Create An Android TextSwitcher Programmatically in Kotlin

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

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

Output

Tutorialwing Kotlin Dynamic TextSwitcher Output Android TextSwitcher Programmatically in Kotlin

Tutorialwing Kotlin Dynamic TextSwitcher Output

Getting Started

We can define android TextSwitcher widget as below –

TextSwitcher, a subclass of ViewSwitcher, is a widget that contains children of type textView. It is used to animates current text out and next text in.

Now, how do we use TextSwitcher in android application ?

Creating New Project

Follow steps below to create any android project in Kotlin –

Step Description
1. Open Android Studio (Ignore if already done).
2. Go to File => New => New Project. This will open a new window. Then, under Phone and Tablet section, select Empty Activity. Then, click Next.
3. In next screen, select project name as DynamicTextSwitcher. Then, fill other required details.
4. Then, clicking on Finish button creates new project.

Newbie in Android ?
Some very important concepts (Recommended to learn before you move ahead)

Before we move ahead, we need to setup for viewBinding to access TextSwitcher 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 TextSwitcher programmatically in kotlin. Please follow the steps below.

2. Modify Values Folder

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

<resources>
    <string name="app_name">DynamicTextSwitcher</string>
    <string name="next">Next</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/btnNext"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="center"
        android:layout_marginTop="40dp"
        android:text="@string/next"
        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:layout_marginTop="40dp"
        android:orientation="vertical"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/btnNext">

    </LinearLayout>

</androidx.constraintlayout.widget.ConstraintLayout>

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

4. Create Android TextSwitcher programmatically in Kotlin

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

package com.tutorialwing.dynamictextswitcher

import android.graphics.Color
import androidx.appcompat.app.AppCompatActivity
import android.os.Bundle
import android.view.Gravity
import android.view.animation.AnimationUtils
import android.widget.TextSwitcher
import android.widget.TextView
import com.tutorialwing.dynamictextswitcher.databinding.ActivityMainBinding

class MainActivity : AppCompatActivity() {

	private lateinit var binding: ActivityMainBinding

	private val textList =
		arrayOf("Panda", "Tiger", "Zebra", "Lion", "Deer", "Goat", "Ape", "Monkey", "Human")
	private var index = 0

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

		setupTextSwitcher()
	}

	private fun setupTextSwitcher() {
		val textSwitcher = TextSwitcher(this)
		textSwitcher.setFactory {
			val textView = TextView(this@MainActivity)
			textView.gravity = Gravity.TOP or Gravity.CENTER_HORIZONTAL
			textView.textSize = 32f
			textView.setTextColor(Color.RED)
			textView
		}
		textSwitcher.setText(textList[index])

		val inAnim = AnimationUtils.loadAnimation(this, android.R.anim.slide_in_left)
		textSwitcher.inAnimation = inAnim

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

		binding.btnNext.setOnClickListener {
			index = if (index + 1 < textList.size) index + 1 else 0
			textSwitcher.setText(textList[index])
		}

		binding.rootContainer.addView(textSwitcher)
	}
}

We have created textSwitcher programmatically in kotlin file (i.e. in MainActivity.kt file) in the application. Then, we have set factory that defines views between which textSwitcher switches. After that, we have set in and out animations that are used when current text is animated out and next text is animated in. Then, we have set click listener to show next text whenever it is clicked. At last, we have added this textSwitcher in linearLayout programmatically.

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

Tutorialwing Kotlin Dynamic TextSwitcher Output Android TextSwitcher Programmatically in Kotlin

Tutorialwing Kotlin Dynamic TextSwitcher Output

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

Set Id of TextSwitcher

Follow steps below to set id of TextSwitcher 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="textSwitcher_ID" />
    </resources>
    
  • Now, we can set id of TextSwitcher dynamically, in MainActivity.kt file, as –

    textSwitcher.id = R.id.textSwitcher_ID  // TextSwitcher
    

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

Learn to Set ID of TextSwitcher Using XML Attribute

Set Width and Height of TextSwitcher

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

textSwitcher.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 TextSwitcher 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 TextSwitcher Using XML Attribute

Set Padding of TextSwitcher

Follow steps below to set padding of TextSwitcher 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 TextSwitcher dynamically, in MainActivity.kt file, as –
    val padding = resources.getDimension(R.dimen.text_padding).toInt()
    textSwitcher.setPadding(padding, padding, padding, padding)
    

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

Learn to Set Padding of TextSwitcher Using XML Attribute

Set Margin of TextSwitcher

Follow steps below to set margin of TextSwitcher 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 TextSwitcher 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)
    textSwitcher.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 TextSwitcher.

Learn to Set Margin of TextSwitcher Using XML Attribute

Set Background of TextSwitcher

Follow steps below to set background of TextSwitcher 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 TextSwitcher dynamically, in MainActivity.kt file, as –
    val color = ContextCompat.getColor(this, R.color.purple_200)
    textSwitcher.setBackgroundColor(color)
    

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

Learn to Set Background of TextSwitcher Using XML Attribute

Set Visibility of TextSwitcher

We can set visibility of TextSwitcher programmatically as –

textSwitcher.visibility = View.VISIBLE

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

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

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