Bug 656826 part.3 Implement static utility methods for Preferences r=roc

modules/libpref/public/Preferences.h

@@ -52,6 +52,8 @@
 #include "nsWeakReference.h"
 
 class nsIFile;
+class nsCString;
+class nsString;
 
 namespace mozilla {
 
@@ -73,7 +75,96 @@ public:
   virtual ~Preferences();
 
   nsresult Init();
-                           
+
+  /**
+   * Returns the singleton instance which is addreffed.
+   */
+  static Preferences* GetInstance();
+
+  /**
+   * Finallizes global members.
+   */
+  static void Shutdown();
+
+  /**
+   * Returns shared pref service instance
+   * NOTE: not addreffed.
+   */
+  static nsIPrefService* GetService() { return sPreferences; }
+
+  /**
+   * Returns shared pref branch instance.
+   * NOTE: not addreffed.
+   */
+  static nsIPrefBranch2* GetRootBranch()
+  {
+    return sPreferences ? sPreferences->mRootBranch.get() : nsnull;
+  }
+
+  /**
+   * Gets int or bool type pref value with default value if failed to get
+   * the pref.
+   */
+  static PRBool GetBool(const char* aPref, PRBool aDefault = PR_FALSE)
+  {
+    PRBool result = aDefault;
+    GetBool(aPref, &result);
+    return result;
+  }
+
+  static PRInt32 GetInt(const char* aPref, PRInt32 aDefault = 0)
+  {
+    PRInt32 result = aDefault;
+    GetInt(aPref, &result);
+    return result;
+  }
+
+  /**
+   * Gets int or bool type pref value with raw return value of nsIPrefBranch.
+   *
+   * @param aPref       A pref name.
+   * @param aResult     Must not be NULL.  The value is never modified when
+   *                    these methods fail.
+   */
+  static nsresult GetBool(const char* aPref, PRBool* aResult);
+  static nsresult GetInt(const char* aPref, PRInt32* aResult);
+
+  /**
+   * Gets string type pref value with raw return value of nsIPrefBranch.
+   *
+   * @param aPref       A pref name.
+   * @param aResult     Must not be NULL.  The value is never modified when
+   *                    these methods fail.
+   */
+  static nsresult GetChar(const char* aPref, nsCString* aResult);
+  static nsresult GetChar(const char* aPref, nsString* aResult);
+  static nsresult GetLocalizedString(const char* aPref, nsString* aResult);
+
+  /**
+   * Sets various type pref values.
+   */
+  static nsresult SetBool(const char* aPref, PRBool aValue);
+  static nsresult SetInt(const char* aPref, PRInt32 aValue);
+  static nsresult SetChar(const char* aPref, const char* aValue);
+  static nsresult SetChar(const char* aPref, const nsCString &aValue);
+  static nsresult SetChar(const char* aPref, const PRUnichar* aValue);
+  static nsresult SetChar(const char* aPref, const nsString &aValue);
+
+  /**
+   * Clears user set pref.
+   */
+  static nsresult ClearUser(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 nsIPrefBran2.idl for the detail.
+   */
+  static nsresult AddStrongObserver(nsIObserver* aObserver, const char* aPref);
+  static nsresult AddWeakObserver(nsIObserver* aObserver, const char* aPref);
+  static nsresult RemoveObserver(nsIObserver* aObserver, const char* aPref);
+
 protected:
   nsresult NotifyServiceObservers(const char *aSubject);
   nsresult UseDefaultPrefFile();
@@ -87,6 +178,14 @@ protected:
 private:
   nsCOMPtr<nsIPrefBranch2> mRootBranch;
   nsCOMPtr<nsIFile>        mCurrentFile;
+
+  static Preferences*      sPreferences;
+  static PRBool            sShutdown;
+
+  /**
+   * Init static members.  TRUE if it succeeded.  Otherwise, FALSE.
+   */
+  static PRBool InitStaticMembers();
 };
 
 } // namespace mozilla

modules/libpref/src/Preferences.cpp

@@ -84,6 +84,49 @@ static nsresult openPrefFile(nsIFile* aFile);
 static nsresult pref_InitInitialObjects(void);
 static nsresult pref_LoadPrefsInDirList(const char *listId);
 
