectionOfTopLevelEditSubAction, aRv);
+
+  MOZ_ASSERT(GetTopLevelEditSubAction() == aTopLevelEditSubAction);
+  MOZ_ASSERT(GetDirectionOfTopLevelEditSubAction() ==
+             aDirectionOfTopLevelEditSubAction);
+
+  if (NS_WARN_IF(Destroyed())) {
+    aRv.Throw(NS_ERROR_EDITOR_DESTROYED);
+    return;
+  }
+
+  if (NS_WARN_IF(!mInitSucceeded)) {
+    return;
+  }
+
+  if (aTopLevelEditSubAction == EditSubAction::eSetText) {
+    // SetText replaces all text, so spell checker handles starting from the
+    // start of new value.
+    SetSpellCheckRestartPoint(EditorDOMPoint(mRootElement, 0));
+    return;
+  }
+
+  if (aTopLevelEditSubAction == EditSubAction::eInsertText ||
+      aTopLevelEditSubAction == EditSubAction::eInsertTextComingFromIME) {
+    // For spell checker, previous selected node should be text node if
+    // possible. If anchor is root of editor, it may become invalid offset
+    // after inserting text.
+    const EditorRawDOMPoint point =
+        FindBetterInsertionPoint(EditorRawDOMPoint(SelectionRef().AnchorRef()));
+    NS_WARNING_ASSERTION(
+        point.IsSet(),
+        "EditorBase::FindBetterInsertionPoint() failed, but ignored");
+    if (point.IsSet()) {
+      SetSpellCheckRestartPoint(point);
+      return;
+    }
+  }
+  if (SelectionRef().AnchorRef().IsSet()) {
+    SetSpellCheckRestartPoint(EditorRawDOMPoint(SelectionRef().AnchorRef()));
+  }
+}
+
+nsresult TextEditor::OnEndHandlingTopLevelEditSubAction() {
+  MOZ_ASSERT(IsTopLevelEditSubActionDataAvailable());
+
+  nsresult rv;
+  while (true) {
+    if (NS_WARN_IF(Destroyed())) {
+      rv = NS_ERROR_EDITOR_DESTROYED;
+      break;
+    }
+
+    // XXX Probably, we should spellcheck again after edit action (not top-level
+    //     sub-action) is handled because the ranges can be referred only by
+    //     users.
+    if (NS_FAILED(rv = HandleInlineSpellCheckAfterEdit())) {
+      NS_WARNING("TextEditor::HandleInlineSpellCheckAfterEdit() failed");
+      break;
+    }
+
+    if (!IsSingleLineEditor() &&
+        NS_FAILED(rv = EnsurePaddingBRElementInMultilineEditor())) {
+      NS_WARNING(
+          "EditorBase::EnsurePaddingBRElementInMultilineEditor() failed");
+      break;
+    }
+
+    rv = EnsureCaretNotAtEndOfTextNode();
+    if (NS_WARN_IF(rv == NS_ERROR_EDITOR_DESTROYED)) {
+      break;
+    }
+    NS_WARNING_ASSERTION(
+        NS_SUCCEEDED(rv),
+        "TextEditor::EnsureCaretNotAtEndOfTextNode() failed, but ignored");
+    rv = NS_OK;
+    break;
+  }
+  DebugOnly<nsresult> rvIgnored =
+      EditorBase::OnEndHandlingTopLevelEditSubAction();
+  NS_WARNING_ASSERTION(
+      NS_SUCCEEDED(rvIgnored),
+      "EditorBase::OnEndHandlingTopLevelEditSubAction() failed, but ignored");
+  MOZ_ASSERT(!GetTopLevelEditSubAction());
+  MOZ_ASSERT(GetDirectionOfTopLevelEditSubAction() == eNone);
+  return rv;
+}
+
+nsresult TextEditor::InsertLineBreakAsSubAction() {
+  MOZ_ASSERT(IsEditActionDataAvailable());
+
+  if (NS_WARN_IF(!mInitSucceeded)) {
+    return NS_ERROR_NOT_INITIALIZED;
+  }
+
+  IgnoredErrorResult ignoredError;
+  AutoEditSubActionNotifier startToHandleEditSubAction(
+      *this, EditSubAction::eInsertLineBreak, nsIEditor::eNext, ignoredError);
+  if (NS_WARN_IF(ignoredError.ErrorCodeIs(NS_ERROR_EDITOR_DESTROYED))) {
+    return ignoredError.StealNSResult();
+  }
+  NS_WARNING_ASSERTION(
+      !ignoredError.Failed(),
+      "TextEditor::OnStartToHandleTopLevelEditSubAction() failed, but ignored");
+
+  Result<EditActionResult, nsresult> result =
