fix sending messages in Viber using its own button causing the last word to reappear, when trying to type right after sending

app/src/main/AndroidManifest.xml

@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="utf-8"?>
 <manifest xmlns:tools="http://schemas.android.com/tools"
-	android:versionCode="556"
+	android:versionCode="558"
 	android:versionName="33.0"
 	xmlns:android="http://schemas.android.com/apk/res/android">
 

app/src/main/java/io/github/sspanak/tt9/hacks/AppHacks.java

@@ -5,6 +5,8 @@ import android.view.inputmethod.InputConnection;
 
 import androidx.annotation.NonNull;
 
+import io.github.sspanak.tt9.ime.helpers.CursorOps;
+import io.github.sspanak.tt9.ime.helpers.SuggestionOps;
 import io.github.sspanak.tt9.ime.helpers.TextField;
 import io.github.sspanak.tt9.ime.modes.InputMode;
 import io.github.sspanak.tt9.preferences.settings.SettingsStore;
@@ -68,6 +70,29 @@ public class AppHacks {
 	}
 
 
+	/**
+	 * Performs extra operations when the cursor moves and returns "true" if the selection was handled, "false" otherwise.
+	 */
+	public boolean onUpdateSelection(
+		@NonNull InputMode inputMode,
+		@NonNull SuggestionOps suggestionOps,
+		int oldSelStart,
+		int oldSelEnd,
+		int newSelStart,
+		int newSelEnd,
+		int candidatesStart,
+		int candidatesEnd
+	) {
+		if (inputType.isViber() && CursorOps.isInputReset(oldSelStart, oldSelEnd, newSelStart, newSelEnd, candidatesStart, candidatesEnd)) {
+			inputMode.onAcceptSuggestion(suggestionOps.acceptIncomplete());
+			inputMode.reset();
+			return true;
+		}
+
+		return false;
+	}
+
+
 	/**
 	 * onEnter
 	 * Tries to guess and send the correct confirmation key code or sequence of key codes,

app/src/main/java/io/github/sspanak/tt9/hacks/InputType.java

@@ -101,6 +101,20 @@ public class InputType extends StandardInputType {
 		return isAppField("com.termux", EditorInfo.TYPE_NULL) && field.fieldId > 0;
 	}
 
+
+	/**
+	 * isViber
+	 * When sending messages using the Viber's SEND button, it does so and clears the text field,
+	 * but without notifying the keyboard. This means, after sending the message, the InputMode still
+	 * holds the old text, while the text field is empty. Attempting to type a new word then results
+	 * in appending to the old word. We use this hack to detect Viber and reset the InputMode upon
+	 * sending a message.
+	 */
+	public boolean isViber() {
+		return isAppField("com.viber.voip", EditorInfo.TYPE_CLASS_TEXT | EditorInfo.TYPE_TEXT_FLAG_MULTI_LINE);
+	}
+
+
 	public boolean isNotUs(Context context) {
 		return !isAppField(context.getPackageName(), EditorInfo.TYPE_NULL);
 	}

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

@@ -13,6 +13,7 @@ import io.github.sspanak.tt9.R;
 import io.github.sspanak.tt9.db.DictionaryLoader;
 import io.github.sspanak.tt9.hacks.AppHacks;
 import io.github.sspanak.tt9.hacks.InputType;
+import io.github.sspanak.tt9.ime.helpers.CursorOps;
 import io.github.sspanak.tt9.ime.helpers.InputModeValidator;
 import io.github.sspanak.tt9.ime.helpers.SuggestionOps;
 import io.github.sspanak.tt9.ime.helpers.TextField;
@@ -275,12 +276,16 @@ public abstract class TypingHandler extends KeyPadHandler {
 
 		super.onUpdateSelection(oldSelStart, oldSelEnd, newSelStart, newSelEnd, candidatesStart, candidatesEnd);
 
+		// in case the app has modified the InputField and moved the cursor without notifiying us...
+		if (appHacks.onUpdateSelection(mInputMode, suggestionOps, oldSelStart, oldSelEnd, newSelStart, newSelEnd, candidatesStart, candidatesEnd)) {
+			return;
+		}
+
 		// If the cursor moves while composing a word (usually, because the user has touched the screen outside the word), we must
 		// end typing end accept the word. Otherwise, the cursor would jump back at the end of the word, after the next key press.
 		// This is confusing from user perspective, so we want to avoid it.
 		if (
-			candidatesStart != -1 && candidatesEnd != -1
-			&& (newSelStart != candidatesEnd || newSelEnd != candidatesEnd)
+			CursorOps.isMovedManually(newSelStart, newSelEnd, candidatesStart, candidatesEnd)
 			&& !suggestionOps.isEmpty()
 		) {
 			mInputMode.onAcceptSuggestion(suggestionOps.acceptIncomplete());

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

@@ -0,0 +1,16 @@
+package io.github.sspanak.tt9.ime.helpers;
+
+public class CursorOps {
+	public static boolean isMovedManually(int newSelStart, int newSelEnd, int candidatesStart, int candidatesEnd) {
+		return
+			candidatesStart != -1 && candidatesEnd != -1
+			&& (newSelStart != candidatesEnd || newSelEnd != candidatesEnd);
+	}
+
+	public static boolean isInputReset(int oldSelStart, int oldSelEnd, int newSelStart, int newSelEnd, int candidatesStart, int candidatesEnd) {
+		return
+			oldSelStart > 0 && oldSelEnd > 0
+			&& newSelStart == 0 && newSelEnd == 0
+			&& candidatesStart == -1 && candidatesEnd == -1;
+	}
+}