android: Putting in work

- Landscape layout.
- Snapshot viewer is now a fragment for future re-use.
- Bugfixes
- Etc'


Former-commit-id: 34365fd143cefdc2b1bb3b68a62f62849f442fa1

AndroidApp/app/build.gradle

@@ -5,7 +5,7 @@ android {
     buildToolsVersion "29.0.3"
     defaultConfig {
         applicationId "com.mrmichel.rustdroid_emu"
-        minSdkVersion 19
+        minSdkVersion 21
         targetSdkVersion 23
         versionCode 1
         versionName "1.0"
@@ -49,6 +49,8 @@ dependencies {
     implementation 'androidx.constraintlayout:constraintlayout:1.1.3'
     implementation 'androidx.lifecycle:lifecycle-extensions:2.2.0'
     implementation 'com.google.android.material:material:1.1.0'
+    implementation "androidx.documentfile:documentfile:1.0.1"
+    implementation 'androidx.preference:preference:1.1.0'
     testImplementation 'junit:junit:4.12'
     androidTestImplementation 'androidx.test.ext:junit:1.1.0'
     androidTestImplementation 'androidx.test.espresso:espresso-core:3.1.1'

AndroidApp/app/src/main/AndroidManifest.xml

@@ -2,7 +2,10 @@
 <manifest xmlns:android="http://schemas.android.com/apk/res/android"
     package="com.mrmichel.rustdroid_emu">
 
-    <uses-feature android:glEsVersion="0x00200000" android:required="true"></uses-feature>
+    <uses-feature
+        android:glEsVersion="0x00200000"
+        android:required="true" />
+
     <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
     <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
 
@@ -13,17 +16,18 @@
         android:roundIcon="@mipmap/ic_launcher_round"
         android:supportsRtl="true"
         android:theme="@style/AppTheme">
+        <activity android:name=".ui.snapshots.SnapshotPickerActivity"></activity>
         <activity
-            android:name=".ui.snapshots.SnapshotActivity"
+            android:name=".ui.snapshots.SnapshotListFragment"
-            android:label="@string/title_activity_snapshot"
+            android:label="@string/title_activity_snapshot" />
-            ></activity>
         <activity
-            android:name=".ui.RomListActivity"
+            android:name=".ui.library.RomListActivity"
             android:label="@string/title_activity_rom_list" />
         <activity
             android:name=".ui.EmulatorActivity"
-            android:label="@string/title_activity_emulator"
+            android:label="@string/title_activity_emulator" />
-            android:theme="@style/AppTheme.NoActionBar" />
+        <activity android:name=".ui.SettingsActivity"
+            android:label="Settings" />
         <activity android:name=".ui.SplashActivity">
             <intent-filter>
                 <action android:name="android.intent.action.MAIN" />

AndroidApp/app/src/main/java/com/mrmichel/rustboyadvance/EmulatorBindings.java

@@ -5,6 +5,10 @@ package com.mrmichel.rustboyadvance;
  */
 public class EmulatorBindings {
 
+    static {
+        System.loadLibrary("rustboyadvance_jni");
+    }
+
     public class NativeBindingException extends Exception {
         public NativeBindingException(String errorMessage) {
             super(errorMessage);
@@ -17,10 +21,20 @@ public class EmulatorBindings {
      * @param rom bytearray of the rom to run
      * @param frameBuffer frameBuffer render target
      * @param save_name name of the save file TODO remove this
+     * @param skipBios skip bios
      * @return the emulator context to use pass to other methods in this class
      * @throws NativeBindingException
      */
-    public static native long openEmulator(byte[] bios, byte[] rom, int[] frameBuffer, String save_name) throws NativeBindingException;
+    public static native long openEmulator(byte[] bios, byte[] rom, int[] frameBuffer, String save_name, boolean skipBios) throws NativeBindingException;
+
+    /**
+     * Open a new emulator context from a saved state buffer
+     * @param savedState
+     * @param frameBuffer
+     * @return
+     * @throws NativeBindingException
+     */
+    public static native long openSavedState(byte[] savedState, int[] frameBuffer) throws NativeBindingException;
 
     /**
      * Make the emulator boot directly into the cartridge

AndroidApp/app/src/main/java/com/mrmichel/rustboyadvance/RomHelper.java

@@ -0,0 +1,12 @@
+package com.mrmichel.rustboyadvance;
+
+public class RomHelper {
+
+    static {
+        System.loadLibrary("rustboyadvance_jni");
+    }
+
+    public static native String getGameCode(byte[] romData);
+
+    public static native String getGameTitle(byte[] romData);
+}

AndroidApp/app/src/main/java/com/mrmichel/rustdroid_emu/Util.java

@@ -0,0 +1,126 @@
+package com.mrmichel.rustdroid_emu;
+
+import android.app.Activity;
+import android.content.Context;
+import android.content.DialogInterface;
+import android.content.Intent;
+import android.graphics.Bitmap;
+import android.util.Log;
+
+import androidx.appcompat.app.AlertDialog;
+
+import com.mrmichel.rustdroid_emu.ui.EmulatorActivity;
+
+import java.io.ByteArrayOutputStream;
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.FileNotFoundException;
+import java.io.FileOutputStream;
+import java.io.IOException;
+import java.security.MessageDigest;
+import java.security.NoSuchAlgorithmException;
+import java.util.zip.GZIPInputStream;
+import java.util.zip.GZIPOutputStream;
+
+public class Util {
+
+    private static final String TAG = "Util";
+
+
+    public static void startEmulator(Context context, byte[] bios, int romId) {
+        Intent intent = new Intent(context, EmulatorActivity.class);
+        intent.putExtra("bios", bios);
+        intent.putExtra("romId", romId);
+        context.startActivity(intent);
+    }
+
+
+    public static void showAlertDiaglogAndExit(final Activity activity, Exception e) {
+        new AlertDialog.Builder(activity)
+                .setTitle(e.toString())
+                .setMessage(e.getMessage())
+                // Specifying a listener allows you to take an action before dismissing the dialog.
+                // The dialog is automatically dismissed when a dialog button is clicked.
+                .setPositiveButton(android.R.string.yes, new DialogInterface.OnClickListener() {
+                    public void onClick(DialogInterface dialog, int which) {
+                        activity.finishAffinity();
+                    }
+                })
+                .setIcon(android.R.drawable.ic_dialog_alert)
+                .show();
+    }
+
+    public static byte[] compressBitmapToByteArray(Bitmap bitmap) {
+        ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();
+        bitmap.compress(Bitmap.CompressFormat.PNG, 10, byteArrayOutputStream);
+        return byteArrayOutputStream.toByteArray();
+    }
+
+    public static void writeCompressedFile(File file, byte[] bytes) {
+        try {
+            FileOutputStream fos = new FileOutputStream(file);
+            GZIPOutputStream gos = new GZIPOutputStream(fos);
+
+            gos.write(bytes);
+            gos.close();
+            fos.close();
+        } catch (Exception e) {
+            Log.e(TAG, "failed to write compressed file " + file.toString() + " error: " + e.getMessage());
+        }
+    }
+
+    public static byte[] readCompressedFile(File file) {
+        try {
+            byte[] buffer = new byte[8192];
+            ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
+            GZIPInputStream gis = new GZIPInputStream(new FileInputStream(file));
+
+            int len;
+
+            while ( (len = gis.read(buffer, 0, 8192)) != -1) {
+                outputStream.write(buffer, 0, len);
+            }
+            gis.close();
+            return outputStream.toByteArray();
+        } catch (Exception e) {
+            Log.e(TAG, "failed to read compressed file " + file.toString() + " error: " + e.getMessage());
+            return null;
+        }
+    }
+
+    public static byte[] readFile(File file) throws FileNotFoundException, IOException {
+        byte[] buffer = new byte[8192];
+        ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
+        FileInputStream fis = new FileInputStream(file);
+
+        int len;
+
+        while ( (len = fis.read(buffer, 0, 8192)) != -1) {
+            outputStream.write(buffer, 0, len);
+        }
+        fis.close();
+        return outputStream.toByteArray();
+    }
+
+    public static String byteArrayToHexString(final byte[] bytes) {
+        StringBuilder sb = new StringBuilder();
+        for (byte b : bytes) {
+            sb.append(String.format("%02x", b & 0xff));
+        }
+        return sb.toString();
+    }
+
+    public static String getHash(final byte[] bytes) {
+        MessageDigest md;
+        try {
+            md = MessageDigest.getInstance("SHA-256");
+        } catch (NoSuchAlgorithmException e) {
+            // impossible
+            Log.e("SnapshotManager", "SHA-256 algo not found");
+            return null;
+        }
+
+        md.update(bytes);
+        return byteArrayToHexString(md.digest());
+    }
+}

AndroidApp/app/src/main/java/com/mrmichel/rustdroid_emu/core/Emulator.java

@@ -16,13 +16,23 @@ public class Emulator {
     private int[] frameBuffer;
     public Keypad keypad;
 
-    static {
+    public Emulator() {
-        System.loadLibrary("rustboyadvance_jni");
+        this.frameBuffer = new int[240 * 160];
+        this.keypad = new Keypad();
     }
 
-    public Emulator() {
+    public Emulator(long ctx) {
-        frameBuffer = new int[240 * 160];
+        this.ctx = ctx;
-        keypad = new Keypad();
+        this.frameBuffer = new int[240 * 160];
+        this.keypad = new Keypad();
+
+    }
+
+    /**
+     * Get the native emulator handle for caching
+     */
+    public long getCtx() {
+        return ctx;
     }
 
     public int[] getFrameBuffer() {
@@ -49,12 +59,20 @@ public class Emulator {
 
 
     public synchronized void loadState(byte[] state) throws EmulatorBindings.NativeBindingException {
-        EmulatorBindings.loadState(this.ctx, state);
+        if (ctx != -1) {
+            EmulatorBindings.loadState(this.ctx, state);
+        } else {
+            openSavedState(state);
+        }
     }
 
 
-    public synchronized void open(byte[] bios, byte[] rom, String saveName) throws EmulatorBindings.NativeBindingException {
+    public synchronized void open(byte[] bios, byte[] rom, String saveName, boolean skipBios) throws EmulatorBindings.NativeBindingException {
-        this.ctx = EmulatorBindings.openEmulator(bios, rom, this.frameBuffer, saveName);
+        this.ctx = EmulatorBindings.openEmulator(bios, rom, this.frameBuffer, saveName, skipBios);
+    }
+
+    public synchronized void openSavedState(byte[] savedState) throws EmulatorBindings.NativeBindingException {
+        this.ctx = EmulatorBindings.openSavedState(savedState, this.frameBuffer);
     }
 
     public synchronized void close() {
@@ -66,11 +84,19 @@ public class Emulator {
     }
 
     public String getGameCode() {
-        return EmulatorBindings.getGameCode(ctx);
+        if (ctx != -1) {
+            return EmulatorBindings.getGameCode(ctx);
+        } else {
+            return null;
+        }
     }
 
     public String getGameTitle() {
-        return EmulatorBindings.getGameTitle(ctx);
+        if (ctx != -1) {
+            return EmulatorBindings.getGameTitle(ctx);
+        } else {
+            return null;
+        }
     }
 
