text: // Copyright (c) 2013 GitHub, Inc. All rights reserved.
  // Use of this source code is governed by the MIT license that can be
  // found in the LICENSE file.
  
  #ifndef ATOM_BROWSER_WINDOW_LIST_H_
  #define ATOM_BROWSER_WINDOW_LIST_H_
  
  #include <vector>
  
  #include "base/basictypes.h"
  #include "base/lazy_instance.h"
  #include "base/observer_list.h"
  
  namespace atom {
  
  class NativeWindow;
  class WindowListObserver;
  
  class WindowList {
   public:
    typedef std::vector<NativeWindow*> WindowVector;
    typedef WindowVector::iterator iterator;
    typedef WindowVector::const_iterator const_iterator;
  
    // Windows are added to the list before they have constructed windows,
    // so the |window()| member function may return NULL.
    const_iterator begin() const { return windows_.begin(); }
    const_iterator end() const { return windows_.end(); }
  
    iterator begin() { return windows_.begin(); }
    iterator end() { return windows_.end(); }
  
    bool empty() const { return windows_.empty(); }
    size_t size() const { return windows_.size(); }
  
    NativeWindow* get(size_t index) const { return windows_[index]; }
  
    static WindowList* GetInstance();
  
    // Adds or removes |window| from the list it is associated with.
    static void AddWindow(NativeWindow* window);
    static void RemoveWindow(NativeWindow* window);
  
    // Called by window when a close is cancelled by beforeunload handler.
    static void WindowCloseCancelled(NativeWindow* window);
  
    // Adds and removes |observer| from the observer list.
    static void AddObserver(WindowListObserver* observer);
    static void RemoveObserver(WindowListObserver* observer);
  
    // Closes all windows.
    static void CloseAllWindows();
  
   private:
    WindowList();
    ~WindowList();
  
    // A vector of the windows in this list, in the order they were added.
    WindowVector windows_;
  
    // A list of observers which will be notified of every window addition and
    // removal across all WindowLists.
    static base::LazyInstance<ObserverList<WindowListObserver>>::Leaky observers_;
  
    static WindowList* instance_;
  
    DISALLOW_COPY_AND_ASSIGN(WindowList);
  };
  
  }  // namespace atom
  
  #endif  // ATOM_BROWSER_WINDOW_LIST_H_
  