[Reland] Refactor the selection code in EventHandler

Source/core/editing/SelectionController.h

Index: Source/core/editing/SelectionController.h
diff --git a/Source/core/editing/SelectionController.h b/Source/core/editing/SelectionController.h
new file mode 100644
index 0000000000000000000000000000000000000000..972ada5868a8541afb7386beab6b5e3c168c0cf0
--- /dev/null
+++ b/Source/core/editing/SelectionController.h
@@ -0,0 +1,65 @@
+// Copyright 2015 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.
+
+#ifndef SelectionController_h
+#define SelectionController_h
+#include "core/CoreExport.h"
+#include "core/editing/TextGranularity.h"
+#include "core/page/EventWithHitTestResults.h"
+#include "platform/heap/Handle.h"
+
+namespace blink {
+
+class LocalFrame;
+class HitTestResult;
+class VisibleSelection;
+
+enum AppendTrailingWhitespace { ShouldAppendTrailingWhitespace, DontAppendTrailingWhitespace };
+
+class CORE_EXPORT SelectionController : public NoBaseWillBeGarbageCollectedFinalized<SelectionController> {
+    WTF_MAKE_NONCOPYABLE(SelectionController);
+public:
+    explicit SelectionController(LocalFrame*);
+    ~SelectionController();
+    DECLARE_TRACE();
+
+    void clear();
+
+    bool updateSelectionForMouseDownDispatchingSelectStart(Node*, const VisibleSelection&, TextGranularity);
+    void selectClosestWordFromHitTestResult(const HitTestResult&, AppendTrailingWhitespace);
+    void selectClosestMisspellingFromHitTestResult(const HitTestResult&, AppendTrailingWhitespace);
+    void selectClosestWordFromMouseEvent(const MouseEventWithHitTestResults&);
+    void selectClosestMisspellingFromMouseEvent(const MouseEventWithHitTestResults&);
+    void selectClosestWordOrLinkFromMouseEvent(const MouseEventWithHitTestResults&);
+
+    void handleMousePressEvent(const MouseEventWithHitTestResults&);
+    bool handleMousePressEventSingleClick(const MouseEventWithHitTestResults&);
+    bool handleMousePressEventDoubleClick(const MouseEventWithHitTestResults&);
+    bool handleMousePressEventTripleClick(const MouseEventWithHitTestResults&);
+    void handleMouseDraggedEvent(const MouseEventWithHitTestResults&, const IntPoint&, const LayoutPoint&, const RefPtr<Node>, const IntPoint&);
+    bool handleMouseReleaseEvent(const MouseEventWithHitTestResults&, const LayoutPoint&);
+    bool handlePasteGlobalSelection(const PlatformMouseEvent&);
+
+    void updateSelectionForMouseDrag(const RefPtr<Node>, const LayoutPoint&, const IntPoint&);
+    void updateSelectionForMouseDrag(const HitTestResult&, const RefPtr<Node>, const LayoutPoint&, const IntPoint&);
+    void selectionForContextMenu(const MouseEventWithHitTestResults&, const LayoutPoint&);
+    void releaseSelection(MouseEventWithHitTestResults&);
+    void notifySelectionChanged();
+
+    void initializeSelectionState() { m_selectionState = HaveNotStartedSelection; }
+    void setAllowSelection(bool allow) { m_allowSelection = allow; }
+    bool allowSelection() const { return m_allowSelection; }
+    bool singleClickInSelection() { return m_singleClickInSelection; }
+
+private:
+    LocalFrame* const m_frame;
+
+    bool m_allowSelection;
+    bool m_singleClickInSelection;
+    enum SelectionState { HaveNotStartedSelection, PlacedCaret, ExtendedSelection };
+    SelectionState m_selectionState;
+};
+
+}
+#endif // SelectionController_h