regression: fixed crashing when changing the language soon after starting up

app/src/main/java/io/github/sspanak/tt9/db/BaseSyncStore.java

@@ -0,0 +1,29 @@
+package io.github.sspanak.tt9.db;
+
+import android.content.Context;
+
+import io.github.sspanak.tt9.db.sqlite.SQLiteOpener;
+import io.github.sspanak.tt9.util.Logger;
+
+public class BaseSyncStore {
+	protected SQLiteOpener sqlite;
+
+	protected BaseSyncStore(Context context) {
+		try {
+			sqlite = SQLiteOpener.getInstance(context);
+			sqlite.getDb();
+		} catch (Exception e) {
+			sqlite = null;
+			Logger.w(getClass().getSimpleName(), "Database connection failure. All operations will return empty results. " + e.getMessage());
+		}
+	}
+
+	protected boolean checkOrNotify() {
+		if (sqlite == null || sqlite.getDb() == null) {
+			Logger.e(getClass().getSimpleName(), "No database connection. Cannot query any data.");
+			return false;
+		}
+
+		return true;
+	}
+}

app/src/main/java/io/github/sspanak/tt9/db/DataStore.java

@@ -8,7 +8,6 @@ import androidx.annotation.NonNull;
 import java.util.ArrayList;
 
 import io.github.sspanak.tt9.db.entities.AddWordResult;
-import io.github.sspanak.tt9.db.sqlite.SQLiteOpener;
 import io.github.sspanak.tt9.db.wordPairs.WordPairStore;
 import io.github.sspanak.tt9.db.words.DictionaryLoader;
 import io.github.sspanak.tt9.db.words.WordStore;
@@ -22,15 +21,8 @@ public class DataStore {
 
 
 	public static void init(Context context) {
-		pairs = pairs == null ? new WordPairStore(context) : pairs;
+		words = words == null ? new WordStore(context.getApplicationContext()) : words;
-		words = words == null ? new WordStore(context) : words;
+		pairs = pairs == null ? new WordPairStore(context.getApplicationContext()) : pairs;
-	}
-
-
-	public static void destroy() {
-		pairs = null;
-		words = null;
-		SQLiteOpener.destroyInstance();
 	}
 
 

app/src/main/java/io/github/sspanak/tt9/db/sqlite/SQLiteOpener.java

@@ -16,11 +16,11 @@ public class SQLiteOpener extends SQLiteOpenHelper {
 	private static final String LOG_TAG = SQLiteOpener.class.getSimpleName();
 	private static final String DATABASE_NAME = "tt9.db";
 	private static final int DATABASE_VERSION = BuildConfig.VERSION_CODE;
-	private static SQLiteOpener self;
 
-	private final ArrayList<Language> allLanguages;
+	private static SQLiteOpener self;
 	private SQLiteDatabase db;
 
+	private final ArrayList<Language> allLanguages;
 
 	private SQLiteOpener(Context context) {
 		super(context, DATABASE_NAME, null, DATABASE_VERSION);
@@ -38,19 +38,6 @@ public class SQLiteOpener extends SQLiteOpenHelper {
 	}
 
 
-	public static void destroyInstance() {
-		try {
-			if (self != null) {
-				self.close();
-			}
-		} catch (IllegalStateException e) {
-			Logger.e(LOG_TAG,  e.getMessage() + ". Ignoring database state and setting reference to NULL.");
-		} finally {
-			self = null;
-		}
-	}
-
-
 	@Override
 	public void onCreate(SQLiteDatabase db) {
 		for (String query : Tables.getCreateQueries(allLanguages)) {

app/src/main/java/io/github/sspanak/tt9/db/wordPairs/WordPairStore.java

@@ -10,19 +10,18 @@ import java.util.HashMap;
 import java.util.Map;
 import java.util.concurrent.ConcurrentHashMap;
 
+import io.github.sspanak.tt9.db.BaseSyncStore;
 import io.github.sspanak.tt9.db.sqlite.DeleteOps;
 import io.github.sspanak.tt9.db.sqlite.InsertOps;
 import io.github.sspanak.tt9.db.sqlite.ReadOps;
-import io.github.sspanak.tt9.db.sqlite.SQLiteOpener;
 import io.github.sspanak.tt9.db.words.DictionaryLoader;
 import io.github.sspanak.tt9.languages.Language;
 import io.github.sspanak.tt9.preferences.settings.SettingsStore;
 import io.github.sspanak.tt9.util.Logger;
 import io.github.sspanak.tt9.util.Timer;
 
