Kotlin Android Popup Menu

Android Popup Menu is a list menu that appears vertically to the view. The popup menu appears below the view if there is room otherwise, appears above. Touching outside to popup menu makes it disappear.
Popup Menu provides actions that are related to the specific content, and it does not affect the corresponding content.
The PopupMenu.OnMenuItemClickListener interface receives the menu items click events if the items don't have their click listener.

Kotlin Android Popup Menu Example

In this example, we will add the popup menu items on a view (button). Clicking on the button shows the popup menu items on which we can perform the relevant action.
Create an android project and select the Basic Activity. This activity auto-generates codes for the menu.

activity_main.xml

Add the following code in layout directory in the activity_main.xml file. This code is auto-generated while creating the Basic Activity.

< ?xml version="1.0" encoding="utf-8"?>  
< android.support.design.widget.CoordinatorLayout 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="example.javatpoint.com.kotlinpopupmenu.MainActivity">  
  
    < android.support.design.widget.AppBarLayout  
        android:layout_width="match_parent"  
        android:layout_height="wrap_content"  
        android:theme="@style/AppTheme.AppBarOverlay">  
  
        < android.support.v7.widget.Toolbar  
            android:id="@+id/toolbar"  
            android:layout_width="match_parent"  
            android:layout_height="?attr/actionBarSize"  
            android:background="?attr/colorPrimary"  
            app:popupTheme="@style/AppTheme.PopupOverlay" />  
  
    < /android.support.design.widget.AppBarLayout>  
  
    < include layout="@layout/content_main" />  
  
<  /android.support.design.widget.CoordinatorLayout>

content_main.xml

Add the following code in the content_main.xml file in layout directory. In this layout, we place a Button View component.

< ?xml version="1.0" encoding="utf-8"?>  
< android.support.constraint.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"  
    app:layout_behavior="@string/appbar_scrolling_view_behavior"  
    tools:context="example.javatpoint.com.kotlinpopupmenu.MainActivity"  
    tools:showIn="@layout/activity_main">  
  
     < Button  
        android:id="@+id/button"  
        android:layout_width="wrap_content"  
        android:layout_height="wrap_content"  
        android:layout_marginBottom="8dp"  
        android:layout_marginEnd="8dp"  
        android:layout_marginStart="8dp"  
        android:layout_marginTop="8dp"  
        android:text="Button"  
        app:layout_constraintBottom_toBottomOf="parent"  
        app:layout_constraintEnd_toEndOf="parent"  
        app:layout_constraintStart_toStartOf="parent"  
        app:layout_constraintTop_toTopOf="parent" />  
< /android.support.constraint.ConstraintLayout>  

strings.xml

• Add the following code in the strings.xml file.

< resources>  
    < string name="app_name">Kotlin PopupMenu< /string>  
    < string name="action_settings">Settings< /string>  
    < string name="action_cricket">Cricket< /string>  
    < string name="action_football">Football< /string>  
    < string name="action_hockey">Hockey< /string>  
< /resources>  

popup_menu.xml

Create a menu resource file named as popup_menu.xml in the menu directory. Add the item tag which creates the menu item for the popup menu.

< ?xml version="1.0" encoding="utf-8"?>  
< menu xmlns:android="http://schemas.android.com/apk/res/android"  
    xmlns:app="http://schemas.android.com/apk/res-auto">  
    < item  
        android:id="@+id/action_crick"  
        android:title="@string/action_cricket"  
        app:showAsAction="never"/>  
    < item  
        android:id="@+id/action_ftbal"  
        android:title="@string/action_football"  
        app:showAsAction="never"/>  
    < item  
        android:id="@+id/action_hockey"  
        android:title="@string/action_hockey"  
        app:showAsAction="never"/>  
< /menu>  

MainActivity.kt

Add the following code in the MainActivity.kt class. In this class, we implement the PopupMenu.OnMenuItemClickListener interface which receives the menu items click events. To display the popup menu, call the PopupMenu.show() method.

package example.javatpoint.com.kotlinpopupmenu  
  
import android.os.Bundle  
import android.support.v7.app.AppCompatActivity  
import android.widget.Button  
import android.widget.PopupMenu  
import android.widget.Toast  
  
import kotlinx.android.synthetic.main.activity_main.*  
  
class MainActivity : AppCompatActivity() {  
    override fun onCreate(savedInstanceState: Bundle?) {  
        super.onCreate(savedInstanceState)  
        setContentView(R.layout.activity_main)  
        setSupportActionBar(toolbar)  
  
        val button = findViewById< Button>(R.id.button)  
        button.setOnClickListener {  
           val popupMenu: PopupMenu = PopupMenu(this,button)  
           popupMenu.menuInflater.inflate(R.menu.popup_menu,popupMenu.menu)  
           popupMenu.setOnMenuItemClickListener(PopupMenu.OnMenuItemClickListener { item ->  
                    when(item.itemId) {  
                    R.id.action_crick ->  
                        Toast.makeText(this@MainActivity, "You Clicked : " + item.title, Toast.LENGTH_SHORT).show()  
                    R.id.action_ftbal ->  
                        Toast.makeText(this@MainActivity, "You Clicked : " + item.title, Toast.LENGTH_SHORT).show()  
                    R.id.action_hockey ->  
                        Toast.makeText(this@MainActivity, "You Clicked : " + item.title, Toast.LENGTH_SHORT).show()  
                }  
                true  
           })  
           popupMenu.show()  
        }  
    }  
}