+Preferences* Preferences::sPreferences = nsnull;
+PRBool Preferences::sShutdown = PR_FALSE;
+
+// static
+Preferences*
+Preferences::GetInstance()
+{
+  NS_ENSURE_TRUE(!sShutdown, nsnull);
+
+  if (sPreferences) {
+    NS_ADDREF(sPreferences);
+    return sPreferences;
+  }
+
+  InitStaticMembers();
+  NS_IF_ADDREF(sPreferences);
+  return sPreferences;
+}
+
+// static
+PRBool
+Preferences::InitStaticMembers()
+{
+  if (sShutdown || sPreferences) {
+    return sPreferences != nsnull;
+  }
+
+  sPreferences = new Preferences();
+  NS_ADDREF(sPreferences);
+  if (NS_FAILED(sPreferences->Init()) || !sPreferences->mRootBranch) {
+    NS_RELEASE(sPreferences);
+  }
+  return sPreferences != nsnull;
+}
+
+// static
+void
+Preferences::Shutdown()
+{
+  sShutdown = PR_TRUE; // Don't create the singleton instance after here.
+  NS_IF_RELEASE(sPreferences);
+}
+
 //-----------------------------------------------------------------------------
 
 /*
@@ -951,4 +994,161 @@ static nsresult pref_InitInitialObjects()
   return pref_LoadPrefsInDirList(NS_EXT_PREFS_DEFAULTS_DIR_LIST);
 }
 
