[WIP] Add support for Android SuggestionSpans when editing text

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

Index: third_party/WebKit/Source/core/editing/TextSuggestionController.cpp
diff --git a/third_party/WebKit/Source/core/editing/TextSuggestionController.cpp b/third_party/WebKit/Source/core/editing/TextSuggestionController.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..287559b9683e96aa4314e9f90d978157689a97dd
--- /dev/null
+++ b/third_party/WebKit/Source/core/editing/TextSuggestionController.cpp
@@ -0,0 +1,375 @@
+// 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/TextSuggestionController.h"
+
+#include "core/dom/Document.h"
+#include "core/editing/Editor.h"
+#include "core/editing/FrameSelection.h"
+#include "core/editing/InputMethodController.h"
+#include "core/editing/PlainTextRange.h"
+#include "core/editing/TextSuggestionInfo.h"
+#include "core/editing/TextSuggestionList.h"
+#include "core/editing/markers/DocumentMarker.h"
+#include "core/editing/markers/DocumentMarkerController.h"
+#include "core/frame/LocalFrame.h"
+#include "core/layout/LayoutTheme.h"
+#include "public/platform/InterfaceProvider.h"
+#include "public/platform/InterfaceRegistry.h"
+#include "wtf/Vector.h"
+
+namespace blink {
+
+namespace {
+
+const int kMaxNumberSuggestions = 5;
+const double kSuggestionUnderlineAlphaMultiplier = 0.4;
+
+}  // anonymous namespace
+
+TextSuggestionController* TextSuggestionController::create(LocalFrame& frame) {
+  return new TextSuggestionController(frame);
+}
+
+TextSuggestionController::TextSuggestionController(LocalFrame& frame)
+    : m_suggestionMenuIsOpen(false), m_frame(&frame) {}
+
+bool TextSuggestionController::suggestionMenuIsOpen() const {
+  return m_suggestionMenuIsOpen;
+}
+
+void TextSuggestionController::applySuggestionReplacement(
+    int suggestionID,
+    int suggestionIndex) {
+  suggestionMenuClosed();
+
+  Element* rootEditableElement =
+      frame()
+          .selection()
+          .computeVisibleSelectionInDOMTreeDeprecated()
+          .rootEditableElement();
+
+  DocumentMarkerVector suggestionMarkers =
+      rootEditableElement->document().markers().markersInRangeInclusive(
+          firstEphemeralRangeOf(
+              m_frame->selection()
+                  .computeVisibleSelectionInDOMTreeDeprecated()),
+          DocumentMarker::Suggestion);
+
+  SuggestionMarker* suggestionMarkerPtr = nullptr;
+  for (Member<DocumentMarker>& marker : suggestionMarkers) {
+    SuggestionMarker& suggestionMarker = toSuggestionMarker(*marker.get());
+    if (suggestionMarker.suggestionID() == suggestionID) {
+      suggestionMarkerPtr = &suggestionMarker;
+      break;
+    }
+  }
+
+  // TODO: replace ALL suggestion markers with ID (could span multiple nodes)
+  // We should always be able to find the marker we're replacing unless we have
+  // a bug
+  DCHECK(suggestionMarkerPtr);
+  if (!suggestionMarkerPtr)
+    return;
+
+  const EphemeralRange rangeToReplace =
+      PlainTextRange(suggestionMarkerPtr->startOffset(), suggestionMarkerPtr->endOffset())
+          .createRange(*rootEditableElement);
+
+  // The entry in the suggestion drop-down that the user tapped on is replaced
+  // by the text they just overwrote
+  String replacement =
+      String::fromUTF8(suggestionMarkerPtr->suggestions()[suggestionIndex].utf8());
+  String newSuggestion;
+  {
+    DocumentLifecycle::DisallowTransitionScope disallowTransition(
+        document().lifecycle());
+    newSuggestion =
+        plainText(rangeToReplace, TextIteratorBehavior::Builder().build());
+  }
+
+  DCHECK(!rangeToReplace.isNull());
+  if (rangeToReplace.isNull())
+    return;
+
+  frame().selection().setSelection(
+      SelectionInDOMTree::Builder().setBaseAndExtent(rangeToReplace).build(),
+      0);