+      InsertLineFeedCharacterAtSelection();
+  if (MOZ_UNLIKELY(result.isErr())) {
+    NS_WARNING(
+        "TextEditor::InsertLineFeedCharacterAtSelection() failed, but ignored");
+    return result.unwrapErr();
+  }
+  return NS_OK;
+}
+
+Result<EditActionResult, nsresult>
+TextEditor::InsertLineFeedCharacterAtSelection() {
+  MOZ_ASSERT(IsEditActionDataAvailable());
+  MOZ_ASSERT(!IsSingleLineEditor());
+
+  UndefineCaretBidiLevel();
+
+  CANCEL_OPERATION_AND_RETURN_EDIT_ACTION_RESULT_IF_READONLY
+
+  if (mMaxTextLength >= 0) {
+    nsAutoString insertionString(u"\n"_ns);
+    Result<EditActionResult, nsresult> result =
+        MaybeTruncateInsertionStringForMaxLength(insertionString);
+    if (MOZ_UNLIKELY(result.isErr())) {
+      NS_WARNING(
+          "TextEditor::MaybeTruncateInsertionStringForMaxLength() failed");
+      return result;
+    }
+    if (result.inspect().Handled()) {
+      // Don't return as handled since we stopped inserting the line break.
+      return EditActionResult::CanceledResult();
+    }
+  }
+
+  // if the selection isn't collapsed, delete it.
+  if (!SelectionRef().IsCollapsed()) {
+    nsresult rv =
+        DeleteSelectionAsSubAction(nsIEditor::eNone, nsIEditor::eNoStrip);
+    if (NS_FAILED(rv)) {
+      NS_WARNING(
+          "EditorBase::DeleteSelectionAsSubAction(eNone, eNoStrip) failed");
+      return Err(rv);
+    }
+  }
+
+  const auto pointToInsert = GetFirstSelectionStartPoint<EditorDOMPoint>();
+  if (NS_WARN_IF(!pointToInsert.IsSet())) {
+    return Err(NS_ERROR_FAILURE);
+  }
+  MOZ_ASSERT(pointToInsert.IsSetAndValid());
+  MOZ_ASSERT(!pointToInsert.IsContainerHTMLElement(nsGkAtoms::br));
+
+  RefPtr<Document> document = GetDocument();
+  if (NS_WARN_IF(!document)) {
+    return Err(NS_ERROR_NOT_INITIALIZED);
+  }
+
+  // Insert a linefeed character.
+  Result<InsertTextResult, nsresult> insertTextResult =
+      InsertTextWithTransaction(*document, u"\n"_ns, pointToInsert);
+  if (MOZ_UNLIKELY(insertTextResult.isErr())) {
+    NS_WARNING("TextEditor::InsertTextWithTransaction(\"\\n\") failed");
+    return insertTextResult.propagateErr();
+  }
+  insertTextResult.inspect().IgnoreCaretPointSuggestion();
+  EditorDOMPoint pointToPutCaret = insertTextResult.inspect().Handled()
+                                       ? insertTextResult.inspect()
+                                             .EndOfInsertedTextRef()
+                                             .To<EditorDOMPoint>()
+                                       : pointToInsert;
+  if (NS_WARN_IF(!pointToPutCaret.IsSetAndValid())) {
+    return Err(NS_ERROR_FAILURE);
+  }
+  // XXX I don't think we still need this.  This must have been required when
+  //     `<textarea>` was implemented with text nodes and `<br>` elements.
+  // We want the caret to stick to the content on the "right".  We want the
+  // caret to stick to whatever is past the break.  This is because the break is
+  // on the same line we were on, but the next content will be on the following
+  // line.
+  pointToPutCaret.SetInterlinePosition(InterlinePosition::StartOfNextLine);
+  nsresult rv = CollapseSelectionTo(pointToPutCaret);
+  if (NS_FAILED(rv)) {
+    NS_WARNING("EditorBase::CollapseSelectionTo() failed");
+    return Err(rv);
+  }
+  return EditActionResult::HandledResult();
+}
+
+nsresult TextEditor::EnsureCaretNotAtEndOfTextNode() {
+  MOZ_ASSERT(IsEditActionDataAvailable());
+
+  // If there is no selection ranges, we should set to the end of the editor.
