Reland of "Move UndoStack from Page to Editor"

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

 /*
  * Copyright (C) 2006, 2007, 2008, 2011 Apple Inc. All rights reserved.
  * Copyright (C) 2008 Nokia Corporation and/or its subsidiary(-ies)
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
@@ skipping 188 matching lines @@
     return client;
 }
 
 EditorClient& Editor::client() const
 {
     if (Page* page = frame().page())
         return page->editorClient();
     return emptyEditorClient();
 }
 
-UndoStack* Editor::undoStack() const
-{
-    if (Page* page = frame().page())
-        return &page->undoStack();
-    return 0;
-}
-
 bool Editor::handleTextEvent(TextEvent* event)
 {
     // Default event handling for Drag and Drop will be handled by DragController
     // so we leave the event for it.
     if (event->isDrop())
         return false;
 
     if (event->isPaste()) {
         if (event->pastingFragment())
             replaceSelectionWithFragment(event->pastingFragment(), false, event->shouldSmartReplace(), event->shouldMatchStyle());
@@ skipping 543 matching lines @@
     if (!cmd->preservesTypingStyle())
         frame().selection().clearTypingStyle();
 
     // Command will be equal to last edit command only in the case of typing
     if (m_lastEditCommand.get() == cmd) {
         DCHECK(cmd->isTypingCommand());
     } else {
         // Only register a new undo command if the command passed in is
         // different from the last command
         m_lastEditCommand = cmd;
-        if (UndoStack* undoStack = this->undoStack())
-            undoStack->registerUndoStep(m_lastEditCommand->ensureComposition());
+        m_undoStack->registerUndoStep(m_lastEditCommand->ensureComposition());
     }
 
     respondToChangedContents(newSelection);
 }
 
 void Editor::unappliedEditing(EditCommandComposition* cmd)
 {
     EventQueueScope scope;
     frame().document()->updateStyleAndLayout();
 
     dispatchEditableContentChangedEvents(cmd->startingRootEditableElement(), cmd->endingRootEditableElement());
     dispatchInputEventEditableContentChanged(cmd->startingRootEditableElement(), cmd->endingRootEditableElement(), InputEvent::InputType::Undo, emptyString(), InputEvent::EventIsComposing::NotComposing);
 
     VisibleSelection newSelection(cmd->startingSelection());
     newSelection.validatePositionsIfNeeded();
     if (newSelection.start().document() == frame().document() && newSelection.end().document() == frame().document())
         changeSelectionAfterCommand(newSelection, FrameSelection::CloseTyping | FrameSelection::ClearTypingStyle);
 
     m_lastEditCommand = nullptr;
-    if (UndoStack* undoStack = this->undoStack())
-        undoStack->registerRedoStep(cmd);
+    m_undoStack->registerRedoStep(cmd);
     respondToChangedContents(newSelection);
 }
 
 void Editor::reappliedEditing(EditCommandComposition* cmd)
 {
     EventQueueScope scope;
     frame().document()->updateStyleAndLayout();
 
     dispatchEditableContentChangedEvents(cmd->startingRootEditableElement(), cmd->endingRootEditableElement());
     dispatchInputEventEditableContentChanged(cmd->startingRootEditableElement(), cmd->endingRootEditableElement(), InputEvent::InputType::Redo, emptyString(), InputEvent::EventIsComposing::NotComposing);
 
     // TODO(yosin): Since |dispatchEditableContentChangedEvents()| and
     // |dispatchInputEventEditableContentChanged()|, we would like to know
     // such case. Once we have a case, this |DCHECK()| should be replaced
     // with if-statement.
     DCHECK(frame().document());
     VisibleSelection newSelection(cmd->endingSelection());
     if (newSelection.isValidFor(*frame().document()))
         changeSelectionAfterCommand(newSelection, FrameSelection::CloseTyping | FrameSelection::ClearTypingStyle);
 
     m_lastEditCommand = nullptr;
-    if (UndoStack* undoStack = this->undoStack())
-        undoStack->registerUndoStep(cmd);
+    m_undoStack->registerUndoStep(cmd);
     respondToChangedContents(newSelection);
 }
 
 Editor* Editor::create(LocalFrame& frame)
 {
     return new Editor(frame);
 }
 
 Editor::Editor(LocalFrame& frame)
     : m_frame(&frame)
+    , m_undoStack(UndoStack::create())
     , m_preventRevealSelection(0)
     , m_shouldStartNewKillRingSequence(false)
     // This is off by default, since most editors want this behavior (this matches IE but not FF).
     , m_shouldStyleWithCSS(false)
     , m_killRing(wrapUnique(new KillRing))
     , m_areMarkedTextMatchesHighlighted(false)
     , m_defaultParagraphSeparator(EditorParagraphSeparatorIsDiv)
     , m_overwriteModeEnabled(false)
 {
 }
@@ skipping 214 matching lines @@
     }
 }
 
 void Editor::copyImage(const HitTestResult& result)
 {
     writeImageNodeToPasteboard(Pasteboard::generalPasteboard(), result.innerNodeOrImageMapImage(), result.altDisplayString());
 }
 
 bool Editor::canUndo()
 {
-    if (UndoStack* undoStack = this->undoStack())
-        return undoStack->canUndo();
-    return false;
+    return m_undoStack->canUndo();
 }
 
 void Editor::undo()
 {
-    if (UndoStack* undoStack = this->undoStack())
-        undoStack->undo();
+    m_undoStack->undo();
 }
 
 bool Editor::canRedo()
 {
-    if (UndoStack* undoStack = this->undoStack())
-        return undoStack->canRedo();
-    return false;
+    return m_undoStack->canRedo();
 }
 
 void Editor::redo()
 {
-    if (UndoStack* undoStack = this->undoStack())
-        undoStack->redo();
+    m_undoStack->redo();
+}
+
+void Editor::clearUndoStack()
+{
+    return m_undoStack->clear();

[yosin_UTC9, 2016/07/06 01:04:51]

How about doing |m_undoStack->clear()| to move |Editor::clear()|, which is
called by |FrameLoader::clear()|?

[Xiaocheng, 2016/07/06 04:18:32]

It seems a saner idea as now UndoStack is just an implementation details of
Editor.

Done.

 }
 
 void Editor::setBaseWritingDirection(WritingDirection direction)
 {
     Element* focusedElement = frame().document()->focusedElement();
     if (isHTMLTextFormControlElement(focusedElement)) {
         if (direction == NaturalWritingDirection)
             return;
         focusedElement->setAttribute(dirAttr, direction == LeftToRightWritingDirection ? "ltr" : "rtl");
         focusedElement->dispatchInputEvent();
@@ skipping 332 matching lines @@
     DCHECK(!document.documentElement());
     document.appendChild(root);
 
     // TODO(tkent): Should we check and move Text node children of <html>?
 }
 
 DEFINE_TRACE(Editor)
 {
     visitor->trace(m_frame);
     visitor->trace(m_lastEditCommand);
+    visitor->trace(m_undoStack);
     visitor->trace(m_mark);
 }
 
 } // namespace blink