+  // Intentionally avoid sending JavaScript composition events
+  frame().editor().replaceSelectionWithText(
+      replacement, false, false, InputEvent::InputType::InsertReplacementText);
+
+  suggestionMarkerPtr->replaceSuggestion(suggestionIndex, newSuggestion.utf8().data());
+}
+
+void TextSuggestionController::deleteSuggestionHighlight() {
+  // We *do* want to remove markers touching the selection for this operation
+  m_suggestionMenuIsOpen = false;
+
+  Element* rootEditableElement =
+      frame()
+          .selection()
+          .computeVisibleSelectionInDOMTreeDeprecated()
+          .rootEditableElement();
+  DocumentMarkerVector suggestionHighlightMarkers =
+      rootEditableElement->document().markers().markersInRangeInclusive(
+          firstEphemeralRangeOf(
+              m_frame->selection()
+                  .computeVisibleSelectionInDOMTreeDeprecated()),
+          DocumentMarker::SuggestionHighlight);
+
+  DCHECK(!suggestionHighlightMarkers.isEmpty());
+  if (suggestionHighlightMarkers.isEmpty())
+    return;
+
+  const DocumentMarker* suggestionHighlightMarkerPtr =
+      suggestionHighlightMarkers[0].get();
+
+  // 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)
+
+  bool deleteNextChar = false;
+
+  const PlainTextRange nextCharacterRange(
+      suggestionHighlightMarkerPtr->endOffset(),
+      suggestionHighlightMarkerPtr->endOffset() + 1);
+  const EphemeralRange& nextCharacterEphemeralRange =
+      nextCharacterRange.createRange(*rootEditableElement);
+  if (!nextCharacterEphemeralRange.isNull()) {
+    String nextCharacterStr = plainText(
+        nextCharacterEphemeralRange,
+        TextIteratorBehavior::Builder().setEmitsSpaceForNbsp(true).build());
+
+    if (WTF::isASCIISpace(nextCharacterStr[0])) {
+      if (suggestionHighlightMarkerPtr->startOffset() == 0) {
+        deleteNextChar = true;
+      } else {
+        const PlainTextRange prevCharacterRange(
+            suggestionHighlightMarkerPtr->startOffset() - 1,
+            suggestionHighlightMarkerPtr->startOffset());
+        const EphemeralRange prevCharacterEphemeralRange =
+            prevCharacterRange.createRange(*rootEditableElement);
+        if (!prevCharacterEphemeralRange.isNull()) {
+          String prevCharacterStr = plainText(prevCharacterEphemeralRange,
+                                              TextIteratorBehavior::Builder()
+                                                  .setEmitsSpaceForNbsp(true)
+                                                  .build());
+          if (WTF::isASCIISpace(prevCharacterStr[0])) {
+            deleteNextChar = true;
+          }
+        }
+      }
+    }
+  }
+
+  const EphemeralRange highlightRange =
+      PlainTextRange(suggestionHighlightMarkerPtr->startOffset(),
+                     suggestionHighlightMarkerPtr->endOffset() + deleteNextChar)
+          .createRange(*rootEditableElement);
+
+  frame().selection().setSelection(
+      SelectionInDOMTree::Builder().setBaseAndExtent(highlightRange).build(),
+      0);
+  // Don't want to send JavaScript composition events here
+  frame().editor().replaceSelectionWithText(
+      "", false, false, InputEvent::InputType::InsertReplacementText);
+
+  suggestionMenuClosed();
+}
+
+void TextSuggestionController::suggestionMenuClosed() {
+  document().markers().removeMarkers(DocumentMarker::SuggestionHighlight);
+  frame().selection().setCaretVisible(true);
+  m_suggestionMenuIsOpen = false;
+}
+
+void TextSuggestionController::handlePotentialTextSuggestionTap() {
+  Vector<blink::TextSuggestionInfo> suggestion_infos =
+      getTextSuggestionInfosUnderCaretAndAddHighlight();
+  if (suggestion_infos.size() == 0)
+    return;
+
+  // The composition is now on the suggestion range highlight
+  // TODO: how to do this?
