In this article, we will learn how to create android ViewFlipper programmatically in Kotlin. We will go through various steps that explains how to create ViewFlipper and add it in kotlin file, use different attributes to customise it etc. in any android application. For example, how to set text in ViewFlipper programmatically, how to set id of ViewFlipper, how to capitalise text of ViewFlipper dynamically etc. We will get answer to all such questions in this post.

Learn to use Different Attributes of ViewFlipper in XML File to Customize it.

Output

Tutorialwing Kotlin Dynamic ViewFlipper Output

Getting Started

We can define android ViewFlipper widget as below –

ViewFlipper is a widget that are used to switch between views that have been added to it. Only one view is shown at a time. We can also set animations that will be used when view is shown / hidden.

Now, how do we use ViewFlipper in android application ?

Before we move ahead, we need to setup for viewBinding to access ViewFlipper in Kotlin file without using findViewById() method.

Setup ViewBinding

Add viewBinding true in app/build.gradle file.

 
 android { 
 	// OTHER CODE... 
 	buildFeatures { 
 		viewBinding true 
 	} 
 } 
 

Now, set content in activity using view binding.
Open MainActivity.kt file and write below code in it.

 
 class MainActivity : AppCompatActivity() { 
 	
 	private lateinit var binding: ActivityMainBinding 
 	
 	override fun onCreate(savedInstanceState: Bundle?) { 
 		super.onCreate(savedInstanceState) 
 		binding = ActivityMainBinding.inflate(layoutInflater) 
 		val view = binding.root 
 		setContentView(view) 
 	} 
 } 
 

Now, we can access view in Kotlin file without using findViewById() method.

Since we have a new project, we will modify the xml and class file to use ViewFlipper programmatically in kotlin. Please follow the steps below.

Download Drawable Resources Needed

We need some images, stored in res/drawable folder, to be by viewFlipper created dynamically in the application. We can click here to download images used in the application.

2. Modify Values Folder

Open res/values/strings.xml file. Add below code into it.

<resources>
    <string name="app_name">DynamicViewFlipper</string>
    <string name="pause">Pause</string>
    <string name="play">Play</string>
    <string name="flipping_started">Flipping Started...</string>
    <string name="flipping_stopped">Flipping Stopped...</string>
</resources>

Other values folders have not been changed. So, we are not going to mention it here.

3. Modify Layout Folder

Open res/layout/activity_main.xml file. Add below code into it.

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">

    <Button
        android:id="@+id/playPause"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="center_horizontal"
        android:layout_marginTop="15dp"
        android:text="@string/pause"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

    <LinearLayout
        android:id="@+id/rootContainer"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="horizontal"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/playPause">

    </LinearLayout>

</androidx.constraintlayout.widget.ConstraintLayout>

Note that LinearLayout has id rootContainer. In Kotlin file, we will create ViewFlipper Dynamically and add it into this LinearLayout having id rootContainer.

4. Create Android ViewFlipper programmatically in Kotlin

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

package com.tutorialwing.dynamicviewflipper

import androidx.appcompat.app.AppCompatActivity
import android.os.Bundle
import android.view.Gravity
import android.view.ViewGroup
import android.widget.*
import com.tutorialwing.dynamicviewflipper.databinding.ActivityMainBinding

class MainActivity : AppCompatActivity() {

	private lateinit var binding: ActivityMainBinding
	private var imageList = intArrayOf(
		R.drawable.guava,
		R.drawable.jackfruit,
		R.drawable.mix_fruit,
		R.drawable.pomegranate,
		R.drawable.strawberry,
		R.drawable.zespri_kiwi
	)

	override fun onCreate(savedInstanceState: Bundle?) {
		super.onCreate(savedInstanceState)
		binding = ActivityMainBinding.inflate(layoutInflater)
		val view = binding.root
		setContentView(view)

		setupViewFlipper()
	}

	private fun setupViewFlipper() {
		// Create ViewFlipper dynamically.
		val viewFlipper = ViewFlipper(this)
		val layoutParams = LinearLayout.LayoutParams(
			ViewGroup.LayoutParams.MATCH_PARENT,
			ViewGroup.LayoutParams.WRAP_CONTENT
		)
		layoutParams.setMargins(30, 30, 30, 30)
		layoutParams.gravity = Gravity.CENTER
		viewFlipper.layoutParams = layoutParams
		viewFlipper.flipInterval = 2000
		viewFlipper.isAutoStart = true

		viewFlipper.setInAnimation(applicationContext, android.R.anim.slide_in_left)
		viewFlipper.setOutAnimation(applicationContext, android.R.anim.slide_out_right)

		// Add imageView for each image to viewFlipper.
		for (image in imageList) {
			val imageView = ImageView(this)
			val params = FrameLayout.LayoutParams(
				ViewGroup.LayoutParams.MATCH_PARENT,
				ViewGroup.LayoutParams.WRAP_CONTENT
			)
			params.setMargins(30, 30, 30, 30)
			params.gravity = Gravity.CENTER
			imageView.layoutParams = params
			imageView.setImageResource(image)
			viewFlipper.addView(imageView)
		}

		binding.rootContainer.addView(viewFlipper)