-public class WordPairStore {
+public class WordPairStore extends BaseSyncStore {
 	// data
-	private final SQLiteOpener sqlite;
 	private final ConcurrentHashMap<Integer, HashMap<WordPair, WordPair>> pairs = new ConcurrentHashMap<>();
 
 	// timing
@@ -33,7 +32,7 @@ public class WordPairStore {
 
 
 	public WordPairStore(Context context) {
-		sqlite = SQLiteOpener.getInstance(context);
+		super(context);
 	}
 
 
@@ -92,6 +91,10 @@ public class WordPairStore {
 
 
 	public void save() {
+		if (!checkOrNotify()) {
+			return;
+		}
+
 		String SAVE_TIMER_NAME = "word_pair_save";
 		Timer.start(SAVE_TIMER_NAME);
 
@@ -113,6 +116,10 @@ public class WordPairStore {
 
 
 	public void load(@NonNull DictionaryLoader dictionaryLoader, ArrayList<Language> languages) {
+		if (!checkOrNotify()) {
+			return;
+		}
+
 		if (dictionaryLoader.isRunning()) {
 			Logger.e(getClass().getSimpleName(), "Cannot load word pairs while the DictionaryLoader is working.");
 			return;
@@ -152,6 +159,10 @@ public class WordPairStore {
 
 
 	public void delete(@NonNull ArrayList<Language> languages) {
+		if (!checkOrNotify()) {
+			return;
+		}
+
 		sqlite.beginTransaction();
 		for (Language language : languages) {
 			DeleteOps.deleteWordPairs(sqlite.getDb(), language.getId());
@@ -187,4 +198,7 @@ public class WordPairStore {
 
 		return sb.toString();
 	}
+
+
+
 }

app/src/main/java/io/github/sspanak/tt9/db/words/WordStore.java

@@ -6,6 +6,7 @@ import androidx.annotation.NonNull;
 
 import java.util.ArrayList;
 
+import io.github.sspanak.tt9.db.BaseSyncStore;
 import io.github.sspanak.tt9.db.entities.AddWordResult;
 import io.github.sspanak.tt9.db.entities.NormalizationList;
 import io.github.sspanak.tt9.db.entities.Word;
@@ -13,7 +14,6 @@ import io.github.sspanak.tt9.db.entities.WordList;
 import io.github.sspanak.tt9.db.sqlite.DeleteOps;
 import io.github.sspanak.tt9.db.sqlite.InsertOps;
 import io.github.sspanak.tt9.db.sqlite.ReadOps;
-import io.github.sspanak.tt9.db.sqlite.SQLiteOpener;
 import io.github.sspanak.tt9.db.sqlite.UpdateOps;
 import io.github.sspanak.tt9.languages.EmojiLanguage;
 import io.github.sspanak.tt9.languages.Language;
@@ -24,21 +24,14 @@ import io.github.sspanak.tt9.util.Text;
 import io.github.sspanak.tt9.util.Timer;
 
 
-public class WordStore {
+public class WordStore extends BaseSyncStore {
 	private final String LOG_TAG = "sqlite.WordStore";
-
+	private final ReadOps readOps;
-	private SQLiteOpener sqlite = null;
-	private ReadOps readOps = null;
 
 
 	public WordStore(@NonNull Context context) {
-		try {
+		super(context);
-			sqlite = SQLiteOpener.getInstance(context);
-			sqlite.getDb();
 		readOps = new ReadOps();
-		} catch (Exception e) {
-			Logger.w(LOG_TAG, "Database connection failure. All operations will return empty results. " + e.getMessage());
-		}
 	}
 
 
@@ -193,16 +186,6 @@ public class WordStore {
 	}
 
 
-	private boolean checkOrNotify() {
-		if (sqlite == null || sqlite.getDb() == null) {
-			Logger.e(LOG_TAG, "No database connection. Cannot query any data.");
-			return false;
-		}
-
-		return true;
-	}
-
-
 	public void makeTopWord(@NonNull Language language, @NonNull String word, @NonNull String sequence) {
 		if (!checkOrNotify() || word.isEmpty() || sequence.isEmpty() || language instanceof NullLanguage) {
 			return;

app/src/main/java/io/github/sspanak/tt9/ime/TraditionalT9.java

@@ -194,7 +194,6 @@ public class TraditionalT9 extends MainViewHandler {
 		requestHideSelf(0);
 		onStop();
 		backgroundTasks.removeCallbacksAndMessages(null);
-		DataStore.destroy();
 		stopSelf();
 	}