     public boolean isOpen() {

AndroidApp/app/src/main/java/com/mrmichel/rustdroid_emu/core/RomManager.java

@@ -0,0 +1,321 @@
+package com.mrmichel.rustdroid_emu.core;
+
+import android.content.ContentResolver;
+import android.content.ContentValues;
+import android.content.Context;
+import android.database.Cursor;
+import android.database.sqlite.SQLiteDatabase;
+import android.database.sqlite.SQLiteOpenHelper;
+import android.graphics.Bitmap;
+import android.graphics.BitmapFactory;
+import android.net.Uri;
+import android.util.Log;
+import android.widget.Toast;
+
+import androidx.annotation.Nullable;
+import androidx.documentfile.provider.DocumentFile;
+
+import com.mrmichel.rustboyadvance.RomHelper;
+import com.mrmichel.rustdroid_emu.Util;
+
+import java.io.File;
+import java.io.FileOutputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.security.MessageDigest;
+import java.security.NoSuchAlgorithmException;
+import java.sql.Timestamp;
+import java.util.ArrayList;
+
+public class RomManager {
+    private static final String TAG = "RomManager";
+    private static RomManager instance;
+    private RomDatabaseHelper dbHelper;
+    private Context context;
+
+    public RomManager(Context context) {
+        this.context = context;
+        this.dbHelper = new RomDatabaseHelper(this.context, 1);
+    }
+
+    public static RomManager getInstance(Context context) {
+        if (instance == null) {
+            instance = new RomManager(context);
+        }
+        return instance;
+    }
+
+    private static String byteArrayToHexString(final byte[] bytes) {
+        StringBuilder sb = new StringBuilder();
+        for (byte b : bytes) {
+            sb.append(String.format("%02x", b & 0xff));
+        }
+        return sb.toString();
+    }
+
+    private static String getHash(final byte[] bytes) {
+        MessageDigest md;
+        try {
+            md = MessageDigest.getInstance("SHA-256");
+        } catch (NoSuchAlgorithmException e) {
+            // impossible
+            Log.e(TAG, "SHA-256 algo not found");
+            return null;
+        }
+
+        md.update(bytes);
+        return byteArrayToHexString(md.digest());
+    }
+
+    public ArrayList<RomMetadataEntry> getAllRomMetaData() {
+        return this.dbHelper.queryRomMetadata("SELECT * FROM " + RomDatabaseHelper.TABLE_METADATA + " ORDER BY lastPlayed DESC");
+    }
+
+    public RomMetadataEntry getRomMetadata(byte[] romData) {
+        String romHash = getHash(romData);
+
+        ArrayList<RomMetadataEntry> metadataEntries = dbHelper.queryRomMetadata(
+                "SELECT * FROM " + RomDatabaseHelper.TABLE_METADATA + " where hash == '" + romHash + "'");
+
+        if (metadataEntries.size() > 0) {
+            return metadataEntries.get(0);
+        } else {
+            return null;
+        }
+    }
+
+    public RomMetadataEntry getRomMetadata(int romId) {
+        ArrayList<RomMetadataEntry> metadataEntries = dbHelper.queryRomMetadata(
+                "SELECT * FROM " + RomDatabaseHelper.TABLE_METADATA + " where id = '" + romId + "'");
+
+        if (metadataEntries.size() > 0) {
+            return metadataEntries.get(0);
+        } else {
+            return null;
+        }
+    }
+
+
+    private byte[] readFromUri(Uri uri) throws IOException {
+        ContentResolver cr = context.getContentResolver();
+
+        InputStream is = cr.openInputStream(uri);
+        byte[] data = new byte[is.available()];
+        is.read(data);
+        return data;
+    }
+
+    public void importRom(DocumentFile documentFile) {
+
+        Uri uri = documentFile.getUri();
+
+        byte[] romData;
+        try {
+            romData = readFromUri(uri);
+        } catch (Exception e) {
+            Log.e(TAG, "could not read rom file");
+            return;
+        }
+
+        if (null != getRomMetadata(romData)) {
+            Toast.makeText(context, "This rom is already imported!", Toast.LENGTH_LONG).show();
+            return;
+        }
+
+        String hash = getHash(romData);
+        String gameCode = RomHelper.getGameCode(romData);
+        String gameTitle = RomHelper.getGameTitle(romData);
+
+        String romFileName = documentFile.getName();
+
+        // Multiple roms can have the same title+code combo, so we rely on a hash to be a unique identifier.
+        File baseDir = new File(context.getFilesDir(), hash);
+        baseDir.mkdirs();
+
+        File romFile = new File(baseDir, romFileName);
+
+        // cache the rom
+        try {
+            FileOutputStream fileOutputStream = new FileOutputStream(romFile);
+            fileOutputStream.write(romData);
+        } catch (Exception e) {
+            Log.e(TAG, "cannot cache rom file");
+        }
+
+        File backupFile = new File(baseDir, romFileName + ".sav");
+
+        SQLiteDatabase db = dbHelper.getWritableDatabase();
+
+        ContentValues cv = new ContentValues();
+
+        cv.put("name", romFileName);
+        cv.put("gameTitle", gameTitle);
+        cv.put("gameCode", gameCode);
+        cv.put("hash", hash);
+        cv.put("path", romFile.getPath());
+        cv.put("backupPath", backupFile.getPath());
+
+        db.insertOrThrow(RomDatabaseHelper.TABLE_METADATA, null, cv);
+        db.close();
+    }
+
+    public void deleteRomMetadata(RomMetadataEntry romMetadataEntry) {
+        SQLiteDatabase db = dbHelper.getWritableDatabase();
+
+        db.delete(RomDatabaseHelper.TABLE_METADATA, "id=" + romMetadataEntry.getId(), null);
+    }
+
+    public void updateLastPlayed(int romId) {
+        Timestamp now = new Timestamp(System.currentTimeMillis());
+
+        ContentValues cv = new ContentValues();
+        cv.put("lastPlayed", now.toString());
+
+        SQLiteDatabase db = dbHelper.getWritableDatabase();
+        db.update(RomDatabaseHelper.TABLE_METADATA, cv, "id=" + romId, null);
+    }
+
+    public void updateScreenshot(int romId, Bitmap bitmap) {
+
+        ContentValues cv = new ContentValues();
+        cv.put("screenshot", Util.compressBitmapToByteArray(bitmap));
+
+        SQLiteDatabase db = dbHelper.getWritableDatabase();
+        db.update(RomDatabaseHelper.TABLE_METADATA, cv, "id=" + romId, null);
+    }
+
+
+    public class RomMetadataEntry {
+        int id;
+        String name;
+        String gameTitle;
+        String gameCode;
+        File romFile;
+        File backupFile;
+        Bitmap screenshot;
+        Timestamp lastPlayed;
+
+        private RomMetadataEntry(int id, String name, String gameTitle, String gameCode, File romFile, File backupFile, Bitmap screenshot, Timestamp lastPlayed) {
+            this.id = id;
+            this.name = name;
+            this.gameTitle = gameTitle;
+            this.gameCode = gameCode;
+            this.romFile = romFile;
+            this.backupFile = backupFile;
+            this.screenshot = screenshot;
+            this.lastPlayed = lastPlayed;
+        }
+
+
+        public String getName() {
+            return name;
+        }
+
+        public int getId() {
+            return id;
+        }
+
+        public Bitmap getScreenshot() {
+            return screenshot;
+        }
+
+        public File getBackupFile() {
+            return backupFile;
+        }
+
+        public File getRomFile() {
+            return romFile;
+        }
+
+        public String getGameTitle() {
+            return gameTitle;
+        }
+
+        public String getGameCode() {
+            return gameCode;
+        }
+
+        public Timestamp getLastPlayed() {
+            return lastPlayed;
+        }
+    }
+
+    private class RomDatabaseHelper extends SQLiteOpenHelper {
+        private static final String DATABASE_NAME = "rom_db";
+
+        private static final String TABLE_METADATA = "rom_metadata";
+
+
+        public RomDatabaseHelper(@Nullable Context context, int version) {
+            super(context, DATABASE_NAME, null, version);
+        }
+
+        @Override
+        public void onCreate(SQLiteDatabase db) {
+            db.execSQL("create table " + TABLE_METADATA +
+                    " (id INTEGER PRIMARY KEY," +
+                    "name TEXT UNIQUE," +
+                    "hash TEXT UNIQUE," +
+                    "gameTitle TEXT," +
+                    "gameCode TEXT," +
+                    "screenshot BLOB," +
+                    "lastPlayed TIMESTAMP," +
+                    "path TEXT UNIQUE," +
+                    "backupPath TEXT UNIQUE" +
+                    ")");
+        }
+
+        public ArrayList<RomMetadataEntry> queryRomMetadata(String query) {
+            ArrayList<RomMetadataEntry> arrayList = new ArrayList<>();
+
+            SQLiteDatabase db = this.getReadableDatabase();
+            Cursor cursor = db.rawQuery(query, null);
+
+            if (cursor.moveToFirst()) {
+                do {
+
+                    String name = cursor.getString(cursor.getColumnIndex("name"));
+
+                    File romFile = new File(cursor.getString(cursor.getColumnIndex("path")));
+                    File backupFile = new File(cursor.getString(cursor.getColumnIndex("backupPath")));
+
+                    byte[] screenshotBlob = cursor.getBlob(cursor.getColumnIndex("screenshot"));
+                    Bitmap screenshot;
+                    if (null != screenshotBlob) {
+                        screenshot = BitmapFactory.decodeByteArray(screenshotBlob, 0, screenshotBlob.length);
+                    } else {
+                        screenshot = null;
+                    }
+
+                    String gameTitle = cursor.getString(cursor.getColumnIndex("gameTitle"));
+                    String gameCode = cursor.getString(cursor.getColumnIndex("gameCode"));
+
+                    int id = cursor.getInt(cursor.getColumnIndex("id"));
+
+                    String lastPlayedString = cursor.getString(cursor.getColumnIndex("lastPlayed"));
+                    Timestamp lastPlayed;
+                    if (lastPlayedString != null) {
+                        lastPlayed = Timestamp.valueOf(lastPlayedString);
+                    } else {
+                        lastPlayed = null;
+                    }
+
+                    arrayList.add(new RomMetadataEntry(id, name, gameTitle, gameCode, romFile, backupFile, screenshot, lastPlayed));
+
+                } while (cursor.moveToNext());
+            }
+
+
+            cursor.close();
+            db.close();
+
+            return arrayList;
+        }
+
+        @Override
+        public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
+            db.execSQL("DROP TABLE IF EXISTS " + TABLE_METADATA);
+            onCreate(db);
+        }
+    }
+}

AndroidApp/app/src/main/java/com/mrmichel/rustdroid_emu/core/Snapshot.java

@@ -2,6 +2,8 @@ package com.mrmichel.rustdroid_emu.core;
 
 import android.graphics.Bitmap;
 
+import com.mrmichel.rustdroid_emu.Util;
+
 import java.io.File;
 
 public class Snapshot {
@@ -27,6 +29,10 @@ public class Snapshot {
         this.timestamp = timestamp;
     }
 
+    public File getFile() {
+        return file;
+    }
+
     public String getGameCode() {
         return gameCode;
     }
@@ -44,6 +50,6 @@ public class Snapshot {
     }
 
     public byte[] load() {
-        return SnapshotManager.readCompressedFile(this.file);
+        return Util.readCompressedFile(this.file);
     }
 }

AndroidApp/app/src/main/java/com/mrmichel/rustdroid_emu/core/SnapshotManager.java

@@ -7,18 +7,13 @@ import android.database.sqlite.SQLiteDatabase;
 import android.database.sqlite.SQLiteOpenHelper;
 import android.graphics.Bitmap;
 import android.graphics.BitmapFactory;
-import android.util.Log;
+
+import com.mrmichel.rustdroid_emu.Util;
 
 import java.io.ByteArrayOutputStream;
 import java.io.File;
-import java.io.FileInputStream;
-import java.io.FileOutputStream;
-import java.security.MessageDigest;
-import java.security.NoSuchAlgorithmException;
 import java.sql.Timestamp;
 import java.util.ArrayList;
-import java.util.zip.GZIPInputStream;
-import java.util.zip.GZIPOutputStream;
 
 public class SnapshotManager {
     private static final String TAG = "SnapshotManager";
@@ -32,6 +27,65 @@ public class SnapshotManager {
 
     private SnapshotDatabaseHelper dbHelper;
 
+    private SnapshotManager(Context context) {
+        this.context = context;
+        this.dbHelper = new SnapshotDatabaseHelper(this.context);
+//        this.snapshotDB = context.openOrCreateDatabase("snapshots", Context.MODE_PRIVATE, null);
+    }
+
+    public static SnapshotManager getInstance(Context context) {
+        if (instance == null) {
+            instance = new SnapshotManager(context);
+        }
+        return instance;
+    }
+
+    private File getPreviewsDir(String gameCode) {
+        File d = new File(context.getFilesDir(), SNAPSHOT_ROOT + "/previews");
+        d.mkdirs();
+        return d;
+    }
+
+    private File getSnapshotDir(String gameCode) {
+        File d = new File(context.getFilesDir(), SNAPSHOT_ROOT + "/data");
+        d.mkdirs();
+        return d;
+    }
+
+    public void saveSnapshot(String gameCode, String gameTitle, Bitmap previewImage, byte[] data) {
+        byte[] previewImageBytes = Util.compressBitmapToByteArray(previewImage);
+
+        String hash = Util.getHash(data);
+
+        File previewsDir = getPreviewsDir(gameCode);
+        File snapshotsDir = getSnapshotDir(gameCode);
+
+        File previewFile = new File(previewsDir, hash);
+        Util.writeCompressedFile(previewFile, previewImageBytes);
+
+        File snapshotFile = new File(snapshotsDir, hash);
+        Util.writeCompressedFile(snapshotFile, data);
+
+        this.dbHelper.insertSnapshot(gameCode, gameTitle, previewFile, snapshotFile);
+    }
+
+    public void deleteSnapshot(Snapshot snapshot) {
+
+        SQLiteDatabase db = dbHelper.getWritableDatabase();
+
+        File file = snapshot.getFile();
+        db.delete(dbHelper.TABLE_NAME, "dataFile = '" + file.toString() + "'", null);
+        file.delete();
+    }
+
+    public ArrayList<Snapshot> getAllSnapshots() {
+        return this.dbHelper.getEntries();
+    }
+
+    public ArrayList<Snapshot> getByGameCode(String gameCode) {
+        return this.dbHelper.getEntries(gameCode);
+    }
+
     public class SnapshotDBEntry {
         String gameCode;
         String gameTitle;
@@ -88,7 +142,7 @@ public class SnapshotManager {
                     File previewImageFile = new File(cursor.getString(4));
                     File dataFile = new File(cursor.getString(5));
 
-                    byte[] previewData = readCompressedFile(previewImageFile);
+                    byte[] previewData = Util.readCompressedFile(previewImageFile);
                     Bitmap previewBitmap = BitmapFactory.decodeByteArray(previewData, 0, previewData.length);
 
                     arrayList.add(new Snapshot(dataFile, gameCode, gameTitle, previewBitmap, timestamp.getTime()));
@@ -100,12 +154,12 @@ public class SnapshotManager {
             return arrayList;
         }
 
-        public ArrayList<Snapshot> getAllEntries() {
+        public ArrayList<Snapshot> getEntries() {
             return getEntriesByQuery("SELECT * FROM " + TABLE_NAME + " ORDER BY timestamp DESC ");
         }
 
-        public ArrayList<Snapshot> getAllEntries(String gameCode) {
+        public ArrayList<Snapshot> getEntries(String gameCode) {
-            return getEntriesByQuery("SELECT * FROM " + TABLE_NAME + "where gameCode = " + gameCode + " ORDER BY timestamp DESC ");
+            return getEntriesByQuery("SELECT * FROM " + TABLE_NAME + " where gameCode = '" + gameCode + "' ORDER BY timestamp DESC ");
         }
 
         @Override
@@ -113,115 +167,4 @@ public class SnapshotManager {
 
         }
     }
-
-    private SnapshotManager(Context context) {
-        this.context = context;
-        this.dbHelper = new SnapshotDatabaseHelper(this.context);
-//        this.snapshotDB = context.openOrCreateDatabase("snapshots", Context.MODE_PRIVATE, null);
-    }
-
-    public static SnapshotManager getInstance(Context context) {
-        if (instance == null) {
-            instance = new SnapshotManager(context);
-        }
-        return instance;
-    }
-
-    private static String byteArrayToHexString(final byte[] bytes) {
-        StringBuilder sb = new StringBuilder();
-        for (byte b : bytes) {
-            sb.append(String.format("%02x", b & 0xff));
-        }
-        return sb.toString();
-    }
-
-    private static String getHash(final byte[] bytes) {
-        MessageDigest md;
-        try {
-            md = MessageDigest.getInstance("SHA-256");
-        } catch (NoSuchAlgorithmException e) {
-            // impossible
-            Log.e("SnapshotManager", "SHA-256 algo not found");
-            return null;
-        }
-
-        md.update(bytes);
-        return byteArrayToHexString(md.digest());
-    }
-
-    private File getPreviewsDir(String gameCode) {
-        File d = new File(context.getFilesDir(), SNAPSHOT_ROOT + "/previews");
-        d.mkdirs();
-        return d;
-    }
-
-
-    private File getSnapshotDir(String gameCode) {
-        File d = new File(context.getFilesDir(), SNAPSHOT_ROOT + "/data");
-        d.mkdirs();
-        return d;
-    }
-
-    public static void writeCompressedFile(File file, byte[] bytes) {
-        try {
-            FileOutputStream fos = new FileOutputStream(file);
-            GZIPOutputStream gos = new GZIPOutputStream(fos);
-
-            gos.write(bytes);
-            gos.close();
-            fos.close();
-        } catch (Exception e) {
-            Log.e(TAG, "failed to write compressed file " + file.toString() + " error: " + e.getMessage());
-        }
-    }
-
-    public static byte[] readCompressedFile(File file) {
-        try {
-            byte[] buffer = new byte[8192];
-            ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
-            GZIPInputStream gis = new GZIPInputStream(new FileInputStream(file));
-
-            int len;
-
-            while ( (len = gis.read(buffer, 0, 8192)) != -1) {
-                outputStream.write(buffer, 0, len);
-            }
-            gis.close();
-            return outputStream.toByteArray();
-        } catch (Exception e) {
-            Log.e(TAG, "failed to read compressed file " + file.toString() + " error: " + e.getMessage());
-            return null;
-        }
-    }
-
-    public static byte[] compressBitmapToByteArray(Bitmap bitmap) {
-        ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();
-        bitmap.compress(Bitmap.CompressFormat.PNG, 10, byteArrayOutputStream);
-        return byteArrayOutputStream.toByteArray();
-    }
-
-    public void saveSnapshot(String gameCode, String gameTitle, Bitmap previewImage, byte[] data) {
-        byte[] previewImageBytes = compressBitmapToByteArray(previewImage);
-
-        String hash = getHash(data);
-
-        File previewsDir = getPreviewsDir(gameCode);
-        File snapshotsDir = getSnapshotDir(gameCode);
-
-        File previewFile = new File(previewsDir, hash);
-        writeCompressedFile(previewFile, previewImageBytes);
-
-        File snapshotFile = new File(snapshotsDir, hash);
-        writeCompressedFile(snapshotFile, data);
-
-        this.dbHelper.insertSnapshot(gameCode, gameTitle, previewFile, snapshotFile);
-    }
-
-    public ArrayList<Snapshot> getAllSnapshots() {
-        return this.dbHelper.getAllEntries();
-    }
-
-    public ArrayList<Snapshot> getByGameCode(String gameCode) {
-        return this.dbHelper.getAllEntries(gameCode);
-    }
 }

