extensions/common/feature_switch.h

   1 // Copyright 2013 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_COMMON_FEATURE_SWITCH_H_
   6 #define EXTENSIONS_COMMON_FEATURE_SWITCH_H_
   7
   8 #include <string>
   9
  10 #include "base/basictypes.h"
  11
  12 namespace base {
  13 class CommandLine;
  14 }
  15
  16 namespace extensions {
  17
  18 // A switch that can turn a feature on or off. Typically controlled via
  19 // command-line switches but can be overridden, e.g., for testing.
  20 class FeatureSwitch {
  21  public:
  22   static FeatureSwitch* easy_off_store_install();
  23   static FeatureSwitch* force_dev_mode_highlighting();
  24   static FeatureSwitch* prompt_for_external_extensions();
  25   static FeatureSwitch* error_console();
  26   static FeatureSwitch* enable_override_bookmarks_ui();
  27   static FeatureSwitch* extension_action_redesign();
  28   static FeatureSwitch* scripts_require_action();
  29   static FeatureSwitch* embedded_extension_options();
  30
  31   enum DefaultValue {
  32     DEFAULT_ENABLED,
  33     DEFAULT_DISABLED
  34   };
  35
  36   enum OverrideValue {
  37     OVERRIDE_NONE,
  38     OVERRIDE_ENABLED,
  39     OVERRIDE_DISABLED
  40   };
  41
  42   // A temporary override for the switch value.
  43   class ScopedOverride {
  44    public:
  45     ScopedOverride(FeatureSwitch* feature, bool override_value);
  46     ~ScopedOverride();
  47    private:
  48     FeatureSwitch* feature_;
  49     FeatureSwitch::OverrideValue previous_value_;
  50     DISALLOW_COPY_AND_ASSIGN(ScopedOverride);
  51   };
  52
  53   // |switch_name| can be NULL, in which case the feature is controlled solely
  54   // by the default and override values.
  55   FeatureSwitch(const char* switch_name,
  56                 DefaultValue default_value);
  57   FeatureSwitch(const base::CommandLine* command_line,
  58                 const char* switch_name,
  59                 DefaultValue default_value);
  60
  61   // Consider using ScopedOverride instead.
  62   void SetOverrideValue(OverrideValue value);
  63   OverrideValue GetOverrideValue() const;
  64
  65   bool IsEnabled() const;
  66
  67  private:
  68   void Init(const base::CommandLine* command_line,
  69             const char* switch_name,
  70             DefaultValue default_value);
  71
  72   std::string GetLegacyEnableFlag() const;
  73   std::string GetLegacyDisableFlag() const;
  74
  75   const base::CommandLine* command_line_;
  76   const char* switch_name_;
  77   bool default_value_;
  78   OverrideValue override_value_;
  79
  80   DISALLOW_COPY_AND_ASSIGN(FeatureSwitch);
  81 };
  82
  83 }  // namespace extensions
  84
  85 #endif  // EXTENSIONS_COMMON_FEATURE_SWITCH_H_