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      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 UI_VIEWS_CULL_SET_H_
      6 #define UI_VIEWS_CULL_SET_H_
      7 
      8 #include "base/containers/hash_tables.h"
      9 #include "base/macros.h"
     10 #include "base/memory/scoped_ptr.h"
     11 #include "ui/views/views_export.h"
     12 
     13 namespace views {
     14 
     15 class View;
     16 
     17 // A CullSet defines a set of View pointers which have been possibly culled
     18 // from painting or other bounds-checking operations. It wraps a set of
     19 // pointers to views, or NULL if no such set is available.
     20 class VIEWS_EXPORT CullSet {
     21  public:
     22   // Default constructor builds a CullSet that will always return true for
     23   // ShouldPaint().
     24   CullSet();
     25   ~CullSet();
     26 
     27   // Wraps a set of pointers to Views, as might be provided by
     28   // gfx::RTree::Query(), that intersect the damage rect and therefore need
     29   // to be painted. CullSet takes ownership of the provided pointer.
     30   CullSet(scoped_ptr<base::hash_set<intptr_t> > cull_set);
     31 
     32   // Returns true if |view| needs to be painted.
     33   bool ShouldPaint(const View* view) const;
     34 
     35  private:
     36   friend class BoundsTreeTestView;
     37 
     38   // The set of Views that collided with the query rectangle provided to the
     39   // RTree data structure, or NULL if one is not available.
     40   scoped_ptr<base::hash_set<intptr_t> > cull_set_;
     41 
     42   DISALLOW_COPY_AND_ASSIGN(CullSet);
     43 };
     44 
     45 }  // namespace views
     46 
     47 #endif  // UI_VIEWS_CULL_SET_H_
     48