gecko-dev/modules/libpref/Preferences.h
Milan Sreckovic 8d2fafb036 Bug 1287215: Replace preferences gDirty global with a callback. r=aklotz,Gijs
MozReview-Commit-ID: 7m5d5ddMTva

--HG--
extra : rebase_source : 6561ded096d914ca6b87d8eeda785538bbc225ac
2016-07-21 15:46:15 -04:00

409 lines
13 KiB
C++

/* -*- 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 nsAdoptingString;
class nsAdoptingCString;
#ifndef have_PrefChangedFunc_typedef
typedef void (*PrefChangedFunc)(const char *, void *);
#define have_PrefChangedFunc_typedef
#endif
namespace mozilla {
namespace dom {
class PrefSetting;
} // namespace dom
class Preferences final : 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();
nsresult Init();
/**
* Returns true if the Preferences service is available, false otherwise.
*/
static bool IsServiceAvailable();
/**
* 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 SetFloat(const char* aPref, float 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 char16ptr_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.
*
* Pass ExactMatch for aMatchKind to only get callbacks for
* exact matches and not prefixes.
*/
enum MatchKind {
PrefixMatch,
ExactMatch,
};
static nsresult RegisterCallback(PrefChangedFunc aCallback,
const char* aPref,
void* aClosure = nullptr,
MatchKind aMatchKind = PrefixMatch);
static nsresult UnregisterCallback(PrefChangedFunc aCallback,
const char* aPref,
void* aClosure = nullptr,
MatchKind aMatchKind = PrefixMatch);
// Like RegisterCallback, but also calls the callback immediately for
// initialization.
static nsresult RegisterCallbackAndCall(PrefChangedFunc aCallback,
const char* aPref,
void* aClosure = nullptr,
MatchKind aMatchKind = PrefixMatch);
/**
* 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);
template <MemoryOrdering Order>
static nsresult AddAtomicUintVarCache(Atomic<uint32_t, Order>* 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 void DirtyCallback();
protected:
virtual ~Preferences();
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;
bool mDirty;
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