AndroidApp/app/src/main/java/com/mrmichel/rustdroid_emu/ui/EmulationThread.java

@@ -0,0 +1,72 @@
+package com.mrmichel.rustdroid_emu.ui;
+
+import com.mrmichel.rustdroid_emu.core.Emulator;
+
+public class EmulationThread extends Thread {
+
+    public static final long NANOSECONDS_PER_MILLISECOND = 1000000;
+    public static final long FRAME_TIME = 1000000000 / 60;
+
+    private Emulator emulator;
+    private ScreenView screenView;
+
+    private boolean turbo;
+    private boolean running;
+    private boolean stopping;
+
+    public EmulationThread(Emulator emulator, ScreenView screenView) {
+        this.emulator = emulator;
+        this.screenView = screenView;
+        this.running = true;
+    }
+
+    public void setStopping(boolean stopping) {
+        this.stopping = stopping;
+    }
+
+    public void pauseEmulation() {
+        running = false;
+    }
+
+    public void resumeEmulation() {
+        running = true;
+    }
+
+    public void setTurbo(boolean turbo) {
+        this.turbo = turbo;
+    }
+
+    public boolean isTurbo() { return turbo; }
+
+    @Override
+    public void run() {
+        super.run();
+
+        // wait until renderer is ready
+        while (!screenView.getRenderer().isReady());
+
+        while (!stopping) {
+            if (running) {
+                long startTimer = System.nanoTime();
+                emulator.runFrame();
+                if (!turbo) {
+                    long currentTime = System.nanoTime();
+                    long timePassed = currentTime - startTimer;
+
+                    long delay = FRAME_TIME - timePassed;
+                    if (delay > 0) {
+                        try {
+                            Thread.sleep(delay / NANOSECONDS_PER_MILLISECOND);
+                        } catch (Exception e) {
+
+                        }
+                    }
+                }
+
+                screenView.updateFrame(emulator.getFrameBuffer());
+            }
+        }
+    }
+
+
+}

AndroidApp/app/src/main/java/com/mrmichel/rustdroid_emu/ui/EmulatorActivity.java

@@ -1,7 +1,9 @@
 package com.mrmichel.rustdroid_emu.ui;
 
+import android.app.Activity;
 import android.content.DialogInterface;
 import android.content.Intent;
+import android.content.SharedPreferences;
 import android.graphics.Bitmap;
 import android.media.AudioFormat;
 import android.media.AudioManager;
@@ -9,57 +11,74 @@ import android.media.AudioTrack;
 import android.net.Uri;
 import android.os.Build;
 import android.os.Bundle;
-
-import androidx.annotation.NonNull;
-import androidx.annotation.Nullable;
-import androidx.appcompat.app.AlertDialog;
-import androidx.appcompat.app.AppCompatActivity;
-
 import android.util.Log;
+import android.view.KeyEvent;
 import android.view.Menu;
 import android.view.MenuItem;
 import android.view.MotionEvent;
 import android.view.View;
 import android.view.WindowManager;
-import android.widget.Switch;
+import android.widget.CompoundButton;
 import android.widget.Toast;
 
+import androidx.annotation.NonNull;
+import androidx.annotation.Nullable;
+import androidx.appcompat.app.AlertDialog;
+import androidx.appcompat.app.AppCompatActivity;
+import androidx.preference.PreferenceManager;
+
 import com.mrmichel.rustboyadvance.EmulatorBindings;
+import com.mrmichel.rustdroid_emu.R;
+import com.mrmichel.rustdroid_emu.Util;
 import com.mrmichel.rustdroid_emu.core.AudioThread;
 import com.mrmichel.rustdroid_emu.core.Emulator;
 import com.mrmichel.rustdroid_emu.core.Keypad;
-import com.mrmichel.rustdroid_emu.R;
+import com.mrmichel.rustdroid_emu.core.RomManager;
+import com.mrmichel.rustdroid_emu.core.Snapshot;
 import com.mrmichel.rustdroid_emu.core.SnapshotManager;
-import com.mrmichel.rustdroid_emu.ui.snapshots.ChosenSnapshot;
+import com.mrmichel.rustdroid_emu.ui.snapshots.SnapshotPickerActivity;
-import com.mrmichel.rustdroid_emu.ui.snapshots.SnapshotActivity;
 
+import java.io.ByteArrayOutputStream;
 import java.io.File;
+import java.io.FileInputStream;
+import java.io.FileOutputStream;
 import java.io.InputStream;
 
 public class EmulatorActivity extends AppCompatActivity implements View.OnClickListener, View.OnTouchListener {
 
     private static final String TAG = "EmulatorActivty";
 
+    private static final String TAG_EMULATOR_STATE = "EmulatorStateFragment";
+
     private static final int LOAD_ROM_REQUESTCODE = 123;
     private static final int LOAD_SNAPSHOT_REQUESTCODE = 124;
 
     private static int SAMPLE_RATE_HZ = 44100;
 
+    private Menu menu;
+
+    private RomManager.RomMetadataEntry romMetadata;
     private byte[] bios;
-    private Emulator emulator = null;
+    private EmulationThread emulationThread;
-    private EmulationRunnable runnable;
-    private Thread emulationThread;
     private AudioThread audioThread;
     private AudioTrack audioTrack;
     private byte[] on_resume_saved_state = null;
-    private boolean turboMode = false;
+
-    private GbaScreenView gbaScreenView;
+    private Emulator emulator;
+    private ScreenView screenView;
+    private CompoundButton turboButton;
+
+    private boolean isEmulatorRunning() {
+        return emulator.isOpen() && emulationThread != null;
+    }
 
     @Override
     public void onClick(View v) {
         if (v.getId() == R.id.tbTurbo) {
-            Switch tbTurbo = (Switch) findViewById(R.id.tbTurbo);
+            if (!isEmulatorRunning()) {
-            this.turboMode = tbTurbo.isChecked();
+                return;
+            }
+            emulationThread.setTurbo(((CompoundButton) findViewById(R.id.tbTurbo)).isChecked());
         }
     }
 
@@ -98,65 +117,125 @@ public class EmulatorActivity extends AppCompatActivity implements View.OnClickL
                 key = Keypad.Key.Select;
                 break;
         }
-        ;
         int action = event.getAction();
         if (key != null) {
             if (action == MotionEvent.ACTION_DOWN) {
                 v.setPressed(true);
-                this.emulator.keypad.onKeyDown(key);
+                emulator.keypad.onKeyDown(key);
             } else if (action == MotionEvent.ACTION_UP) {
                 v.setPressed(false);
-                this.emulator.keypad.onKeyUp(key);
+                emulator.keypad.onKeyUp(key);
+            } else if (action == MotionEvent.ACTION_OUTSIDE) {
+                v.setPressed(false);
+                emulator.keypad.onKeyUp(key);
             }
         }
-        return action == MotionEvent.ACTION_DOWN;
+
+        return true;
     }
 
-    private void showAlertDiaglogAndExit(Exception e) {
+    public Keypad.Key keyCodeToGbaKey(int keyCode) {
-        new AlertDialog.Builder(this)
+        switch (keyCode) {
-                .setTitle("Exception")
+            case KeyEvent.KEYCODE_DPAD_UP:
-                .setMessage(e.getMessage())
+                return Keypad.Key.Up;
-                // Specifying a listener allows you to take an action before dismissing the dialog.
+            case KeyEvent.KEYCODE_DPAD_DOWN:
-                // The dialog is automatically dismissed when a dialog button is clicked.
+                return Keypad.Key.Down;
-                .setPositiveButton(android.R.string.yes, new DialogInterface.OnClickListener() {
+            case KeyEvent.KEYCODE_DPAD_LEFT:
-                    public void onClick(DialogInterface dialog, int which) {
+                return Keypad.Key.Left;
-                        finishAffinity();
+            case KeyEvent.KEYCODE_DPAD_RIGHT:
-                    }
+                return Keypad.Key.Right;
-                })
+            case KeyEvent.KEYCODE_Z:
-                .setIcon(android.R.drawable.ic_dialog_alert)
+                return Keypad.Key.ButtonB;
-                .show();
+            case KeyEvent.KEYCODE_X:
+                return Keypad.Key.ButtonA;
+            case KeyEvent.KEYCODE_A:
+                return Keypad.Key.ButtonL;
+            case KeyEvent.KEYCODE_S:
+                return Keypad.Key.ButtonR;
+            case KeyEvent.KEYCODE_DEL:
+                return Keypad.Key.Select;
+            case KeyEvent.KEYCODE_COMMA:
+                return Keypad.Key.Start;
+        }
+        return null;
+    }
+
+    @Override
+    public boolean onKeyLongPress(int keyCode, KeyEvent event) {
+        if (!isEmulatorRunning()) {
+            return false;
+        }
+        Keypad.Key key = keyCodeToGbaKey(keyCode);
+        Log.d(TAG, "onKeyLongPress(: keyCode = " + keyCode + " GBAKey:" + key);
+        if (null != key) {
+            this.emulator.keypad.onKeyDown(key);
+            return false;
+        } else {
+            return super.onKeyDown(keyCode, event);
+        }
+    }
+
+    @Override
+    public boolean onKeyDown(int keyCode, KeyEvent event) {
+        if (!isEmulatorRunning()) {
+            return false;
+        }
+        Keypad.Key key = keyCodeToGbaKey(keyCode);
+        Log.d(TAG, "onKeyDown: keyCode = " + keyCode + " GBAKey:" + key);
+        if (null != key) {
+            switch (event.getAction()) {
+                case KeyEvent.ACTION_DOWN:
+                    this.emulator.keypad.onKeyDown(key);
+                    break;
+                case KeyEvent.ACTION_UP:
+                    this.emulator.keypad.onKeyUp(key);
+                    break;
+            }
+            return event.getAction() == KeyEvent.ACTION_DOWN;
+        } else {
+            return super.onKeyDown(keyCode, event);
+        }
     }
 
     @Override
     protected void onActivityResult(int requestCode, int resultCode, @Nullable Intent data) {
         super.onActivityResult(requestCode, resultCode, data);
         if (resultCode == RESULT_OK) {
-            if (requestCode == LOAD_ROM_REQUESTCODE) {
+//            if (requestCode == LOAD_ROM_REQUESTCODE) {
-                Uri uri = data.getData();
+//                Uri uri = data.getData();
-                try {
+//                try {
-                    InputStream inputStream = getContentResolver().openInputStream(uri);
+//                    InputStream inputStream = getContentResolver().openInputStream(uri);
-                    byte[] rom = new byte[inputStream.available()];
+//                    byte[] rom = new byte[inputStream.available()];
-                    inputStream.read(rom);
+//                    inputStream.read(rom);
-                    inputStream.close();
+//                    inputStream.close();
-
+//
-                    String filename = new File(uri.getPath()).getName();
+//                    String filename = new File(uri.getPath()).getName();
-
+//
-                    File saveRoot = getFilesDir();
+//                    File saveRoot = getFilesDir();
-                    String savePath = saveRoot.getAbsolutePath() + "/" + filename + ".sav";
+//                    String savePath = saveRoot.getAbsolutePath() + "/" + filename + ".sav";
-                    onRomLoaded(rom, savePath);
+//                    onRomLoaded(rom, savePath);
-                } catch (Exception e) {
+//                } catch (Exception e) {
-                    Log.e(TAG, "got error while reading rom file");
+//                    Log.e(TAG, "got error while reading rom file");
-                    showAlertDiaglogAndExit(e);
+//                    Util.showAlertDiaglogAndExit(this, e);
-                }
+//                }
-            }
+//          }
             if (requestCode == LOAD_SNAPSHOT_REQUESTCODE) {
-                byte[] state = ChosenSnapshot.takeSnapshot().load();
+                Snapshot pickedSnapshot = SnapshotPickerActivity.obtainPickedSnapshot();
-                if (emulator.isOpen()) {
+
-                    try {
+                Toast.makeText(this, "Loading snapshot from " + pickedSnapshot.getTimestamp(), Toast.LENGTH_LONG).show();
-                        emulator.loadState(state);
+
-                    } catch (EmulatorBindings.NativeBindingException e) {
+                boolean emulatorWasRunning = isEmulatorRunning();
-                        showAlertDiaglogAndExit(e);
+
-                    }
+                pauseEmulation();
+                try {
+                    emulator.loadState(pickedSnapshot.load());
+                } catch (Exception e) {
+                    Util.showAlertDiaglogAndExit(this, e);
+                }
+                resumeEmulation();
+
+                if (!emulatorWasRunning) {
+                    createThreads();
                 }
             }
         } else {
@@ -164,75 +243,90 @@ public class EmulatorActivity extends AppCompatActivity implements View.OnClickL
         }
     }
 
-    public void onRomLoaded(byte[] rom, String savePath) {
+    private void killThreads() {
-        if (emulationThread != null) {
-            runnable.stop();
-            try {
-                emulationThread.join();
-            } catch (InterruptedException e) {
-                Log.e(TAG, "emulation thread join interrupted");
-            }
-            emulationThread = null;
-        }
         if (audioThread != null) {
             audioThread.setStopping(true);
             try {
                 audioThread.join();
             } catch (InterruptedException e) {
                 Log.e(TAG, "audio thread join interrupted");
-            };
+            }
             audioThread = null;
         }
-
+        if (emulationThread != null) {
-        if (emulator.isOpen()) {
+            try {
-            emulator.close();
+                emulationThread.setStopping(true);
+                emulationThread.join();
+            } catch (InterruptedException e) {
+                Log.e(TAG, "emulation thread join interrupted");
+            }
+            emulationThread = null;
         }
+    }
 
-        findViewById(R.id.bStart).setOnTouchListener(this);
+    private void createThreads() {
-        findViewById(R.id.bSelect).setOnTouchListener(this);
+        emulationThread = new EmulationThread(emulator, screenView);
-        findViewById(R.id.buttonA).setOnTouchListener(this);
-        findViewById(R.id.buttonB).setOnTouchListener(this);
-        findViewById(R.id.buttonL).setOnTouchListener(this);
-        findViewById(R.id.buttonR).setOnTouchListener(this);
-        findViewById(R.id.bDpadUp).setOnTouchListener(this);
-        findViewById(R.id.bDpadDown).setOnTouchListener(this);
-        findViewById(R.id.bDpadLeft).setOnTouchListener(this);
-        findViewById(R.id.bDpadRight).setOnTouchListener(this);
-        findViewById(R.id.tbTurbo).setOnClickListener(this);
-
-        try {
-            emulator.open(this.bios, rom, savePath);
-        } catch (EmulatorBindings.NativeBindingException e) {
-            showAlertDiaglogAndExit(e);
-        }
-        runnable = new EmulationRunnable(this.emulator, this);
-        emulationThread = new Thread(runnable);
-        emulationThread.start();
-
         audioThread = new AudioThread(audioTrack, emulator);
+
+        emulationThread.setTurbo(turboButton.isChecked());
+
+        emulationThread.start();
         audioThread.start();
     }
 
-    public void loadRomButton(View v) {
+    public void onRomLoaded(byte[] rom, String savePath) {
-        if (runnable != null) {
+//        killThreads();
-            runnable.pauseEmulation();
+//
-        }
+//        try {
+//            emulator.open(bios, rom, savePath);
+//        } catch (EmulatorBindings.NativeBindingException e) {
+//            Util.showAlertDiaglogAndExit(this, e);
+//        }
+//
+//        createThreads();
+    }
+
+    public void doLoadRom() {
         Intent intent = new Intent(Intent.ACTION_OPEN_DOCUMENT);
         intent.setType("*/*");
         intent.putExtra("android.content.extra.SHOW_ADVANCED", true);
         startActivityForResult(intent, LOAD_ROM_REQUESTCODE);
     }
 
