components/mus/public/cpp/view_tracker.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 COMPONENTS_MUS_PUBLIC_CPP_VIEW_TRACKER_H_
   6 #define COMPONENTS_MUS_PUBLIC_CPP_VIEW_TRACKER_H_
   7
   8 #include <stdint.h>
   9 #include <set>
  10
  11 #include "components/mus/public/cpp/view_observer.h"
  12 #include "third_party/mojo/src/mojo/public/cpp/system/macros.h"
  13
  14 namespace mus {
  15
  16 class ViewTracker : public ViewObserver {
  17  public:
  18   using Views = std::set<View*>;
  19
  20   ViewTracker();
  21   ~ViewTracker() override;
  22
  23   // Returns the set of views being observed.
  24   const std::set<View*>& views() const { return views_; }
  25
  26   // Adds |view| to the set of Views being tracked.
  27   void Add(View* view);
  28
  29   // Removes |view| from the set of views being tracked.
  30   void Remove(View* view);
  31
  32   // Returns true if |view| was previously added and has not been removed or
  33   // deleted.
  34   bool Contains(View* view);
  35
  36   // ViewObserver overrides:
  37   void OnViewDestroying(View* view) override;
  38
  39  private:
  40   Views views_;
  41
  42   MOJO_DISALLOW_COPY_AND_ASSIGN(ViewTracker);
  43 };
  44
  45 }  // namespace mus
  46
  47 #endif  // COMPONENTS_MUS_PUBLIC_CPP_VIEW_TRACKER_H_