JNI: Tidying

modules/juce_audio_devices/native/juce_Oboe_android.cpp

@@ -1146,7 +1146,7 @@ public:
 
         auto* env = getEnv();
 
-        jclass audioManagerClass = env->FindClass ("android/media/AudioManager");
+        LocalRef<jclass> audioManagerClass { env->FindClass ("android/media/AudioManager") };
 
         // We should be really entering here only if API supports it.
         jassert (audioManagerClass != nullptr);
@@ -1202,7 +1202,7 @@ public:
 
     void addDevice (const LocalRef<jobject>& device, JNIEnv* env)
     {
-        auto deviceClass = LocalRef<jclass> ((jclass) env->FindClass ("android/media/AudioDeviceInfo"));
+        LocalRef<jclass> deviceClass { env->FindClass ("android/media/AudioDeviceInfo") };
 
         jmethodID getProductNameMethod = env->GetMethodID (deviceClass, "getProductName",
                                                            "()Ljava/lang/CharSequence;");

modules/juce_core/native/juce_JNIHelpers_android.cpp

@@ -286,7 +286,7 @@ void JNIClassBase::initialise (JNIEnv* env, jobject context)
 
     if (sdkVersion >= minSDK)
     {
-        LocalRef<jstring> classNameAndPackage (javaString (String (classPath).replaceCharacter (L'/', L'.')));
+        const auto classNameAndPackage = javaString (String (classPath).replaceCharacter (L'/', L'.'));
         static Array<GlobalRef> byteCodeLoaders;
 
         if (! SystemJavaClassComparator::isSystemClass (this))
@@ -294,8 +294,9 @@ void JNIClassBase::initialise (JNIEnv* env, jobject context)
             // We use the context's class loader, rather than the 'system' class loader, because we
             // may need to load classes from our library dependencies (such as the BillingClient
             // library), and the system class loader is not aware of those libraries.
+            const LocalRef<jclass> contextClass { env->FindClass ("android/content/Context") };
             const LocalRef<jobject> defaultClassLoader { env->CallObjectMethod (context,
-                                                                                env->GetMethodID (env->FindClass ("android/content/Context"),
+                                                                                env->GetMethodID (contextClass,
                                                                                                   "getClassLoader",
                                                                                                   "()Ljava/lang/ClassLoader;")) };
 
@@ -466,12 +467,12 @@ LocalRef<jobject> CreateJavaInterface (AndroidInterfaceImplementer* implementer,
     // you need to override at least one interface
     jassert (interfaceNames.size() > 0);
 
-    auto classArray = LocalRef<jobject> (env->NewObjectArray (interfaceNames.size(), JavaClass, nullptr));
+    LocalRef<jobject> classArray { env->NewObjectArray (interfaceNames.size(), JavaClass, nullptr) };
     LocalRef<jobject> classLoader;
 
     for (auto i = 0; i < interfaceNames.size(); ++i)
     {
-        auto aClass = LocalRef<jobject> (env->FindClass (interfaceNames[i].toRawUTF8()));
+        LocalRef<jobject> aClass { env->FindClass (interfaceNames[i].toRawUTF8()) };
 
         if (aClass != nullptr)
         {
@@ -487,8 +488,8 @@ LocalRef<jobject> CreateJavaInterface (AndroidInterfaceImplementer* implementer,
         }
     }
 
-    auto invocationHandler = LocalRef<jobject> (env->NewObject (JuceInvocationHandler, JuceInvocationHandler.constructor,
+    LocalRef<jobject> invocationHandler { env->NewObject (JuceInvocationHandler, JuceInvocationHandler.constructor,
-                                                                reinterpret_cast<jlong> (implementer)));
+                                                          reinterpret_cast<jlong> (implementer)) };
 
     // CreateJavaInterface() is expected to be called just once for a given implementer
     jassert (implementer->invocationHandler == nullptr);
@@ -631,7 +632,7 @@ int getAndroidSDKVersion()
         // when this method is used
         auto* env = getEnv();
 
