Android alert display functionality using JNI

base/VulkanAndroid.cpp

@@ -11,6 +11,7 @@
 #if defined(__ANDROID__)
 	#include <android/log.h>
 	#include <dlfcn.h>
+	#include <android/native_window_jni.h>
 
 android_app* androidApp;
 
@@ -292,6 +293,23 @@ namespace vks
 			vks::android::screenDensity = AConfiguration_getDensity(config);
 			AConfiguration_delete(config);
 		}
+
+		// Displays a native alert dialog using JNI
+		void showAlert(const char* message) {
+			JNIEnv* jni;
+			androidApp->activity->vm->AttachCurrentThread(&jni, NULL);
+
+			jstring jmessage = jni->NewStringUTF(message);
+
+			jclass clazz = jni->GetObjectClass(androidApp->activity->clazz);
+			// Signature has to match java implementation (arguments)
+			jmethodID methodID = jni->GetMethodID(clazz, "showAlert", "(Ljava/lang/String;)V");
+			jni->CallVoidMethod(androidApp->activity->clazz, methodID, jmessage);
+			jni->DeleteLocalRef(jmessage);
+
+			androidApp->activity->vm->DetachCurrentThread();
+			return;
+		}
 	}
 }
 

base/VulkanAndroid.h

@@ -26,6 +26,7 @@
 #include <android_native_app_glue.h>
 #include <android/configuration.h>
 #include <memory>
+#include <string>
 
 // Missing from the NDK
 namespace std
@@ -169,6 +170,7 @@ namespace vks
 		void loadVulkanFunctions(VkInstance instance);
 		void freeVulkanLibrary();
 		void getDeviceConfig();
+		void showAlert(const char* message);
 	}
 }
 

base/VulkanTools.cpp

@@ -268,8 +268,9 @@ namespace vks
 			if (!errorModeSilent) {
 				MessageBox(NULL, message.c_str(), NULL, MB_OK | MB_ICONERROR);
 			}
-#elif defined(__ANDROID__)	
-			LOGE("Fatal error: %s", message.c_str());
+#elif defined(__ANDROID__)
+            LOGE("Fatal error: %s", message.c_str());
+			vks::android::showAlert(message.c_str());
 #endif
 			std::cerr << message << "\n";
 			exit(exitCode);