ui/views/view_model.h

   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
  15 namespace views {
  16
  17 class 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.
  24 class 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_