1// Copyright 2014 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 EXTENSIONS_BROWSER_EXTENSION_FUNCTION_REGISTRY_H_
6#define EXTENSIONS_BROWSER_EXTENSION_FUNCTION_REGISTRY_H_
7
8#include <map>
9#include <string>
10#include <vector>
11
12#include "extensions/browser/extension_function_histogram_value.h"
13
14class ExtensionFunction;
15
16// A factory function for creating new ExtensionFunction instances.
17typedef ExtensionFunction* (*ExtensionFunctionFactory)();
18
19// Template for defining ExtensionFunctionFactory.
20template <class T>
21ExtensionFunction* NewExtensionFunction() {
22  return new T();
23}
24
25// Contains a list of all known extension functions and allows clients to
26// create instances of them.
27class ExtensionFunctionRegistry {
28 public:
29  static ExtensionFunctionRegistry* GetInstance();
30  explicit ExtensionFunctionRegistry();
31  virtual ~ExtensionFunctionRegistry();
32
33  // Adds all function names to 'names'.
34  void GetAllNames(std::vector<std::string>* names);
35
36  // Allows overriding of specific functions (e.g. for testing).  Functions
37  // must be previously registered.  Returns true if successful.
38  bool OverrideFunction(const std::string& name,
39                        ExtensionFunctionFactory factory);
40
41  // Factory method for the ExtensionFunction registered as 'name'.
42  ExtensionFunction* NewFunction(const std::string& name);
43
44  template <class T>
45  void RegisterFunction() {
46    ExtensionFunctionFactory factory = &NewExtensionFunction<T>;
47    factories_[T::function_name()] =
48        FactoryEntry(factory, T::histogram_value());
49  }
50
51  struct FactoryEntry {
52   public:
53    explicit FactoryEntry();
54    explicit FactoryEntry(
55        ExtensionFunctionFactory factory,
56        extensions::functions::HistogramValue histogram_value);
57
58    ExtensionFunctionFactory factory_;
59    extensions::functions::HistogramValue histogram_value_;
60  };
61
62  typedef std::map<std::string, FactoryEntry> FactoryMap;
63  FactoryMap factories_;
64};
65
66#endif  // EXTENSIONS_BROWSER_EXTENSION_FUNCTION_REGISTRY_H_
67