+  //  UpdateCompositionInfo(false /* not an immediate request */);
+  prepareForTextSuggestionMenuToBeShown();
+
+  if (!text_suggestion_host_) {
+    frame().interfaceProvider()->getInterface(
+        mojo::MakeRequest(&text_suggestion_host_));
+  }
+
+  Vector<mojom::blink::TextSuggestionInfoPtr> suggestion_info_ptrs;
+  for (const blink::TextSuggestionInfo& info : suggestion_infos) {
+    mojom::blink::TextSuggestionInfoPtr info_ptr(
+        mojom::blink::TextSuggestionInfo::New());
+    info_ptr->suggestionID = info.suggestionID;
+    info_ptr->suggestionIndex = info.suggestionIndex;
+    info_ptr->prefix = info.prefix;
+    info_ptr->suggestion = info.suggestion;
+    info_ptr->suffix = info.suffix;
+
+    suggestion_info_ptrs.push_back(std::move(info_ptr));
+  }
+
+  text_suggestion_host_->ShowTextSuggestionMenu(
+      std::move(suggestion_info_ptrs));
+}
+
+void TextSuggestionController::prepareForTextSuggestionMenuToBeShown() {
+  m_suggestionMenuIsOpen = true;
+  frame().selection().setCaretVisible(false);
+}
+
+void TextSuggestionController::removeSuggestionMarkersAffectedByEditing(
+    bool doNotRemoveIfSelectionAtWordBoundary) {
+  // Don't remove suggestion markers when we're doing a replace operation
+  if (suggestionMenuIsOpen())
+    return;
+
+  document().markers().removeMarkersForWordsAffectedByEditing(
+      DocumentMarker::Suggestion, doNotRemoveIfSelectionAtWordBoundary);
+}
+
+bool TextSuggestionController::isAvailable() const {
+  return frame().document();
+}
+
+Document& TextSuggestionController::document() const {
+  DCHECK(isAvailable());
+  return *frame().document();
+}
+
+Vector<blink::TextSuggestionInfo>
+TextSuggestionController::getTextSuggestionInfosUnderCaretAndAddHighlight()
+    const {
+  Element* rootEditableElement =
+      frame()
+          .selection()
+          .computeVisibleSelectionInDOMTreeDeprecated()
+          .rootEditableElement();
+  if (!rootEditableElement)
+    return Vector<blink::TextSuggestionInfo>();
+
+  DocumentMarkerVector suggestionMarkers =
+      rootEditableElement->document().markers().markersInRangeInclusive(
+          firstEphemeralRangeOf(
+              m_frame->selection()
+                  .computeVisibleSelectionInDOMTreeDeprecated()),
+          DocumentMarker::Suggestion);
+
+  Vector<TextSuggestionList> suggestionSpans;
+  for (const Member<DocumentMarker>& marker : suggestionMarkers) {
+    // ignore ranges that have been collapsed as a result of editing
+    // operations
+    if (marker->endOffset() == marker->startOffset())
+      continue;
+
+    const SuggestionMarker& suggestionMarker = toSuggestionMarker(*marker);
+
+    TextSuggestionList suggestionList;
+    suggestionList.suggestionID = suggestionMarker.suggestionID();
+    suggestionList.start = suggestionMarker.startOffset();
+    suggestionList.end = suggestionMarker.endOffset();
+    suggestionList.suggestions = suggestionMarker.suggestions();
+    suggestionSpans.push_back(suggestionList);
+  }
+  std::sort(suggestionSpans.begin(), suggestionSpans.end());
+
+  Vector<TextSuggestionInfo> suggestionInfos;
+
+  for (const TextSuggestionList& suggestionList : suggestionSpans) {