+  // This is usually performed in InitEditorContentAndSelection(), however,
+  // if the editor is reframed, this may be called by
+  // OnEndHandlingTopLevelEditSubAction().
+  if (SelectionRef().RangeCount()) {
+    return NS_OK;
+  }
+
+  nsresult rv = CollapseSelectionToEndOfTextNode();
+  if (MOZ_UNLIKELY(rv == NS_ERROR_EDITOR_DESTROYED)) {
+    NS_WARNING(
+        "TextEditor::CollapseSelectionToEndOfTextNode() caused destroying the "
+        "editor");
+    return NS_ERROR_EDITOR_DESTROYED;
+  }
+  NS_WARNING_ASSERTION(
+      NS_SUCCEEDED(rv),
+      "TextEditor::CollapseSelectionToEndOfTextNode() failed, but ignored");
+
+  return NS_OK;
+}
+
+void TextEditor::HandleNewLinesInStringForSingleLineEditor(
+    nsString& aString) const {
+  static const char16_t kLF = static_cast<char16_t>('\n');
+  MOZ_ASSERT(IsEditActionDataAvailable());
+  MOZ_ASSERT(aString.FindChar(static_cast<uint16_t>('\r')) == kNotFound);
+
+  // First of all, check if aString contains '\n' since if the string
+  // does not include it, we don't need to do nothing here.
+  int32_t firstLF = aString.FindChar(kLF, 0);
+  if (firstLF == kNotFound) {
+    return;
+  }
+
+  switch (mNewlineHandling) {
+    case nsIEditor::eNewlinesReplaceWithSpaces:
+      // Default of Firefox:
+      // Strip trailing newlines first so we don't wind up with trailing spaces
+      aString.Trim(LFSTR, false, true);
+      aString.ReplaceChar(kLF, ' ');
+      break;
+    case nsIEditor::eNewlinesStrip:
+      aString.StripChar(kLF);
+      break;
+    case nsIEditor::eNewlinesPasteToFirst:
+    default: {
+      // we get first *non-empty* line.
+      int32_t offset = 0;
+      while (firstLF == offset) {
+        offset++;
+        firstLF = aString.FindChar(kLF, offset);
+      }
+      if (firstLF > 0) {
+        aString.Truncate(firstLF);
+      }
+      if (offset > 0) {
+        aString.Cut(0, offset);
+      }
+      break;
+    }
+    case nsIEditor::eNewlinesReplaceWithCommas:
+      // Default of Thunderbird:
+      aString.Trim(LFSTR, true, true);
+      aString.ReplaceChar(kLF, ',');
+      break;
+    case nsIEditor::eNewlinesStripSurroundingWhitespace: {
+      nsAutoString result;
+      uint32_t offset = 0;
+      while (offset < aString.Length()) {
+        int32_t nextLF = !offset ? firstLF : aString.FindChar(kLF, offset);
+        if (nextLF < 0) {
+          result.Append(nsDependentSubstring(aString, offset));
+          break;
+        }
+        uint32_t wsBegin = nextLF;
+        // look backwards for the first non-white-space char
+        while (wsBegin > offset && NS_IS_SPACE(aString[wsBegin - 1])) {
+          --wsBegin;
+        }
+        result.Append(nsDependentSubstring(aString, offset, wsBegin - offset));
+        offset = nextLF + 1;
+        while (offset < aString.Length() && NS_IS_SPACE(aString[offset])) {
+          ++offset;
+        }
+      }
+      aString = result;
+      break;
+    }
+    case nsIEditor::eNewlinesPasteIntact:
+      // even if we're pasting newlines, don't paste leading/trailing ones
+      aString.Trim(LFSTR, true, true);
+      break;
+  }
+}
+
+Result<EditActionResult, nsresult> TextEditor::HandleInsertText(
+    EditSubAction aEditSubAction, const nsAString& aInsertionString,
+    SelectionHandling aSelectionHandling) {
+  MOZ_ASSERT(IsEditActionDataAvailable());
+  MOZ_ASSERT(aEditSubAction == EditSubAction::eInsertText ||
+             aEditSubAction == EditSubAction::eInsertTextComingFromIME);
+  MOZ_ASSERT_IF(aSelectionHandling == SelectionHandling::Ignore,
+                aEditSubAction == EditSubAction::eInsertTextComingFromIME);
+
+  UndefineCaretBidiLevel();
+
+  if (aInsertionString.IsEmpty() &&
+      aEditSubAction != EditSubAction::eInsertTextComingFromIME) {
+    // HACK: this is a fix for bug 19395
+    // I can't outlaw all empty insertions
+    // because IME transaction depend on them
+    // There is more work to do to make the
+    // world safe for IME.
