Animate Display Hosts on Android

android/app/src/main/java/com/metallic/chiaki/main/MainActivity.kt

@@ -24,6 +24,7 @@ import android.os.Bundle
 import android.view.Menu
 import android.view.MenuItem
 import android.view.View
+import android.view.animation.AnimationUtils
 import androidx.lifecycle.Observer
 import androidx.lifecycle.ViewModelProviders
 import androidx.recyclerview.widget.LinearLayoutManager
@@ -72,7 +73,10 @@ class MainActivity : AppCompatActivity()
 		val recyclerViewAdapter = DisplayHostRecyclerViewAdapter()
 		hostsRecyclerView.adapter = recyclerViewAdapter
 		hostsRecyclerView.layoutManager = LinearLayoutManager(this)
-		viewModel.displayHosts.observe(this, Observer { recyclerViewAdapter.hosts = it })
+		viewModel.displayHosts.observe(this, Observer {
+			recyclerViewAdapter.hosts = it
+			hostsRecyclerView.scheduleLayoutAnimation()
+		})
 
 		viewModel.discoveryActive.observe(this, Observer { active ->
 			discoveryMenuItem?.let { updateDiscoveryMenuItem(it, active) }

android/app/src/main/res/anim/item_drop.xml

@@ -0,0 +1,13 @@
+<?xml version="1.0" encoding="utf-8"?>
+<set xmlns:android="http://schemas.android.com/apk/res/android"
+    android:duration="200">
+    <translate
+        android:fromXDelta="20%"
+        android:toXDelta="0"
+        android:interpolator="@android:anim/decelerate_interpolator"/>
+
+    <alpha
+        android:fromAlpha="0.0"
+        android:toAlpha="1.0"
+        android:interpolator="@android:anim/decelerate_interpolator"/>
+</set>

android/app/src/main/res/anim/layout_drop.xml

@@ -0,0 +1,6 @@
+<?xml version="1.0" encoding="utf-8"?>
+<layoutAnimation
+    xmlns:android="http://schemas.android.com/apk/res/android"
+    android:animation="@anim/item_drop"
+    android:delay="15%"
+    android:animationOrder="normal" />

android/app/src/main/res/layout/activity_main.xml

@@ -14,6 +14,7 @@
         android:paddingBottom="8dp"
         android:clipToPadding="false"
         android:clipChildren="false"
+        android:layoutAnimation="@anim/layout_drop"
         app:layout_behavior="@string/appbar_scrolling_view_behavior"/>
 
     <FrameLayout