+
+/******************************************************************************
+ *
+ * static utilities
+ *
+ ******************************************************************************/
+
+// static
+nsresult
+Preferences::GetBool(const char* aPref, PRBool* aResult)
+{
+  NS_PRECONDITION(aResult, "aResult must not be NULL");
+  NS_ENSURE_TRUE(InitStaticMembers(), NS_ERROR_NOT_AVAILABLE);
+  return sPreferences->mRootBranch->GetBoolPref(aPref, aResult);
+}
+
+// static
+nsresult
+Preferences::GetInt(const char* aPref, PRInt32* aResult)
+{
+  NS_PRECONDITION(aResult, "aResult must not be NULL");
+  NS_ENSURE_TRUE(InitStaticMembers(), NS_ERROR_NOT_AVAILABLE);
+  return sPreferences->mRootBranch->GetIntPref(aPref, aResult);
+}
+
+// static
+nsresult
+Preferences::GetChar(const char* aPref, nsCString* aResult)
+{
+  NS_PRECONDITION(aResult, "aResult must not be NULL");
+  NS_ENSURE_TRUE(InitStaticMembers(), NS_ERROR_NOT_AVAILABLE);
+  nsAdoptingCString result;
+  nsresult rv =
+    sPreferences->mRootBranch->GetCharPref(aPref, getter_Copies(result));
+  if (NS_SUCCEEDED(rv)) {
+    *aResult = result;
+  }
+  return rv;
+}
+
+// static
+nsresult
+Preferences::GetChar(const char* aPref, nsString* aResult)
+{
+  NS_PRECONDITION(aResult, "aResult must not be NULL");
+  NS_ENSURE_TRUE(InitStaticMembers(), NS_ERROR_NOT_AVAILABLE);
+  nsAdoptingCString result;
+  nsresult rv =
+    sPreferences->mRootBranch->GetCharPref(aPref, getter_Copies(result));
+  if (NS_SUCCEEDED(rv)) {
+    CopyUTF8toUTF16(result, *aResult);
+  }
+  return rv;
+}
+
+// static
+nsresult
+Preferences::GetLocalizedString(const char* aPref, nsString* aResult)
+{
+  NS_PRECONDITION(aResult, "aResult must not be NULL");
+  NS_ENSURE_TRUE(InitStaticMembers(), NS_ERROR_NOT_AVAILABLE);
+  nsCOMPtr<nsIPrefLocalizedString> prefLocalString;
+  nsresult rv = sPreferences->mRootBranch->GetComplexValue(aPref,
+                                             NS_GET_IID(nsIPrefLocalizedString),
+                                             getter_AddRefs(prefLocalString));
+  if (NS_SUCCEEDED(rv)) {
+    if (prefLocalString) {
+      prefLocalString->GetData(getter_Copies(*aResult));
+    } else {
+      aResult->Truncate();
+    }
+  }
+  return rv;
+}
+
+// static
+nsresult
+Preferences::SetChar(const char* aPref, const char* aValue)
+{
+  NS_ENSURE_TRUE(InitStaticMembers(), PR_FALSE);
+  return sPreferences->mRootBranch->SetCharPref(aPref, aValue);
+}
+
+// static
+nsresult
+Preferences::SetChar(const char* aPref, const nsCString &aValue)
+{
+  return SetChar(aPref, nsPromiseFlatCString(aValue).get());
+}
+
+// static
+nsresult
+Preferences::SetChar(const char* aPref, const PRUnichar* aValue)
+{
+  NS_ConvertUTF16toUTF8 utf8(aValue);
+  return SetChar(aPref, utf8.get());
+}
+
+// static
+nsresult
+Preferences::SetChar(const char* aPref, const nsString &aValue)
+{
+  NS_ConvertUTF16toUTF8 utf8(aValue);
+  return SetChar(aPref, utf8.get());
+}
+
+// static
+nsresult
+Preferences::SetBool(const char* aPref, PRBool aValue)
+{
+  NS_ENSURE_TRUE(InitStaticMembers(), PR_FALSE);
+  return sPreferences->mRootBranch->SetBoolPref(aPref, aValue);
+}
+
+// static
+nsresult
+Preferences::SetInt(const char* aPref, PRInt32 aValue)
+{
+  NS_ENSURE_TRUE(InitStaticMembers(), PR_FALSE);
+  return sPreferences->mRootBranch->SetIntPref(aPref, aValue);
+}
+
+// static
+nsresult
+Preferences::ClearUser(const char* aPref)
+{
+  NS_ENSURE_TRUE(InitStaticMembers(), PR_FALSE);
+  return sPreferences->mRootBranch->ClearUserPref(aPref);
+}
+
+// static
+nsresult
+Preferences::AddStrongObserver(nsIObserver* aObserver,
+                               const char* aPref)
+{
+  NS_ENSURE_TRUE(InitStaticMembers(), NS_ERROR_NOT_AVAILABLE);
+  return sPreferences->mRootBranch->AddObserver(aPref, aObserver, PR_FALSE);
+}
+
+// static
+nsresult
+Preferences::AddWeakObserver(nsIObserver* aObserver,
+                             const char* aPref)
+{
+  NS_ENSURE_TRUE(InitStaticMembers(), NS_ERROR_NOT_AVAILABLE);
+  return sPreferences->mRootBranch->AddObserver(aPref, aObserver, PR_TRUE);
+}
+
+// static
+nsresult
+Preferences::RemoveObserver(nsIObserver* aObserver,
+                            const char* aPref)
+{
+  NS_ENSURE_TRUE(InitStaticMembers(), NS_ERROR_NOT_AVAILABLE);
+  return sPreferences->mRootBranch->RemoveObserver(aPref, aObserver);
+}
+
 } // namespace mozilla

modules/libpref/src/nsPrefsFactory.cpp

@@ -43,7 +43,7 @@
 
 using namespace mozilla;
 
-NS_GENERIC_FACTORY_CONSTRUCTOR_INIT(Preferences, Init)
+NS_GENERIC_FACTORY_SINGLETON_CONSTRUCTOR(Preferences, Preferences::GetInstance)
 NS_GENERIC_FACTORY_CONSTRUCTOR_INIT(nsPrefLocalizedString, Init)
 NS_GENERIC_FACTORY_CONSTRUCTOR(nsRelativeFilePref)
 
@@ -70,6 +70,7 @@ static mozilla::Module::ContractIDEntry kPrefContracts[] = {
 static void
 UnloadPrefsModule()
 {
+  Preferences::Shutdown();
   PREF_Cleanup();
 }