+    return EditActionResult::CanceledResult();
+  }
+
+  nsAutoString insertionString(aInsertionString);
+  if (mMaxTextLength >= 0) {
+    Result<EditActionResult, nsresult> result =
+        MaybeTruncateInsertionStringForMaxLength(insertionString);
+    if (MOZ_UNLIKELY(result.isErr())) {
+      NS_WARNING(
+          "TextEditor::MaybeTruncateInsertionStringForMaxLength() failed");
+      EditActionResult unwrappedResult = result.unwrap();
+      unwrappedResult.MarkAsHandled();
+      return unwrappedResult;
+    }
+    // If we're exceeding the maxlength when composing IME, we need to clean up
+    // the composing text, so we shouldn't return early.
+    if (result.inspect().Handled() && insertionString.IsEmpty() &&
+        aEditSubAction != EditSubAction::eInsertTextComingFromIME) {
+      return EditActionResult::CanceledResult();
+    }
+  }
+
+  uint32_t start = 0;
+  if (IsPasswordEditor()) {
+    if (GetComposition() && !GetComposition()->String().IsEmpty()) {
+      start = GetComposition()->XPOffsetInTextNode();
+    } else {
+      uint32_t end = 0;
+      nsContentUtils::GetSelectionInTextControl(&SelectionRef(), GetRoot(),
+                                                start, end);
+    }
+  }
+
+  // if the selection isn't collapsed, delete it.
+  if (!SelectionRef().IsCollapsed() &&
+      aSelectionHandling == SelectionHandling::Delete) {
+    nsresult rv =
+        DeleteSelectionAsSubAction(nsIEditor::eNone, nsIEditor::eNoStrip);
+    if (NS_FAILED(rv)) {
+      NS_WARNING(
+          "EditorBase::DeleteSelectionAsSubAction(eNone, eNoStrip) failed");
+      return Err(rv);
+    }
+  }
+
+  // XXX Why don't we cancel here?  Shouldn't we do this first?
+  CANCEL_OPERATION_AND_RETURN_EDIT_ACTION_RESULT_IF_READONLY
+
+  MaybeDoAutoPasswordMasking();
+
+  // People have lots of different ideas about what text fields
+  // should do with multiline pastes.  See bugs 21032, 23485, 23485, 50935.
+  // The six possible options are:
+  // 0. paste newlines intact
+  // 1. paste up to the first newline (default)
+  // 2. replace newlines with spaces
+  // 3. strip newlines
+  // 4. replace with commas
+  // 5. strip newlines and surrounding white-space
+  // So find out what we're expected to do:
+  if (IsSingleLineEditor()) {
+    // XXX Some callers of TextEditor::InsertTextAsAction()  already make the
+    //     string use only \n as a linebreaker.  However, they are not hot
+    //     path and nsContentUtils::PlatformToDOMLineBreaks() does nothing
+    //     if the string doesn't include \r.  So, let's convert linebreakers
+    //     here.  Note that there are too many callers of
+    //     TextEditor::InsertTextAsAction().  So, it's difficult to keep
+    //     maintaining all of them won't reach here without \r nor \r\n.
+    // XXX Should we handle do this before truncating the string for
+    //     `maxlength`?
