Implementing directional selection strategy in Blink.

Source/core/editing/FrameSelection.cpp

 /*
  * Copyright (C) 2004, 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 20 matching lines @@
 #include "core/InputTypeNames.h"
 #include "core/css/StylePropertySet.h"
 #include "core/dom/AXObjectCache.h"
 #include "core/dom/CharacterData.h"
 #include "core/dom/Document.h"
 #include "core/dom/Element.h"
 #include "core/dom/ElementTraversal.h"
 #include "core/dom/NodeTraversal.h"
 #include "core/dom/Text.h"
 #include "core/editing/Editor.h"
+#include "core/editing/GranularityStrategy.h"
 #include "core/editing/InputMethodController.h"
 #include "core/editing/RenderedPosition.h"
 #include "core/editing/SpellChecker.h"
 #include "core/editing/TypingCommand.h"
 #include "core/editing/VisibleUnits.h"
 #include "core/editing/htmlediting.h"
 #include "core/editing/iterators/TextIterator.h"
 #include "core/editing/markup.h"
 #include "core/events/Event.h"
 #include "core/frame/FrameView.h"
@@ skipping 164 matching lines @@
 
     newSelection.setIsDirectional(isDirectional); // Adjusting base and extent will make newSelection always directional
     if (m_selection == newSelection)
         return;
 
     setSelection(newSelection, granularity);
 }
 
 void FrameSelection::setSelection(const VisibleSelection& newSelection, SetSelectionOptions options, CursorAlignOnScroll align, TextGranularity granularity)
 {
+    if (m_granularityStrategy && (options & FrameSelection::DoNotClearStrategy) == 0) {
+        m_granularityStrategy->Clear();
+    }
     bool closeTyping = options & CloseTyping;
     bool shouldClearTypingStyle = options & ClearTypingStyle;
     EUserTriggered userTriggered = selectionOptionsToUserTriggered(options);
 
     VisibleSelection s = validateSelection(newSelection);
+
     if (shouldAlwaysUseDirectionalSelection(m_frame))
         s.setIsDirectional(true);
 
     if (!m_frame) {
         m_selection = s;
         return;
     }
 
     // <http://bugs.webkit.org/show_bug.cgi?id=23464>: Infinite recursion at FrameSelection::setSelection
     // if document->frame() == m_frame we can get into an infinite loop
@@ skipping 926 matching lines @@
         m_xPosForVerticalArrowNavigation = x;
     } else
         x = m_xPosForVerticalArrowNavigation;
 
     return x;
 }
 
 void FrameSelection::clear()
 {
     m_granularity = CharacterGranularity;
+    if (m_granularityStrategy)
+        m_granularityStrategy->Clear();
     setSelection(VisibleSelection());
 }
 
 void FrameSelection::prepareForDestruction()
 {
     m_granularity = CharacterGranularity;
 
     m_caretBlinkTimer.stop();
 
     LayoutView* view = m_frame->contentRenderer();
@@ skipping 720 matching lines @@
         String text = plainText(start.deepEquivalent(), end.deepEquivalent());
         if (!text.isEmpty() && !isSeparator(text.characterStartingAt(0))) {
             setSelection(VisibleSelection(start, end), WordGranularity);
             return true;
         }
     }
 
     return false;
 }
 
-void FrameSelection::moveRangeSelectionExtent(const VisiblePosition& extentPosition, TextGranularity granularity)
+GranularityStrategy* FrameSelection::granularityStrategy()
 {
-    if (isNone())
+    // We do lazy initalization for m_granularityStrategy, because if we initialize it
+    // right in the constructor - the correct settings may not be set yet.
+    SelectionStrategy strategyType = StrategyCharacter;
+    Settings* settings = m_frame ? m_frame->settings() : 0;
+    if (settings && settings->selectionStrategy() == StrategyDirection)
+        strategyType = StrategyDirection;
+
+    if (m_granularityStrategy && m_granularityStrategy->GetType() == strategyType)
+        return m_granularityStrategy.get();
+
+    if (strategyType == StrategyDirection)
+        m_granularityStrategy = adoptPtr(new DirectionGranularityStrategy());
+    else
+        m_granularityStrategy = adoptPtr(new CharacterGranularityStrategy());
+    return m_granularityStrategy.get();
+}
+
+void FrameSelection::moveRangeSelectionExtent(const VisiblePosition& extentPosition)
+{
+    const VisiblePosition base = m_selection.visibleBase();
+
+    if (isNone() || base == extentPosition)
         return;
 
-    const VisiblePosition basePosition = m_selection.isBaseFirst() ? m_selection.visibleStart() : m_selection.visibleEnd();
-    VisibleSelection newSelection(basePosition, extentPosition);
-    if (newSelection.isBaseFirst())
-        newSelection.setEndRespectingGranularity(granularity);
-    else
-        newSelection.setStartRespectingGranularity(granularity);
-    if (!newSelection.isRange())
-        return;
-
-    setSelection(newSelection, FrameSelection::CloseTyping | FrameSelection::ClearTypingStyle | UserTriggered, FrameSelection::AlignCursorOnScrollIfNeeded, granularity);
+    VisibleSelection newSelection = granularityStrategy()->updateExtent(extentPosition, selection());
+    setSelection(
+        newSelection,
+        FrameSelection::CloseTyping | FrameSelection::ClearTypingStyle | FrameSelection::DoNotClearStrategy | UserTriggered,
+        FrameSelection::AlignCursorOnScrollIfNeeded,
+        CharacterGranularity);
 }
 
 void FrameSelection::moveRangeSelection(const VisiblePosition& basePosition, const VisiblePosition& extentPosition, TextGranularity granularity)
 {
     VisibleSelection newSelection(basePosition, extentPosition);
     newSelection.expandUsingGranularity(granularity);
 
     if (newSelection.isNone())
         return;
 
     setSelection(newSelection, granularity);
 }
 
 }
 
 #ifndef NDEBUG
 
 void showTree(const blink::FrameSelection& sel)
 {
     sel.showTreeForThis();
 }
 
 void showTree(const blink::FrameSelection* sel)
 {
     if (sel)
         sel->showTreeForThis();
 }
 
 #endif