Add support for Android spellcheck menu in Chrome/WebViews

third_party/WebKit/Source/core/editing/suggestion/TextSuggestionController.cpp

+// Copyright 2017 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "core/editing/suggestion/TextSuggestionController.h"
+
+#include "core/editing/EditingUtilities.h"
+#include "core/editing/Editor.h"
+#include "core/editing/FrameSelection.h"
+#include "core/editing/PlainTextRange.h"
+#include "core/editing/Position.h"
+#include "core/editing/markers/DocumentMarkerController.h"
+#include "core/editing/markers/SpellCheckMarker.h"
+#include "core/editing/spellcheck/SpellChecker.h"
+#include "core/frame/FrameView.h"
+#include "core/frame/LocalFrame.h"
+#include "core/layout/LayoutTheme.h"
+#include "services/service_manager/public/cpp/interface_provider.h"
+
+namespace blink {
+
+namespace {
+
+bool ShouldDeleteNextCharacter(const Node& marker_text_node,
+                               const DocumentMarker& marker) {
+  // If the character immediately following the range to be deleted is a space,
+  // delete it if either of these conditions holds:
+  // - We're deleting at the beginning of the editable text (to avoid ending up
+  //   with a space at the beginning)
+  // - The character immediately before the range being deleted is also a space
+  //   (to avoid ending up with two adjacent spaces)
+  const EphemeralRange next_character_range =
+      PlainTextRange(marker.EndOffset(), marker.EndOffset() + 1)
+          .CreateRange(*marker_text_node.parentNode());
+  // No character immediately following the range (so it can't be a space)
+  if (next_character_range.IsNull())
+    return false;
+
+  const String next_character_str =
+      PlainText(next_character_range, TextIteratorBehavior::Builder().Build());
+  const UChar next_character = next_character_str[0];
+  // Character immediately following the range is not a space
+  if (next_character != kSpaceCharacter &&
+      next_character != kNoBreakSpaceCharacter)
+    return false;
+
+  // First case: we're deleting at the beginning of the editable text
+  if (marker.StartOffset() == 0)
+    return true;
+
+  const EphemeralRange prev_character_range =
+      PlainTextRange(marker.StartOffset() - 1, marker.StartOffset())
+          .CreateRange(*marker_text_node.parentNode());
+  // Not at beginning, but there's no character immediately before the range
+  // being deleted (so it can't be a space)
+  if (prev_character_range.IsNull())
+    return false;
+
+  const String prev_character_str =
+      PlainText(prev_character_range, TextIteratorBehavior::Builder().Build());
+  // Return true if the character immediately before the range is a space, false
+  // otherwise
+  const UChar prev_character = prev_character_str[0];
+  return prev_character == kSpaceCharacter ||
+         prev_character == kNoBreakSpaceCharacter;
+}
+
+EphemeralRangeInFlatTree ComputeRangeSurroundingCaret(
+    const VisiblePositionInFlatTree& caret_visible_position) {
+  const PositionInFlatTree& caret_position =
+      caret_visible_position.DeepEquivalent();
+
+  const Node* const position_node = caret_position.ComputeContainerNode();
+  const bool is_text_node = position_node->IsTextNode();
+  const unsigned position_offset_in_node =
+      caret_position.ComputeOffsetInContainerNode();
+
+  // If we're in the interior of a text node, we can avoid calling
+  // PreviousPositionOf/NextPositionOf for better efficiency.