+    nsContentUtils::PlatformToDOMLineBreaks(insertionString);
+    HandleNewLinesInStringForSingleLineEditor(insertionString);
+  }
+
+  const auto atStartOfSelection = GetFirstSelectionStartPoint<EditorDOMPoint>();
+  if (NS_WARN_IF(!atStartOfSelection.IsSetAndValid())) {
+    return Err(NS_ERROR_FAILURE);
+  }
+  MOZ_ASSERT(!atStartOfSelection.IsContainerHTMLElement(nsGkAtoms::br));
+
+  RefPtr<Document> document = GetDocument();
+  if (NS_WARN_IF(!document)) {
+    return Err(NS_ERROR_NOT_INITIALIZED);
+  }
+
+  if (aEditSubAction == EditSubAction::eInsertTextComingFromIME) {
+    EditorDOMPoint compositionStartPoint =
+        GetFirstIMESelectionStartPoint<EditorDOMPoint>();
+    if (!compositionStartPoint.IsSet()) {
+      compositionStartPoint = FindBetterInsertionPoint(atStartOfSelection);
+      NS_WARNING_ASSERTION(
+          compositionStartPoint.IsSet(),
+          "EditorBase::FindBetterInsertionPoint() failed, but ignored");
+    }
+    Result<InsertTextResult, nsresult> insertTextResult =
+        InsertTextWithTransaction(*document, insertionString,
+                                  compositionStartPoint);
+    if (MOZ_UNLIKELY(insertTextResult.isErr())) {
+      NS_WARNING("EditorBase::InsertTextWithTransaction() failed");
+      return insertTextResult.propagateErr();
+    }
+    nsresult rv = insertTextResult.unwrap().SuggestCaretPointTo(
+        *this, {SuggestCaret::OnlyIfHasSuggestion,
+                SuggestCaret::OnlyIfTransactionsAllowedToDoIt,
+                SuggestCaret::AndIgnoreTrivialError});
+    if (NS_FAILED(rv)) {
+      NS_WARNING("CaretPoint::SuggestCaretPointTo() failed");
+      return Err(rv);
+    }
+    NS_WARNING_ASSERTION(
+        rv != NS_SUCCESS_EDITOR_BUT_IGNORED_TRIVIAL_ERROR,
+        "CaretPoint::SuggestCaretPointTo() failed, but ignored");
+  } else {
+    MOZ_ASSERT(aEditSubAction == EditSubAction::eInsertText);
+
+    Result<InsertTextResult, nsresult> insertTextResult =
+        InsertTextWithTransaction(*document, insertionString,
+                                  atStartOfSelection);
+    if (MOZ_UNLIKELY(insertTextResult.isErr())) {
+      NS_WARNING("EditorBase::InsertTextWithTransaction() failed");
+      return insertTextResult.propagateErr();
+    }
+    // Ignore caret suggestion because there was
+    // AutoTransactionsConserveSelection.
+    insertTextResult.inspect().IgnoreCaretPointSuggestion();
+    if (insertTextResult.inspect().Handled()) {
+      // Make the caret attach to the inserted text, unless this text ends with
+      // a LF, in which case make the caret attach to the next line.
+      const bool endsWithLF =
+          !insertionString.IsEmpty() && insertionString.Last() == nsCRT::LF;
+      EditorDOMPoint pointToPutCaret = insertTextResult.inspect()
+                                           .EndOfInsertedTextRef()
+                                           .To<EditorDOMPoint>();
+      pointToPutCaret.SetInterlinePosition(
+          endsWithLF ? InterlinePosition::StartOfNextLine
+                     : InterlinePosition::EndOfLine);
+      MOZ_ASSERT(pointToPutCaret.IsInTextNode(),
+                 "After inserting text into a text node, insertTextResult "
+                 "should return a point in a text node");
+      nsresult rv = CollapseSelectionTo(pointToPutCaret);
+      if (NS_WARN_IF(rv == NS_ERROR_EDITOR_DESTROYED)) {
+        return Err(NS_ERROR_EDITOR_DESTROYED);
+      }
+      NS_WARNING_ASSERTION(
+          NS_SUCCEEDED(rv),
+          "EditorBase::CollapseSelectionTo() failed, but ignored");
+    }
+  }
+
+  // Unmask inputted character(s) if necessary.
+  if (IsPasswordEditor() && IsMaskingPassword() && CanEchoPasswordNow()) {
+    nsresult rv = SetUnmaskRangeAndNotify(start, insertionString.Length(),
+                                          LookAndFeel::GetPasswordMaskDelay());
+    if (NS_FAILED(rv)) {
+      NS_WARNING("TextEditor::SetUnmaskRangeAndNotify() failed");
+      return Err(rv);
+    }
+    return EditActionResult::HandledResult();
+  }
+
+  return EditActionResult::HandledResult();
+}
+
+Result<EditActionResult, nsresult> TextEditor::SetTextWithoutTransaction(
+    const nsAString& aValue) {
+  MOZ_ASSERT(IsEditActionDataAvailable());
+  MOZ_ASSERT(!IsIMEComposing());
+  MOZ_ASSERT(!IsUndoRedoEnabled());
+  MOZ_ASSERT(GetEditAction() != EditAction::eReplaceText);
+  MOZ_ASSERT(mMaxTextLength < 0);
+  MOZ_ASSERT(aValue.FindChar(static_cast<char16_t>('\r')) == kNotFound);
+
+  UndefineCaretBidiLevel();
+
+  // XXX If we're setting value, shouldn't we keep setting the new value here?
