1 // Copyright (c) 2011 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 #include "ui/base/view_prop.h"
6
7 #include <set>
8
9 namespace ui {
10
11 // Maints the actual view, key and data.
12 class ViewProp::Data : public base::RefCounted<ViewProp::Data> {
13 public:
14 // Returns the Data* for the view/key pair. If |create| is false and |Get|
15 // has not been invoked for the view/key pair, NULL is returned.
Get(gfx::AcceleratedWidget view,const char * key,bool create,scoped_refptr<Data> * data)16 static void Get(gfx::AcceleratedWidget view,
17 const char* key,
18 bool create,
19 scoped_refptr<Data>* data) {
20 if (!data_set_)
21 data_set_ = new DataSet;
22 scoped_refptr<Data> new_data(new Data(view, key));
23 DataSet::const_iterator i = data_set_->find(new_data.get());
24 if (i != data_set_->end()) {
25 *data = *i;
26 return;
27 }
28 if (!create)
29 return;
30 data_set_->insert(new_data.get());
31 *data = new_data.get();
32 }
33
34 // The data.
set_data(void * data)35 void set_data(void* data) { data_ = data; }
data() const36 void* data() const { return data_; }
37
key() const38 const char* key() const { return key_; }
39
40 private:
41 friend class base::RefCounted<Data>;
42
43 // Used to order the Data in the map.
44 class DataComparator {
45 public:
operator ()(const Data * d1,const Data * d2) const46 bool operator()(const Data* d1, const Data* d2) const {
47 return (d1->view_ == d2->view_) ? (d1->key_ < d2->key_) :
48 (d1->view_ < d2->view_);
49 }
50 };
51
52 typedef std::set<Data*, DataComparator> DataSet;
53
Data(gfx::AcceleratedWidget view,const char * key)54 Data(gfx::AcceleratedWidget view, const char* key)
55 : view_(view),
56 key_(key),
57 data_(NULL) {}
58
~Data()59 ~Data() {
60 DataSet::iterator i = data_set_->find(this);
61 // Also check for equality using == as |Get| creates dummy values in order
62 // to look up a value.
63 if (i != data_set_->end() && *i == this)
64 data_set_->erase(i);
65 }
66
67 // The existing set of Data is stored here. ~Data removes from the set.
68 static DataSet* data_set_;
69
70 const gfx::AcceleratedWidget view_;
71 const char* key_;
72 void* data_;
73
74 DISALLOW_COPY_AND_ASSIGN(Data);
75 };
76
77 // static
78 ViewProp::Data::DataSet* ViewProp::Data::data_set_ = NULL;
79
ViewProp(gfx::AcceleratedWidget view,const char * key,void * data)80 ViewProp::ViewProp(gfx::AcceleratedWidget view, const char* key, void* data) {
81 Data::Get(view, key, true, &data_);
82 data_->set_data(data);
83 }
84
~ViewProp()85 ViewProp::~ViewProp() {
86 // This is done to provide similar semantics to SetProp. In particular it's
87 // assumed that ~ViewProp should behave as though RemoveProp was invoked.
88 data_->set_data(NULL);
89 }
90
91 // static
GetValue(gfx::AcceleratedWidget view,const char * key)92 void* ViewProp::GetValue(gfx::AcceleratedWidget view, const char* key) {
93 scoped_refptr<Data> data;
94 Data::Get(view, key, false, &data);
95 return data.get() ? data->data() : NULL;
96 }
97
98 // static
Key() const99 const char* ViewProp::Key() const {
100 return data_->key();
101 }
102
103 } // namespace ui
104