+  if (is_text_node && position_offset_in_node != 0 &&
+      position_offset_in_node !=
+          static_cast<unsigned>(position_node->MaxCharacterOffset())) {
+    return EphemeralRangeInFlatTree(
+        PositionInFlatTree(position_node, position_offset_in_node - 1),
+        PositionInFlatTree(position_node, position_offset_in_node + 1));
+  }
+
+  const PositionInFlatTree& previous_position =
+      PreviousPositionOf(caret_visible_position).DeepEquivalent();
+
+  const PositionInFlatTree& next_position =
+      NextPositionOf(caret_visible_position).DeepEquivalent();
+
+  return EphemeralRangeInFlatTree(
+      previous_position.IsNull() ? caret_position : previous_position,
+      next_position.IsNull() ? caret_position : next_position);
+}
+
+}  // namespace
+
+TextSuggestionController::TextSuggestionController(LocalFrame& frame)
+    : is_suggestion_menu_open_(false), frame_(&frame) {}
+
+void TextSuggestionController::DocumentAttached(Document* document) {
+  DCHECK(document);
+  SetContext(document);
+}
+
+bool TextSuggestionController::IsMenuOpen() const {
+  return is_suggestion_menu_open_;
+}
+
+void TextSuggestionController::HandlePotentialMisspelledWordTap(
+    const VisiblePositionInFlatTree& caret_visible_position) {
+  const EphemeralRangeInFlatTree& range_to_check =
+      ComputeRangeSurroundingCaret(caret_visible_position);
+
+  const Optional<std::pair<const Node*, const DocumentMarker*>>&
+      node_and_marker = FirstMarkerIntersectingRange(
+          range_to_check, DocumentMarker::MisspellingMarkers());
+  if (!node_and_marker)
+    return;
+
+  if (!text_suggestion_host_) {
+    GetFrame().GetInterfaceProvider().GetInterface(
+        mojo::MakeRequest(&text_suggestion_host_));
+  }
+
+  text_suggestion_host_->StartSpellCheckMenuTimer();
+}
+
+DEFINE_TRACE(TextSuggestionController) {
+  visitor->Trace(frame_);
+  DocumentShutdownObserver::Trace(visitor);
+}
+
+void TextSuggestionController::ApplySpellCheckSuggestion(
+    const String& suggestion) {
+  ReplaceSpellingMarkerTouchingSelectionWithText(suggestion);
+  SuggestionMenuClosed();
+}
+
+void TextSuggestionController::DeleteActiveSuggestionRange() {
+  AttemptToDeleteActiveSuggestionRange();
+  SuggestionMenuClosed();
+}
+
+void TextSuggestionController::NewWordAddedToDictionary(const String& word) {
+  // Android pops up a dialog to let the user confirm they actually want to add
+  // the word to the dictionary; this method gets called as soon as the dialog
+  // is shown. So the word isn't actually in the dictionary here, even if the
+  // user will end up confirming the dialog, and we shouldn't try to re-run
+  // spellcheck here.
+
+  // Note: this actually matches the behavior in native Android text boxes
+  GetDocument().Markers().RemoveSpellingMarkersUnderWords(
+      Vector<String>({word}));
+  SuggestionMenuClosed();
+}
+
+void TextSuggestionController::SpellCheckMenuTimeoutCallback() {
+  const Optional<std::pair<const Node*, const DocumentMarker*>>&
+      node_and_marker =
+          FirstMarkerTouchingSelection(DocumentMarker::MisspellingMarkers());
+  if (!node_and_marker)
+    return;
+
+  const Node* const marker_text_node = node_and_marker.value().first;
+  const SpellCheckMarker* const marker =
+      ToSpellCheckMarker(node_and_marker.value().second);
+
+  const EphemeralRange marker_range =
+      EphemeralRange(Position(marker_text_node, marker->StartOffset()),
+                     Position(marker_text_node, marker->EndOffset()));
+  const String& misspelled_word = PlainText(marker_range);
+  const String& description = marker->Description();
+
+  is_suggestion_menu_open_ = true;
+  GetFrame().Selection().SetCaretVisible(false);
+  GetDocument().Markers().AddActiveSuggestionMarker(
+      marker_range, SK_ColorTRANSPARENT, StyleableMarker::Thickness::kThin,
+      LayoutTheme::GetTheme().PlatformActiveSpellingMarkerHighlightColor());
+
+  Vector<String> suggestions;
+  description.Split('\n', suggestions);
+
+  Vector<mojom::blink::SpellCheckSuggestionPtr> suggestion_ptrs;
+  for (const String& suggestion : suggestions) {
+    mojom::blink::SpellCheckSuggestionPtr info_ptr(
+        mojom::blink::SpellCheckSuggestion::New());
+    info_ptr->suggestion = suggestion;
+    suggestion_ptrs.push_back(std::move(info_ptr));
+  }
+
+  const IntRect& absolute_bounds = GetFrame().Selection().AbsoluteCaretBounds();
+  const IntRect& viewport_bounds =
+      GetFrame().View()->ContentsToViewport(absolute_bounds);
+
+  text_suggestion_host_->ShowSpellCheckSuggestionMenu(
+      viewport_bounds.X(), viewport_bounds.MaxY(), std::move(misspelled_word),
+      std::move(suggestion_ptrs));
+}
+
+void TextSuggestionController::SuggestionMenuClosed() {
+  if (!IsAvailable())
+    return;
+
+  GetDocument().Markers().RemoveMarkersOfTypes(
+      DocumentMarker::kActiveSuggestion);
+  GetFrame().Selection().SetCaretVisible(true);
+  is_suggestion_menu_open_ = false;
+}
+
+Document& TextSuggestionController::GetDocument() const {