+    @Override
+    protected void onSaveInstanceState(@NonNull Bundle outState) {
+        super.onSaveInstanceState(outState);
+
+        if (!isEmulatorRunning()) {
+            return;
+        }
+        // save the emulator state
+        try {
+            byte[] savedState = emulator.saveState();
+
+            File saveFile = new File(getCacheDir(), "saved_state");
+            FileOutputStream fis = new FileOutputStream(saveFile);
+
+            fis.write(savedState);
+
+            fis.close();
+
+            outState.putString("saveFile", saveFile.getPath());
+
+            outState.putBoolean("turbo", emulationThread.isTurbo());
+
+        } catch (Exception e) {
+            Util.showAlertDiaglogAndExit(this, e);
+        }
+    }
+
     @Override
     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
         setContentView(R.layout.activity_emulator);
 
         this.getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN, WindowManager.LayoutParams.FLAG_FULLSCREEN);
-
+        getWindow().getDecorView().setSystemUiVisibility(View.SYSTEM_UI_FLAG_HIDE_NAVIGATION);
-
-        this.bios = getIntent().getByteArrayExtra("bios");
-        this.emulator = new Emulator();
 
         if (Build.VERSION.SDK_INT >= 23) {
             AudioTrack.Builder audioTrackBuilder = new AudioTrack.Builder()
@@ -259,7 +353,83 @@ public class EmulatorActivity extends AppCompatActivity implements View.OnClickL
         }
         this.audioTrack.play();
 
-        this.gbaScreenView = findViewById(R.id.gba_view);
+        findViewById(R.id.bStart).setOnTouchListener(this);
+        findViewById(R.id.bSelect).setOnTouchListener(this);
+        findViewById(R.id.buttonA).setOnTouchListener(this);
+        findViewById(R.id.buttonB).setOnTouchListener(this);
+        findViewById(R.id.buttonL).setOnTouchListener(this);
+        findViewById(R.id.buttonR).setOnTouchListener(this);
+        findViewById(R.id.bDpadUp).setOnTouchListener(this);
+        findViewById(R.id.bDpadDown).setOnTouchListener(this);
+        findViewById(R.id.bDpadLeft).setOnTouchListener(this);
+        findViewById(R.id.bDpadRight).setOnTouchListener(this);
+        findViewById(R.id.dpad_layout).setOnTouchListener(this);
+
+        turboButton = findViewById(R.id.tbTurbo);
+        turboButton.setOnClickListener(this);
+
+        this.bios = getIntent().getByteArrayExtra("bios");
+
+        this.screenView = findViewById(R.id.gba_view);
+        this.emulator = new Emulator();
+
+        final String saveFilePath;
+
+        SharedPreferences sharedPreferences =
+                PreferenceManager.getDefaultSharedPreferences(this /* Activity context */);
+        Boolean skipBios = sharedPreferences.getBoolean("skip_bios", false);
+
+        if (null != savedInstanceState && (saveFilePath = savedInstanceState.getString("saveFile")) != null) {
+            final EmulatorActivity thisActivity = this;
+
+            // busy wait until surface view is ready
+            try {
+                ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
+
+                byte[] buffer = new byte[4096];
+                File saveFile = new File(saveFilePath);
+                FileInputStream fis = new FileInputStream(saveFile);
+
+                int read = 0;
+                while ((read = fis.read(buffer)) != -1) {
+                    outputStream.write(buffer);
+                }
+
+                fis.close();
+
+                saveFile.delete();
+
+                byte[] savedState = outputStream.toByteArray();
+                emulator.openSavedState(savedState);
+
+                createThreads();
+
+                boolean turbo = savedInstanceState.getBoolean("turbo");
+
+                turboButton.setPressed(turbo);
+                emulationThread.setTurbo(turbo);
+
+            } catch (Exception e) {
+                Util.showAlertDiaglogAndExit(thisActivity, e);
+            }
+
+        } else {
+            int romId = getIntent().getIntExtra("romId", -1);
+            if (-1 != romId) {
+                this.romMetadata = RomManager.getInstance(this).getRomMetadata(romId);
+
+                byte[] romData;
+                try {
+                    romData = Util.readFile(romMetadata.getRomFile());
+                    this.emulator.open(bios, romData, romMetadata.getBackupFile().getAbsolutePath(), skipBios);
+                } catch (Exception e) {
+                    Util.showAlertDiaglogAndExit(this, e);
+                    return;
+                }
+
+                createThreads();
+            }
+        }
     }
 
     @Override
@@ -271,48 +441,73 @@ public class EmulatorActivity extends AppCompatActivity implements View.OnClickL
 
     @Override
     public boolean onOptionsItemSelected(@NonNull MenuItem item) {
-        return super.onOptionsItemSelected(item);
+        switch (item.getItemId()) {
+            case R.id.action_load_rom:
+                doLoadRom();
+                return true;
+            case R.id.action_view_snapshots:
+                doViewSnapshots();
+                return true;
+            case R.id.action_save_snapshot:
+                doSaveSnapshot();
+                return true;
+            default:
+                return super.onOptionsItemSelected(item);
+        }
+    }
+
+
+    @Override
+    public boolean onPrepareOptionsMenu(Menu menu) {
+        menu.findItem(R.id.action_save_snapshot).setEnabled(isEmulatorRunning());
+        return super.onPrepareOptionsMenu(menu);
+    }
+
+    private void pauseEmulation() {
+        if (null != emulationThread) {
+            emulationThread.pauseEmulation();
+        }
+    }
+
+    private void resumeEmulation() {
+        if (null != emulationThread) {
+            emulationThread.resumeEmulation();
+        }
+    }
+
+    @Override
+    protected void onDestroy() {
+        super.onDestroy();
+        audioTrack.stop();
+        pauseEmulation();
+        killThreads();
     }
 
     @Override
     protected void onPause() {
         super.onPause();
         audioTrack.stop();
-        if (emulator.isOpen()) {
+        pauseEmulation();
-            if (runnable != null) {
+        screenView.onPause();
-                runnable.pauseEmulation();
-            }
-            Log.d(TAG, "onPause - saving emulator state");
-//            try {
-//                on_resume_saved_state = emulator.saveState();
-//            } catch (EmulatorBindings.NativeBindingException e) {
-//                showAlertDiaglogAndExit(e);
-//            }
-        }
     }
 
     @Override
     protected void onResume() {
         super.onResume();
-        if (emulator.isOpen()) {
+        screenView.onResume();
-            Log.d(TAG, "onResume - loading emulator state");
+        resumeEmulation();
-//            try {
-//                emulator.loadState(on_resume_saved_state);
-//            } catch (EmulatorBindings.NativeBindingException e) {
-//                showAlertDiaglogAndExit(e);
-//            }
-//            on_resume_saved_state = null;
-            if (runnable != null) {
-                runnable.resumeEmulation();
-            }
-        }
         audioTrack.play();
     }
 
-    public void onSaveSnapshot(View v) {
+    public void doSaveSnapshot() {
+        if (!isEmulatorRunning()) {
+            Toast.makeText(this, "No game is running!", Toast.LENGTH_LONG).show();
+            return;
+        }
+
         SnapshotManager snapshotManager = SnapshotManager.getInstance(this);
 
-        runnable.pauseEmulation();
+        pauseEmulation();
         try {
             String gameCode = emulator.getGameCode();
             String gameTitle = emulator.getGameTitle();
@@ -324,73 +519,48 @@ public class EmulatorActivity extends AppCompatActivity implements View.OnClickL
 
         } catch (EmulatorBindings.NativeBindingException e) {
             Log.e(TAG, e.toString());
-            showAlertDiaglogAndExit(e);
+            Util.showAlertDiaglogAndExit(this, e);
         } finally {
-            runnable.resumeEmulation();
+            resumeEmulation();
         }
     }
 
-
+    public void doViewSnapshots() {
-    public void onViewSnapshots(View v) {
+        Intent intent = new Intent(this, SnapshotPickerActivity.class);
-        Intent intent = new Intent(this, SnapshotActivity.class);
+        if (emulator.isOpen()) {
+            intent.putExtra("gameCode", emulator.getGameCode());
+        }
         startActivityForResult(intent, LOAD_SNAPSHOT_REQUESTCODE);
     }
 
-    private class EmulationRunnable implements Runnable {
+    @Override
+    public void onBackPressed() {
+        boolean emulatorIsRunning = isEmulatorRunning();
 
-        public static final long NANOSECONDS_PER_MILLISECOND = 1000000;
+        if (!emulatorIsRunning) {
-        public static final long FRAME_TIME = 1000000000 / 60;
+            super.onBackPressed();
-
+            return;
-        EmulatorActivity emulatorActivity;
-        Emulator emulator;
-        boolean running;
-        boolean stopping;
-
-        public EmulationRunnable(Emulator emulator, EmulatorActivity emulatorActivity) {
-            this.emulator = emulator;
-            this.emulatorActivity = emulatorActivity;
-            resumeEmulation();
         }
 
-        private void emulate() {
+        new AlertDialog.Builder(this)
-            long startTimer = System.nanoTime();
+                .setIcon(android.R.drawable.ic_dialog_alert)
-            emulator.runFrame();
+                .setTitle("Closing Emulator")
-            if (!emulatorActivity.turboMode) {
+                .setCancelable(false)
-                long currentTime = System.nanoTime();
+                .setMessage("Are you sure you want to close the emulator?")
-                long timePassed = currentTime - startTimer;
+                .setPositiveButton(android.R.string.yes, new DialogInterface.OnClickListener() {
-
+                    @Override
-                long delay = FRAME_TIME - timePassed;
+                    public void onClick(DialogInterface dialog, int which) {
-                if (delay > 0) {
+                        EmulatorActivity.super.onBackPressed();
-                    try {
-                        Thread.sleep(delay / NANOSECONDS_PER_MILLISECOND);
-                    } catch (Exception e) {
-
                     }
-                }
+                })
-            }
+                .setNeutralButton("Yes - but save snapshot", new DialogInterface.OnClickListener() {
-
+                    @Override
-            emulatorActivity.gbaScreenView.updateFrame(emulator.getFrameBuffer());
+                    public void onClick(DialogInterface dialog, int which) {
-        }
+                        doSaveSnapshot();
-
+                        EmulatorActivity.super.onBackPressed();
-        public void pauseEmulation() {
+                    }
-            running = false;
+                })
-        }
+                .setNegativeButton(android.R.string.no, null)
-
+                .show();
-        public void resumeEmulation() {
-            running = true;
-        }
-
-        public void stop() {
-            stopping = true;
-        }
-
-        @Override
-        public void run() {
-            while (!stopping) {
-                if (running) {
-                    emulate();
-                }
-            }
-        }
     }
 }

AndroidApp/app/src/main/java/com/mrmichel/rustdroid_emu/ui/RomListActivity.java

@@ -1,32 +0,0 @@
-package com.mrmichel.rustdroid_emu.ui;
-
-import android.os.Bundle;
-
-import com.google.android.material.floatingactionbutton.FloatingActionButton;
-import com.google.android.material.snackbar.Snackbar;
-import com.mrmichel.rustdroid_emu.R;
-
-import androidx.appcompat.app.AppCompatActivity;
-import androidx.appcompat.widget.Toolbar;
-
-import android.view.View;
-
-public class RomListActivity extends AppCompatActivity {
-
-    @Override
-    protected void onCreate(Bundle savedInstanceState) {
-        super.onCreate(savedInstanceState);
-        setContentView(R.layout.activity_rom_list);
-        Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
-        setSupportActionBar(toolbar);
-
-        FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);
-        fab.setOnClickListener(new View.OnClickListener() {
-            @Override
-            public void onClick(View view) {
-                Snackbar.make(view, "Replace with your own action", Snackbar.LENGTH_LONG)
-                        .setAction("Action", null).show();
-            }
-        });
-    }
-}

AndroidApp/app/src/main/java/com/mrmichel/rustdroid_emu/ui/ScreenRenderer.java

@@ -1,12 +1,9 @@
 package com.mrmichel.rustdroid_emu.ui;
 
-import android.content.Context;
 import android.graphics.Bitmap;
 import android.opengl.GLES20;
 import android.opengl.GLSurfaceView;
 import android.opengl.GLUtils;
-import android.util.AttributeSet;
-import android.view.SurfaceHolder;
 
 import java.nio.ByteBuffer;
 import java.nio.ByteOrder;
@@ -15,8 +12,10 @@ import java.nio.FloatBuffer;
 import javax.microedition.khronos.egl.EGLConfig;
 import javax.microedition.khronos.opengles.GL10;
 
-public class GbaScreenView extends GLSurfaceView implements GLSurfaceView.Renderer {
+public class ScreenRenderer implements GLSurfaceView.Renderer {
-    ScreenTexture texture;
+
+    private ScreenTexture texture;
+    private boolean ready = false;
 
     /**
      * Private class to manage the screen texture rendering
@@ -72,7 +71,8 @@ public class GbaScreenView extends GLSurfaceView implements GLSurfaceView.Render
                         "uniform sampler2D s_texture;                        \n" +
                         "void main()                                         \n" +
                         "{                                                   \n" +
-                        "  gl_FragColor = texture2D( s_texture, v_texCoord );\n" +
+                        "  vec4 color = texture2D( s_texture, v_texCoord );  \n" +
+                        "  gl_FragColor = color;                             \n" +
                         "}                                                   \n";
 
 
@@ -191,34 +191,20 @@ public class GbaScreenView extends GLSurfaceView implements GLSurfaceView.Render
         }
     }
 
-    public GbaScreenView(Context context) {
+    public void updateTexture(int[] frameBuffer) {
-        super(context);
-        init();
-    }
-
-    public GbaScreenView(Context context, AttributeSet attrs) {
-        super(context, attrs);
-        init();
-    }
-
-    private void init() {
-        this.setEGLContextClientVersion(2);
-        this.setPreserveEGLContextOnPause(true);
-        this.setRenderer(this);
-        this.setRenderMode(RENDERMODE_WHEN_DIRTY);
-    }
-
-    public void updateFrame(int[] frameBuffer) {
         this.texture.update(frameBuffer);
-        requestRender();
     }
 
+    public void initTextureIfNotInitialized() {
+        if (this.texture == null) {
+            this.texture = new ScreenTexture();
+        }
+    }
 
     @Override
     public void onSurfaceCreated(GL10 gl, EGLConfig config) {
-        texture = new ScreenTexture();
+        initTextureIfNotInitialized();
-
+        ready = true;
-        getHolder().setKeepScreenOn(true);
     }
 
     @Override
@@ -231,10 +217,7 @@ public class GbaScreenView extends GLSurfaceView implements GLSurfaceView.Render
         this.texture.render();
     }
 
-    @Override
+    public boolean isReady() {
-    public void surfaceDestroyed(SurfaceHolder holder) {
+        return ready;
-        holder.setKeepScreenOn(false);
-        this.texture.destroy();
-        super.surfaceDestroyed(holder);
     }
 }

