How do make Android confetti by picture drop from top animation?

Question

I want to make an animation animation on clicking the button as follows:

But I don't know how to make it disappear when it touch the bottom read line.

I want to upload a gif file, but it seems that stackoverflow doesn't support gif at this moment.

The code of MainActivity.kt :

class MainActivity : AppCompatActivity() {

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

        val btn: Button = findViewById(R.id.button)

        btn.setOnClickListener {
            val animation = AnimationUtils.loadAnimation(this@MainActivity, R.anim.drop_down)
            val confetti: ImageView = findViewById(R.id.place_holder_animation)
            val resId = R.drawable.confetti

            animation.setAnimationListener(object : Animation.AnimationListener {
                override fun onAnimationRepeat(animation: Animation?) {
                }

                override fun onAnimationEnd(animation: Animation?) {
                    confetti.visibility = View.GONE
                }

                override fun onAnimationStart(animation: Animation?) {
                }
            })

            confetti.setImageDrawable(resources.getDrawable(resId))
            confetti.startAnimation(animation)
        }
    }
}

With the drop_down.xml for the animation description:

<?xml version="1.0" encoding="utf-8"?>
<set xmlns:android="http://schemas.android.com/apk/res/android"
     >
    <translate android:fromYDelta="-80%p" android:toYDelta="10%p" android:duration="2000"/>
</set>

The layout file is just a RelativeLayout:

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
                android:layout_width="match_parent"
                android:layout_height="match_parent">

    <ImageView
            android:id="@+id/place_holder_animation"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"/>

    <ImageView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:src="@drawable/jbean"
            android:id="@+id/imageView2"/>

    <ImageView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:src="@drawable/jbean"
            android:id="@+id/imageView3"
            android:layout_toEndOf="@+id/imageView2"
            android:layout_marginStart="20dp"/>

    <ImageView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:src="@drawable/jbean"
            android:layout_toEndOf="@+id/imageView3"
            android:id="@+id/imageView4"
            android:layout_marginStart="20dp"/>
    <Button
            android:id="@+id/button"
            android:text="Show"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginTop="100dp"
            android:layout_below="@+id/imageView3"
            android:layout_alignStart="@+id/imageView3"/>
</RelativeLayout>

Answer 1

Use this animation for disappearing -

<?xml version="1.0" encoding="utf-8"?>
<set 
xmlns:android="http://schemas.android.com/apk/res/android"
    android:interpolator="@android:anim/linear_interpolator">
   <alpha
        android:duration="2000"
        android:fromAlpha="1.0"
        android:toAlpha="0.0" >
   </alpha>
 </set>