It is time.

ui/views/view_model.h

-// Copyright (c) 2012 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#ifndef UI_VIEWS_VIEW_MODEL_H_
-#define UI_VIEWS_VIEW_MODEL_H_
-
-#include <vector>
-
-#include "base/basictypes.h"
-#include "base/logging.h"
-#include "ui/gfx/rect.h"
-#include "ui/views/views_export.h"
-
-namespace views {
-
-class View;
-class ViewModelUtils;
-
-// Internal implementation of the templated ViewModelT class. Provides
-// non-templated "unsafe" methods for ViewModelT to wrap around. Any methods
-// that allow insertion of or access to a View* should be protected, and have a
-// public method in the ViewModelT subclass that provides type-safe access to
-// the correct View subclass.
-class VIEWS_EXPORT ViewModelBase {
- public:
-  ~ViewModelBase();
-
-  // Removes the view at the specified index. This does not actually remove the
-  // view from the view hierarchy.
-  void Remove(int index);
-
-  // Moves the view at |index| to |target_index|. |target_index| is in terms
-  // of the model *after* the view at |index| is removed.
-  void Move(int index, int target_index);
-
-  // Variant of Move() that leaves the bounds as is. That is, after invoking
-  // this the bounds of the view at |target_index| (and all other indices) are
-  // exactly the same as the bounds of the view at |target_index| before
-  // invoking this.
-  void MoveViewOnly(int index, int target_index);
-
-  // Returns the number of views.
-  int view_size() const { return static_cast<int>(entries_.size()); }
-
-  // Removes and deletes all the views.
-  void Clear();
-
-  void set_ideal_bounds(int index, const gfx::Rect& bounds) {
-    check_index(index);
-    entries_[index].ideal_bounds = bounds;
-  }
-
-  const gfx::Rect& ideal_bounds(int index) const {
-    check_index(index);
-    return entries_[index].ideal_bounds;
-  }
-
-  // Returns the index of the specified view, or -1 if the view isn't in the
-  // model.
-  int GetIndexOfView(const View* view) const;
-
- protected:
-  ViewModelBase();
-
-  // Returns the view at the specified index. Note: Most users should use
-  // view_at() in the subclass, to get a view of the correct type. (Do not call
-  // ViewAtBase then static_cast to the desired type.)
-  View* ViewAtBase(int index) const {
-    check_index(index);
-    return entries_[index].view;
-  }
-
-  // Adds |view| to this model. This does not add |view| to a view hierarchy,
-  // only to this model.
-  void AddUnsafe(View* view, int index);
-
- private:
-  // For access to ViewAtBase().
-  friend class ViewModelUtils;
-
-  struct Entry {
-    Entry() : view(NULL) {}
-
-    View* view;
-    gfx::Rect ideal_bounds;
-  };
-  typedef std::vector<Entry> Entries;
-
-#if !defined(NDEBUG)
-  void check_index(int index) const {
-    DCHECK_LT(index, static_cast<int>(entries_.size()));
-    DCHECK_GE(index, 0);
-  }
-#else
-  void check_index(int index) const {}
-#endif
-
-  Entries entries_;
-
-  DISALLOW_COPY_AND_ASSIGN(ViewModelBase);
-};
-
-// ViewModelT is used to track an 'interesting' set of a views. Often times
-// during animations views are removed after a delay, which makes for tricky
-// coordinate conversion as you have to account for the possibility of the
-// indices from the model not lining up with those you expect. This class lets
-// you define the 'interesting' views and operate on those views.
-template <class T>
-class ViewModelT : public ViewModelBase {
- public:
-  ViewModelT<T>() {}
-
-  // Adds |view| to this model. This does not add |view| to a view hierarchy,
-  // only to this model.
-  void Add(T* view, int index) { AddUnsafe(view, index); }
-
-  // Returns the view at the specified index.
-  T* view_at(int index) const { return static_cast<T*>(ViewAtBase(index)); }
-
- private:
-  DISALLOW_COPY_AND_ASSIGN(ViewModelT<T>);
-};
-
-// ViewModel is a collection of views with no specfic type. If all views have
-// the same type, the use of ViewModelT is preferred so that the views can be
-// retrieved without potentially unsafe downcasts.
-typedef ViewModelT<View> ViewModel;
-
-}  // namespace views
-
-#endif  // UI_VIEWS_VIEW_MODEL_H_