AndroidApp/app/src/main/java/com/mrmichel/rustdroid_emu/ui/ScreenView.java

@@ -0,0 +1,37 @@
+package com.mrmichel.rustdroid_emu.ui;
+
+import android.content.Context;
+import android.opengl.GLSurfaceView;
+import android.util.AttributeSet;
+
+public class ScreenView extends GLSurfaceView {
+    private ScreenRenderer mRenderer;
+
+    public ScreenView(Context context) {
+        super(context);
+        init();
+    }
+
+    public ScreenView(Context context, AttributeSet attrs) {
+        super(context, attrs);
+        init();
+    }
+
+    private void init() {
+        this.setEGLContextClientVersion(2);
+        this.setPreserveEGLContextOnPause(true);
+
+        mRenderer = new ScreenRenderer();
+        this.setRenderer(mRenderer);
+        this.setRenderMode(RENDERMODE_WHEN_DIRTY);
+    }
+
+    public void updateFrame(int[] frameBuffer) {
+        mRenderer.updateTexture(frameBuffer);
+        requestRender();
+    }
+
+    public ScreenRenderer getRenderer() {
+        return mRenderer;
+    }
+}

AndroidApp/app/src/main/java/com/mrmichel/rustdroid_emu/ui/SettingsActivity.java

@@ -0,0 +1,19 @@
+package com.mrmichel.rustdroid_emu.ui;
+
+import android.os.Bundle;
+
+import androidx.appcompat.app.AppCompatActivity;
+
+import com.mrmichel.rustdroid_emu.R;
+
+public class SettingsActivity extends AppCompatActivity {
+    @Override
+    protected void onCreate(Bundle savedInstanceState) {
+        super.onCreate(savedInstanceState);
+        setContentView(R.layout.activity_settings);
+        getSupportFragmentManager()
+                .beginTransaction()
+                .replace(R.id.settings_container, new SettingsFragment())
+                .commit();
+    }
+}

AndroidApp/app/src/main/java/com/mrmichel/rustdroid_emu/ui/SettingsFragment.java

@@ -0,0 +1,17 @@
+package com.mrmichel.rustdroid_emu.ui;
+
+import android.os.Bundle;
+
+import androidx.preference.PreferenceFragment;
+import androidx.preference.PreferenceFragmentCompat;
+
+import com.mrmichel.rustdroid_emu.R;
+
+
+public class SettingsFragment extends PreferenceFragmentCompat {
+
+    @Override
+    public void onCreatePreferences(Bundle savedInstanceState, String rootKey) {
+        setPreferencesFromResource(R.xml.app_preferences, rootKey);
+    }
+}

AndroidApp/app/src/main/java/com/mrmichel/rustdroid_emu/ui/SplashActivity.java

@@ -1,12 +1,5 @@
 package com.mrmichel.rustdroid_emu.ui;
 
-import androidx.annotation.NonNull;
-import androidx.annotation.Nullable;
-import androidx.appcompat.app.AlertDialog;
-import androidx.appcompat.app.AppCompatActivity;
-import androidx.core.app.ActivityCompat;
-import androidx.core.content.ContextCompat;
-
 import android.Manifest;
 import android.app.ActivityManager;
 import android.content.Context;
@@ -19,7 +12,15 @@ import android.os.Bundle;
 import android.util.Log;
 import android.widget.Toast;
 
+import androidx.annotation.NonNull;
+import androidx.annotation.Nullable;
+import androidx.appcompat.app.AlertDialog;
+import androidx.appcompat.app.AppCompatActivity;
+import androidx.core.app.ActivityCompat;
+import androidx.core.content.ContextCompat;
+
 import com.mrmichel.rustdroid_emu.R;
+import com.mrmichel.rustdroid_emu.ui.library.RomListActivity;
 
 import java.io.FileInputStream;
 import java.io.FileNotFoundException;
@@ -49,7 +50,7 @@ public class SplashActivity extends AppCompatActivity {
     }
 
     private void checkOpenGLES20() {
-        ActivityManager am = (ActivityManager)getSystemService(Context.ACTIVITY_SERVICE);
+        ActivityManager am = (ActivityManager) getSystemService(Context.ACTIVITY_SERVICE);
         ConfigurationInfo configurationInfo = am.getDeviceConfigurationInfo();
         if (configurationInfo.reqGlEsVersion >= 0x20000) {
             // Supported
@@ -81,7 +82,7 @@ public class SplashActivity extends AppCompatActivity {
             // No explanation needed; request the permission
             ActivityCompat.requestPermissions(this
                     ,
-                    new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE},
+                    new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE, Manifest.permission.READ_EXTERNAL_STORAGE},
                     REQUEST_PERMISSION_CODE);
         } else {
             // Permission has already been granted
@@ -90,7 +91,7 @@ public class SplashActivity extends AppCompatActivity {
         }
     }
 
-    private void cacheBiosInAppFiles(byte[] bios) throws FileNotFoundException, IOException {
+    private void cacheBiosInAppFiles(byte[] bios) throws IOException {
         FileOutputStream fos = openFileOutput("gba_bios.bin", MODE_PRIVATE);
         fos.write(bios);
         fos.close();
@@ -110,7 +111,7 @@ public class SplashActivity extends AppCompatActivity {
 
                     cacheBiosInAppFiles(bios);
 
-                    initEmulator(bios);
+                    startLibraryActivity(bios);
                 } catch (Exception e) {
                     Log.e(TAG, "can't open bios file");
                     this.finishAffinity();
@@ -126,7 +127,7 @@ public class SplashActivity extends AppCompatActivity {
             FileInputStream fis = openFileInput("gba_bios.bin");
             byte[] bios = new byte[fis.available()];
             fis.read(bios);
-            initEmulator(bios);
+            startLibraryActivity(bios);
         } catch (FileNotFoundException e) {
             Intent intent = new Intent(Intent.ACTION_OPEN_DOCUMENT);
             intent.setType("*/*");
@@ -138,9 +139,10 @@ public class SplashActivity extends AppCompatActivity {
         }
     }
 
-    private void initEmulator(byte[] bios) {
+    private void startLibraryActivity(byte[] bios) {
-        Intent intent = new Intent(this, EmulatorActivity.class);
+        Intent intent = new Intent(this, RomListActivity.class);
         intent.putExtra("bios", bios);
         startActivity(intent);
+        finish();
     }
 }

AndroidApp/app/src/main/java/com/mrmichel/rustdroid_emu/ui/library/RomListActivity.java

@@ -0,0 +1,223 @@
+package com.mrmichel.rustdroid_emu.ui.library;
+
+import android.content.ContentResolver;
+import android.content.Context;
+import android.content.Intent;
+import android.graphics.Bitmap;
+import android.net.Uri;
+import android.os.Bundle;
+import android.provider.MediaStore;
+import android.util.Log;
+import android.view.ContextMenu;
+import android.view.Menu;
+import android.view.MenuInflater;
+import android.view.MenuItem;
+import android.view.View;
+import android.webkit.MimeTypeMap;
+import android.widget.AdapterView;
+import android.widget.GridView;
+
+import androidx.annotation.NonNull;
+import androidx.annotation.Nullable;
+import androidx.appcompat.app.AppCompatActivity;
+import androidx.documentfile.provider.DocumentFile;
+
+import com.mrmichel.rustdroid_emu.R;
+import com.mrmichel.rustdroid_emu.Util;
+import com.mrmichel.rustdroid_emu.core.RomManager;
+import com.mrmichel.rustdroid_emu.ui.SettingsActivity;
+import com.mrmichel.rustdroid_emu.ui.SettingsFragment;
+
+import java.io.File;
+import java.util.ArrayList;
+import java.util.Arrays;
+
+public class RomListActivity extends AppCompatActivity {
+
+    private static final String TAG = "RomListActivity";
+
+    private static final int REQUEST_IMPORT_ROM = 100;
+    private static final int REQUEST_IMPORT_DIR = 101;
+    private static final int REQUEST_SET_IMAGE = 102;
+
+    private static String[] ALLOWED_EXTENSIONS = {"gba", "zip", "bin"};
+
+    private GridView mGridView;
+    private RomListItemAdapter itemAdapter;
+
+    private RomManager.RomMetadataEntry selectedEntry;
+
+    private byte[] bios;
+
+    @Override
+    protected void onCreate(Bundle savedInstanceState) {
+        super.onCreate(savedInstanceState);
+        setContentView(R.layout.activity_rom_list);
+
+        this.bios = getIntent().getByteArrayExtra("bios");
+
+        mGridView = findViewById(R.id.gridview_rom_list);
+
+        final RomManager romManager = RomManager.getInstance(this);
+
+        ArrayList<RomManager.RomMetadataEntry> entries = romManager.getAllRomMetaData();
+
+        itemAdapter = new RomListItemAdapter(this, entries);
+        mGridView.setAdapter(itemAdapter);
+
+        final Context context = this;
+        mGridView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
+            @Override
+            public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
+                RomManager.RomMetadataEntry entry = itemAdapter.getItem(position);
+                romManager.updateLastPlayed(entry.getId());
+                Util.startEmulator(context, bios, entry.getId());
+            }
+        });
+
+        registerForContextMenu(mGridView);
+    }
+
+
+    @Override
+    public void onCreateContextMenu(ContextMenu menu, View v, ContextMenu.ContextMenuInfo menuInfo) {
+        super.onCreateContextMenu(menu, v, menuInfo);
+        if (v.getId() == R.id.gridview_rom_list) {
+            MenuInflater inflater = getMenuInflater();
+            inflater.inflate(R.menu.menu_context_rom, menu);
+        }
+    }
+
+
+    @Override
+    public boolean onContextItemSelected(@NonNull MenuItem item) {
+        AdapterView.AdapterContextMenuInfo menuInfo = (AdapterView.AdapterContextMenuInfo)item.getMenuInfo();
+
+        RomManager romManager = RomManager.getInstance(this);
+
+        RomManager.RomMetadataEntry entry = itemAdapter.getItem(menuInfo.position);
+
+        selectedEntry = entry;
+
+        switch (item.getItemId()) {
+            case R.id.action_play:
+                romManager.updateLastPlayed(entry.getId());
+                Util.startEmulator(this, this.bios, entry.getId());
+                return true;
+            case R.id.action_delete:
+                romManager.deleteRomMetadata(itemAdapter.getItem(menuInfo.position));
+                return true;
+            case R.id.action_set_screenshot:
+                Intent intent = new Intent(Intent.ACTION_OPEN_DOCUMENT);
+                intent.setType("image/*");
+                intent.putExtra("romId", entry.getId());
+                startActivityForResult(intent, REQUEST_SET_IMAGE);
+            default:
+                return super.onContextItemSelected(item);
+        }
+    }
+
+    @Override
+    public boolean onCreateOptionsMenu(Menu menu) {
+        super.onCreateOptionsMenu(menu);
+        getMenuInflater().inflate(R.menu.menu_rom_list, menu);
+        return true;
+    }
+
+    @Override
+    public boolean onOptionsItemSelected(@NonNull MenuItem item) {
+        switch (item.getItemId()) {
+            case R.id.action_import_rom:
+                doImportRom();
+            case R.id.action_import_directory:
+                doImportDirectory();
+                return true;
+            case R.id.action_settings:
+                Intent intent = new Intent(this, SettingsActivity.class);
+                startActivity(intent);
+            default:
+                return super.onOptionsItemSelected(item);
+        }
+    }
+
+    String getFileExtension(String name) {
+        if (name == null) {
+            return "";
+        }
+        int i = name.lastIndexOf('.');
+        String ext = i > 0 ? name.substring(i + 1) : "";
+        return ext;
+    }
+
+    @Override
+    protected void onActivityResult(int requestCode, int resultCode, @Nullable Intent data) {
+        super.onActivityResult(requestCode, resultCode, data);
+        if (resultCode == RESULT_OK) {
+            ContentResolver contentResolver = getContentResolver();
+            RomManager romManager = RomManager.getInstance(this);
+            switch (requestCode) {
+                case REQUEST_IMPORT_ROM:
+                    Uri uri = data.getData();
+                    contentResolver.takePersistableUriPermission(uri, Intent.FLAG_GRANT_READ_URI_PERMISSION);
+
+                    romManager.importRom(DocumentFile.fromSingleUri(this, uri));
+
+                    break;
+                case REQUEST_IMPORT_DIR:
+
+                    Uri treeUri = data.getData();
+
+                    contentResolver.takePersistableUriPermission(treeUri, Intent.FLAG_GRANT_READ_URI_PERMISSION | Intent.FLAG_GRANT_WRITE_URI_PERMISSION);
+
+                    DocumentFile pickedDir = DocumentFile.fromTreeUri(this, treeUri);
+
+                    for (DocumentFile file : pickedDir.listFiles()) {
+
+                        String extension = getFileExtension(file.getName());
+                        if (Arrays.asList(ALLOWED_EXTENSIONS).contains(extension)) {
+                            Log.d(TAG, "Importing ROM " + file.getName() + " with size " + file.length() + " and type: " + extension);
+                            romManager.importRom(file);
+                        }
+                    }
+
+                    break;
+                case REQUEST_SET_IMAGE:
+                    int romId = selectedEntry.getId();
+
+                    Bitmap bitmap;
+                    try {
+                        bitmap = MediaStore.Images.Media.getBitmap(this.getContentResolver(), data.getData());
+
+                    }
+                    catch (Exception e) {
+                        Util.showAlertDiaglogAndExit(this, e);
+                        return;
+                    }
+
+                    Log.d(TAG, "found bitmap");
+                    romManager.updateScreenshot(romId, bitmap);
+
+            }
+
+            mGridView.setAdapter(new RomListItemAdapter(this, romManager.getAllRomMetaData()));
+            mGridView.invalidate();
+
+        } else {
+            Log.e(TAG, "got error for request code " + requestCode);
+        }
+    }
+
+    void doImportRom() {
+        Intent intent = new Intent(Intent.ACTION_GET_CONTENT);
+        intent.addCategory(Intent.CATEGORY_OPENABLE);
+        intent.setType("*/*");
+        Log.d(TAG, "pressed import rom");
+        Intent chooser = Intent.createChooser(intent, "choose GBA rom file to import");
+        startActivityForResult(chooser, REQUEST_IMPORT_ROM);
+    }
+
+    void doImportDirectory() {
+        Intent intent = new Intent(Intent.ACTION_OPEN_DOCUMENT_TREE);
+        startActivityForResult(intent, REQUEST_IMPORT_DIR);
+    }
+}

AndroidApp/app/src/main/java/com/mrmichel/rustdroid_emu/ui/library/RomListItemAdapter.java

@@ -0,0 +1,61 @@
+package com.mrmichel.rustdroid_emu.ui.library;
+
+import android.content.Context;
+import android.graphics.Bitmap;
+import android.graphics.BitmapFactory;
+import android.view.LayoutInflater;
+import android.view.View;
+import android.view.ViewGroup;
+import android.widget.ArrayAdapter;
+import android.widget.ImageView;
+import android.widget.TextView;
+
+import androidx.annotation.NonNull;
+import androidx.annotation.Nullable;
+
+import com.mrmichel.rustdroid_emu.R;
+import com.mrmichel.rustdroid_emu.core.RomManager.RomMetadataEntry;
+
+import java.util.ArrayList;
+
+public class RomListItemAdapter extends ArrayAdapter<RomMetadataEntry> {
+
+    Context context;
+    ArrayList<RomMetadataEntry> items;
+
+    public RomListItemAdapter(Context context, ArrayList<RomMetadataEntry> romEntries) {
+        super(context, 0, romEntries);
+        this.context = context;
+        this.items = romEntries;
+    }
+
+    @Override
+    public long getItemId(int position) {
+        return 0;
+    }
+
+    @NonNull
+    @Override
+    public View getView(int position, @Nullable View convertView, @NonNull ViewGroup parent) {
+        RomMetadataEntry item = getItem(position);
+
+        if (convertView == null) {
+            convertView = LayoutInflater.from(getContext()).inflate(R.layout.rom_item, parent, false);
+        }
+
+        ImageView screenshotImageView = convertView.findViewById(R.id.imageview_screenshot);
+
+        Bitmap screenshot = item.getScreenshot();
+        if (screenshot != null) {
+            screenshotImageView.setImageBitmap(screenshot);
+        } else {
+            screenshotImageView.setImageBitmap(BitmapFactory.decodeResource(context.getResources(), R.drawable.icon));
+        }
+
+
+        TextView tvTitle = convertView.findViewById(R.id.textview_game_title);
+        tvTitle.setText(item.getName());
+
+        return convertView;
+    }
+}

