android: frontend: Limit game list to a single directory.

src/android/app/src/main/java/org/citra/citra_emu/model/Game.java

@@ -4,6 +4,9 @@ import android.content.ContentValues;
 import android.database.Cursor;
 import android.os.Environment;
 
+import java.nio.file.Path;
+import java.nio.file.Paths;
+
 public final class Game {
     private static final String PATH_SCREENSHOT_FOLDER =
             "file://" + Environment.getExternalStorageDirectory().getPath() + "/citra-emu/ScreenShots/";
@@ -32,6 +35,11 @@ public final class Game {
                                                 int country, String path, String gameId, String company) {
         ContentValues values = new ContentValues();
 
+        if (gameId.isEmpty()) {
+            // Homebrew, etc. may not have a game ID, use filename as a unique identifier
+            gameId = Paths.get(path).getFileName().toString();
+        }
+
         String screenPath = PATH_SCREENSHOT_FOLDER + gameId + "/" + gameId + "-1.png";
 
         values.put(GameDatabase.KEY_GAME_TITLE, title);

src/android/app/src/main/java/org/citra/citra_emu/model/GameDatabase.java

@@ -103,6 +103,14 @@ public final class GameDatabase extends SQLiteOpenHelper {
         scanLibrary(database);
     }
 
+    public void resetDatabase(SQLiteDatabase database) {
+        execSqlAndLog(database, SQL_DELETE_FOLDERS);
+        execSqlAndLog(database, SQL_CREATE_FOLDERS);
+
+        execSqlAndLog(database, SQL_DELETE_GAMES);
+        execSqlAndLog(database, SQL_CREATE_GAMES);
+    }
+
     public void scanLibrary(SQLiteDatabase database) {
         // Before scanning known folders, go through the game table and remove any entries for which the file itself is missing.
         Cursor fileCursor = database.query(TABLE_NAME_GAMES,

src/android/app/src/main/java/org/citra/citra_emu/model/GameProvider.java

@@ -16,6 +16,7 @@ import org.citra.citra_emu.utils.Log;
  */
 public final class GameProvider extends ContentProvider {
     public static final String REFRESH_LIBRARY = "refresh";
+    public static final String RESET_LIBRARY = "reset";
 
     public static final String AUTHORITY = "content://" + BuildConfig.APPLICATION_ID + ".provider";
     public static final Uri URI_FOLDER =
@@ -23,6 +24,7 @@ public final class GameProvider extends ContentProvider {
     public static final Uri URI_GAME =
             Uri.parse(AUTHORITY + "/" + GameDatabase.TABLE_NAME_GAMES + "/");
     public static final Uri URI_REFRESH = Uri.parse(AUTHORITY + "/" + REFRESH_LIBRARY + "/");
+    public static final Uri URI_RESET = Uri.parse(AUTHORITY + "/" + RESET_LIBRARY + "/");
 
     public static final String MIME_TYPE_FOLDER = "vnd.android.cursor.item/vnd.dolphin.folder";
     public static final String MIME_TYPE_GAME = "vnd.android.cursor.item/vnd.dolphin.game";
@@ -89,6 +91,10 @@ public final class GameProvider extends ContentProvider {
         long id = -1;
 
         if (table != null) {
+            if (table.equals(RESET_LIBRARY)) {
+                mDbHelper.resetDatabase(database);
+                return uri;
+            }
             if (table.equals(REFRESH_LIBRARY)) {
                 Log.info(
                         "[GameProvider] URI specified table REFRESH_LIBRARY. No insertion necessary; refreshing library contents...");

src/android/app/src/main/java/org/citra/citra_emu/ui/main/MainActivity.java

@@ -148,6 +148,11 @@ public final class MainActivity extends AppCompatActivity implements MainView {
             case MainPresenter.REQUEST_ADD_DIRECTORY:
                 // If the user picked a file, as opposed to just backing out.
                 if (resultCode == MainActivity.RESULT_OK) {
+                    // When a new directory is picked, we currently will reset the existing games
+                    // database. This effectively means that only one game directory is supported.
+                    // TODO(bunnei): Consider fixing this in the future, or removing code for this.
+                    getContentResolver().insert(GameProvider.URI_RESET, null);
+                    // Add the new directory
                     mPresenter.onDirectorySelected(FileBrowserHelper.getSelectedDirectory(result));
                 }
                 break;