dom/camera/CameraPreferences.h

   1 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* This Source Code Form is subject to the terms of the Mozilla Public
   3  * License, v. 2.0. If a copy of the MPL was not distributed with this
   4  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   5
   6 #ifndef DOM_CAMERA_CAMERAPREFERENCES_H
   7 #define DOM_CAMERA_CAMERAPREFERENCES_H
   8
   9 #include "nsString.h"
  10 #include "nsIObserver.h"
  11 #ifdef MOZ_WIDGET_GONK
  12 #include "mozilla/StaticPtr.h"
  13 #endif
  14
  15 #if defined(MOZ_HAVE_CXX11_STRONG_ENUMS) || defined(MOZ_HAVE_CXX11_ENUM_TYPE)
  16 // Older compilers that don't support strongly-typed enums
  17 // just typedef uint32_t to nsresult, which results in conflicting
  18 // overloaded members in CameraPreferences.
  19 #define CAMERAPREFERENCES_HAVE_SEPARATE_UINT32_AND_NSRESULT
  20 #endif
  21
  22 namespace mozilla {
  23
  24 template<class T> class StaticAutoPtr;
  25
  26 class CameraPreferences
  27 #ifdef MOZ_WIDGET_GONK
  28   : public nsIObserver
  29 #endif
  30 {
  31 public:
  32 #ifdef MOZ_WIDGET_GONK
  33   NS_DECL_ISUPPORTS
  34   NS_DECL_NSIOBSERVER
  35 #endif
  36
  37   static bool Initialize();
  38   static void Shutdown();
  39
  40   static bool GetPref(const char* aPref, nsACString& aVal);
  41 #ifdef CAMERAPREFERENCES_HAVE_SEPARATE_UINT32_AND_NSRESULT
  42   static bool GetPref(const char* aPref, nsresult& aVal);
  43 #endif
  44   static bool GetPref(const char* aPref, uint32_t& aVal);
  45   static bool GetPref(const char* aPref, bool& aVal);
  46
  47 protected:
  48   static const uint32_t kPrefNotFound = UINT32_MAX;
  49   static uint32_t PrefToIndex(const char* aPref);
  50
  51   static void PreferenceChanged(const char* aPref, void* aClosure);
  52 #ifdef CAMERAPREFERENCES_HAVE_SEPARATE_UINT32_AND_NSRESULT
  53   static nsresult UpdatePref(const char* aPref, nsresult& aVar);
  54 #endif
  55   static nsresult UpdatePref(const char* aPref, uint32_t& aVar);
  56   static nsresult UpdatePref(const char* aPref, nsACString& aVar);
  57   static nsresult UpdatePref(const char* aPref, bool& aVar);
  58
  59   enum PrefValueType {
  60     kPrefValueIsNsResult,
  61     kPrefValueIsUint32,
  62     kPrefValueIsCString,
  63     kPrefValueIsBoolean
  64   };
  65   struct Pref {
  66     const char* const           mPref;
  67     PrefValueType               mValueType;
  68     union {
  69       // The 'mAsVoid' member must be first and is required to allow 'mValue'
  70       // to be initialized with any pointer type, as not all of our platforms
  71       // support the use of designated initializers; in their absence, only
  72       // the first element of a union can be statically initialized, and
  73       // 'void*' lets us stuff any pointer type into it.
  74       void*                     mAsVoid;
  75       StaticAutoPtr<nsCString>* mAsCString;
  76       nsresult*                 mAsNsResult;
  77       uint32_t*                 mAsUint32;
  78       bool*                     mAsBoolean;
  79     } mValue;
  80   };
  81   static Pref sPrefs[];
  82
  83   static StaticAutoPtr<nsCString> sPrefTestEnabled;
  84   static StaticAutoPtr<nsCString> sPrefHardwareTest;
  85   static StaticAutoPtr<nsCString> sPrefGonkParameters;
  86
  87   static nsresult sPrefCameraControlMethodErrorOverride;
  88   static nsresult sPrefCameraControlAsyncErrorOverride;
  89
  90   static uint32_t sPrefCameraControlLowMemoryThresholdMB;
  91
  92   static bool sPrefCameraParametersIsLowMemory;
  93
  94 #ifdef MOZ_WIDGET_GONK
  95   static StaticRefPtr<CameraPreferences> sObserver;
  96
  97   nsresult PreinitCameraHardware();
  98
  99 protected:
 100   // Objects may be instantiated for use as observers.
 101   CameraPreferences() { }
 102   virtual ~CameraPreferences() { }
 103 #else
 104 private:
 105   // Static class only.
 106   CameraPreferences();
 107   ~CameraPreferences();
 108 #endif
 109 };
 110
 111 } // namespace mozilla
 112
 113 #endif // DOM_CAMERA_CAMERAPREFERENCES_H