+  DCHECK(IsAvailable());
+  return *LifecycleContext();
+}
+
+bool TextSuggestionController::IsAvailable() const {
+  return LifecycleContext();
+}
+
+LocalFrame& TextSuggestionController::GetFrame() const {
+  DCHECK(frame_);
+  return *frame_;
+}
+
+Optional<std::pair<const Node*, const DocumentMarker*>>
+TextSuggestionController::FirstMarkerIntersectingRange(
+    const EphemeralRangeInFlatTree& range,
+    DocumentMarker::MarkerTypes types) const {
+  const Node* const range_start_container =
+      range.StartPosition().ComputeContainerNode();
+  const unsigned range_start_offset =
+      range.StartPosition().ComputeOffsetInContainerNode();
+  const Node* const range_end_container =
+      range.EndPosition().ComputeContainerNode();
+  const unsigned range_end_offset =
+      range.EndPosition().ComputeOffsetInContainerNode();
+
+  for (const Node& node : range.Nodes()) {
+    if (!node.IsTextNode())
+      continue;
+
+    const unsigned start_offset =
+        node == range_start_container ? range_start_offset : 0;
+    const unsigned end_offset = node == range_end_container
+                                    ? range_end_offset
+                                    : node.MaxCharacterOffset();
+
+    const DocumentMarker* const found_marker =
+        GetFrame().GetDocument()->Markers().FirstMarkerIntersectingOffsetRange(
+            ToText(node), start_offset, end_offset, types);
+    if (found_marker)
+      return std::make_pair(&node, found_marker);
+  }
+
+  return Optional<std::pair<const Node*, const DocumentMarker*>>();
+}
+
+Optional<std::pair<const Node*, const DocumentMarker*>>
+TextSuggestionController::FirstMarkerTouchingSelection(
+    DocumentMarker::MarkerTypes types) const {
+  const VisibleSelectionInFlatTree& selection =
+      GetFrame().Selection().ComputeVisibleSelectionInFlatTree();
+  if (selection.IsNone())
+    return Optional<std::pair<const Node*, const DocumentMarker*>>();
+
+  const EphemeralRangeInFlatTree& range_to_check =
+      selection.IsRange()
+          ? selection.ToNormalizedEphemeralRange()
+          : ComputeRangeSurroundingCaret(selection.VisibleStart());
+
+  return FirstMarkerIntersectingRange(range_to_check, types);
+}
+
+void TextSuggestionController::AttemptToDeleteActiveSuggestionRange() {
+  const Optional<std::pair<const Node*, const DocumentMarker*>>&
+      node_and_marker =
+          FirstMarkerTouchingSelection(DocumentMarker::kActiveSuggestion);
+  if (!node_and_marker)
+    return;
+
+  const Node* const marker_text_node = node_and_marker.value().first;
+  const DocumentMarker* const marker = node_and_marker.value().second;
+
+  const bool delete_next_char =
+      ShouldDeleteNextCharacter(*marker_text_node, *marker);
+
+  const EphemeralRange range_to_delete = EphemeralRange(
+      Position(marker_text_node, marker->StartOffset()),
+      Position(marker_text_node, marker->EndOffset() + delete_next_char));
+  ReplaceRangeWithText(range_to_delete, "");
+}
+
+void TextSuggestionController::ReplaceSpellingMarkerTouchingSelectionWithText(
+    const String& suggestion) {
+  const Optional<std::pair<const Node*, const DocumentMarker*>>&
+      node_and_marker =
+          FirstMarkerTouchingSelection(DocumentMarker::MisspellingMarkers());
+  if (!node_and_marker)
+    return;
+
+  const Node* const marker_text_node = node_and_marker.value().first;
+  const DocumentMarker* const marker = node_and_marker.value().second;
+
+  const EphemeralRange range_to_replace(
+      Position(marker_text_node, marker->StartOffset()),
+      Position(marker_text_node, marker->EndOffset()));
+  ReplaceRangeWithText(range_to_replace, suggestion);
+}
+
+void TextSuggestionController::ReplaceRangeWithText(const EphemeralRange& range,
+                                                    const String& replacement) {
+  GetFrame().Selection().SetSelection(
+      SelectionInDOMTree::Builder().SetBaseAndExtent(range).Build());
+
+  // Dispatch 'beforeinput'.
+  Element* const target = GetFrame().GetEditor().FindEventTargetFromSelection();
+  DataTransfer* const data_transfer = DataTransfer::Create(
+      DataTransfer::DataTransferType::kInsertReplacementText,
+      DataTransferAccessPolicy::kDataTransferReadable,
+      DataObject::CreateFromString(replacement));
+
+  const bool is_canceled =
+      DispatchBeforeInputDataTransfer(
+          target, InputEvent::InputType::kInsertReplacementText,
+          data_transfer) != DispatchEventResult::kNotCanceled;
+
+  // 'beforeinput' event handler may destroy target frame.
+  if (!IsAvailable())
+    return;
+
+  // TODO(editing-dev): The use of updateStyleAndLayoutIgnorePendingStylesheets
+  // needs to be audited.  See http://crbug.com/590369 for more details.
+  GetFrame().GetDocument()->UpdateStyleAndLayoutIgnorePendingStylesheets();
+
+  if (is_canceled)
+    return;
+  GetFrame().GetEditor().ReplaceSelectionWithText(
+      replacement, false, false, InputEvent::InputType::kInsertReplacementText);
+}
+
+}  // namespace blink