Android: Toast when ROM fails to load

src/jni_driver.cpp

@@ -81,10 +81,12 @@ AlberFunction(void, Finalize)(JNIEnv* env, jobject obj) {
 
 AlberFunction(jboolean, HasRomLoaded)(JNIEnv* env, jobject obj) { return romLoaded; }
 
-AlberFunction(void, LoadRom)(JNIEnv* env, jobject obj, jstring path) {
+AlberFunction(jboolean, LoadRom)(JNIEnv* env, jobject obj, jstring path) {
 	const char* pathStr = env->GetStringUTFChars(path, nullptr);
 	romLoaded = emulator->loadROM(pathStr);
 	env->ReleaseStringUTFChars(path, pathStr);
+
+	return romLoaded;
 }
 
 AlberFunction(void, LoadLuaScript)(JNIEnv* env, jobject obj, jstring script) {

src/pandroid/app/src/main/java/com/panda3ds/pandroid/AlberDriver.java

@@ -9,7 +9,7 @@ public class AlberDriver {
 	public static native void Initialize();
 	public static native void RunFrame(int fbo);
 	public static native boolean HasRomLoaded();
-	public static native void LoadRom(String path);
+	public static native boolean LoadRom(String path);
 	public static native void Finalize();
 
 	public static native void KeyDown(int code);

src/pandroid/app/src/main/java/com/panda3ds/pandroid/view/PandaGlRenderer.java

@@ -2,20 +2,23 @@ package com.panda3ds.pandroid.view;
 
 import static android.opengl.GLES32.*;
 
+import android.content.Context;
 import android.content.res.Resources;
 import android.graphics.Rect;
 import android.opengl.GLSurfaceView;
+import android.os.Handler;
 import android.util.Log;
+import android.widget.Toast;
 import com.panda3ds.pandroid.AlberDriver;
+import com.panda3ds.pandroid.data.SMDH;
 import com.panda3ds.pandroid.data.config.GlobalConfig;
+import com.panda3ds.pandroid.data.game.GameMetadata;
 import com.panda3ds.pandroid.utils.Constants;
 import com.panda3ds.pandroid.utils.GameUtils;
 import com.panda3ds.pandroid.utils.PerformanceMonitor;
 import com.panda3ds.pandroid.view.renderer.ConsoleRenderer;
 import com.panda3ds.pandroid.view.renderer.layout.ConsoleLayout;
 import com.panda3ds.pandroid.view.renderer.layout.DefaultScreenLayout;
-import com.panda3ds.pandroid.data.SMDH;
-import com.panda3ds.pandroid.data.game.GameMetadata;
 import javax.microedition.khronos.egl.EGLConfig;
 import javax.microedition.khronos.opengles.GL10;
 
@@ -25,9 +28,11 @@ public class PandaGlRenderer implements GLSurfaceView.Renderer, ConsoleRenderer
 	private int screenWidth, screenHeight;
 	private int screenTexture;
 	public int screenFbo;
+	private final Context context;
 
-	PandaGlRenderer(String romPath) {
+	PandaGlRenderer(Context context, String romPath) {
 		super();
+		this.context = context;
 		this.romPath = romPath;
 
 		screenWidth = Resources.getSystem().getDisplayMetrics().widthPixels;
@@ -84,7 +89,29 @@ public class PandaGlRenderer implements GLSurfaceView.Renderer, ConsoleRenderer
 
 		AlberDriver.Initialize();
 		AlberDriver.setShaderJitEnabled(GlobalConfig.get(GlobalConfig.KEY_SHADER_JIT));
-		AlberDriver.LoadRom(romPath);
+
+		// If loading the ROM failed, display an error message and early exit
+		if (!AlberDriver.LoadRom(romPath)) {
+			// Get a handler that can be used to post to the main thread
+			Handler mainHandler = new Handler(context.getMainLooper());
+
+			Runnable runnable = new Runnable() {
+				@Override
+				public void run() {
+					Toast
+						.makeText(
+							context, "Failed to load ROM! Make sure it's a valid 3DS ROM and that storage permissions are configured properly.",
+							Toast.LENGTH_LONG
+						)
+						.show();
+				}
+			};
+			mainHandler.post(runnable);
+
+			GameMetadata game = GameUtils.getCurrentGame();
+			GameUtils.removeGame(game);
+			return;
+		}
 
 		// Load the SMDH
 		byte[] smdhData = AlberDriver.GetSmdh();
@@ -93,7 +120,7 @@ public class PandaGlRenderer implements GLSurfaceView.Renderer, ConsoleRenderer
 		} else {
 			SMDH smdh = new SMDH(smdhData);
 			Log.i(Constants.LOG_TAG, "Loaded rom SDMH");
-			Log.i(Constants.LOG_TAG, String.format("Are you playing '%s' published by '%s'", smdh.getTitle(), smdh.getPublisher()));
+			Log.i(Constants.LOG_TAG, String.format("You are playing '%s' published by '%s'", smdh.getTitle(), smdh.getPublisher()));
 			GameMetadata game = GameUtils.getCurrentGame();
 			GameUtils.removeGame(game);
 			GameUtils.addGame(GameMetadata.applySMDH(game, smdh));

src/pandroid/app/src/main/java/com/panda3ds/pandroid/view/PandaGlSurfaceView.java

@@ -21,7 +21,7 @@ public class PandaGlSurfaceView extends GLSurfaceView implements TouchScreenNode
 		if (Debug.isDebuggerConnected()) {
 			setDebugFlags(DEBUG_LOG_GL_CALLS);
 		}
-		renderer = new PandaGlRenderer(romPath);
+		renderer = new PandaGlRenderer(getContext(), romPath);
 		setRenderer(renderer);
 	}