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 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */

 /* This Source Code Form is subject to the terms of the Mozilla Public

  * License, v. 2.0. If a copy of the MPL was not distributed with this

  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

 #ifndef mozilla_Preferences_h

 #define mozilla_Preferences_h

 #ifndef MOZILLA_INTERNAL_API

 #error "This header is only usable from within libxul (MOZILLA_INTERNAL_API)."

 #endif

 #include "nsIPrefService.h"

 #include "nsIPrefBranch.h"

 #include "nsIPrefBranchInternal.h"

 #include "nsIObserver.h"

 #include "nsCOMPtr.h"

 #include "nsTArray.h"

 #include "nsWeakReference.h"

 #include "mozilla/MemoryReporting.h"

 class nsIFile;

 class nsCString;

 class nsString;

 class nsAdoptingString;

 class nsAdoptingCString;

 #ifndef have_PrefChangedFunc_typedef

 typedef void (*PrefChangedFunc)(const char *, void *);

 #define have_PrefChangedFunc_typedef

 #endif

 namespace mozilla {

 namespace dom {

 class PrefSetting;

 }

 class Preferences : public nsIPrefService,

                     public nsIObserver,

                     public nsIPrefBranchInternal,

                     public nsSupportsWeakReference

 {

 public:

   typedef mozilla::dom::PrefSetting PrefSetting;

   NS_DECL_THREADSAFE_ISUPPORTS

   NS_DECL_NSIPREFSERVICE

   NS_FORWARD_NSIPREFBRANCH(sRootBranch->)

   NS_DECL_NSIOBSERVER

   Preferences();

   virtual ~Preferences();

   nsresult Init();

   /**

    * Reset loaded user prefs then read them

    */

   static nsresult ResetAndReadUserPrefs();

   /**

    * Returns the singleton instance which is addreffed.

    */

   static Preferences* GetInstanceForService();

   /**

    * Finallizes global members.

    */

   static void Shutdown();

   /**

    * Returns shared pref service instance

    * NOTE: not addreffed.

    */

   static nsIPrefService* GetService()

   {

     NS_ENSURE_TRUE(InitStaticMembers(), nullptr);

     return sPreferences;

   }

   /**

    * Returns shared pref branch instance.

    * NOTE: not addreffed.

    */

   static nsIPrefBranch* GetRootBranch()

   {

     NS_ENSURE_TRUE(InitStaticMembers(), nullptr);

     return sRootBranch;

   }

   /**

    * Returns shared default pref branch instance.

    * NOTE: not addreffed.

    */

   static nsIPrefBranch* GetDefaultRootBranch()

   {

     NS_ENSURE_TRUE(InitStaticMembers(), nullptr);

     return sDefaultRootBranch;

   }

   /**

    * Gets int or bool type pref value with default value if failed to get

    * the pref.

    */

   static bool GetBool(const char* aPref, bool aDefault = false)

   {

     bool result = aDefault;

     GetBool(aPref, &result);

     return result;

   }

   static int32_t GetInt(const char* aPref, int32_t aDefault = 0)

   {

     int32_t result = aDefault;

     GetInt(aPref, &result);

     return result;

   }

   static uint32_t GetUint(const char* aPref, uint32_t aDefault = 0)

   {

     uint32_t result = aDefault;

     GetUint(aPref, &result);

     return result;

   }

   static float GetFloat(const char* aPref, float aDefault = 0)

   {

     float result = aDefault;

     GetFloat(aPref, &result);

     return result;

   }

   /**

    * Gets char type pref value directly.  If failed, the get() of result

    * returns nullptr.  Even if succeeded but the result was empty string, the

    * get() does NOT return nullptr.  So, you can check whether the method

    * succeeded or not by:

    *

    * nsAdoptingString value = Prefereces::GetString("foo.bar");

    * if (!value) {

    *   // failed

    * }

    *

    * Be aware.  If you wrote as:

    *

    * nsAutoString value = Preferences::GetString("foo.bar");

    * if (!value.get()) {

    *   // the condition is always FALSE!!

    * }

    *

    * The value.get() doesn't return nullptr. You must use nsAdoptingString

    * when you need to check whether it was failure or not.

    */

   static nsAdoptingCString GetCString(const char* aPref);

   static nsAdoptingString GetString(const char* aPref);

   static nsAdoptingCString GetLocalizedCString(const char* aPref);

   static nsAdoptingString GetLocalizedString(const char* aPref);

   /**

    * Gets int, float, or bool type pref value with raw return value of

    * nsIPrefBranch.

