Home | History | Annotate | Download | only in extensions 
      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 CHROME_BROWSER_EXTENSIONS_EXTENSION_FUNCTION_REGISTRY_H_
      6 #define CHROME_BROWSER_EXTENSIONS_EXTENSION_FUNCTION_REGISTRY_H_
      7 
      8 #include <map>
      9 #include <string>
     10 #include <vector>
     11 
     12 #include "chrome/browser/extensions/extension_function_histogram_value.h"
     13 
     14 class ExtensionFunction;
     15 
     16 // A factory function for creating new ExtensionFunction instances.
     17 typedef ExtensionFunction* (*ExtensionFunctionFactory)();
     18 
     19 // Template for defining ExtensionFunctionFactory.
     20 template<class T>
     21 ExtensionFunction* 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.
     27 class ExtensionFunctionRegistry {
     28  public:
     29   static ExtensionFunctionRegistry* GetInstance();
     30   explicit ExtensionFunctionRegistry();
     31   virtual ~ExtensionFunctionRegistry();
     32 
     33   // Resets all functions to their default values.
     34   void ResetFunctions();
     35 
     36   // Adds all function names to 'names'.
     37   void GetAllNames(std::vector<std::string>* names);
     38 
     39   // Allows overriding of specific functions (e.g. for testing).  Functions
     40   // must be previously registered.  Returns true if successful.
     41   bool OverrideFunction(const std::string& name,
     42                         ExtensionFunctionFactory factory);
     43 
     44   // Factory method for the ExtensionFunction registered as 'name'.
     45   ExtensionFunction* NewFunction(const std::string& name);
     46 
     47   template<class T>
     48   void RegisterFunction() {
     49     ExtensionFunctionFactory factory = &NewExtensionFunction<T>;
     50     factories_[T::function_name()] =
     51         FactoryEntry(factory, T::histogram_value());
     52   }
     53 
     54   struct FactoryEntry {
     55    public:
     56     explicit FactoryEntry();
     57     explicit FactoryEntry(ExtensionFunctionFactory factory,
     58       extensions::functions::HistogramValue histogram_value);
     59 
     60     ExtensionFunctionFactory factory_;
     61     extensions::functions::HistogramValue histogram_value_;
     62   };
     63 
     64   typedef std::map<std::string, FactoryEntry> FactoryMap;
     65   FactoryMap factories_;
     66 };
     67 
     68 #endif  // CHROME_BROWSER_EXTENSIONS_EXTENSION_FUNCTION_REGISTRY_H_
     69