+  CANCEL_OPERATION_AND_RETURN_EDIT_ACTION_RESULT_IF_READONLY
+
+  MaybeDoAutoPasswordMasking();
+
+  RefPtr<Element> anonymousDivElement = GetRoot();
+  RefPtr<Text> textNode =
+      Text::FromNodeOrNull(anonymousDivElement->GetFirstChild());
+  MOZ_ASSERT(textNode);
+
+  // We can use this fast path only when:
+  //  - we need to insert a text node.
+  //  - we need to replace content of existing text node.
+  // Additionally, for avoiding odd result, we should check whether we're in
+  // usual condition.
+  if (!IsSingleLineEditor()) {
+    // If we're a multiline text editor, i.e., <textarea>, there is a padding
+    // <br> element for empty last line followed by scrollbar/resizer elements.
+    // Otherwise, a text node is followed by them.
+    if (!textNode->GetNextSibling() ||
+        !EditorUtils::IsPaddingBRElementForEmptyLastLine(
+            *textNode->GetNextSibling())) {
+      return EditActionResult::IgnoredResult();
+    }
+  }
+
+  // XXX Password fields accept line breaks as normal characters with this code.
+  //     Is this intentional?
+  nsAutoString sanitizedValue(aValue);
+  if (IsSingleLineEditor() && !IsPasswordEditor()) {
+    HandleNewLinesInStringForSingleLineEditor(sanitizedValue);
+  }
+
+  nsresult rv = SetTextNodeWithoutTransaction(sanitizedValue, *textNode);
+  if (NS_FAILED(rv)) {
+    NS_WARNING("EditorBase::SetTextNodeWithoutTransaction() failed");
+    return Err(rv);
+  }
+
+  return EditActionResult::HandledResult();
+}
+
+Result<EditActionResult, nsresult> TextEditor::HandleDeleteSelection(
+    nsIEditor::EDirection aDirectionAndAmount,
+    nsIEditor::EStripWrappers aStripWrappers) {
+  MOZ_ASSERT(IsEditActionDataAvailable());
+  MOZ_ASSERT(aStripWrappers == nsIEditor::eNoStrip);
+
+  UndefineCaretBidiLevel();
+
+  CANCEL_OPERATION_AND_RETURN_EDIT_ACTION_RESULT_IF_READONLY
+
+  if (IsEmpty()) {
+    return EditActionResult::CanceledResult();
+  }
+  Result<EditActionResult, nsresult> result =
+      HandleDeleteSelectionInternal(aDirectionAndAmount, nsIEditor::eNoStrip);
+  // HandleDeleteSelectionInternal() creates SelectionBatcher.  Therefore,
+  // quitting from it might cause having destroyed the editor.
+  if (NS_WARN_IF(Destroyed())) {
+    return Err(NS_ERROR_EDITOR_DESTROYED);
+  }
+  NS_WARNING_ASSERTION(
+      result.isOk(),
+      "TextEditor::HandleDeleteSelectionInternal(eNoStrip) failed");
+  return result;
+}
+
+Result<EditActionResult, nsresult> TextEditor::HandleDeleteSelectionInternal(
+    nsIEditor::EDirection aDirectionAndAmount,
+    nsIEditor::EStripWrappers aStripWrappers) {
+  MOZ_ASSERT(IsEditActionDataAvailable());
+  MOZ_ASSERT(aStripWrappers == nsIEditor::eNoStrip);
+
+  // If the current selection is empty (e.g the user presses backspace with
+  // a collapsed selection), then we want to avoid sending the selectstart
+  // event to the user, so we hide selection changes. However, we still
+  // want to send a single selectionchange event to the document, so we
+  // batch the selectionchange events, such that a single event fires after
+  // the AutoHideSelectionChanges destructor has been run.