-        auto buildVersion = env->FindClass ("android/os/Build$VERSION");
+        LocalRef<jclass> buildVersion { env->FindClass ("android/os/Build$VERSION") };
         jassert (buildVersion != nullptr);
 
         auto sdkVersionField = env->GetStaticFieldID (buildVersion, "SDK_INT", "I");
@@ -825,19 +826,17 @@ String audioManagerGetProperty (const String& property)
     LocalRef<jobject> audioManager (env->CallObjectMethod (getAppContext().get(), AndroidContext.getSystemService,
                                                            javaString ("audio").get()));
 
-    if (audioManager != nullptr)
+    if (audioManager == nullptr)
-    {
+        return {};
-        LocalRef<jstring> jProperty (javaString (property));
 
-        auto methodID = env->GetMethodID (AndroidAudioManager, "getProperty", "(Ljava/lang/String;)Ljava/lang/String;");
+    auto methodID = env->GetMethodID (AndroidAudioManager, "getProperty", "(Ljava/lang/String;)Ljava/lang/String;");
 
-        if (methodID != nullptr)
+    if (methodID == nullptr)
-            return juceString (LocalRef<jstring> ((jstring) env->CallObjectMethod (audioManager.get(),
+        return {};
-                                                                                   methodID,
-                                                                                   javaString (property).get())));
-    }
 
-    return {};
+    return juceString (LocalRef<jstring> ((jstring) env->CallObjectMethod (audioManager.get(),
+                                                                           methodID,
+                                                                           javaString (property).get())));
 }
 
 }

modules/juce_core/native/juce_SystemStats_android.cpp

@@ -63,7 +63,7 @@ namespace AndroidStatsHelpers
     {
         auto* env = getEnv();
 
-        if (auto settings = (jclass) env->FindClass ("android/provider/Settings$Secure"))
+        if (LocalRef<jclass> settings { env->FindClass ("android/provider/Settings$Secure") })
         {
             if (auto fId = env->GetStaticFieldID (settings, "ANDROID_ID", "Ljava/lang/String;"))
             {

modules/juce_core/native/juce_Threads_android.cpp

@@ -84,7 +84,7 @@ extern "C" jint JNIEXPORT JNI_OnLoad (JavaVM* vm, void*)
     auto* env = getEnv();
 
     // register the initialisation function
-    auto juceJavaClass = env->FindClass ("com/rmsl/juce/Java");
+    LocalRef<jclass> juceJavaClass { env->FindClass ("com/rmsl/juce/Java") };
 
     if (juceJavaClass != nullptr)
     {
@@ -195,7 +195,7 @@ private:
 
         if (mainActivity == nullptr)
         {
-            LocalRef<jobject> appContext (getAppContext());
+            auto appContext = getAppContext();
             auto mainActivityPath = getMainActivityClassPath();
 
             if (mainActivityPath.isNotEmpty())
@@ -217,7 +217,7 @@ private:
 
         if (mainActivityClassPath.isEmpty())
         {
-            LocalRef<jobject> appContext (getAppContext());
+            auto appContext = getAppContext();
 
             if (appContext != nullptr)
             {

modules/juce_events/native/juce_Messaging_android.cpp

@@ -62,7 +62,7 @@ namespace Android
 
     struct Handler
     {
-        Handler() : nativeHandler (LocalRef<jobject> (getEnv()->NewObject (AndroidHandler, AndroidHandler.constructor))) {}
+        Handler() = default;
         ~Handler() { clearSingletonInstance(); }
 
         JUCE_DECLARE_SINGLETON_INLINE (Handler, false)
@@ -72,7 +72,7 @@ namespace Android
             return (getEnv()->CallBooleanMethod (nativeHandler.get(), AndroidHandler.post, runnable) != 0);
         }
 
-        GlobalRef nativeHandler;
+        GlobalRef nativeHandler { LocalRef<jobject> { getEnv()->NewObject (AndroidHandler, AndroidHandler.constructor) } };
     };
 }
 
@@ -81,10 +81,7 @@ struct AndroidMessageQueue final : private Android::Runnable
 {
     JUCE_DECLARE_SINGLETON_SINGLETHREADED_INLINE (AndroidMessageQueue, true)
 
-    AndroidMessageQueue()
+    AndroidMessageQueue() = default;
-        : self (CreateJavaInterface (this, "java/lang/Runnable"))
-    {
-    }
 
     ~AndroidMessageQueue() override
     {
@@ -115,11 +112,11 @@ private:
         }
     }
 
