Android: Expose config changed callbacks

Source/Android/app/src/main/java/org/dolphinemu/dolphinemu/features/settings/model/ConfigChangedCallback.kt

@@ -0,0 +1,33 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+package org.dolphinemu.dolphinemu.features.settings.model
+
+import androidx.annotation.Keep
+
+/**
+ * Calls the passed-in Runnable when Dolphin's config changes.
+ *
+ * Please note: The Runnable may be called from any thread.
+ */
+class ConfigChangedCallback(runnable: Runnable) {
+    @Keep
+    private var pointer: Long = initialize(runnable)
+
+    /**
+     * Stops the callback from being called in the future.
+     */
+    fun unregister() {
+        if (pointer != 0L) {
+            deinitialize(pointer)
+            pointer = 0L
+        }
+    }
+
+    companion object {
+        @JvmStatic
+        private external fun initialize(runnable: Runnable): Long
+
+        @JvmStatic
+        private external fun deinitialize(pointer: Long)
+    }
+}

Source/Android/jni/AndroidCommon/IDCache.cpp

@@ -109,6 +109,8 @@ static jclass s_core_device_control_class;
 static jfieldID s_core_device_control_pointer;
 static jmethodID s_core_device_control_constructor;
 
+static jmethodID s_runnable_run;
+
 namespace IDCache
 {
 JNIEnv* GetEnvForThread()
@@ -504,6 +506,11 @@ jmethodID GetCoreDeviceControlConstructor()
   return s_core_device_control_constructor;
 }
 
+jmethodID GetRunnableRun()
+{
+  return s_runnable_run;
+}
+
 }  // namespace IDCache
 
 extern "C" {
@@ -709,6 +716,10 @@ JNIEXPORT jint JNI_OnLoad(JavaVM* vm, void* reserved)
                        "(Lorg/dolphinemu/dolphinemu/features/input/model/CoreDevice;J)V");
   env->DeleteLocalRef(core_device_control_class);
 
+  const jclass runnable_class = env->FindClass("java/lang/Runnable");
+  s_runnable_run = env->GetMethodID(runnable_class, "run", "()V");
+  env->DeleteLocalRef(runnable_class);
+
   return JNI_VERSION;
 }
 

Source/Android/jni/AndroidCommon/IDCache.h

@@ -108,4 +108,6 @@ jclass GetCoreDeviceControlClass();
 jfieldID GetCoreDeviceControlPointer();
 jmethodID GetCoreDeviceControlConstructor();
 
+jmethodID GetRunnableRun();
+
 }  // namespace IDCache

Source/Android/jni/CMakeLists.txt

@@ -5,6 +5,7 @@ add_library(main SHARED
   Cheats/GraphicsMod.cpp
   Cheats/GraphicsModGroup.cpp
   Cheats/PatchCheat.cpp
+  Config/ConfigChangedCallback.cpp
   Config/NativeConfig.cpp
   Config/PostProcessing.cpp
   GameList/GameFile.cpp

Source/Android/jni/Config/ConfigChangedCallback.cpp

@@ -0,0 +1,44 @@
+// Copyright 2023 Dolphin Emulator Project
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#include <jni.h>
+
+#include "Common/Config/Config.h"
+#include "jni/AndroidCommon/AndroidCommon.h"
+#include "jni/AndroidCommon/IDCache.h"
+
+struct ConfigChangedCallbackContext
+{
+  jobject runnable;
+  Config::ConfigChangedCallbackID callback_id;
+};
+
+extern "C" {
+
+JNIEXPORT jlong JNICALL
+Java_org_dolphinemu_dolphinemu_features_settings_model_ConfigChangedCallback_initialize(
+    JNIEnv* env, jclass, jobject runnable)
+{
+  auto* context = new ConfigChangedCallbackContext;
+
+  jobject runnable_global = env->NewGlobalRef(runnable);
+  context->runnable = runnable_global;
+  context->callback_id = Config::AddConfigChangedCallback([runnable_global] {
+    IDCache::GetEnvForThread()->CallVoidMethod(runnable_global, IDCache::GetRunnableRun());
+  });
+
+  return reinterpret_cast<jlong>(context);
+}
+
+JNIEXPORT void JNICALL
+Java_org_dolphinemu_dolphinemu_features_settings_model_ConfigChangedCallback_deinitialize(
+    JNIEnv* env, jclass, jlong pointer)
+{
+  auto* context = reinterpret_cast<ConfigChangedCallbackContext*>(pointer);
+
+  Config::RemoveConfigChangedCallback(context->callback_id);
+  env->DeleteGlobalRef(context->runnable);
+
+  delete context;
+}
+}