+  SelectionBatcher selectionBatcher(SelectionRef(), __FUNCTION__);
+  AutoHideSelectionChanges hideSelection(SelectionRef());
+  nsAutoScriptBlocker scriptBlocker;
+
+  if (IsPasswordEditor() && IsMaskingPassword()) {
+    MaskAllCharacters();
+  } else {
+    const auto selectionStartPoint =
+        GetFirstSelectionStartPoint<EditorRawDOMPoint>();
+    if (NS_WARN_IF(!selectionStartPoint.IsSet())) {
+      return Err(NS_ERROR_FAILURE);
+    }
+
+    if (!SelectionRef().IsCollapsed()) {
+      nsresult rv = DeleteSelectionWithTransaction(aDirectionAndAmount,
+                                                   nsIEditor::eNoStrip);
+      if (NS_FAILED(rv)) {
+        NS_WARNING(
+            "EditorBase::DeleteSelectionWithTransaction(eNoStrip) failed");
+        return Err(rv);
+      }
+      return EditActionResult::HandledResult();
+    }
+
+    // Test for distance between caret and text that will be deleted
+    AutoCaretBidiLevelManager bidiLevelManager(*this, aDirectionAndAmount,
+                                               selectionStartPoint);
+    if (MOZ_UNLIKELY(bidiLevelManager.Failed())) {
+      NS_WARNING("EditorBase::AutoCaretBidiLevelManager() failed");
+      return Err(NS_ERROR_FAILURE);
+    }
+    bidiLevelManager.MaybeUpdateCaretBidiLevel(*this);
+    if (bidiLevelManager.Canceled()) {
+      return EditActionResult::CanceledResult();
+    }
+  }
+
+  AutoRangeArray rangesToDelete(SelectionRef());
+  Result<nsIEditor::EDirection, nsresult> result =
+      rangesToDelete.ExtendAnchorFocusRangeFor(*this, aDirectionAndAmount);
+  if (result.isErr()) {
+    NS_WARNING("AutoRangeArray::ExtendAnchorFocusRangeFor() failed");
+    return result.propagateErr();
+  }
+  if (const Text* theTextNode = GetTextNode()) {
+    rangesToDelete.EnsureRangesInTextNode(*theTextNode);
+  }
+
+  Result<CaretPoint, nsresult> caretPointOrError = DeleteRangesWithTransaction(
+      result.unwrap(), nsIEditor::eNoStrip, rangesToDelete);
+  if (MOZ_UNLIKELY(caretPointOrError.isErr())) {
+    NS_WARNING("EditorBase::DeleteRangesWithTransaction(eNoStrip) failed");
+    return caretPointOrError.propagateErr();
+  }
+
+  nsresult rv = caretPointOrError.inspect().SuggestCaretPointTo(
+      *this, {SuggestCaret::OnlyIfHasSuggestion,
+              SuggestCaret::OnlyIfTransactionsAllowedToDoIt,
+              SuggestCaret::AndIgnoreTrivialError});
+  if (NS_FAILED(rv)) {
+    NS_WARNING("CaretPoint::SuggestCaretPointTo() failed");
+    return Err(rv);
+  }
+  NS_WARNING_ASSERTION(rv != NS_SUCCESS_EDITOR_BUT_IGNORED_TRIVIAL_ERROR,
+                       "CaretPoint::SuggestCaretPointTo() failed, but ignored");
+
+  return EditActionResult::HandledResult();
+}
+
+Result<EditActionResult, nsresult>
+TextEditor::ComputeValueFromTextNodeAndBRElement(nsAString& aValue) const {
+  MOZ_ASSERT(IsEditActionDataAvailable());
+  MOZ_ASSERT(!IsHTMLEditor());
+
+  Element* anonymousDivElement = GetRoot();
+  if (MOZ_UNLIKELY(!anonymousDivElement)) {
+    // Don't warn this case, this is possible, e.g., 997805.html
+    aValue.Truncate();
+    return EditActionResult::HandledResult();
+  }
+
+  Text* textNode = Text::FromNodeOrNull(anonymousDivElement->GetFirstChild());
+  MOZ_ASSERT(textNode);
+
+  if (!textNode->Length()) {
+    aValue.Truncate();
+    return EditActionResult::HandledResult();
+  }
+
+  nsIContent* firstChildExceptText = textNode->GetNextSibling();
+  // If the DOM tree is unexpected, fall back to the expensive path.
