Creating subText with visible/invisible method across TextViews

Question

I have created two textViews that the first one is the main title and the second one is the subtext of the title. So I want to make the subtexts visibility to depend on clicking the main title. It looks so easy as saying butI tried a lot of methods and MainActivity.java crashes all the time.

On the second step I want a different main title under the first one and the subtext above can toggle between them.

Maybe there is an easier widget instead of textView but I couldn't find any.

Please help. Thanks.

Ps: The strings work well, there is no problem with them.

Activity_main.xml

<?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:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MainActivity">

<ScrollView
    android:layout_width="match_parent"
    android:layout_height="match_parent">
    <RelativeLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content">

        <TextView
            android:id="@+id/textView"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:textSize="18sp"
            android:layout_marginStart="20dp"
            android:layout_marginLeft="20dp"
            android:layout_marginTop="20dp"
            android:layout_marginEnd="20dp"
            android:layout_marginRight="20dp"
            android:layout_marginBottom="100dp"
            android:clickable="true"
            android:focusable="true"
            android:text="@string/text1"
            app:layout_constraintBottom_toBottomOf="parent"
            app:layout_constraintEnd_toEndOf="parent"
            app:layout_constraintStart_toStartOf="parent"
            app:layout_constraintTop_toTopOf="parent"
            app:layout_constraintVertical_bias="0.062" />

        <TextView
            android:id="@+id/textView2"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:text="@string/text11"
            android:textAppearance="@android:style/TextAppearance.Medium"
            android:textSize="15sp"
            android:layout_alignTop="@id/textView"
            android:layout_marginTop="35dp"
            android:layout_marginLeft="20dp"
            android:layout_marginRight="20dp"
            app:layout_constraintVertical_bias="0.083"
            android:visibility="invisible"
            tools:visibility="visible" />
    </RelativeLayout>

MainActivity.java

package com.example.Notes;

import androidx.appcompat.app.AppCompatActivity;

import android.annotation.SuppressLint;
import android.os.Bundle;
import android.text.style.ClickableSpan;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;
import android.widget.CompoundButton;
import android.widget.TextView;
import android.widget.ToggleButton;

public class MainActivity extends AppCompatActivity {

    @SuppressLint("ClickableViewAccessibility")
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_MainActivity);

    }
}

Edit: adding to java this code is the solution:

TextView title = findViewById(R.id.textView);
        TextView subText = findViewById(R.id.textView2);

        title.setOnClickListener(v -> {
             if (subText.getVisibility() == View.VISIBLE)
                        subText.setVisibility(View.INVISIBLE);
                    else
                        subText.setVisibility(View.VISIBLE);
        });

Answer 1

To change the visibility of the subText by clicking the title textview one could do:

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_MainActivity);

        TextView title = findViewById(R.id.textView);
        TextView subText = findViewById(R.id.textView2);

        title.setOnClickListener(v -> {
            subText.setVisibility(View.VISIBLE); //OR View.GONE OR View.INVISIBLE
        });
    }
}