Add PPB_VarDictionary_Dev support - part 1.

ppapi/cpp/dev/var_dictionary_dev.h

+// Copyright (c) 2013 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 PPAPI_CPP_DEV_VAR_DICTIONARY_DEV_H_
+#define PPAPI_CPP_DEV_VAR_DICTIONARY_DEV_H_
+
+#include "ppapi/c/pp_bool.h"
+#include "ppapi/cpp/var.h"
+
+/// @file
+/// This file defines the API for interacting with dictionary vars.
+
+namespace pp {
+
+class VarDictionary_Dev : public Var {
+ public:
+  /// Constructs a new dictionary var.
+  VarDictionary_Dev();
+
+  /// Contructs a <code>VarDictionary_Dev</code> given a var for which
+  /// is_dictionary() is true. This will refer to the same dictionary var, but
+  /// allow you to access methods specific to dictionary.
+  ///
+  /// @param[in] var A dictionary var.
+  explicit VarDictionary_Dev(const Var& var);
+
+  /// Copy constructor.
+  VarDictionary_Dev(const VarDictionary_Dev& other);
+
+  virtual ~VarDictionary_Dev();
+
+  /// Assignment operator.
+  VarDictionary_Dev& operator=(const VarDictionary_Dev& other);
+
+  /// The <code>Var</code> assignment operator is overridden here so that we can
+  /// check for assigning a non-dictionary var to a
+  /// <code>VarDictionary_Dev</code>.
+  ///
+  /// @param[in] other The dictionary var to be assigned.
+  ///
+  /// @return The resulting <code>VarDictionary_Dev</code> (as a
+  /// <code>Var</code>&).
+  virtual Var& operator=(const Var& other);
+
+  /// Gets the value associated with the specified key.
+  ///
+  /// @param[in] key A string var.
+  ///
+  /// @return The value that is associated with <code>key</code>. If
+  /// <code>key</code> is not a string var, or it doesn't exist in the
+  /// dictionary, an undefined var is returned.
+  Var Get(const Var& key) const;
+
+  /// Sets the value associated with the specified key.
+  ///
+  /// @param[in] key A string var. If this key hasn't existed in the dictionary,
+  /// it is added and associated with <code>value</code>; otherwise, the
+  /// previous value is replaced with <code>value</code>.
+  /// @param[in] value The value to set.
+  ///
+  /// @return A <code>PP_Bool</code> indicating whether the operation succeeds.
+  PP_Bool Set(const Var& key, const Var& value);
+
+  /// Deletes the specified key and its associated value, if the key exists.
+  ///
+  /// @param[in] key A string var.
+  void Delete(const Var& key);
+
+  /// Checks whether a key exists.
+  ///
+  /// @param[in] key A string var.
+  ///
+  /// @return A <code>PP_Bool</code> indicating whether the key exists.
+  PP_Bool HasKey(const Var& key) const;
+
+  /// Gets all the keys in the dictionary.
+  ///
+  /// @return An array var which contains all the keys of the dictionary.
+  /// The elements are string vars. Returns a null var if failed.
+  /// TODO(yzshen): Change Var to VarArray_Dev once it is supported.
+  Var GetKeys() const;
+};
+
+}  // namespace pp
+
+#endif  // PPAPI_CPP_DEV_VAR_DICTIONARY_DEV_H_