+  bool isInput = IsSingleLineEditor();
+  bool isTextarea = !isInput;
+  if (NS_WARN_IF(isInput && firstChildExceptText) ||
+      NS_WARN_IF(isTextarea && !firstChildExceptText) ||
+      NS_WARN_IF(isTextarea &&
+                 !EditorUtils::IsPaddingBRElementForEmptyLastLine(
+                     *firstChildExceptText) &&
+                 !firstChildExceptText->IsXULElement(nsGkAtoms::scrollbar))) {
+    return EditActionResult::IgnoredResult();
+  }
+
+  // Otherwise, the text data is the value.
+  textNode->GetData(aValue);
+  return EditActionResult::HandledResult();
+}
+
+Result<EditActionResult, nsresult>
+TextEditor::MaybeTruncateInsertionStringForMaxLength(
+    nsAString& aInsertionString) {
+  MOZ_ASSERT(IsEditActionDataAvailable());
+  MOZ_ASSERT(mMaxTextLength >= 0);
+
+  if (IsIMEComposing()) {
+    return EditActionResult::IgnoredResult();
+  }
+
+  // Ignore user pastes
+  switch (GetEditAction()) {
+    case EditAction::ePaste:
+    case EditAction::ePasteAsQuotation:
+    case EditAction::eDrop:
+    case EditAction::eReplaceText:
+      // EditActionPrinciple() is non-null iff the edit was requested by
+      // javascript.
+      if (!GetEditActionPrincipal()) {
+        // By now we are certain that this is a user paste, before we ignore it,
+        // lets check if the user explictly enabled truncating user pastes.
+        if (!StaticPrefs::editor_truncate_user_pastes()) {
+          return EditActionResult::IgnoredResult();
+        }
+      }
+      [[fallthrough]];
+    default:
+      break;
+  }
+
+  uint32_t currentLength = UINT32_MAX;
+  nsresult rv = GetTextLength(&currentLength);
+  if (NS_FAILED(rv)) {
+    NS_WARNING("TextEditor::GetTextLength() failed");
+    return Err(rv);
+  }
+
+  uint32_t selectionStart, selectionEnd;
+  nsContentUtils::GetSelectionInTextControl(&SelectionRef(), GetRoot(),
+                                            selectionStart, selectionEnd);
+
+  TextComposition* composition = GetComposition();
+  const uint32_t kOldCompositionStringLength =
+      composition ? composition->String().Length() : 0;
+
+  const uint32_t kSelectionLength = selectionEnd - selectionStart;
+  // XXX This computation must be wrong.  If we'll support non-collapsed
+  //     selection even during composition for Korean IME, kSelectionLength
+  //     is part of kOldCompositionStringLength.
+  const uint32_t kNewLength =
+      currentLength - kSelectionLength - kOldCompositionStringLength;
+  if (kNewLength >= AssertedCast<uint32_t>(mMaxTextLength)) {
+    aInsertionString.Truncate();  // Too long, we cannot accept new character.
+    return EditActionResult::HandledResult();
+  }
+
+  if (aInsertionString.Length() + kNewLength <=
+      AssertedCast<uint32_t>(mMaxTextLength)) {
+    return EditActionResult::IgnoredResult();  // Enough short string.
+  }
+
+  int32_t newInsertionStringLength = mMaxTextLength - kNewLength;
+  MOZ_ASSERT(newInsertionStringLength > 0);
+  char16_t maybeHighSurrogate =
+      aInsertionString.CharAt(newInsertionStringLength - 1);
+  char16_t maybeLowSurrogate =
+      aInsertionString.CharAt(newInsertionStringLength);
+  // Don't split the surrogate pair.
+  if (NS_IS_SURROGATE_PAIR(maybeHighSurrogate, maybeLowSurrogate)) {
+    newInsertionStringLength--;
+  }
+  // XXX What should we do if we're removing IVS but its preceding
+  //     character won't be removed?
+  aInsertionString.Truncate(newInsertionStringLength);
+  return EditActionResult::HandledResult();
+}
+
+bool TextEditor::CanEchoPasswordNow() const {
+  if (!LookAndFeel::GetEchoPassword() || EchoingPasswordPrevented()) {
+    return false;
+  }
+
+  return GetEditAction() != EditAction::eDrop &&
+         GetEditAction() != EditAction::ePaste;
+}
+
+}  // namespace mozilla