ToggleButton in Kotlin

In Android, ToggleButton is just like a switch containing two states either ON or OFF which is represented using boolean values true and false respectively. ToggleButton unlike switch does not have a slider interface i.e we cannot slide to change the states. It is just like a button. In this article, we will be discussing how to create a ToggleButton in Kotlin.

Android ToggleButton XML Attributes

Note: ToggleButton inherits the button class of android. Therefore, all the attributes of the button are also applicable here.

Following are some of the additional important attributes available along ToggleButton

Attribute	Description
android:id	The id assigned to the toggle button
android:textOff	The text shown on the button when it is not checked
android:textOn	The text shown on the button when it is checked
android:disabledAlpha	The alpha (opacity) to apply to the when disabled.

Create a new project in Android Studio

To create a new project in Android Studio follow these steps:

1. Click on File, then New and then New Project and give name whatever you like.
2. Choose “Empty Activity” for the project template.
3. Then, select Kotlin language Support and click next button.
4. Select minimum SDK, whatever you need

Modify activity_main.xml

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">

    <ToggleButton
        android:id="@+id/toggleButton"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />
</androidx.constraintlayout.widget.ConstraintLayout>

Accessing the Toggle Button

The toggle button in the layout can be accessed using the findViewById() function.

val toggle: ToggleButton = findViewById(R.id.toggleButton)

After accessing set a listener to perform actions based on the toggle state using setOnCheckedChangeListener() method.

toggle.setOnCheckedChangeListener { _, isChecked -> **Perform Any Action Here**}

Modify MainActivity.kt file

Java

package com.example.togglebuttonsample
import androidx.appcompat.app.AppCompatActivity
import android.os.Bundle
import android.widget.Toast
import android.widget.ToggleButton

class MainActivity : AppCompatActivity() {

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)

        val toggle: ToggleButton = findViewById(R.id.toggleButton)
        toggle.setOnCheckedChangeListener { _, isChecked ->
            Toast.makeText(this, if(isChecked) "Geek Mode ON" else "Geek Mode OFF", Toast.LENGTH_SHORT).show()
        }
    }
}

Run on Emulator