-    // the this pointer to this class in Java land
-    GlobalRef self;
-
     ReferenceCountedArray<MessageManager::MessageBase, CriticalSection> queue;
     Android::Handler handler;
+
+    // the this pointer to this class in Java land
+    GlobalRef self { CreateJavaInterface (this, "java/lang/Runnable") };
 };
 
 //==============================================================================
@@ -149,7 +146,7 @@ void MessageManager::stopDispatchLoop()
         void messageCallback() override
         {
             auto* env = getEnv();
-            LocalRef<jobject> activity (getCurrentActivity());
+            auto activity = getCurrentActivity();
 
             if (activity != nullptr)
             {
@@ -180,7 +177,9 @@ void MessageManager::stopDispatchLoop()
 class JuceAppLifecycle final : public ActivityLifecycleCallbacks
 {
 public:
-    JuceAppLifecycle (juce::JUCEApplicationBase* (*initSymbolAddr)())
+    using CreateApp = juce::JUCEApplicationBase* (*)();
+
+    explicit JuceAppLifecycle (CreateApp initSymbolAddr)
         : createApplicationSymbol (initSymbolAddr)
     {
     }
@@ -200,8 +199,8 @@ public:
             JUCEApplicationBase::appWillTerminateByForce();
             JNIClassBase::releaseAllClasses (env);
 
-            jclass systemClass = (jclass) env->FindClass ("java/lang/System");
+            LocalRef<jclass> systemClass { env->FindClass ("java/lang/System") };
-            jmethodID exitMethod = env->GetStaticMethodID (systemClass, "exit", "(I)V");
+            jmethodID exitMethod = env->GetStaticMethodID (systemClass.get(), "exit", "(I)V");
             env->CallStaticVoidMethod (systemClass, exitMethod, 0);
         }
     }
@@ -225,7 +224,7 @@ public:
             app->resumed();
     }
 
-    static JuceAppLifecycle& getInstance (juce::JUCEApplicationBase* (*initSymbolAddr)())
+    static JuceAppLifecycle& getInstance (CreateApp initSymbolAddr)
     {
         static JuceAppLifecycle juceAppLifecycle (initSymbolAddr);
         return juceAppLifecycle;
@@ -267,7 +266,7 @@ private:
 
     std::optional<ScopedJuceInitialiser_GUI> initialiser;
     GlobalRef myself;
-    juce::JUCEApplicationBase* (*createApplicationSymbol)();
+    CreateApp createApplicationSymbol{};
     bool hasBeenInitialised = false;
     ActivityLifecycleCallbackForwarder forwarder { GlobalRef { getAppContext() }, this };
 };
@@ -279,8 +278,8 @@ void juce_juceEventsAndroidStartApp();
 void juce_juceEventsAndroidStartApp()
 {
     auto dllPath = juce_getExecutableFile().getFullPathName();
-    auto addr = reinterpret_cast<juce::JUCEApplicationBase*(*)()> (DynamicLibrary (dllPath)
+    auto addr = reinterpret_cast<juce::JUCEApplicationBase* (*)()> (DynamicLibrary (dllPath)
-                                                                    .getFunction ("juce_CreateApplication"));
+                                                                     .getFunction ("juce_CreateApplication"));
 
     if (addr != nullptr)
         JuceAppLifecycle::getInstance (addr);

modules/juce_gui_basics/native/juce_ContentSharer_android.cpp

@@ -375,8 +375,8 @@ private:
 
         const auto context = getAppContext();
 
-        auto* klass = env->FindClass ("com/rmsl/juce/Receiver");
+        LocalRef<jclass> klass { env->FindClass ("com/rmsl/juce/Receiver") };
-        const LocalRef<jobject> replyIntent (env->NewObject (AndroidIntent, AndroidIntent.constructorWithContextAndClass, context.get(), klass));
+        const LocalRef<jobject> replyIntent (env->NewObject (AndroidIntent, AndroidIntent.constructorWithContextAndClass, context.get(), klass.get()));
         getEnv()->CallObjectMethod (replyIntent, AndroidIntent.putExtraInt, javaString ("com.rmsl.juce.JUCE_REQUEST_CODE").get(), request);
 
         const auto flags = FLAG_UPDATE_CURRENT | FLAG_IMMUTABLE;

