Implementing directional selection strategy in Blink.

Source/core/editing/FrameSelection.h

 /*
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010 Apple Inc. All rights reserved.
  *
  * 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
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 23 matching lines @@
 #include "platform/Timer.h"
 #include "platform/geometry/IntRect.h"
 #include "platform/geometry/LayoutRect.h"
 #include "platform/heap/Handle.h"
 #include "wtf/Noncopyable.h"
 
 namespace blink {
 
 class CharacterData;
 class LocalFrame;
+class GranularityStrategy;
 class GraphicsContext;
 class HTMLFormElement;
 class Text;
 class VisiblePosition;
 
 enum EUserTriggered { NotUserTriggered = 0, UserTriggered = 1 };
 
 enum RevealExtentOption {
     RevealExtent,
     DoNotRevealExtent
@@ skipping 13 matching lines @@
     enum EAlteration { AlterationMove, AlterationExtend };
     enum CursorAlignOnScroll { AlignCursorOnScrollIfNeeded,
                                AlignCursorOnScrollAlways };
     enum SetSelectionOption {
         // 1 << 0 is reserved for EUserTriggered
         CloseTyping = 1 << 1,
         ClearTypingStyle = 1 << 2,
         SpellCorrectionTriggered = 1 << 3,
         DoNotSetFocus = 1 << 4,
         DoNotUpdateAppearance = 1 << 5,
+        DoNotClearStrategy = 1 << 6,
     };
     typedef unsigned SetSelectionOptions; // Union of values in SetSelectionOption and EUserTriggered
     static inline EUserTriggered selectionOptionsToUserTriggered(SetSelectionOptions options)
     {
         return static_cast<EUserTriggered>(options & UserTriggered);
     }
 
     enum DirectoinalOption {
         NonDirectional,
         Directional
@@ skipping 28 matching lines @@
 
     bool contains(const LayoutPoint&);
 
     SelectionType selectionType() const { return m_selection.selectionType(); }
 
     EAffinity affinity() const { return m_selection.affinity(); }
 
     bool modify(EAlteration, SelectionDirection, TextGranularity, EUserTriggered = NotUserTriggered);
     enum VerticalDirection { DirectionUp, DirectionDown };
     bool modify(EAlteration, unsigned verticalDistance, VerticalDirection, EUserTriggered = NotUserTriggered, CursorAlignOnScroll = AlignCursorOnScrollIfNeeded);
-    // Currently we support only CharaterGranularity and WordGranurarity.
-    void moveRangeSelectionExtent(const VisiblePosition&, TextGranularity);
+
+    // Moves the selection extent based on the selection granularity strategy.
+    // This function does not allow the selection to collapse. If the new extent
+    // is set to the same position as the current base, this function will do nothing.
+    void moveRangeSelectionExtent(const VisiblePosition&);
     void moveRangeSelection(const VisiblePosition& base, const VisiblePosition& extent, TextGranularity);
 
     TextGranularity granularity() const { return m_granularity; }
 
     void setStart(const VisiblePosition &, EUserTriggered = NotUserTriggered);
     void setEnd(const VisiblePosition &, EUserTriggered = NotUserTriggered);
 
     void setBase(const VisiblePosition&, EUserTriggered = NotUserTriggered);
     void setExtent(const VisiblePosition&, EUserTriggered = NotUserTriggered);
 
@@ skipping 127 matching lines @@
 
     bool dispatchSelectStart();
 
     void updateSelectionIfNeeded(const Position& base, const Position& extent, const Position& start, const Position& end);
 
     void startObservingVisibleSelectionChange();
     void stopObservingVisibleSelectionChangeIfNecessary();
 
     VisibleSelection validateSelection(const VisibleSelection&);
 
+    GranularityStrategy& granularityStrategy();
+
     RawPtrWillBeMember<LocalFrame> m_frame;
 
     LayoutUnit m_xPosForVerticalArrowNavigation;
 
     VisibleSelection m_selection;
     bool m_observingVisibleSelection;
     VisiblePosition m_originalBase; // Used to store base before the adjustment at bidi boundary
     TextGranularity m_granularity;
 
     // The range specified by the user, which may not be visually canonicalized (hence "logical").
     // This will be invalidated if the underlying VisibleSelection changes. If that happens, this variable will
     // become null, in which case logical positions == visible positions.
     RefPtrWillBeMember<Range> m_logicalRange;
 
     RefPtrWillBeMember<Node> m_previousCaretNode; // The last node which painted the caret. Retained for clearing the old caret when it moves.
     LayoutRect m_previousCaretRect;
 
     RefPtrWillBeMember<EditingStyle> m_typingStyle;
 
     Timer<FrameSelection> m_caretBlinkTimer;
 
     bool m_caretRectDirty : 1;
     bool m_shouldPaintCaret : 1;
     bool m_isCaretBlinkingSuspended : 1;
     bool m_focused : 1;
     bool m_shouldShowBlockCursor : 1;
+
+    // Controls text granularity used to adjust the selection's extent in moveRangeSelectionExtent.
+    OwnPtr<GranularityStrategy> m_granularityStrategy;
 };
 
 inline EditingStyle* FrameSelection::typingStyle() const
 {
     return m_typingStyle.get();
 }
 
 inline void FrameSelection::clearTypingStyle()
 {
     m_typingStyle.clear();
 }
 
 inline void FrameSelection::setTypingStyle(PassRefPtrWillBeRawPtr<EditingStyle> style)
 {
     m_typingStyle = style;
 }
 } // namespace blink
 
 #ifndef NDEBUG
 // Outside the WebCore namespace for ease of invocation from gdb.
 void showTree(const blink::FrameSelection&);
 void showTree(const blink::FrameSelection*);
 #endif
 
 #endif // FrameSelection_h