AndroidApp/app/src/main/java/com/mrmichel/rustdroid_emu/ui/snapshots/ChosenSnapshot.java

@@ -1,21 +0,0 @@
-package com.mrmichel.rustdroid_emu.ui.snapshots;
-
-import com.mrmichel.rustdroid_emu.core.Snapshot;
-
-/**
- * static class to transfer big byte arrays between activities
- */
-public class ChosenSnapshot {
-
-    static Snapshot snapshot;
-
-    public static void setSnapshot(Snapshot snapshot) {
-        ChosenSnapshot.snapshot = snapshot;
-    }
-
-    public static Snapshot takeSnapshot() {
-        Snapshot result = ChosenSnapshot.snapshot;
-        ChosenSnapshot.snapshot = null;
-        return result;
-    }
-}

AndroidApp/app/src/main/java/com/mrmichel/rustdroid_emu/ui/snapshots/ISnapshotListener.java

@@ -0,0 +1,8 @@
+package com.mrmichel.rustdroid_emu.ui.snapshots;
+
+import com.mrmichel.rustdroid_emu.core.Snapshot;
+
+public interface ISnapshotListener {
+
+    public void onSnapshotClicked(Snapshot snapshot);
+}

AndroidApp/app/src/main/java/com/mrmichel/rustdroid_emu/ui/snapshots/SnapshotActivity.java

@@ -1,60 +0,0 @@
-package com.mrmichel.rustdroid_emu.ui.snapshots;
-
-import android.content.Intent;
-import android.os.Bundle;
-
-import androidx.appcompat.app.AppCompatActivity;
-
-import android.view.View;
-import android.widget.AdapterView;
-import android.widget.GridView;
-import android.widget.Toast;
-
-import com.mrmichel.rustdroid_emu.R;
-import com.mrmichel.rustdroid_emu.core.Snapshot;
-import com.mrmichel.rustdroid_emu.core.SnapshotManager;
-
-import java.util.ArrayList;
-
-public class SnapshotActivity extends AppCompatActivity {
-
-    private ArrayList<Snapshot> snapshots;
-    public static final String EXTRA_GAME_CODE = "GAME_CODE";
-
-    public void onChosenSnapshot(Snapshot snapshot) {
-        Toast.makeText(this, "loading snapshot", Toast.LENGTH_SHORT).show();
-        Intent intent = new Intent();
-        setResult(RESULT_OK, intent);
-        ChosenSnapshot.setSnapshot(snapshot);
-        SnapshotActivity.this.finish();
-    }
-
-    @Override
-    protected void onCreate(Bundle savedInstanceState) {
-        super.onCreate(savedInstanceState);
-        setContentView(R.layout.activity_snapshot);
-
-        SnapshotManager manager = SnapshotManager.getInstance(this);
-
-        String gameCode = getIntent().getStringExtra(EXTRA_GAME_CODE);
-
-        if (gameCode == null) {
-            snapshots = manager.getAllSnapshots();
-        } else {
-            snapshots = manager.getByGameCode(gameCode);
-        }
-
-        SnapshotItemAdapter adapter = new SnapshotItemAdapter(this, snapshots);
-
-        GridView view = findViewById(R.id.gridview_snapshots);
-        view.setAdapter(adapter);
-        view.setOnItemClickListener(new AdapterView.OnItemClickListener() {
-            @Override
-            public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
-                final Snapshot snapshot = snapshots.get(position);
-                onChosenSnapshot(snapshot);
-            }
-        });
-    }
-}
-

AndroidApp/app/src/main/java/com/mrmichel/rustdroid_emu/ui/snapshots/SnapshotListFragment.java

@@ -0,0 +1,116 @@
+package com.mrmichel.rustdroid_emu.ui.snapshots;
+
+import android.os.Bundle;
+import android.util.Log;
+import android.view.ContextMenu;
+import android.view.LayoutInflater;
+import android.view.MenuInflater;
+import android.view.MenuItem;
+import android.view.View;
+import android.view.ViewGroup;
+import android.widget.AdapterView;
+import android.widget.GridView;
+
+import androidx.annotation.NonNull;
+import androidx.annotation.Nullable;
+import androidx.fragment.app.Fragment;
+
+import com.mrmichel.rustdroid_emu.R;
+import com.mrmichel.rustdroid_emu.core.Snapshot;
+import com.mrmichel.rustdroid_emu.core.SnapshotManager;
+
+import java.util.ArrayList;
+
+public class SnapshotListFragment extends Fragment {
+
+    private static final String TAG = "SnapshotListFragment";
+
+    private GridView mGridView;
+
+    private ArrayList<Snapshot> snapshots;
+
+    private ISnapshotListener mListener;
+
+    public SnapshotListFragment() {
+        super();
+        mListener = new ISnapshotListener() {
+            @Override
+            public void onSnapshotClicked(Snapshot snapshot) {
+                Log.d(TAG, "stub onSnapshotClicked");
+            }
+        };
+    }
+
+    public SnapshotListFragment(ISnapshotListener listener) {
+        super();
+        mListener = listener;
+    }
+
+    public static SnapshotListFragment newInstance(ISnapshotListener listener) {
+        return new SnapshotListFragment(listener);
+    }
+
+    @Override
+    public void onCreateContextMenu(@NonNull ContextMenu menu, @NonNull View v, @Nullable ContextMenu.ContextMenuInfo menuInfo) {
+        super.onCreateContextMenu(menu, v, menuInfo);
+        if (v.getId() == R.id.gridview_snapshots) {
+            MenuInflater inflater = getActivity().getMenuInflater();
+            inflater.inflate(R.menu.menu_context_snapshot, menu);
+        }
+    }
+
+    @Override
+    public boolean onContextItemSelected(@NonNull MenuItem item) {
+        AdapterView.AdapterContextMenuInfo menuInfo = (AdapterView.AdapterContextMenuInfo) item.getMenuInfo();
+
+        Snapshot snapshot = snapshots.get(menuInfo.position);
+        switch (item.getItemId()) {
+            case R.id.action_delete:
+                SnapshotManager.getInstance(getContext()).deleteSnapshot(snapshot);
+                snapshots.remove(menuInfo.position);
+
+                SnapshotItemAdapter adapter = new SnapshotItemAdapter(getContext(), snapshots);
+                mGridView.setAdapter(adapter);
+                mGridView.invalidate();
+
+                return true;
+            default:
+                return super.onContextItemSelected(item);
+        }
+    }
+
+    @Nullable
+    @Override
+    public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
+        return inflater.inflate(R.layout.snapshot_list_fragment, container, false);
+    }
+
+    @Override
+    public void onStart() {
+        super.onStart();
+
+        Bundle args = getArguments();
+
+        SnapshotManager manager = SnapshotManager.getInstance(getContext());
+
+        String gameCode;
+        if (args != null && (gameCode = args.getString("gameCode")) != null) {
+            snapshots = manager.getByGameCode(gameCode);
+        } else {
+            snapshots = manager.getAllSnapshots();
+        }
+
+        mGridView = getActivity().findViewById(R.id.gridview_snapshots);
+        SnapshotItemAdapter adapter = new SnapshotItemAdapter(getContext(), snapshots);
+        mGridView.setAdapter(adapter);
+        mGridView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
+            @Override
+            public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
+                final Snapshot snapshot = snapshots.get(position);
+                mListener.onSnapshotClicked(snapshot);
+            }
+        });
+        registerForContextMenu(mGridView);
+    }
+}
+

AndroidApp/app/src/main/java/com/mrmichel/rustdroid_emu/ui/snapshots/SnapshotPickerActivity.java

@@ -0,0 +1,39 @@
+package com.mrmichel.rustdroid_emu.ui.snapshots;
+
+import androidx.appcompat.app.AppCompatActivity;
+
+import android.content.Intent;
+import android.os.Bundle;
+
+import com.mrmichel.rustdroid_emu.R;
+import com.mrmichel.rustdroid_emu.core.Snapshot;
+
+public class SnapshotPickerActivity extends AppCompatActivity implements ISnapshotListener {
+
+    static Snapshot pickedSnapshot;
+
+    public static Snapshot obtainPickedSnapshot() {
+        Snapshot ret = pickedSnapshot;
+        pickedSnapshot = null;
+        return ret;
+    }
+
+    @Override
+    protected void onCreate(Bundle savedInstanceState) {
+        super.onCreate(savedInstanceState);
+        setContentView(R.layout.snapshot_picker_activity);
+        if (savedInstanceState == null) {
+            getSupportFragmentManager().beginTransaction()
+                    .replace(R.id.container, SnapshotListFragment.newInstance(this))
+                    .commitNow();
+        }
+    }
+
+    @Override
+    public void onSnapshotClicked(Snapshot snapshot) {
+        Intent data = new Intent();
+        pickedSnapshot = snapshot;
+        setResult(RESULT_OK, data);
+        finish();
+    }
+}

AndroidApp/app/src/main/res/drawable/round_button.xml

@@ -1,28 +1,5 @@
-<?xml version="1.0" encoding="utf-8"?>
+<shape xmlns:android="http://schemas.android.com/apk/res/android"
-<selector xmlns:android="http://schemas.android.com/apk/res/android">
+    android:shape="rectangle">
-    <item android:state_pressed="false">
+    <solid android:color="@color/colorAccent" />
-        <shape android:shape="rectangle">
+    <corners android:radius="500dp" />
-            <corners android:radius="1000dp" />
+</shape>
-            <stroke
-                android:width="2dip"/>
-            <padding
-                android:bottom="4dp"
-                android:left="4dp"
-                android:right="4dp"
-                android:top="4dp" />
-        </shape>
-    </item>
-    <item android:state_pressed="true">
-        <shape android:shape="rectangle">
-            <corners android:radius="1000dp" />
-            <stroke
-                android:width="2dip"
-                android:color="#03ae3c" />
-            <padding
-                android:bottom="4dp"
-                android:left="4dp"
-                android:right="4dp"
-                android:top="4dp" />
-        </shape>
-    </item>
-</selector>

AndroidApp/app/src/main/res/layout-land/activity_emulator.xml

@@ -0,0 +1,18 @@
+<?xml version="1.0" encoding="utf-8"?>
+<androidx.coordinatorlayout.widget.CoordinatorLayout xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:app="http://schemas.android.com/apk/res-auto"
+    xmlns:tools="http://schemas.android.com/tools"
+    android:layout_width="match_parent"
+    android:layout_height="match_parent"
+    tools:context=".ui.EmulatorActivity">
+
+
+    <FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
+        android:id="@+id/fragment_container"
+        android:layout_width="match_parent"
+        android:layout_height="match_parent">
+
+        <include layout="@layout/content_emulator" />
+    </FrameLayout>
+
+</androidx.coordinatorlayout.widget.CoordinatorLayout>

AndroidApp/app/src/main/res/layout-land/content_emulator.xml

@@ -0,0 +1,122 @@
+<?xml version="1.0" encoding="utf-8"?>
+<androidx.constraintlayout.widget.ConstraintLayout
+    xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:app="http://schemas.android.com/apk/res-auto"
+    xmlns:tools="http://schemas.android.com/tools"
+    android:background="@color/gbaBackground"
+    android:layout_width="match_parent"
+    android:layout_height="match_parent">
+
+
+    <com.mrmichel.rustdroid_emu.ui.ScreenView
+        android:id="@+id/gba_view"
+        android:layout_width="0dp"
+        android:layout_height="match_parent"
+        android:layout_marginTop="16dp"
+        android:layout_marginBottom="16dp"
+        app:layout_constraintBottom_toBottomOf="parent"
+        app:layout_constraintDimensionRatio="V, 3:2"
+        app:layout_constraintEnd_toEndOf="parent"
+        app:layout_constraintStart_toStartOf="parent"
+        app:layout_constraintTop_toTopOf="parent"
+        app:layout_constraintVertical_bias="0.0" />
+
+    <include
+        android:id="@+id/include"
+        layout="@layout/dpad"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:layout_marginBottom="8dp"
+        android:alpha=".5"
+        app:layout_constraintBottom_toBottomOf="parent"
+        app:layout_constraintStart_toStartOf="parent" />
+
+
+    <Button
+        android:id="@+id/buttonB"
+        style="@style/Widget.AppCompat.Button.Small"
+        android:layout_width="52dp"
+        android:layout_height="54dp"
+        android:layout_marginEnd="8dp"
+        android:layout_marginBottom="32dp"
+        android:background="@drawable/round_button"
+        android:text="B"
+        android:alpha=".5"
+        app:layout_constraintBottom_toBottomOf="parent"
+        app:layout_constraintEnd_toStartOf="@+id/buttonA"
+        tools:text="B" />
+
+    <Button
+        android:id="@+id/buttonA"
+        style="@style/Widget.AppCompat.Button.Small"
+        android:layout_width="52dp"
+        android:layout_height="54dp"
+        android:layout_marginEnd="8dp"
+        android:layout_marginBottom="48dp"
+        android:background="@drawable/round_button"
+        android:text="A"
+        android:alpha=".5"
+        app:layout_constraintBottom_toBottomOf="parent"
+        app:layout_constraintEnd_toEndOf="parent"
+        tools:text="A" />
+
+    <Button
+        android:id="@+id/bSelect"
+        style="@style/Widget.AppCompat.Button.Small"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:layout_marginStart="16dp"
+        android:text="select"
+        android:textSize="8dp"
+        app:layout_constraintBottom_toTopOf="@+id/bStart"
+        app:layout_constraintStart_toStartOf="parent" />
+
+    <Button
+        android:id="@+id/bStart"
+        style="@style/Widget.AppCompat.Button.Small"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:layout_marginStart="16dp"
+        android:layout_marginBottom="20dp"
+        android:text="start"
+        android:textSize="8dp"
+        app:layout_constraintBottom_toTopOf="@+id/include"
+        app:layout_constraintStart_toStartOf="parent" />
+
+    <Button
+        android:id="@+id/buttonL"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:layout_marginStart="8dp"
+        android:layout_marginTop="8dp"
+        android:text="L"
+        android:alpha=".5"
+        app:layout_constraintStart_toStartOf="parent"
+        app:layout_constraintTop_toTopOf="parent" />
+
+    <Button
+        android:id="@+id/buttonR"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:layout_marginTop="8dp"
+        android:layout_marginEnd="8dp"
+        android:text="R"
+        android:alpha=".5"
+        app:layout_constraintEnd_toEndOf="parent"
+        app:layout_constraintTop_toTopOf="parent" />
+
+    <ToggleButton
+        android:id="@+id/tbTurbo"
+        android:layout_width="98dp"
+        android:layout_height="wrap_content"
+        android:layout_marginStart="8dp"
+        android:layout_marginBottom="16dp"
+        android:checked="false"
+        android:text="Turbo Mode"
+        android:textOff="Turbo OFF"
+        android:textOn="Turbo ON"
+        app:layout_constraintBottom_toTopOf="@+id/bSelect"
+        app:layout_constraintStart_toStartOf="parent" />
+
+
+</androidx.constraintlayout.widget.ConstraintLayout>

