Android Fade In/Out in Kotlin (original) (raw)

Last Updated : 28 Oct, 2021

In Android Animations are the visuals that are added to make the user interface more interactive, clear and good looking. Fade In and Fade out animations are used to modify the appearance of any view over a set interval of time so that user can be notified about the changes that are occurring in our application.
In this article we will be discussing how to create a Fade In/Out animation in Kotlin .

First step is to create a new Project in Android Studio. For this follow these steps:

• Click on File, then New and then New Project and give name whatever you like
• Then, select Kotlin language Support and click next button.
• Select minimum SDK, whatever you need
• Select Empty activity and then click finish.

After that, we need to design our layout. For that we need to work with the XML file. Go to app > res > layout and paste the following code:

Modify activity_main.xml file

XML `

<TextView
        android:id="@+id/textView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="GeeksForGeeks"
        android:layout_centerInParent="true"
        android:textSize="30sp"
        android:textStyle="bold" />

<Button
        android:id="@+id/fade_in"
        android:layout_width="100dp"
        android:layout_height="wrap_content"
        android:text="Fade In"
        android:layout_marginTop="140dp"
        android:layout_marginLeft="100dp" />
<Button
        android:id="@+id/fade_out"
        android:layout_width="100dp"
        android:layout_height="wrap_content"
        android:layout_marginTop="140dp"
        android:layout_toRightOf="@+id/fade_in"
        android:text="Fade Out"
        android:textAllCaps="false" />

`

Add anim folder

In this folder, we will be adding the XML files which will be used to produce the animations. For this to happen, go to app/res right click and then select, Android Resource Directory and name it as anim.
Again right click this anim folder and select Animation resource file and name it as fade_in. Similarly, also create fade_out.xml and paste the following code.
fade_in.xml

XML `

`

fade_out.xml

XML `

`

Modify MainActivity.kt file

Open app/src/main/java/yourPackageName/MainActivity.kt and do the following changes:

Java `

package com.geeksforgeeks.myfirstKotlinapp

import androidx.appcompat.app.AppCompatActivity import android.os.Bundle import android.os.Handler import android.view.View import android.view.animation.AnimationUtils import kotlinx.android.synthetic.main.activity_main.*

class MainActivity : AppCompatActivity() {

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

    //setting button onClickListener
    fade_in.setOnClickListener {
    textView.visibility = View.VISIBLE
    //loading our custom made animations
    val animation = AnimationUtils.loadAnimation(this, R.anim.fade_in)
    //starting the animation
    textView.startAnimation(animation)
}
fade_out.setOnClickListener {
    val animation = AnimationUtils.loadAnimation(this, R.anim.fade_out)
    textView.startAnimation(animation)
    //textview will be invisible after the specified amount
    // of time elapses, here it is 1000 milliseconds
    Handler().postDelayed({
        textView.visibility = View.GONE
    }, 1000)
}

} }

`

AndroidManifest.xml file

XML `

<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>

`

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