    *

    * @param aPref       A pref name.

    * @param aResult     Must not be nullptr.  The value is never modified

    *                    when these methods fail.

    */

   static nsresult GetBool(const char* aPref, bool* aResult);

   static nsresult GetInt(const char* aPref, int32_t* aResult);

   static nsresult GetFloat(const char* aPref, float* aResult);

   static nsresult GetUint(const char* aPref, uint32_t* aResult)

   {

     int32_t result;

     nsresult rv = GetInt(aPref, &result);

     if (NS_SUCCEEDED(rv)) {

       *aResult = static_cast<uint32_t>(result);

     }

     return rv;

   }

   /**

    * Gets string type pref value with raw return value of nsIPrefBranch.

    *

    * @param aPref       A pref name.

    * @param aResult     Must not be nullptr.  The value is never modified

    *                    when these methods fail.

    */

   static nsresult GetCString(const char* aPref, nsACString* aResult);

   static nsresult GetString(const char* aPref, nsAString* aResult);

   static nsresult GetLocalizedCString(const char* aPref, nsACString* aResult);

   static nsresult GetLocalizedString(const char* aPref, nsAString* aResult);

   static nsresult GetComplex(const char* aPref, const nsIID &aType,

                              void** aResult);

   /**

    * Sets various type pref values.

    */

   static nsresult SetBool(const char* aPref, bool aValue);

   static nsresult SetInt(const char* aPref, int32_t aValue);

   static nsresult SetUint(const char* aPref, uint32_t aValue)

   {

     return SetInt(aPref, static_cast<int32_t>(aValue));

   }

   static nsresult SetCString(const char* aPref, const char* aValue);

   static nsresult SetCString(const char* aPref, const nsACString &aValue);

   static nsresult SetString(const char* aPref, const char16_t* aValue);

   static nsresult SetString(const char* aPref, const nsAString &aValue);

   static nsresult SetComplex(const char* aPref, const nsIID &aType,

                              nsISupports* aValue);

   /**

    * Clears user set pref.

    */

   static nsresult ClearUser(const char* aPref);

   /**

    * Whether the pref has a user value or not.

    */

   static bool HasUserValue(const char* aPref);

   /**

    * Gets the type of the pref.

    */

   static int32_t GetType(const char* aPref);

   /**

    * Adds/Removes the observer for the root pref branch.

    * The observer is referenced strongly if AddStrongObserver is used.  On the

    * other hand, it is referenced weakly, if AddWeakObserver is used.

    * See nsIPrefBranch.idl for details.

    */

   static nsresult AddStrongObserver(nsIObserver* aObserver, const char* aPref);

   static nsresult AddWeakObserver(nsIObserver* aObserver, const char* aPref);

   static nsresult RemoveObserver(nsIObserver* aObserver, const char* aPref);

   /**

    * Adds/Removes two or more observers for the root pref branch.

    * Pass to aPrefs an array of const char* whose last item is nullptr.

    */

   static nsresult AddStrongObservers(nsIObserver* aObserver,

                                      const char** aPrefs);

   static nsresult AddWeakObservers(nsIObserver* aObserver,

                                    const char** aPrefs);

   static nsresult RemoveObservers(nsIObserver* aObserver,

                                   const char** aPrefs);

   /**

    * Registers/Unregisters the callback function for the aPref.

    */

   static nsresult RegisterCallback(PrefChangedFunc aCallback,

                                    const char* aPref,

                                    void* aClosure = nullptr);

   static nsresult UnregisterCallback(PrefChangedFunc aCallback,

                                      const char* aPref,

                                      void* aClosure = nullptr);

   // Like RegisterCallback, but also calls the callback immediately for

   // initialization.

   static nsresult RegisterCallbackAndCall(PrefChangedFunc aCallback,

                                           const char* aPref,

                                           void* aClosure = nullptr);

   /**

    * Adds the aVariable to cache table.  aVariable must be a pointer for a

    * static variable.  The value will be modified when the pref value is

    * changed but note that even if you modified it, the value isn't assigned to

    * the pref.