AndroidApp/app/src/main/res/layout/activity_emulator.xml

@@ -4,35 +4,15 @@
     xmlns:tools="http://schemas.android.com/tools"
     android:layout_width="match_parent"
     android:layout_height="match_parent"
+    android:background="@color/gbaBackground"
     tools:context=".ui.EmulatorActivity">
 
-
+    <FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
-    <com.google.android.material.appbar.AppBarLayout
+        android:id="@+id/fragment_container"
-        android:id="@+id/app_bar"
         android:layout_width="match_parent"
-        android:layout_height="@dimen/app_bar_height"
+        android:layout_height="match_parent">
-        android:fitsSystemWindows="true"
-        android:theme="@style/AppTheme.AppBarOverlay">
 
-        <com.google.android.material.appbar.CollapsingToolbarLayout
+        <include layout="@layout/content_emulator" />
-            android:id="@+id/toolbar_layout"
+    </FrameLayout>
-            android:layout_width="match_parent"
-            android:layout_height="match_parent"
-            android:fitsSystemWindows="true"
-            app:contentScrim="?attr/colorPrimary"
-            app:layout_scrollFlags="scroll|exitUntilCollapsed"
-            app:toolbarId="@+id/toolbar">
-
-            <androidx.appcompat.widget.Toolbar
-                android:id="@+id/toolbar"
-                android:layout_width="match_parent"
-                android:layout_height="?attr/actionBarSize"
-                app:layout_collapseMode="pin"
-                app:popupTheme="@style/AppTheme.PopupOverlay" />
-
-        </com.google.android.material.appbar.CollapsingToolbarLayout>
-    </com.google.android.material.appbar.AppBarLayout>
-
-    <include layout="@layout/content_emulator" />
 
 </androidx.coordinatorlayout.widget.CoordinatorLayout>

AndroidApp/app/src/main/res/layout/activity_rom_list.xml

@@ -5,7 +5,7 @@
     android:layout_width="match_parent"
     android:layout_height="match_parent"
     android:fitsSystemWindows="true"
-    tools:context=".ui.RomListActivity">
+    tools:context=".ui.library.RomListActivity">
 
     <com.google.android.material.appbar.AppBarLayout
         android:id="@+id/app_bar"
@@ -19,7 +19,7 @@
             android:layout_width="match_parent"
             android:layout_height="match_parent"
             android:fitsSystemWindows="true"
-            app:contentScrim="?attr/colorPrimary"
+            app:contentScrim="?attr/colorAccent"
             app:layout_scrollFlags="scroll|exitUntilCollapsed"
             app:toolbarId="@+id/toolbar">
 
@@ -33,8 +33,6 @@
         </com.google.android.material.appbar.CollapsingToolbarLayout>
     </com.google.android.material.appbar.AppBarLayout>
 
-    <include layout="@layout/content_rom_list" />
-
     <com.google.android.material.floatingactionbutton.FloatingActionButton
         android:id="@+id/fab"
         android:layout_width="wrap_content"
@@ -42,6 +40,8 @@
         android:layout_margin="@dimen/fab_margin"
         app:layout_anchor="@id/app_bar"
         app:layout_anchorGravity="bottom|end"
-        app:srcCompat="@android:drawable/ic_dialog_email" />
+        app:srcCompat="@android:drawable/ic_media_play" />
+
+    <include layout="@layout/content_rom_list" />
 
 </androidx.coordinatorlayout.widget.CoordinatorLayout>

AndroidApp/app/src/main/res/layout/activity_settings.xml

@@ -0,0 +1,13 @@
+<?xml version="1.0" encoding="utf-8"?>
+<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
+    android:layout_width="match_parent"
+    android:layout_height="match_parent"
+    android:orientation="vertical" >
+
+    <FrameLayout
+        android:id="@+id/settings_container"
+        android:layout_width="match_parent"
+        android:layout_height="match_parent">
+    </FrameLayout>
+
+</LinearLayout>

AndroidApp/app/src/main/res/layout/content_emulator.xml

@@ -2,7 +2,7 @@
 <androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
     xmlns:app="http://schemas.android.com/apk/res-auto"
     xmlns:tools="http://schemas.android.com/tools"
-    android:background="#6c45c0"
+    android:background="@color/gbaBackground"
     android:layout_width="match_parent"
     android:layout_height="match_parent">
 
@@ -16,17 +16,16 @@
         app:layout_constraintBottom_toBottomOf="parent"
         app:layout_constraintStart_toStartOf="parent" />
 
-
+    <com.mrmichel.rustdroid_emu.ui.ScreenView
-    <com.mrmichel.rustdroid_emu.ui.GbaScreenView
         android:id="@+id/gba_view"
         android:layout_width="match_parent"
         android:layout_height="0dp"
-        android:layout_marginTop="120dp"
+        android:layout_marginTop="32dp"
         app:layout_constraintDimensionRatio="H, 3:2"
         app:layout_constraintEnd_toEndOf="parent"
         app:layout_constraintHorizontal_bias="0.517"
         app:layout_constraintStart_toStartOf="parent"
-        app:layout_constraintTop_toBottomOf="@+id/bSnapshotSave" />
+        app:layout_constraintTop_toTopOf="parent" />
 
     <Button
         android:id="@+id/buttonB"
@@ -113,53 +112,12 @@
         app:layout_constraintBottom_toBottomOf="parent"
         app:layout_constraintEnd_toEndOf="parent" />
 
-    <Button
-        android:id="@+id/bLoadRom"
-        android:layout_width="wrap_content"
-        android:layout_height="wrap_content"
-        android:layout_marginStart="16dp"
-        android:layout_marginTop="16dp"
-        android:layout_marginBottom="12dp"
-        android:onClick="loadRomButton"
-        android:text="Load Rom"
-        app:layout_constraintBottom_toTopOf="@+id/gbaMockImageView"
-        app:layout_constraintStart_toStartOf="parent"
-        app:layout_constraintTop_toTopOf="parent" />
-
-    <Button
-        android:id="@+id/bSnapshotSave"
-        style="@style/Widget.AppCompat.Button.Small"
-        android:layout_width="wrap_content"
-        android:layout_height="wrap_content"
-        android:layout_marginTop="16dp"
-        android:layout_marginEnd="4dp"
-        android:onClick="onSaveSnapshot"
-        android:text="@string/action_save_snapshot"
-        app:layout_constraintEnd_toStartOf="@+id/bRestore"
-        app:layout_constraintStart_toEndOf="@+id/bLoadRom"
-        app:layout_constraintTop_toTopOf="parent" />
-
-    <Button
-        android:id="@+id/bRestore"
-        style="@style/Widget.AppCompat.Button.Small"
-        android:layout_width="wrap_content"
-        android:layout_height="wrap_content"
-        android:layout_marginTop="16dp"
-        android:layout_marginEnd="16dp"
-        android:layout_marginBottom="12dp"
-        android:onClick="onViewSnapshots"
-        android:text="@string/action_view_snapshot"
-        app:layout_constraintBottom_toTopOf="@+id/gbaMockImageView"
-        app:layout_constraintEnd_toEndOf="parent"
-        app:layout_constraintTop_toTopOf="parent"
-        app:layout_constraintVertical_bias="0.0" />
-
     <TextView
         android:id="@+id/tvFPS"
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
         android:layout_marginTop="8dp"
-        app:layout_constraintTop_toBottomOf="@+id/gbaMockImageView"
+        app:layout_constraintTop_toBottomOf="@+id/gba_view"
         tools:layout_editor_absoluteX="176dp" />
 
 </androidx.constraintlayout.widget.ConstraintLayout>

AndroidApp/app/src/main/res/layout/content_rom_list.xml

@@ -1,17 +1,19 @@
 <?xml version="1.0" encoding="utf-8"?>
-<androidx.core.widget.NestedScrollView xmlns:android="http://schemas.android.com/apk/res/android"
+<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
     xmlns:app="http://schemas.android.com/apk/res-auto"
     xmlns:tools="http://schemas.android.com/tools"
     android:layout_width="match_parent"
     android:layout_height="match_parent"
     app:layout_behavior="@string/appbar_scrolling_view_behavior"
-    tools:context=".ui.RomListActivity"
+    tools:context=".ui.library.RomListActivity"
     tools:showIn="@layout/activity_rom_list">
 
-    <TextView
+    <GridView
-        android:layout_width="wrap_content"
+        android:id="@+id/gridview_rom_list"
-        android:layout_height="wrap_content"
+        android:layout_width="match_parent"
-        android:layout_margin="@dimen/text_margin"
+        android:layout_height="match_parent"
-        android:text="@string/large_text" />
+        android:gravity="center"
+        android:numColumns="auto_fit"
+        tools:context=".ui.library.RomListActivity"></GridView>
 
-</androidx.core.widget.NestedScrollView>
+</LinearLayout>

AndroidApp/app/src/main/res/layout/rom_item.xml

@@ -0,0 +1,38 @@
+<?xml version="1.0" encoding="utf-8"?>
+<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:app="http://schemas.android.com/apk/res-auto"
+    android:orientation="vertical"
+    android:layout_width="wrap_content"
+    android:layout_height="wrap_content"
+    android:gravity="center"
+    android:padding="5dp"
+    >
+
+    <ImageView
+        android:id="@+id/imageview_screenshot"
+        android:layout_width="180dp"
+        android:layout_height="120dp"
+        android:layout_alignParentTop="true"
+        android:layout_centerHorizontal="true"
+        android:layout_margin="5dp"
+        android:scaleType="centerCrop"
+        android:background="@drawable/round_button"
+        app:srcCompat="@drawable/icon" />
+
+    <TextView
+        android:id="@+id/textview_game_title"
+        android:layout_width="180dp"
+        android:layout_height="wrap_content"
+        android:gravity="center_horizontal"
+        android:paddingLeft="8dp"
+        android:paddingTop="4dp"
+        android:paddingBottom="4dp"
+        android:paddingRight="8dp"
+        android:text="Cool Game - III"
+        android:textAppearance="@style/TextAppearance.AppCompat.Medium"
+        android:textSize="12sp"
+        android:textStyle="bold"
+        android:layout_below="@+id/imageview_screenshot"
+        />
+
+</RelativeLayout>

AndroidApp/app/src/main/res/layout/snapshot_item.xml

@@ -5,12 +5,13 @@
     android:layout_width="match_parent"
     android:layout_height="match_parent"
     android:gravity="center"
+    android:layout_margin="10dp"
     >
 
     <ImageView
         android:id="@+id/imageview_snapshot_preview"
         android:layout_width="180dp"
-        android:layout_height="160dp"
+        android:layout_height="120dp"
         android:scaleType="centerCrop"
         app:srcCompat="@drawable/icon" />
 

AndroidApp/app/src/main/res/layout/snapshot_list_fragment.xml

@@ -4,27 +4,10 @@
     xmlns:tools="http://schemas.android.com/tools"
     android:layout_width="match_parent"
     android:layout_height="match_parent"
-    android:background="#6c45c0"
+    android:background="@color/colorAccent"
-    tools:context=".ui.snapshots.SnapshotActivity">
+    tools:context=".ui.snapshots.SnapshotListFragment">
 
 
-    <TextView
-        android:id="@+id/textView"
-        android:layout_width="wrap_content"
-        android:layout_height="wrap_content"
-        android:layout_marginStart="126dp"
-        android:layout_marginTop="8dp"
-        android:layout_marginEnd="126dp"
-        android:gravity="center"
-        android:text="Choose snapshot to load"
-        android:textAppearance="@style/TextAppearance.AppCompat.Display1"
-        android:textSize="14sp"
-        android:textStyle="bold"
-        android:typeface="monospace"
-        app:layout_constraintEnd_toEndOf="parent"
-        app:layout_constraintStart_toStartOf="parent"
-        app:layout_constraintTop_toBottomOf="@+id/edittext_snapshot_filter" />
-
     <EditText
         android:id="@+id/edittext_snapshot_filter"
         style="@style/Widget.AppCompat.EditText"
@@ -50,9 +33,9 @@
         app:layout_behavior="@string/appbar_scrolling_view_behavior"
         app:layout_constraintEnd_toEndOf="parent"
         app:layout_constraintStart_toStartOf="parent"
-        app:layout_constraintTop_toBottomOf="@+id/textView"
+        app:layout_constraintTop_toBottomOf="@+id/edittext_snapshot_filter"
-        tools:context=".ui.snapshots.SnapshotActivity"
+        tools:context=".ui.snapshots.SnapshotListFragment"
-        tools:showIn="@layout/activity_snapshot">
+        tools:showIn="@layout/snapshot_list_fragment">
 
     </GridView>
 

AndroidApp/app/src/main/res/layout/snapshot_picker_activity.xml

@@ -0,0 +1,7 @@
+<?xml version="1.0" encoding="utf-8"?>
+<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:tools="http://schemas.android.com/tools"
+    android:id="@+id/container"
+    android:layout_width="match_parent"
+    android:layout_height="match_parent"
+    tools:context=".ui.snapshots.SnapshotPickerActivity" />

AndroidApp/app/src/main/res/layout/splash_activity.xml

@@ -5,7 +5,6 @@
     xmlns:tools="http://schemas.android.com/tools"
     android:layout_width="match_parent"
     android:layout_height="match_parent"
-    android:background="#6c45c0"
     tools:context=".ui.SplashActivity">
 
     <ImageView

AndroidApp/app/src/main/res/menu/menu_context_rom.xml

@@ -0,0 +1,31 @@
+<menu xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:app="http://schemas.android.com/apk/res-auto"
+    xmlns:tools="http://schemas.android.com/tools"
+
+    android:id="@+id/menu_context_rom"
+    tools:context="com.mrmichel.rustdroid_emu.ui.library.RomListActivity">
+
+
+    <item
+        android:id="@+id/action_play"
+        android:icon="@android:drawable/ic_media_play"
+        android:title="@string/action_load_rom"
+        app:showAsAction="ifRoom|withText" />
+
+    <item
+        android:id="@+id/action_set_screenshot"
+        android:title="@string/action_set_screenshot"
+    />
+
+    <item
+        android:title="@string/action_view_snapshot"
+        app:showAsAction="withText"
+        android:id="@+id/action_view_snapshots" />
+
+
+    <item
+        android:id="@+id/action_delete"
+        android:icon="@android:drawable/ic_menu_delete"
+        android:title="@string/action_delete"
+        app:showAsAction="ifRoom|withText" />
+</menu>

AndroidApp/app/src/main/res/menu/menu_context_snapshot.xml

@@ -0,0 +1,12 @@
+<menu xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:app="http://schemas.android.com/apk/res-auto"
+    xmlns:tools="http://schemas.android.com/tools"
+    >
+
+
+    <item
+        android:id="@+id/action_delete"
+        android:icon="@android:drawable/ic_menu_delete"
+        android:title="@string/action_delete"
+        app:showAsAction="ifRoom|withText" />
+</menu>

