Hello Readers! In this post, we are going to learn about how to use android imageSwitcher programmatically in kotlin in the application. We will also learn how to add imageSwitcher to linearLayout programmatically in android application.

Output

Tutorialwing Kotlin Dynamic ImageSwitcher Output

Getting Started

At first, we will create android project. Then, we will create and use imageSwitcher programmatically in kotlin file.

1. Creating New Project in Kotlin

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

Now, we will modify xml and kotlin file to use imageSwitcher dynamically.

2. Modify Values Folder

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

<resources>
	<string name="app_name">DynamicImageSwitcher</string>
	<string name="next">Next</string>
</resources>

3. Modify Layout Folder

Open res/layout/activity_main.xml file. Then, 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">

	<Button
		android:id="@+id/button"
		android:layout_width="wrap_content"
		android:layout_height="wrap_content"
		android:layout_gravity="center"
		android:layout_marginTop="40dp"
		android:text="@string/next"/>

	<LinearLayout
		android:id="@+id/rootContainer"
		android:layout_width="match_parent"
		android:layout_height="wrap_content"
		android:gravity="center"
		android:orientation="vertical">

	</LinearLayout>

</LinearLayout>

In activity_main.xml file, we have defined button and linearLayout, with id rootContainer, that will act as container for the imageSwitcher created programmatically in the application.

4. Create Android ImageSwitcher Programmatically / Dynamically in Kotlin

Open app/src/main/java/com.tutorialwing.dynamicimageswitcher/MainActivity.kt file. Then, add below code into it.

package com.tutorialwing.dynamicimageswitcher

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

class MainActivity : AppCompatActivity() {

    private var nameList = intArrayOf(R.drawable.chinchilla, R.drawable.cod, R.drawable.crane, R.drawable.crocodile, R.drawable.deer, R.drawable.dog, R.drawable.dolphin, R.drawable.dove, R.drawable.eel, R.drawable.elephant, R.drawable.emu, R.drawable.fly)

    private var index = 0

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

        val imageSwitcher = ImageSwitcher(this)
        val layoutParams = LinearLayout.LayoutParams(900, 900)
        layoutParams.setMargins(20, 20, 20, 20)
        imageSwitcher.layoutParams = layoutParams

        imageSwitcher.setFactory {
            val imageView = ImageView(applicationContext)
            imageView.scaleType = ImageView.ScaleType.FIT_CENTER
            imageView.layoutParams = FrameLayout.LayoutParams(FrameLayout.LayoutParams.WRAP_CONTENT, FrameLayout.LayoutParams.WRAP_CONTENT)
            imageView
        }

        imageSwitcher.setImageResource(nameList[index])

        val `in` = AnimationUtils.loadAnimation(this, android.R.anim.slide_in_left)
        imageSwitcher.inAnimation = `in`

        val out = AnimationUtils.loadAnimation(this, android.R.anim.slide_out_right)
        imageSwitcher.outAnimation = out

        val linearLayout = findViewById<LinearLayout>(R.id.rootContainer)
        linearLayout?.addView(imageSwitcher)

        val button = findViewById<Button>(R.id.button)
        button?.setOnClickListener {
            index = if (++index < nameList.size) index else 0
            imageSwitcher.setImageResource(nameList[index])
        }
    }
}

You need drawable images for this tutorial. So, you can click here to download all the images required> for this tutorial.

We have created imageSwitcher programmatically in kotlin file (i.e. in MainActivity.kt file). Then, we have set layout params, margins etc. in it. Then, we have set factory of imageSwitcher to provide views between which imageSwitcher will flip. Then, we will set animation to apply when image disappears/appears from/on the screen. After that, we have added this imageSwitcher in linearLayout having id rootContainer. At last, we have accessed button and set click listener to show next image in the imageSwitcher.

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 src/main/AndroidManifest.xml file is –

<?xml version="1.0" encoding="utf-8"?>
<manifest package="com.tutorialwing.dynamicimageswitcher"
		  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 Creating Android ImageSwitcher Programmatically in Kotlin.