Hello Readers! In this post, we are going to learn about android ViewAnimator using kotlin in any android application. We will also learn about different attributes of android ViewAnimator that can be used to customise this widget.

Output

Tutorialwing Kotlin ViewAnimator Output

Getting Started

Android ViewAnimator can be defined as below –

ViewAnimator is a widget that are used to switch between views using animations.

Different Attributes of Android ViewAnimator Widget

Some of the popular attributes of android ViewAnimator widget are –

Some of the popular attributes of android ViewAnimator inherited from FrameLayout are –

Some of the popular attributes of android ViewAnimator inherited from ViewGroup are –

Some of the popular attributes of android ViewAnimator inherited from View are –

Example of Android ViewAnimator Using Kotlin

At first, we will create android application. Then, we will use viewAnimator using kotlin in the application.

1. Creating New Project in Kotlin

Follow steps below to create new project. Please ignore the steps if you have already created the project.

Since we have a project now, we will modify xml and other files to use viewAnimator using kotlin in the application.

2. Modify values folder

Open res/values/strings.xml file. Then, add below code into it.

<resources>
	<string name="app_name">ViewAnimator</string>
	<string name="next">Next</string>
	<string name="prev">Previous</string>
	<string name="item_post_1">Text at position 1</string>
	<string name="item_post_2">Button at position 2</string>
	<string name="item_post_4">Text at positon 4</string>
</resources>

3. Use ViewAnimator Widget in xml file

Open src/main/res/layout/activity_main.xml file and add below code into it.

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

	<LinearLayout
		android:layout_width="match_parent"
		android:layout_height="wrap_content"
		android:gravity="center"
		android:orientation="horizontal"
		android:padding="10dp">

		<Button
			android:id="@+id/buttonPrev"
			android:layout_width="wrap_content"
			android:layout_height="wrap_content"
			android:text="@string/prev"/>

		<Button
			android:id="@+id/buttonNext"
			android:layout_width="wrap_content"
			android:layout_height="wrap_content"
			android:text="@string/next"/>

	</LinearLayout>

	<ViewAnimator
		android:id="@+id/viewAnimator"
		android:layout_width="match_parent"
		android:layout_height="match_parent">

		<TextView
			android:layout_width="wrap_content"
			android:layout_height="wrap_content"
			android:layout_gravity="center_horizontal"
			android:text="@string/item_post_1"
			android:textColor="@android:color/holo_red_dark"
			android:textSize="20sp"/>

		<Button
			android:layout_width="wrap_content"
			android:layout_height="wrap_content"
			android:layout_gravity="center_horizontal"
			android:text="@string/item_post_2">
		</Button>

		<ImageView
			android:layout_width="wrap_content"
			android:layout_height="wrap_content"
			android:layout_gravity="center_horizontal"
			android:src="@mipmap/ic_launcher"/>

		<TextView
			android:layout_width="wrap_content"
			android:layout_height="wrap_content"
			android:layout_gravity="center_horizontal"
			android:text="@string/item_post_4"
			android:textColor="@android:color/holo_red_dark"
			android:textSize="20sp"/>

	</ViewAnimator>

</LinearLayout>

In activity_main.xml file, we have two buttons and ViewAnimator. ViewAnimator contains four child views(TextView, Button, ImageView and TextView). At a time, only one view is shown in viewAnimator. You can switch between views, using viewAnimator, with animation. Now, we will access these widgets in kotlin file to perform some actions on it.

4. Access ViewAnimator Widget in Kotlin file

Open src/main/java/com.tutorialwing.viewanimator/MainActivity.kt file and add below code into it.

package com.tutorialwing.viewanimator

import android.os.Bundle
import android.support.v7.app.AppCompatActivity
import android.view.animation.AnimationUtils
import android.widget.Button
import android.widget.ViewAnimator

class MainActivity : AppCompatActivity() {

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

        val animator = findViewById<ViewAnimator>(R.id.viewAnimator)

        val animationIn = AnimationUtils.loadAnimation(this, android.R.anim.slide_in_left)
        val animationOut = AnimationUtils.loadAnimation(this, android.R.anim.slide_out_right)

        animator.inAnimation = animationIn
        animator.outAnimation = animationOut

        val buttonPrev = findViewById<Button>(R.id.buttonPrev)
        buttonPrev.setOnClickListener { animator.showPrevious() }

        val buttonNext = findViewById<Button>(R.id.buttonNext)
        buttonNext.setOnClickListener { animator.showNext() }
    }
}

We have accessed viewAnimator using kotlin file (i.e. MainActivity.kt file). Then, we have set in and out animations that are applied when current view is replaced by either previous view or next view. Then, we have set click listener on buttons (Prev and Next buttons) that shows previous/next view in viewAnimator respectively.

Since AndroidManifest.xml file is very important in any android application, we are also going to see the content inside this file.

AndroidManifest.xml file

Code inside main/AndroidManifest.xml file is as below.

<?xml version="1.0" encoding="utf-8"?>
<manifest package="com.tutorialwing.viewanimator"
		  xmlns:android="http://schemas.android.com/apk/res/android">

	<application
		android:allowBackup="true"
		android:icon="@mipmap/ic_launcher"
		android:label="@string/app_name"
		android:roundIcon="@mipmap/ic_launcher_round"
		android:supportsRtl="true"
		android:theme="@style/AppTheme">
		<activity android:name=".MainActivity">
			<intent-filter>
				<action android:name="android.intent.action.MAIN"/>

				<category android:name="android.intent.category.LAUNCHER"/>
			</intent-filter>
		</activity>
	</application>

</manifest>

When we run the program, we will get output as shown above.

That’s end of our tutorial on Android ViewAnimator using Kotlin.