In this article, we will learn about android StackView using Kotlin. We will go through various example that demonstrates how to use different attributes of StackView. For example,

In this article, we will get answer to questions like –

• What is StackView?
• Why should we consider StackView while designing ui for any app?
• What are possibilities using StackView while designing ui? etc.

Let’s have a quick demo of things we want to cover in this tutorial –

Output

Tutorialwing Kotlin StackView Output

Getting Started

We can define android StackView widget as below –

StackView is a widget that are used to create views like stack cards in the application. You can flip current views to create space for views just after it. Whenever current view is flipped, next view, just after it, comes forward and takes place of current view.

Now, how do we use StackView in android application ?

Creating New Project

At first, we will create an application.
So, follow steps below to create any android project in Kotlin –

Newbie in Android ?

Some very important concepts (Recommended to learn before you move ahead)

• Install Android Studio
• Create New Project in Android Studio
• Android Project Structure
• Run / Debug / Test Android App

Before we move ahead, we need to setup for viewBinding to access Android StackView Using 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.

Using StackView in Kotlin

Follow steps below to use StackView in newly created project –

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

  <resources>
      <string name="app_name">StackView</string>
      <string name="no_image">No image</string>
  </resources>
  

• We will need some drawable images for this application. So, we can click here to download images to be used in this application.

• Create View for single item

  We will create view for single item in stackView. Create a new file, item.xml, in res/layout folder. Then, add below code into it.

  <?xml version="1.0" encoding="utf-8"?>
  <FrameLayout
      xmlns:android="http://schemas.android.com/apk/res/android"
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:background="@android:color/black">
  
      <ImageView
          android:id="@+id/imageView"
          android:layout_width="260dp"
          android:layout_height="260dp"
          android:layout_margin="3dp"
          android:contentDescription="@string/no_image"/>
  
  </FrameLayout>
  

• Create Adapter for StackView

  We will create adapter for stackView. This will be responsible to create different views using stackView. So, create a new file, StackAdapter.kt, in main/java/com.tutorialwing.stackview package. Then, add below code into it.

  package com.tutorialwing.stackview
  
  import android.content.Context
  import android.view.LayoutInflater
  import android.view.View
  import android.view.ViewGroup
  import android.widget.BaseAdapter
  import android.widget.ImageView
  import com.tutorialwing.stackview.databinding.ItemBinding
  
  class StackAdapter internal constructor(context: Context, private val nameList: IntArray) :
  	BaseAdapter() {
  
  	private val inflater: LayoutInflater = LayoutInflater.from(context)
  
  	override fun getCount(): Int {
  		return nameList.size
  	}
  
  	override fun getItem(position: Int): Any {
  		return nameList[position]
  	}
  
  	override fun getItemId(position: Int): Long {
  		return position.toLong()
  	}
  
  	override fun getView(position: Int, view: View?, parent: ViewGroup): View {
  		var convertView = view
  		val holder: ViewHolder
  		if (convertView == null) {
  			val binding = ItemBinding.inflate(inflater)
  			convertView = binding.root
  			holder = ViewHolder()
  			holder.imageView = binding.imageView
  			convertView.tag = holder
  		} else {
  			holder = convertView.tag as ViewHolder
  		}
  		holder.imageView!!.setBackgroundResource(nameList[position])
  		return convertView
  	}
  
  	inner class ViewHolder {
  		internal var imageView: ImageView? = null
  	}
  }
  

  In Adapter class, we have mentioned below things –

  • We have defined a constructor, StackAdapter(…, …) method, that accepts context and nameList array. nameList contains the list of image to be used to create views.
  • getCount() method returns the size of rows in stackView. i.e. total number of views to be created in the stackView.
  • getItem() method returns the item at given index(i.e. position).
  • getItemId() method returns the id of the view at given index(i.e. position).
  • getView() method defines the view at given index. Note that we have used viewHolder pattern to create a view in stackView.
• Open res/layout/activity_main.xml file. Then, add below code in 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"
      android:background="@android:color/darker_gray"
      android:padding="20dp"
      tools:context=".MainActivity">
  
      <StackView
          android:id="@+id/stackView"
          android:layout_width="match_parent"
          android:layout_height="match_parent"
          android:animateLayoutChanges="true"
          app:layout_constraintBottom_toBottomOf="parent"
          app:layout_constraintLeft_toLeftOf="parent"
          app:layout_constraintRight_toRightOf="parent"
          app:layout_constraintTop_toTopOf="parent" />
  
  </androidx.constraintlayout.widget.ConstraintLayout>
  

  In activity_main.xml file, we have defined stackView. Now, we will access this widget in java file to perform some operations in it.

