cc/CCScrollbarGeometryFixedThumb.h

   1 // Copyright 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef CCScrollbarGeometryFixedThumb_h
   6 #define CCScrollbarGeometryFixedThumb_h
   7
   8 #include "CCScrollbarGeometryStub.h"
   9 #include "IntSize.h"
  10
  11 namespace WebCore {
  12
  13 // This scrollbar geometry class behaves exactly like a normal geometry except
  14 // it always returns a fixed thumb length. This allows a page to zoom (changing
  15 // the total size of the scrollable area, changing the thumb length) while not
  16 // requiring the thumb resource to be repainted.
  17 class CCScrollbarGeometryFixedThumb : public CCScrollbarGeometryStub {
  18 public:
  19     static PassOwnPtr<CCScrollbarGeometryFixedThumb> create(PassOwnPtr<WebKit::WebScrollbarThemeGeometry>);
  20     virtual ~CCScrollbarGeometryFixedThumb();
  21
  22     // Update thumb length from scrollbar
  23     void update(WebKit::WebScrollbar*);
  24
  25     // WebScrollbarThemeGeometry interface
  26     virtual WebKit::WebScrollbarThemeGeometry* clone() const OVERRIDE;
  27     virtual int thumbLength(WebKit::WebScrollbar*) OVERRIDE;
  28     virtual int thumbPosition(WebKit::WebScrollbar*) OVERRIDE;
  29     virtual void splitTrack(WebKit::WebScrollbar*, const WebKit::WebRect& track, WebKit::WebRect& startTrack, WebKit::WebRect& thumb, WebKit::WebRect& endTrack) OVERRIDE;
  30
  31 private:
  32     explicit CCScrollbarGeometryFixedThumb(PassOwnPtr<WebKit::WebScrollbarThemeGeometry>);
  33
  34     IntSize m_thumbSize;
  35 };
  36
  37 }
  38
  39 #endif