		// set clickListener of button to play/pause viewFlipper.
		binding.playPause.setOnClickListener {
			if (viewFlipper.isFlipping)
				viewFlipper.stopFlipping()
			else
				viewFlipper.startFlipping()

			binding.playPause.text =
				getString(if (viewFlipper.isFlipping) R.string.pause else R.string.play)
			Toast.makeText(
				this@MainActivity,
				getString(if (viewFlipper.isFlipping) R.string.flipping_started else R.string.flipping_stopped),
				Toast.LENGTH_SHORT
			).show()
		}
	}
}

We have created viewFlipper using kotlin file (i.e. in MainActivity.kt file) in the application. Then, we have set layout params, margins, animations (in and out animations) etc. in it. Then, we have created imageViews dynamically that are equal to length of imageList array in the application. Then, we have added these imageViews into viewFlipper. After that, we have accessed button, having id playPause and set click listener into it. Whenever button is clicked, viewFlipper stops flipping the view if is already flipping the view and vice-versa. We are also showing a toast message that display the current status viewFlipper. At last, we have added viewFlipper into linearLayout having id rootContainer.

Finally, when you run the application, you will get output as shown above.

Tutorialwing Kotlin Dynamic ViewFlipper Output

Now, Let’s check how to use different attributes of ViewFlipper to customize it dynamically –

Set Id of ViewFlipper

Follow steps below to set id of ViewFlipper programmatically –

• Create ids.xml file in res/values folder. Then, add below code into it –

  <?xml version="1.0" encoding="utf-8"?>
  <resources>
      <item type="id" name="viewFlipper_ID" />
  </resources>
  

• Now, we can set id of ViewFlipper dynamically, in MainActivity.kt file, as –

  ViewFlipper.id = R.id.viewFlipper_ID  // ViewFlipper
  

  Here, we have set id of ViewFlipper using property access syntax – ViewFlipper.id

Learn to Set ID of ViewFlipper Using XML Attribute

Set Width and Height of ViewFlipper

We use layoutParams to set width and height of any View programmatically. In this article, we have added ViewFlipper in LinearLayout. So, we will define LayoutParams as below –

ViewFlipper.layoutParams = LinearLayout.LayoutParams(
	ViewGroup.LayoutParams.WRAP_CONTENT,
	ViewGroup.LayoutParams.WRAP_CONTENT
)

Here, we have set width and height as WRAP_CONTENT. Some of possible values for width and height are –

• WRAP_CONTENT: Sets value of width or height depending on text inside it.
• MATCH_PARENT: Sets value of width of height depending on width or height of parent layout . i.e. width or height of ViewFlipper will be same as width or height of parent layout.
• Fixed Value: Sets width or height as per value provided.

Learn to Set Width or Height of ViewFlipper Using XML Attribute

Set Padding of ViewFlipper

Follow steps below to set padding of ViewFlipper Dynamically –

• If there is no dimens.xml file, create dimens.xml file in res/values folder. Then, add below code in it –

  <?xml version="1.0" encoding="utf-8"?>
  <resources>
      <dimen name="text_padding">16dp</dimen>
  </resources>
  

• Now, we can set padding of ViewFlipper dynamically, in MainActivity.kt file, as –

  val padding = resources.getDimension(R.dimen.text_padding).toInt()
  ViewFlipper.setPadding(padding, padding, padding, padding)
  

  Here, we have accessed dimension defined in dimens.xml using getDimension() method. Then, set padding of ViewFlipper using setPadding() method.

Learn to Set Padding of ViewFlipper Using XML Attribute

Set Margin of ViewFlipper

Follow steps below to set margin of ViewFlipper Dynamically –

• If there is no dimens.xml file, create dimens.xml file in res/values folder. Then, add below code in it –

  <?xml version="1.0" encoding="utf-8"?>
  <resources>
      <dimen name="text_margin">16dp</dimen>
  </resources>
  

• Now, we can set margin of ViewFlipper dynamically, in MainActivity.kt file, as –

  val margin = resources.getDimension(R.dimen.text_margin).toInt()
  val layoutParams = LinearLayout.LayoutParams(
  	ViewGroup.LayoutParams.WRAP_CONTENT,
  	ViewGroup.LayoutParams.WRAP_CONTENT
  )
  layoutParams.setMargins(margin, margin, margin, margin)
  ViewFlipper.layoutParams = layoutParams
  

  Here, we have accessed dimension defined in dimens.xml using getDimension() method. Then, we have defined layoutParams, set margin to layoutParams. After that, set layoutParams to ViewFlipper.

Learn to Set Margin of ViewFlipper Using XML Attribute

Set Background of ViewFlipper

Follow steps below to set background of ViewFlipper programmatically –

• If there is no colors.xml file, create colors.xml file in res/values folder. Then, add below code in it –

  <?xml version="1.0" encoding="utf-8"?>
  <resources>
      <color name="purple_200">#FFBB86FC</color>
  </resources>
  

• Now, we can set background of ViewFlipper dynamically, in MainActivity.kt file, as –

  val color = ContextCompat.getColor(this, R.color.purple_200)
  ViewFlipper.setBackgroundColor(color)
  

  Here, we used setBackgroundColor() method to set background color in ViewFlipper.

Learn to Set Background of ViewFlipper Using XML Attribute

Set Visibility of ViewFlipper

We can set visibility of ViewFlipper programmatically as –

ViewFlipper.visibility = View.VISIBLE

Here, we have set visibility of ViewFlipper using ViewFlipper.visibility attribute. Visibility can be of three types – gone, visible and invisible.
Learn to Set Visibility of ViewFlipper Using XML Attribute

That’s end of tutorial on ViewFlipper Programmatically in Kotlin With Example.