• We can also access it in Kotlin File, MainActivity.kt, as below –

  package com.tutorialwing.stackview
  
  import androidx.appcompat.app.AppCompatActivity
  import android.os.Bundle
  import com.tutorialwing.stackview.databinding.ActivityMainBinding
  
  class MainActivity : AppCompatActivity() {
  
  	private lateinit var binding: ActivityMainBinding
  
  	private var nameList = intArrayOf(
  		R.drawable.guava,
  		R.drawable.jackfruit,
  		R.drawable.mix_fruit,
  		R.drawable.pizza,
  		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)
  
  		setupStackView()
  	}
  
  	private fun setupStackView() {
  		val adapter = StackAdapter(this, nameList)
  		binding.stackView.adapter = adapter
  		adapter.notifyDataSetChanged()
  	}
  }
  

  In MainActivity.kt file, we have accessed stackView widget. Then, we have created an adapter and assigned it to stackView.

Now, run the application. We will get output as below –

Tutorialwing Kotlin StackView Output

Different Attributes of StackView in XML

Now, we will see how to use different attributes of Android StackView using Kotlin to customise it –

Set Id of StackView

Many a time, we need id of View to access it in kotlin file or create ui relative to that view in xml file. So, we can set id of StackView using android:id attribute like below –

    <StackView
        android:id="@+id/stackView_ID"
        />

Here, we have set id of StackView as stackView_ID using android:id=”” attribute. So, if we need to reference this StackView, we need to use this id – stackView_ID.
Learn to Set ID of StackView Dynamically

Set Width of StackView

We use android:layout_width=”” attribute to set width of StackView.
We can do it as below –

    <StackView
        android:id="@+id/stackView_ID"
        android:layout_width="wrap_content"
        />

Width can be either “MATCH_PARENT” or “WRAP_CONTENT” or any fixed value (like 20dp, 30dp etc.).
Learn to Set Width of StackView Dynamically

Set Height of StackView

We use android:layout_height=”” attribute to set height of StackView.
We can do it as below –

    <StackView
        android:id="@+id/stackView_ID"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        />

Height can be either “MATCH_PARENT” or “WRAP_CONTENT” or any fixed value.
Learn to Set Height of StackView Dynamically

Set Padding of StackView

We use android:padding=”” attribute to set padding of StackView.
We can do it as below –

    <StackView
        android:id="@+id/stackView_ID"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:padding="10dp"
        />

Here, we have set padding of 10dp in StackView using android:padding=”” attribute.
Learn to Set Padding of StackView Dynamically

Set Margin of StackView

We use android:layout_margin=”” attribute to set margin of StackView.
We can do it as below –

    <StackView
        android:id="@+id/stackView_ID"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_margin="10dp"
        />

Here, we have set margin of 10dp in StackView using android:layout_margin=”” attribute.
Learn to Set Margin of StackView Dynamically

Set Background of StackView

We use android:background=”” attribute to set background of StackView.
We can do it as below –

    <StackView
        android:id="@+id/stackView_ID"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:background="#ff0000"
        />

Here, we have set background of color #ff0000 in StackView using android:background=”” attribute.
Learn to Set Background of StackView Dynamically

Set Visibility of StackView

We use android:visibility=”” attribute to set visibility of StackView.
We can do it as below –

    <StackView
        android:id="@+id/stackView_ID"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:visibility="gone"
        />

Here, we have set visibility of StackView using android:visiblity=”” attribute. Visibility can be of three types – gone, visible and invisible
Learn to Set Visibility of StackView Dynamically

Till now, we have see how to use android StackView using Kotlin. We have also gone through different attributes of StackView to perform certain task. Let’s have a look at list of such attributes and it’s related task.

Different Attributes of Android StackView Widget

Below are the various attributes that are used to customise android StackView Widget. However, you can check the complete list of attributes of StackView in it’s official documentation site. Here, we are going to list some of the important attributes of this widget –

Some of the popular attributes of android stackView inherited from AdapterViewAnimator are –

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

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

We have seen different attributes of StackView and how to use it. If you wish to visit post to learn more about it

Thus, we have seen what is StackView, how can we use android StackView using Kotlin ? etc. We also went through different attributes of android StackView.