modules/juce_gui_basics/native/juce_Windowing_android.cpp

@@ -1329,7 +1329,7 @@ public:
         {
             // we don't know if the user is holding on to a local ref to this, so
             // explicitly create a new one
-            auto nativeView = LocalRef<jobject> (env->NewLocalRef (static_cast<jobject> (nativeViewHandle)));
+            LocalRef<jobject> nativeView { env->NewLocalRef (static_cast<jobject> (nativeViewHandle)) };
 
             if (env->IsInstanceOf (nativeView.get(), AndroidActivity))
             {
@@ -1838,7 +1838,7 @@ public:
 
         if (! handled)
         {
-            LocalRef<jobject> activity (getCurrentActivity());
+            auto activity = getCurrentActivity();
 
             if (activity != nullptr)
             {
@@ -2003,7 +2003,7 @@ public:
     }
 
     //==============================================================================
-    static void handleDoFrameCallback (JNIEnv*, AndroidComponentPeer& t, [[maybe_unused]] int64 frameTimeNanos)
+    static void handleDoFrameCallback (JNIEnv*, AndroidComponentPeer& t, [[maybe_unused]] jlong frameTimeNanos)
     {
         const auto timestampSec = (double) frameTimeNanos / (double) 1'000'000'000;
         t.callVBlankListeners (timestampSec);
@@ -2631,13 +2631,13 @@ Desktop::DisplayOrientation Desktop::getCurrentOrientation() const
     };
 
     JNIEnv* env = getEnv();
-    LocalRef<jstring> windowServiceString (javaString ("window"));
+    const auto windowServiceString = javaString ("window");
 
-    LocalRef<jobject> windowManager = LocalRef<jobject> (env->CallObjectMethod (getAppContext().get(), AndroidContext.getSystemService, windowServiceString.get()));
+    LocalRef<jobject> windowManager { env->CallObjectMethod (getAppContext().get(), AndroidContext.getSystemService, windowServiceString.get()) };
 
     if (windowManager.get() != nullptr)
     {
-        LocalRef<jobject> display = LocalRef<jobject> (env->CallObjectMethod (windowManager, AndroidWindowManager.getDefaultDisplay));
+        LocalRef<jobject> display { env->CallObjectMethod (windowManager, AndroidWindowManager.getDefaultDisplay) };
 
         if (display.get() != nullptr)
         {
@@ -2688,7 +2688,7 @@ bool KeyPress::isKeyCurrentlyDown (int /*keyCode*/)
 JUCE_API void JUCE_CALLTYPE Process::hide()
 {
     auto* env = getEnv();
-    LocalRef<jobject> currentActivity (getCurrentActivity().get());
+    auto currentActivity = getCurrentActivity();
 
     if (env->CallBooleanMethod (currentActivity.get(), AndroidActivity.moveTaskToBack, true) == 0)
     {
@@ -2751,7 +2751,7 @@ public:
 
         if (methodName == "onCancel" || methodName == "onClick")
         {
-            auto* dialog = env->GetObjectArrayElement (args, 0);
+            LocalRef<jobject> dialog { env->GetObjectArrayElement (args, 0) };
             env->CallVoidMethod (dialog, AndroidDialogInterface.dismiss);
 
             NullCheckedInvocation::invoke (callback);
@@ -2853,8 +2853,7 @@ void Displays::findDisplays (float masterScale)
 {
     auto* env = getEnv();
 
-    LocalRef<jstring> windowServiceString (javaString ("window"));
+    const auto windowServiceString = javaString ("window");
-
     LocalRef<jobject> windowManager (env->CallObjectMethod (getAppContext(), AndroidContext.getSystemService, windowServiceString.get()));
     LocalRef<jobject> display (env->CallObjectMethod (windowManager, AndroidWindowManager.getDefaultDisplay));
 

modules/juce_gui_extra/native/juce_PushNotifications_android.cpp

@@ -337,7 +337,7 @@ struct PushNotifications::Impl
     void notifyListenersAboutLocalNotification (const LocalRef<jobject>& intent)
     {
         auto* env = getEnv();
-        LocalRef<jobject> context (getMainActivity());
+        auto context = getMainActivity();
 
         auto bundle = LocalRef<jobject> (env->CallObjectMethod (intent, AndroidIntent.getExtras));
 