AndroidApp/app/src/main/res/menu/menu_emulator.xml

@@ -1,20 +1,40 @@
 <menu xmlns:android="http://schemas.android.com/apk/res/android"
     xmlns:app="http://schemas.android.com/apk/res-auto"
     xmlns:tools="http://schemas.android.com/tools"
-    tools:context="com.mrmichel.rustdroid_emu.ui.RomListActivity">
+    tools:context="com.mrmichel.rustdroid_emu.ui.EmulatorActivity">
+
+
+    <item
+        android:id="@+id/action_load_rom"
+        android:orderInCategory="1"
+        android:title="@string/action_load_rom" />
+
+<!--    <item-->
+<!--        android:title="@string/submenu_snapshots"-->
+<!--        android:orderInCategory="2"-->
+<!--        >-->
+<!--        <menu>-->
+    <item
+        android:id="@+id/action_save_snapshot"
+        android:enabled="false"
+        android:icon="@android:drawable/ic_menu_save"
+        android:orderInCategory="100"
+        android:title="@string/action_save_snapshot"
+        app:showAsAction="ifRoom|withText" />
+    <item
+        android:id="@+id/action_view_snapshots"
+        android:icon="@android:drawable/ic_menu_gallery"
+        android:orderInCategory="101"
+        android:title="@string/action_view_snapshot"
+        app:showAsAction="ifRoom|withText" />
+<!--        </menu>-->
+<!--    </item>-->
+
     <item
         android:id="@+id/action_settings"
         android:orderInCategory="100"
+        android:menuCategory="system"
         android:title="@string/action_settings"
         app:showAsAction="never" />
-    <item
+
-        android:id="@+id/action_save_snapshot"
-        android:icon="@android:drawable/ic_input_add"
-        android:orderInCategory="101"
-        android:title="@string/action_save_snapshot"
-        app:showAsAction="withText" />
-    <item
-        android:id="@+id/action_view_snapshots"
-        android:orderInCategory="102"
-        android:title="@string/action_view_snapshot" />
 </menu>

AndroidApp/app/src/main/res/menu/menu_rom_list.xml

@@ -1,7 +1,14 @@
 <menu xmlns:android="http://schemas.android.com/apk/res/android"
     xmlns:app="http://schemas.android.com/apk/res-auto"
     xmlns:tools="http://schemas.android.com/tools"
-    tools:context="com.mrmichel.rustdroid_emu.ui.RomListActivity">
+    tools:context="com.mrmichel.rustdroid_emu.ui.library.RomListActivity">
+
+    <item
+        android:title="@string/action_load_rom"
+        android:id="@+id/action_import_rom" />
+    <item
+        android:title="@string/action_import_directory"
+        android:id="@+id/action_import_directory" />
     <item
         android:id="@+id/action_settings"
         android:orderInCategory="100"

AndroidApp/app/src/main/res/menu/menu_snapshot.xml

@@ -1,7 +1,7 @@
 <menu xmlns:android="http://schemas.android.com/apk/res/android"
     xmlns:app="http://schemas.android.com/apk/res-auto"
     xmlns:tools="http://schemas.android.com/tools"
-    tools:context="com.mrmichel.rustdroid_emu.ui.snapshots.SnapshotActivity">
+    tools:context="com.mrmichel.rustdroid_emu.ui.snapshots.SnapshotListFragment">
     <item
         android:id="@+id/action_settings"
         android:orderInCategory="100"

AndroidApp/app/src/main/res/values/colors.xml

@@ -1,6 +1,7 @@
 <?xml version="1.0" encoding="utf-8"?>
 <resources>
-    <color name="colorPrimary">#008577</color>
+    <color name="colorPrimary">#6c45c0</color>
-    <color name="colorPrimaryDark">#00574B</color>
+    <color name="colorPrimaryDark">#331573</color>
-    <color name="colorAccent">#D81B60</color>
+    <color name="colorAccent">#ad8cf4</color>
+    <color name="gbaBackground">#6c45c0</color>
 </resources>

AndroidApp/app/src/main/res/values/strings.xml

@@ -1,99 +1,19 @@
 <resources>
     <string name="app_name">RustdroidAdvance</string>
     <string name="title_activity_emulator">RustdroidAdvance</string>
-    <string name="title_activity_rom_list">Roms</string>
+    <string name="title_activity_rom_list">Rom Library</string>
-    <string name="large_text">
-        "Material is the metaphor.\n\n"
 
-        "A material metaphor is the unifying theory of a rationalized space and a system of motion."
+    <string name="action_load_rom">Load ROM</string>
-        "The material is grounded in tactile reality, inspired by the study of paper and ink, yet "
+    <string name="action_import_directory">Import Directory</string>
-        "technologically advanced and open to imagination and magic.\n"
-        "Surfaces and edges of the material provide visual cues that are grounded in reality. The "
-        "use of familiar tactile attributes helps users quickly understand affordances. Yet the "
-        "flexibility of the material creates new affordances that supercede those in the physical "
-        "world, without breaking the rules of physics.\n"
-        "The fundamentals of light, surface, and movement are key to conveying how objects move, "
-        "interact, and exist in space and in relation to each other. Realistic lighting shows "
-        "seams, divides space, and indicates moving parts.\n\n"
-
-        "Bold, graphic, intentional.\n\n"
-
-        "The foundational elements of print based design typography, grids, space, scale, color, "
-        "and use of imagery guide visual treatments. These elements do far more than please the "
-        "eye. They create hierarchy, meaning, and focus. Deliberate color choices, edge to edge "
-        "imagery, large scale typography, and intentional white space create a bold and graphic "
-        "interface that immerse the user in the experience.\n"
-        "An emphasis on user actions makes core functionality immediately apparent and provides "
-        "waypoints for the user.\n\n"
-
-        "Motion provides meaning.\n\n"
-
-        "Motion respects and reinforces the user as the prime mover. Primary user actions are "
-        "inflection points that initiate motion, transforming the whole design.\n"
-        "All action takes place in a single environment. Objects are presented to the user without "
-        "breaking the continuity of experience even as they transform and reorganize.\n"
-        "Motion is meaningful and appropriate, serving to focus attention and maintain continuity. "
-        "Feedback is subtle yet clear. Transitions are efficient yet coherent.\n\n"
-
-        "3D world.\n\n"
-
-        "The material environment is a 3D space, which means all objects have x, y, and z "
-        "dimensions. The z-axis is perpendicularly aligned to the plane of the display, with the "
-        "positive z-axis extending towards the viewer. Every sheet of material occupies a single "
-        "position along the z-axis and has a standard 1dp thickness.\n"
-        "On the web, the z-axis is used for layering and not for perspective. The 3D world is "
-        "emulated by manipulating the y-axis.\n\n"
-
-        "Light and shadow.\n\n"
-
-        "Within the material environment, virtual lights illuminate the scene. Key lights create "
-        "directional shadows, while ambient light creates soft shadows from all angles.\n"
-        "Shadows in the material environment are cast by these two light sources. In Android "
-        "development, shadows occur when light sources are blocked by sheets of material at "
-        "various positions along the z-axis. On the web, shadows are depicted by manipulating the "
-        "y-axis only. The following example shows the card with a height of 6dp.\n\n"
-
-        "Resting elevation.\n\n"
-
-        "All material objects, regardless of size, have a resting elevation, or default elevation "
-        "that does not change. If an object changes elevation, it should return to its resting "
-        "elevation as soon as possible.\n\n"
-
-        "Component elevations.\n\n"
-
-        "The resting elevation for a component type is consistent across apps (e.g., FAB elevation "
-        "does not vary from 6dp in one app to 16dp in another app).\n"
-        "Components may have different resting elevations across platforms, depending on the depth "
-        "of the environment (e.g., TV has a greater depth than mobile or desktop).\n\n"
-
-        "Responsive elevation and dynamic elevation offsets.\n\n"
-
-        "Some component types have responsive elevation, meaning they change elevation in response "
-        "to user input (e.g., normal, focused, and pressed) or system events. These elevation "
-        "changes are consistently implemented using dynamic elevation offsets.\n"
-        "Dynamic elevation offsets are the goal elevation that a component moves towards, relative "
-        "to the component’s resting state. They ensure that elevation changes are consistent "
-        "across actions and component types. For example, all components that lift on press have "
-        "the same elevation change relative to their resting elevation.\n"
-        "Once the input event is completed or cancelled, the component will return to its resting "
-        "elevation.\n\n"
-
-        "Avoiding elevation interference.\n\n"
-
-        "Components with responsive elevations may encounter other components as they move between "
-        "their resting elevations and dynamic elevation offsets. Because material cannot pass "
-        "through other material, components avoid interfering with one another any number of ways, "
-        "whether on a per component basis or using the entire app layout.\n"
-        "On a component level, components can move or be removed before they cause interference. "
-        "For example, a floating action button (FAB) can disappear or move off screen before a "
-        "user picks up a card, or it can move if a snackbar appears.\n"
-        "On the layout level, design your app layout to minimize opportunities for interference. "
-        "For example, position the FAB to one side of stream of a cards so the FAB won’t interfere "
-        "when a user tries to pick up one of cards.\n\n"
-    </string>
     <string name="action_settings">Settings</string>
+
+    <string name="submenu_snapshots">Snapshots</string>
     <string name="action_save_snapshot">Save Snapshot</string>
     <string name="action_view_snapshot">View Snapshots</string>
 
+    <string name="action_set_screenshot">Set Image</string>
+
+    <string name="action_delete">Delete</string>
+
     <string name="title_activity_snapshot">Snapshot Manager</string>
 </resources>

AndroidApp/app/src/main/res/xml/app_preferences.xml

@@ -0,0 +1,8 @@
+<PreferenceScreen
+    xmlns:app="http://schemas.android.com/apk/res-auto">
+
+    <CheckBoxPreference
+        app:key="skip_bios"
+        app:title="Skip bios boot animation"/>
+
+</PreferenceScreen>

rustboyadvance-jni/src/lib.rs

@@ -1,5 +1,7 @@
 /// JNI Bindings for rustboyadvance
 ///
+mod rom_helper;
+
 use std::cell::RefCell;
 use std::os::raw::c_void;
 use std::path::Path;
@@ -85,6 +87,7 @@ unsafe fn internal_open_context(
     rom: jbyteArray,
     frame_buffer: jintArray,
     save_file: JString,
+    skip_bios: jboolean,
 ) -> Result<Context, String> {
     let bios = env
         .convert_byte_array(bios)
@@ -119,7 +122,12 @@ unsafe fn internal_open_context(
     };
     let hw = Rc::new(RefCell::new(hw));
 
-    let gba = GameBoyAdvance::new(bios, gamepak, hw.clone(), hw.clone(), hw.clone());
+    let mut gba = GameBoyAdvance::new(bios, gamepak, hw.clone(), hw.clone(), hw.clone());
+
+    if skip_bios != 0 {
+        debug!("skipping bios");
+        gba.skip_bios();
+    }
 
     debug!("creating context");
     let context = Context {
@@ -182,12 +190,64 @@ pub mod bindings {
         rom: jbyteArray,
         frame_buffer: jintArray,
         save_file: JString,
+        skip_bios: jboolean
     ) -> jlong {
-        match internal_open_context(&env, bios, rom, frame_buffer, save_file) {
+        match internal_open_context(&env, bios, rom, frame_buffer, save_file, skip_bios) {
             Ok(ctx) => Box::into_raw(Box::new(Mutex::new(ctx))) as jlong,
             Err(msg) => {
                 env.throw_new(NATIVE_EXCEPTION_CLASS, msg).unwrap();
-                0
+                -1
+            }
+        }
+    }
+
+    fn inetrnal_open_saved_state(
+        env: &JNIEnv,
+        state: jbyteArray,
+        frame_buffer: jintArray,
+    ) -> Result<Context, String> {
+        let state = env
+            .convert_byte_array(state)
+            .map_err(|e| format!("could not get state buffer, error {}", e))?;
+
+        let frame_buffer_global_ref = env
+            .new_global_ref(JObject::from(frame_buffer))
+            .map_err(|e| format!("failed to add new global ref, error: {:?}", e))?;
+
+        let hw = Hardware {
+            jvm: env.get_java_vm().unwrap(),
+            frame_buffer_global_ref: frame_buffer_global_ref,
+            audio_buffer: AudioRingBuffer::new(),
+            key_state: 0xffff,
+        };
+        let hw = Rc::new(RefCell::new(hw));
+
+        let gba = GameBoyAdvance::from_saved_state(&state, hw.clone(), hw.clone(), hw.clone())
+            .map_err(|e| {
+                format!(
+                    "failed to create GameBoyAdvance from saved state, error {:?}",
+                    e
+                )
+            })?;
+
+        Ok(Context {
+            gba: gba,
+            hwif: hw.clone(),
+        })
+    }
+
+    #[no_mangle]
+    pub unsafe extern "C" fn Java_com_mrmichel_rustboyadvance_EmulatorBindings_openSavedState(
+        env: JNIEnv,
+        _obj: JClass,
+        state: jbyteArray,
+        frame_buffer: jintArray,
+    ) -> jlong {
+        match inetrnal_open_saved_state(&env, state, frame_buffer) {
+            Ok(ctx) => Box::into_raw(Box::new(Mutex::new(ctx))) as jlong,
+            Err(msg) => {
+                env.throw_new(NATIVE_EXCEPTION_CLASS, msg).unwrap();
+                -1
             }
         }
     }

rustboyadvance-jni/src/rom_helper.rs

@@ -0,0 +1,30 @@
+use jni::objects::*;
+use jni::sys::*;
+use jni::{JNIEnv, JavaVM};
+
+use rustboyadvance_ng::core::cartridge;
+
+fn parse_rom_header(env: &JNIEnv, barr: jbyteArray) -> cartridge::header::CartridgeHeader {
+    let rom_data = env.convert_byte_array(barr).unwrap();
+    cartridge::header::parse(&rom_data)
+}
+
+#[no_mangle]
+pub unsafe extern "C" fn Java_com_mrmichel_rustboyadvance_RomHelper_getGameCode(
+    env: JNIEnv,
+    _obj: JClass,
+    rom_data: jbyteArray,
+) -> jstring {
+    let header = parse_rom_header(&env, rom_data);
+    env.new_string(header.game_code).unwrap().into_inner()
+}
+
+#[no_mangle]
+pub unsafe extern "C" fn Java_com_mrmichel_rustboyadvance_RomHelper_getGameTitle(
+    env: JNIEnv,
+    _obj: JClass,
+    rom_data: jbyteArray,
+) -> jstring {
+    let header = parse_rom_header(&env, rom_data);
+    env.new_string(header.game_title).unwrap().into_inner()
+}

src/core/cartridge/mod.rs

@@ -2,7 +2,7 @@ use serde::{Deserialize, Serialize};
 
 use super::{Addr, Bus};
 
-mod header;
+pub mod header;
 use header::CartridgeHeader;
 
 mod backup;

src/core/gba.rs

@@ -68,6 +68,26 @@ impl GameBoyAdvance {
         gba
     }
 
+    pub fn from_saved_state(
+        savestate: &[u8],
+        video_device: Rc<RefCell<dyn VideoInterface>>,
+        audio_device: Rc<RefCell<dyn AudioInterface>>,
+        input_device: Rc<RefCell<dyn InputInterface>>,
+    ) -> bincode::Result<GameBoyAdvance> {
+        let decoded: Box<SaveState> = bincode::deserialize_from(savestate)?;
+
+        Ok(GameBoyAdvance {
+            cpu: decoded.cpu,
+            sysbus: decoded.sysbus,
+
+            video_device: video_device,
+            audio_device: audio_device,
+            input_device: input_device,
+
+            cycles_to_next_event: 1,
+        })
+    }
+
     pub fn save_state(&self) -> bincode::Result<Vec<u8>> {
         let s = SaveState {
             cpu: self.cpu.clone(),