Converts usage of SetProp/GetProp to a map. Even after making sure we

app/view_prop.cc

+// Copyright (c) 2010 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.
+
+#include "app/view_prop.h"
+
+#include <set>
+
+namespace app {
+
+// Maints the actual view, key and data.
+class ViewProp::Data : public base::RefCounted<ViewProp::Data> {
+ public:
+  // Returns the Data* for the view/key pair. If |create| is false and |Get|
+  // has not been invoked for the view/key pair, NULL is returned.
+  static void Get(gfx::NativeView view,
+                  const char* key,
+                  bool create,
+                  scoped_refptr<Data>* data) {
+    if (!data_set_)
+      data_set_ = new DataSet;
+    scoped_refptr<Data> new_data(new Data(view, key));
+    DataSet::const_iterator i = data_set_->find(new_data.get());
+    if (i != data_set_->end()) {
+      *data = *i;
+      return;
+    }
+    if (!create)
+      return;
+    data_set_->insert(new_data.get());
+    *data = new_data.get();
+  }
+
+  // The data.
+  void set_data(void* data) { data_ = data; }
+  void* data() const { return data_; }
+
+  const char* key() const { return key_; }
+
+ private:
+  friend class base::RefCounted<Data>;
+
+  // Used to order the Data in the map.
+  class DataComparator {
+   public:
+    bool operator()(const Data* d1, const Data* d2) const {
+      return (d1->view_ == d2->view_) ? (d1->key_ < d2->key_) :
+                                        (d1->view_ < d2->view_);
+    }
+  };
+
+  typedef std::set<Data*, DataComparator> DataSet;
+
+  Data(gfx::NativeView view, const char* key)
+      : view_(view),
+        key_(key),
+        data_(NULL) {}
+
+  ~Data() {
+    DataSet::iterator i = data_set_->find(this);
+    // Also check for equality using == as |Get| creates dummy values in order
+    // to look up a value.
+    if (i != data_set_->end() && *i == this)
+      data_set_->erase(i);
+  }
+
+  // The existing set of Data is stored here. ~Data removes from the set.
+  static DataSet* data_set_;
+
+  const gfx::NativeView view_;
+  const char* key_;
+  void* data_;
+
+  DISALLOW_COPY_AND_ASSIGN(Data);
+};
+
+// static
+ViewProp::Data::DataSet* ViewProp::Data::data_set_ = NULL;
+
+ViewProp::ViewProp(gfx::NativeView view, const char* key, void* data) {
+  Data::Get(view, key, true, &data_);
+  data_->set_data(data);
+}
+
+ViewProp::~ViewProp() {
+  // This is done to provide similar semantics to SetProp. In particular it's
+  // assumed that ~ViewProp should behave as though RemoveProp was invoked.
+  data_->set_data(NULL);
+}
+
+// static
+void* ViewProp::GetValue(gfx::NativeView view, const char* key) {
+  scoped_refptr<Data> data;
+  Data::Get(view, key, false, &data);
+  return data.get() ? data->data() : NULL;
+}
+
+// static
+const char* ViewProp::Key() const {
+  return data_->key();
+}
+
+}  // namespace app