1// Copyright (c) 2012 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_VIEW_MODEL_H_
6#define UI_VIEWS_VIEW_MODEL_H_
7
8#include <vector>
9
10#include "base/basictypes.h"
11#include "base/logging.h"
12#include "ui/gfx/rect.h"
13#include "ui/views/views_export.h"
14
15namespace views {
16
17class View;
18
19// ViewModel is used to track an 'interesting' set of a views. Often times
20// during animations views are removed after a delay, which makes for tricky
21// coordinate conversion as you have to account for the possibility of the
22// indices from the model not lining up with those you expect. This class lets
23// you define the 'interesting' views and operate on those views.
24class VIEWS_EXPORT ViewModel {
25 public:
26  ViewModel();
27  ~ViewModel();
28
29  // Adds |view| to this model. This does not add |view| to a view hierarchy,
30  // only to this model.
31  void Add(View* view, int index);
32
33  // Removes the view at the specified index. This does not actually remove the
34  // view from the view hierarchy.
35  void Remove(int index);
36
37  // Moves the view at |index| to |target_index|. |target_index| is in terms
38  // of the model *after* the view at |index| is removed.
39  void Move(int index, int target_index);
40
41  // Variant of Move() that leaves the bounds as is. That is, after invoking
42  // this the bounds of the view at |target_index| (and all other indices) are
43  // exactly the same as the bounds of the view at |target_index| before
44  // invoking this.
45  void MoveViewOnly(int index, int target_index);
46
47  // Returns the number of views.
48  int view_size() const { return static_cast<int>(entries_.size()); }
49
50  // Removes and deletes all the views.
51  void Clear();
52
53  // Returns the view at the specified index.
54  View* view_at(int index) const {
55    check_index(index);
56    return entries_[index].view;
57  }
58
59  void set_ideal_bounds(int index, const gfx::Rect& bounds) {
60    check_index(index);
61    entries_[index].ideal_bounds = bounds;
62  }
63
64  const gfx::Rect& ideal_bounds(int index) const {
65    check_index(index);
66    return entries_[index].ideal_bounds;
67  }
68
69  // Returns the index of the specified view, or -1 if the view isn't in the
70  // model.
71  int GetIndexOfView(const View* view) const;
72
73 private:
74  struct Entry {
75    Entry() : view(NULL) {}
76
77    View* view;
78    gfx::Rect ideal_bounds;
79  };
80  typedef std::vector<Entry> Entries;
81
82#if !defined(NDEBUG)
83  void check_index(int index) const {
84    DCHECK_LT(index, static_cast<int>(entries_.size()));
85    DCHECK_GE(index, 0);
86  }
87#else
88  void check_index(int index) const {}
89#endif
90
91  Entries entries_;
92
93  DISALLOW_COPY_AND_ASSIGN(ViewModel);
94};
95
96}  // namespace views
97
98#endif  // UI_VIEWS_VIEW_MODEL_H_
99