chrome/common/extensions/permissions/chrome_permission_message_rules.h

   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 CHROME_COMMON_EXTENSIONS_PERMISSIONS_CHROME_PERMISSION_MESSAGE_RULES_H_
   6 #define CHROME_COMMON_EXTENSIONS_PERMISSIONS_CHROME_PERMISSION_MESSAGE_RULES_H_
   7
   8 #include <set>
   9 #include <vector>
  10
  11 #include "base/memory/linked_ptr.h"
  12 #include "extensions/common/permissions/api_permission.h"
  13 #include "extensions/common/permissions/api_permission_set.h"
  14 #include "extensions/common/permissions/permission_message.h"
  15
  16 namespace extensions {
  17
  18 // A formatter which generates a single permission message for all permissions
  19 // that match a given rule. All remaining permissions that match the given rule
  20 // are bucketed together, then GetPermissionMessage() is called with the
  21 // resultant permission set.
  22 // Note: since a ChromePermissionMessageFormatter can only produce a single
  23 // PermissionMessage and applies to all permissions with a given ID, this
  24 // maintains the property that one permission ID can still only produce one
  25 // message (that is, multiple permissions with the same ID cannot appear in
  26 // multiple messages).
  27 class ChromePermissionMessageFormatter {
  28  public:
  29   ChromePermissionMessageFormatter() {}
  30   virtual ~ChromePermissionMessageFormatter() {}
  31
  32   // Returns the permission message for the given set of |permissions|.
  33   // |permissions| is guaranteed to have the IDs specified by the
  34   // required/optional permissions for the rule. The set will never be empty.
  35   virtual PermissionMessage GetPermissionMessage(
  36       const PermissionIDSet& permissions) const = 0;
  37
  38  private:
  39   DISALLOW_COPY_AND_ASSIGN(ChromePermissionMessageFormatter);
  40 };
  41
  42 // A simple rule to generate a coalesced permission message that stores the
  43 // corresponding
  44 // message ID for a given set of permission IDs. This rule generates the message
  45 // with the given |message_id| if all the |required| permissions are present. If
  46 // any |optional| permissions are present, they are also 'absorbed' by the rule
  47 // to generate the final coalesced message.
  48 // An optional |formatter| can be provided, which decides how the final
  49 // PermissionMessage appears. The default formatter simply displays the message
  50 // with the ID |message_id|.
  51 // Once a permission is used in a rule, it cannot apply to any future rules.
  52 // TODO(sashab): Move all ChromePermissionMessageFormatters to their own
  53 // provider class and remove ownership from ChromePermissionMessageRule.
  54 class ChromePermissionMessageRule {
  55  public:
  56   virtual ~ChromePermissionMessageRule();
  57
  58   // Returns all the rules used to generate permission messages for Chrome apps
  59   // and extensions.
  60   static std::vector<ChromePermissionMessageRule> GetAllRules();
  61
  62   std::set<APIPermission::ID> required_permissions() const;
  63   std::set<APIPermission::ID> optional_permissions() const;
  64   std::set<APIPermission::ID> all_permissions() const;
  65
  66   PermissionMessage GetPermissionMessage(
  67       const PermissionIDSet& permissions) const;
  68
  69  private:
  70   class PermissionIDSetInitializer;
  71
  72   // Create a rule using the default formatter (display the message with ID
  73   // |message_id|).
  74   ChromePermissionMessageRule(int message_id,
  75                               const PermissionIDSetInitializer& required,
  76                               const PermissionIDSetInitializer& optional);
  77   // Create a rule with a custom formatter. Takes ownership of |formatter|.
  78   ChromePermissionMessageRule(ChromePermissionMessageFormatter* formatter,
  79                               const PermissionIDSetInitializer& required,
  80                               const PermissionIDSetInitializer& optional);
  81
  82   std::set<APIPermission::ID> required_permissions_;
  83   std::set<APIPermission::ID> optional_permissions_;
  84
  85   // Owned by this class. linked_ptr is needed because this object is copyable
  86   // and stored in a returned vector.
  87   linked_ptr<ChromePermissionMessageFormatter> formatter_;
  88 };
  89
  90 }  // namespace extensions
  91
  92 #endif  // CHROME_COMMON_EXTENSIONS_PERMISSIONS_CHROME_PERMISSION_MESSAGE_RULES_H_