third_party/WebKit/Source/core/layout/ClipRectsCache.h

   1 // Copyright 2014 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 ClipRectsCache_h
   6 #define ClipRectsCache_h
   7
   8 #include "core/layout/ClipRects.h"
   9
  10 #if ENABLE(ASSERT)
  11 #include "core/layout/LayoutBox.h" // For OverlayScrollbarSizeRelevancy.
  12 #endif
  13
  14 namespace blink {
  15
  16 class DeprecatedPaintLayer;
  17
  18 enum ClipRectsCacheSlot {
  19     // Relative to the ancestor treated as the root (e.g. transformed layer). Used for hit testing.
  20     RootRelativeClipRects,
  21     RootRelativeClipRectsIgnoringViewportClip,
  22
  23     // Relative to the LayoutView's layer. Used for compositing overlap testing.
  24     AbsoluteClipRects,
  25
  26     // Relative to painting ancestor. Used for painting.
  27     PaintingClipRects,
  28     PaintingClipRectsIgnoringOverflowClip,
  29
  30     NumberOfClipRectsCacheSlots,
  31     UncachedClipRects,
  32 };
  33
  34 class ClipRectsCache {
  35     WTF_MAKE_FAST_ALLOCATED(ClipRectsCache);
  36 public:
  37     struct Entry {
  38         Entry()
  39             : root(nullptr)
  40 #if ENABLE(ASSERT)
  41             , scrollbarRelevancy(IgnoreOverlayScrollbarSize)
  42 #endif
  43         {
  44         }
  45         const DeprecatedPaintLayer* root;
  46         RefPtr<ClipRects> clipRects;
  47 #if ENABLE(ASSERT)
  48         OverlayScrollbarSizeRelevancy scrollbarRelevancy;
  49 #endif
  50     };
  51     Entry& get(ClipRectsCacheSlot slot)
  52     {
  53         ASSERT(slot < NumberOfClipRectsCacheSlots);
  54         return m_entries[slot];
  55     }
  56     void clear(ClipRectsCacheSlot slot)
  57     {
  58         ASSERT(slot < NumberOfClipRectsCacheSlots);
  59         m_entries[slot] = Entry();
  60     }
  61 private:
  62     Entry m_entries[NumberOfClipRectsCacheSlots];
  63 };
  64
  65 } // namespace blink
  66
  67 #endif // ClipRectsCache_h