fixed backspace not working in constrained input fields where composing text can not be displayed

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

@@ -85,6 +85,10 @@ public class SuggestionOps {
 
 
 	String acceptPrevious(int sequenceLength) {
+		if (sequenceLength <= 0) {
+			set(null);
+		}
+
 		String lastComposingText = getCurrent(sequenceLength - 1);
 		commitCurrent(false);
 		return lastComposingText;

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

@@ -98,6 +98,7 @@ public abstract class TypingHandler extends KeyPadHandler {
 	}
 
 
+	@Override
 	public boolean onBackspace() {
 		// Dialer fields seem to handle backspace on their own and we must ignore it,
 		// otherwise, keyDown race condition occur for all keys.
@@ -105,9 +106,7 @@ public abstract class TypingHandler extends KeyPadHandler {
 			return false;
 		}
 
-		// * Some app may need special treatment, so let them be.
-		// * When there is no text, allow double function keys to function normally (e.g. "Back" navigates back)
-		if (appHacks.onBackspace(mInputMode) || textField.getStringBeforeCursor(1).isEmpty()) {
+		if (appHacks.onBackspace(mInputMode)) {
 			mInputMode.reset();
 			return false;
 		}

app/src/main/java/io/github/sspanak/tt9/ime/helpers/AppHacks.java

@@ -138,10 +138,11 @@ public class AppHacks {
 		if (isKindleInvertedTextField()) {
 			inputMode.clearWordStem();
 		} else if (isTermux()) {
-			sendDownUpKeyEvents(KeyEvent.KEYCODE_DEL);
+			return false;
 		}
 
-		return false;
+		// When there is no text, allow double function keys to function normally (e.g. "Back" navigates back)
+		return inputMode.getSuggestions().isEmpty() && textField.getStringBeforeCursor(1).isEmpty();
 	}
 
 

app/src/main/java/io/github/sspanak/tt9/ime/modes/Mode123.java

@@ -17,7 +17,6 @@ public class Mode123 extends ModePassthrough {
 
 	@Override public final boolean is123() { return true; }
 	@Override public boolean isPassthrough() { return false; }
-	@Override public int getSequenceLength() { return 1; }
 	@Override public boolean shouldAcceptPreviousSuggestion(int nextKey) { return true; }
 
 	private final ArrayList<ArrayList<String>> KEY_CHARACTERS = new ArrayList<>();
@@ -86,6 +85,16 @@ public class Mode123 extends ModePassthrough {
 		return digitSequence.equals(NaturalLanguage.SPECIAL_CHARS_KEY) && super.nextSpecialCharacters();
 	}
 
+
+	@Override public boolean onBackspace() {
+		if (suggestions.isEmpty()) {
+			return false;
+		}
+
+		reset();
+		return true;
+	}
+
 	@Override public boolean onNumber(int number, boolean hold, int repeat) {
 		reset();
 		digitSequence = String.valueOf(number);
@@ -100,7 +109,6 @@ public class Mode123 extends ModePassthrough {
 		return true;
 	}
 
-
 	/**
 	 * shouldIgnoreText
 	 * Since this is a numeric mode, we allow typing only numbers and:
@@ -120,6 +128,9 @@ public class Mode123 extends ModePassthrough {
 			);
 	}
 
+	@Override public void onAcceptSuggestion(@NonNull String ignored, boolean ignored2) {
+		reset();
+	}
 
 	@Override public void reset() {
 		super.reset();

app/src/main/java/io/github/sspanak/tt9/ime/modes/ModeABC.java

@@ -20,8 +20,12 @@ public class ModeABC extends InputMode {
 
 	@Override
 	public boolean onBackspace() {
+		if (suggestions.isEmpty()) {
+			return false;
+		}
+
 		reset();
-		return false;
+		return true;
 	}
 
 	@Override