Split computeScrollDimensions() out of RenderLayer

Source/core/rendering/RenderLayerScrollableArea.h

 /*
  * Copyright (C) 2003, 2009, 2012 Apple Inc. All rights reserved.
  *
  * Portions are Copyright (C) 1998 Netscape Communications Corporation.
  *
  * Other contributors:
  *   Robert O'Callahan <roc+@cs.cmu.edu>
  *   David Baron <dbaron@fas.harvard.edu>
  *   Christian Biesinger <cbiesinger@web.de>
  *   Randall Jesup <rjesup@wgate.com>
@@ skipping 35 matching lines @@
 
 #include "core/platform/ScrollableArea.h"
 
 namespace WebCore {
 
 enum ResizerHitTestType {
     ResizerForPointer,
     ResizerForTouch
 };
 
+enum ScrollOffsetClamping {
+    ScrollOffsetUnclamped,
+    ScrollOffsetClamped
+};
+
 class RenderLayer;
 class RenderLayerModelObject;
 
 class RenderLayerScrollableArea FINAL : public ScrollableArea {
     // FIXME: Remove once the bits from RenderLayer have been moved here.
     friend class RenderLayer;
 public:
     RenderLayerScrollableArea(RenderLayer*);
     virtual ~RenderLayerScrollableArea();
 
@@ skipping 32 matching lines @@
     virtual bool scrollbarsCanBeActive() const OVERRIDE;
     virtual IntRect scrollableAreaBoundingBox() const OVERRIDE;
     virtual bool userInputScrollable(ScrollbarOrientation) const OVERRIDE;
     virtual int pageStep(ScrollbarOrientation) const OVERRIDE;
 
     int scrollXOffset() const { return m_scrollOffset.width() + scrollOrigin().x(); }
     int scrollYOffset() const { return m_scrollOffset.height() + scrollOrigin().y(); }
 
     IntSize scrollOffset() const { return m_scrollOffset; }
 
+    // FIXME: We shouldn't allow access to m_overflowRect outside this class.
+    LayoutRect overflowRect() const { return m_overflowRect; }
+
+    void scrollToOffset(const IntSize& scrollOffset, ScrollOffsetClamping = ScrollOffsetUnclamped);
+
+    void updateAfterLayout();
+    void updateAfterStyleChange(const RenderStyle*);
+
 private:
+    bool hasHorizontalOverflow() const;
+    bool hasVerticalOverflow() const;
+    bool hasScrollableHorizontalOverflow() const;
+    bool hasScrollableVerticalOverflow() const;
+
+    int scrollWidth() const;
+    int scrollHeight() const;
+
+    void computeScrollDimensions();
+
+    IntSize clampScrollOffset(const IntSize&) const;
+    IntSize adjustedScrollOffset() const { return IntSize(scrollXOffset(), scrollYOffset()); }
+
     void setScrollOffset(const IntSize& scrollOffset) { m_scrollOffset = scrollOffset; }
 
     RenderLayerModelObject* renderer() const;
 
     RenderLayer* m_layer;
 
+    unsigned m_scrollDimensionsDirty : 1;
+
+    // The width/height of our scrolled area.
+    LayoutRect m_overflowRect;
+
     // This is the (scroll) offset from scrollOrigin().
     IntSize m_scrollOffset;
 };
 
 } // Namespace WebCore
 
 #endif // RenderLayerScrollableArea_h