    */

   static nsresult AddBoolVarCache(bool* aVariable,

                                   const char* aPref,

                                   bool aDefault = false);

   static nsresult AddIntVarCache(int32_t* aVariable,

                                  const char* aPref,

                                  int32_t aDefault = 0);

   static nsresult AddUintVarCache(uint32_t* aVariable,

                                   const char* aPref,

                                   uint32_t aDefault = 0);

   static nsresult AddFloatVarCache(float* aVariable,

                                    const char* aPref,

                                    float aDefault = 0.0f);

   /**

    * Gets the default bool, int or uint value of the pref.

    * The result is raw result of nsIPrefBranch::Get*Pref().

    * If the pref could have any value, you needed to use these methods.

    * If not so, you could use below methods.

    */

   static nsresult GetDefaultBool(const char* aPref, bool* aResult);

   static nsresult GetDefaultInt(const char* aPref, int32_t* aResult);

   static nsresult GetDefaultUint(const char* aPref, uint32_t* aResult)

   {

     return GetDefaultInt(aPref, reinterpret_cast<int32_t*>(aResult));

   }

   /**

    * Gets the default bool, int or uint value of the pref directly.

    * You can set an invalid value of the pref to aFailedResult.  If these

    * methods failed to get the default value, they would return the

    * aFailedResult value.

    */

   static bool GetDefaultBool(const char* aPref, bool aFailedResult)

   {

     bool result;

     return NS_SUCCEEDED(GetDefaultBool(aPref, &result)) ? result :

                                                           aFailedResult;

   }

   static int32_t GetDefaultInt(const char* aPref, int32_t aFailedResult)

   {

     int32_t result;

     return NS_SUCCEEDED(GetDefaultInt(aPref, &result)) ? result : aFailedResult;

   }

   static uint32_t GetDefaultUint(const char* aPref, uint32_t aFailedResult)

   {

    return static_cast<uint32_t>(

      GetDefaultInt(aPref, static_cast<int32_t>(aFailedResult)));

   }

   /**

    * Gets the default value of the char type pref.

    * If the get() of the result returned nullptr, that meant the value didn't

    * have default value.

    *

    * See the comment at definition at GetString() and GetCString() for more

    * details of the result.

    */

   static nsAdoptingString GetDefaultString(const char* aPref);

   static nsAdoptingCString GetDefaultCString(const char* aPref);

   static nsAdoptingString GetDefaultLocalizedString(const char* aPref);

   static nsAdoptingCString GetDefaultLocalizedCString(const char* aPref);

   static nsresult GetDefaultCString(const char* aPref, nsACString* aResult);

   static nsresult GetDefaultString(const char* aPref, nsAString* aResult);

   static nsresult GetDefaultLocalizedCString(const char* aPref,

                                              nsACString* aResult);

   static nsresult GetDefaultLocalizedString(const char* aPref,

                                             nsAString* aResult);

   static nsresult GetDefaultComplex(const char* aPref, const nsIID &aType,

                                     void** aResult);

   /**

    * Gets the type of the pref.

    */

   static int32_t GetDefaultType(const char* aPref);

   // Used to synchronise preferences between chrome and content processes.

   static void GetPreferences(InfallibleTArray<PrefSetting>* aPrefs);

   static void GetPreference(PrefSetting* aPref);

   static void SetPreference(const PrefSetting& aPref);

   static int64_t SizeOfIncludingThisAndOtherStuff(mozilla::MallocSizeOf aMallocSizeOf);

   static nsresult SetFloat(const char* aPref, float aValue);

 protected:

   nsresult NotifyServiceObservers(const char *aSubject);

   /**

    * Reads the default pref file or, if that failed, try to save a new one.

    *

    * @return NS_OK if either action succeeded,

    *         or the error code related to the read attempt.

    */

   nsresult UseDefaultPrefFile();

   nsresult UseUserPrefFile();

   nsresult ReadAndOwnUserPrefFile(nsIFile *aFile);

   nsresult ReadAndOwnSharedUserPrefFile(nsIFile *aFile);

   nsresult SavePrefFileInternal(nsIFile* aFile);

   nsresult WritePrefFile(nsIFile* aFile);

   nsresult MakeBackupPrefFile(nsIFile *aFile);

 private:

   nsCOMPtr<nsIFile>        mCurrentFile;

   static Preferences*      sPreferences;

   static nsIPrefBranch*    sRootBranch;

   static nsIPrefBranch*    sDefaultRootBranch;

   static bool              sShutdown;

   /**

    * Init static members.  TRUE if it succeeded.  Otherwise, FALSE.

    */

   static bool InitStaticMembers();

 };

 } // namespace mozilla

 #endif // mozilla_Preferences_h