+    if (suggestionInfos.size() == kMaxNumberSuggestions)
+      break;
+
+    for (size_t suggestionIndex = 0;
+         suggestionIndex < suggestionList.suggestions.size();
+         suggestionIndex++) {
+      const String& suggestion = suggestionList.suggestions[suggestionIndex];
+      bool isDupe = false;
+      for (size_t i = 0; i < suggestionInfos.size(); i++) {
+        const TextSuggestionInfo& otherSuggestionInfo = suggestionInfos[i];
+        if (otherSuggestionInfo.suggestion == suggestion) {
+          if (suggestionList.start == otherSuggestionInfo.spanStart &&
+              suggestionList.end == otherSuggestionInfo.spanEnd) {
+            isDupe = true;
+            break;
+          }
+        }
+      }
+
+      if (isDupe)
+        continue;
+
+      TextSuggestionInfo suggestionInfo;
+      suggestionInfo.suggestionID = suggestionList.suggestionID;
+      suggestionInfo.suggestionStart = 0;
+      suggestionInfo.suggestionEnd = suggestion.length();
+      suggestionInfo.spanStart = suggestionList.start;
+      suggestionInfo.spanEnd = suggestionList.end;
+      suggestionInfo.suggestionIndex = suggestionIndex;
+      suggestionInfo.suggestion = suggestion;
+      suggestionInfos.push_back(suggestionInfo);
+      if (suggestionInfos.size() == kMaxNumberSuggestions)
+        break;
+    }
+  }
+
+  if (suggestionInfos.size() == 0)
+    return Vector<blink::TextSuggestionInfo>();
+
+  int spanUnionStart = suggestionInfos[0].spanStart;
+  int spanUnionEnd = suggestionInfos[0].spanEnd;
+
+  for (size_t i = 1; i < suggestionInfos.size(); i++) {
+    spanUnionStart = std::min(spanUnionStart, suggestionInfos[i].spanStart);
+    spanUnionEnd = std::max(spanUnionEnd, suggestionInfos[i].spanEnd);
+  }
+
+  for (TextSuggestionInfo& info : suggestionInfos) {
+    const EphemeralRange& prefixRange =
+        PlainTextRange(spanUnionStart, info.spanStart)
+            .createRange(*rootEditableElement);
+    String prefix =
+        plainText(prefixRange, TextIteratorBehavior::Builder().build());
+
+    const EphemeralRange& suffixRange =
+        PlainTextRange(info.spanEnd, spanUnionEnd)
+            .createRange(*rootEditableElement);
+    String suffix =
+        plainText(suffixRange, TextIteratorBehavior::Builder().build());
+
+    info.prefix = prefix.utf8().data();
+    info.suffix = suffix.utf8().data();
+  }
+
+  Color highlightColor;
+  const SuggestionMarker& firstSuggestionMarker = *toSuggestionMarker(suggestionMarkers[0]);
+  if (firstSuggestionMarker.underlineColor() != 0) {
+    highlightColor = firstSuggestionMarker.underlineColor().combineWithAlpha(
+        kSuggestionUnderlineAlphaMultiplier);
+  } else {
+    highlightColor = LayoutTheme::tapHighlightColor();
+  }
+
+  EphemeralRange backgroundHighlightRange =
+      PlainTextRange(spanUnionStart, spanUnionEnd)
+          .createRange(*rootEditableElement);
+  document().markers().addSuggestionHighlightMarker(
+      backgroundHighlightRange,
+      Color::black, false,
+      highlightColor);
+
+  return suggestionInfos;
+}
+
+DEFINE_TRACE(TextSuggestionController) {
+  visitor->trace(m_frame);
+}
+
+}  // namespace blink