@@ -575,7 +575,7 @@ struct PushNotifications::Impl
     static LocalRef<jobject> getNotificationManager()
     {
         auto* env = getEnv();
-        LocalRef<jobject> context (getMainActivity());
+        auto context = getMainActivity();
 
         return LocalRef<jobject> (env->CallObjectMethod (context.get(),
                                                          AndroidContext.getSystemService,
@@ -601,9 +601,9 @@ struct PushNotifications::Impl
     static LocalRef<jobject> createNotificationBuilder (const Notification& n)
     {
         auto* env = getEnv();
-        LocalRef<jobject> context (getMainActivity());
+        auto context = getMainActivity();
 
-        jclass builderClass = env->FindClass ("android/app/Notification$Builder");
+        LocalRef<jclass> builderClass { env->FindClass ("android/app/Notification$Builder") };
         jassert (builderClass != nullptr);
 
         if (builderClass == nullptr)
@@ -621,7 +621,7 @@ struct PushNotifications::Impl
         jassert (builderConstructor != nullptr);
 
         if (builderConstructor == nullptr)
-            return LocalRef<jobject> (nullptr);
+            return LocalRef<jobject>();
 
         if (apiAtLeast26)
             return LocalRef<jobject> (env->NewObject (builderClass, builderConstructor,
@@ -638,7 +638,7 @@ struct PushNotifications::Impl
             return notificationBuilder;
 
         auto* env = getEnv();
-        LocalRef<jobject> context (getMainActivity());
+        auto context = getMainActivity();
 
         auto activityClass = LocalRef<jobject> (env->CallObjectMethod (context.get(), JavaObject.getClass));
         auto notifyIntent  = LocalRef<jobject> (env->NewObject (AndroidIntent, AndroidIntent.constructorWithContextAndClass, context.get(), activityClass.get()));
@@ -875,7 +875,7 @@ struct PushNotifications::Impl
             return notificationBuilder;
 
         auto* env = getEnv();
-        LocalRef<jobject> context (getMainActivity());
+        auto context = getMainActivity();
 
         auto activityClass = LocalRef<jobject> (env->CallObjectMethod (context.get(), JavaObject.getClass));
         auto deleteIntent  = LocalRef<jobject> (env->NewObject (AndroidIntent, AndroidIntent.constructorWithContextAndClass, context.get(), activityClass.get()));
@@ -905,7 +905,7 @@ struct PushNotifications::Impl
             return notificationBuilder;
 
         auto* env = getEnv();
-        LocalRef<jobject> context (getMainActivity());
+        auto context = getMainActivity();
 
         for (const auto [actionIndex, action] : enumerate (n.actions))
         {
@@ -998,7 +998,7 @@ struct PushNotifications::Impl
     static LocalRef<jobject> juceUrlToAndroidUri (const URL& url)
     {
         auto* env = getEnv();
-        LocalRef<jobject> context (getMainActivity());
+        auto context = getMainActivity();
 
         auto packageNameString = LocalRef<jstring> ((jstring) (env->CallObjectMethod (context.get(), AndroidContext.getPackageName)));
 
@@ -1462,7 +1462,7 @@ struct PushNotifications::Impl
     static bool intentActionContainsAnyOf (jobject intent, const StringArray& strings, bool includePackageName)
     {
         auto* env = getEnv();
-        LocalRef<jobject> context (getMainActivity());
+        auto context = getMainActivity();
 
         String packageName = includePackageName ? juceString ((jstring) env->CallObjectMethod (context.get(),
                                                                                                AndroidContext.getPackageName))

modules/juce_video/native/juce_Video_android.h

@@ -1484,7 +1484,7 @@ private:
 
             auto* env = getEnv();
 
-            auto requestBuilderClass = LocalRef<jclass> (env->FindClass ("android/media/AudioFocusRequest$Builder"));
+            LocalRef<jclass> requestBuilderClass { env->FindClass ("android/media/AudioFocusRequest$Builder") };
 
             static jmethodID constructor = env->GetMethodID (requestBuilderClass, "<init>", "(I)V");
             static jmethodID buildMethod = env->GetMethodID (requestBuilderClass, "build", "()Landroid/media/AudioFocusRequest;");