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

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

Output

Tutorialwing Kotlin Dynamic TextClock Output

Getting Started

We can define android TextClock widget as below –

TextClock is a widget that are used to display current date and/or time in specified format.

Now, how do we use TextClock in android application ?

Before we move ahead, we need to setup for viewBinding to access TextClock 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 TextClock 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">DynamicTextClock</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"?>
<LinearLayout
    android:id="@+id/rootContainer"
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:gravity="center"
    android:orientation="vertical">

</LinearLayout>

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

4. Create Android TextClock programmatically in Kotlin

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

package com.tutorialwing.dynamictextclock

import androidx.appcompat.app.AppCompatActivity
import android.os.Bundle
import android.view.ViewGroup
import android.widget.LinearLayout
import android.widget.TextClock
import com.tutorialwing.dynamictextclock.databinding.ActivityMainBinding

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)

		setupTextClock()
	}

	private fun setupTextClock() {
		val textClock = TextClock(this)
		val layoutParams = LinearLayout.LayoutParams(
			ViewGroup.LayoutParams.WRAP_CONTENT,
			ViewGroup.LayoutParams.WRAP_CONTENT
		)
		layoutParams.setMargins(40, 40, 40, 40)
		textClock.layoutParams = layoutParams

		textClock.format12Hour = "hh:mm:ss a"

		binding.rootContainer.addView(textClock)
	}
}

We have created textClock programmatically in kotlin file (i.e. in MainActivity.kt file) in the application. After that, we have set layout params, margins etc. in it. Then, we have set format string for 12 hour format time.

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

Tutorialwing Kotlin Dynamic TextClock Output

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

Set Id of TextClock

Follow steps below to set id of TextClock 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="textClock_ID" />
  </resources>
  

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

  textClock.id = R.id.textClock_ID  // TextClock
  

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

Learn to Set ID of TextClock Using XML Attribute

Set Width and Height of TextClock

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

textClock.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 TextClock 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 TextClock Using XML Attribute

Set Padding of TextClock

Follow steps below to set padding of TextClock 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 TextClock dynamically, in MainActivity.kt file, as –

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

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

Learn to Set Padding of TextClock Using XML Attribute

Set Margin of TextClock

Follow steps below to set margin of TextClock 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 TextClock 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)
  textClock.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 TextClock.

Learn to Set Margin of TextClock Using XML Attribute

Set Background of TextClock

Follow steps below to set background of TextClock 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 TextClock dynamically, in MainActivity.kt file, as –

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

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

Learn to Set Background of TextClock Using XML Attribute

Set Visibility of TextClock

We can set visibility of TextClock programmatically as –

textClock.visibility = View.VISIBLE

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

Set Text of TextClock

Follow steps below to set text of TextClock programmatically –

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

  <resources>
      <string name="click_on_me">Click on me</string>
  </resources>
  

• Now, we can set text of TextClock dynamically, in MainActivity.kt file, as –

  textClock.text = getString(R.string.click_on_me)
  

  Here, we used textClock.text to set text in textClock.

Learn to Set Text of TextClock Using XML Attribute

Set Color of Text of TextClock

Follow steps below to set color of text of TextClock programmatically in Kotlin –

• 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="black">#FF000000</color>
  </resources>
  

• Now, we can set color of text of TextClock dynamically, in MainActivity.kt file, as –

  val textColor = ContextCompat.getColor(this, R.color.black)
  textClock.setTextColor(textColor)
  

  Here, we used setTextColor() method to set color of TextClock of textClock.

Learn to Set Color of TextClock Using XML Attribute

Set Gravity of TextClock

We can set gravity of text of TextClock programmatically in Kotlin as –

textClock.gravity = Gravity.CENTER

Here, we have set gravity of TextClock as center. So, all the text of TextClock will be center aligned.
We can also apply multiple gravity values as –

textClock.gravity = Gravity.CENTER_HORIZONTAL or Gravity.BOTTOM

Here, we have applied multiple gravity values, in Kotlin, to TextClock. In above case, text will be aligned as horizontally centered to bottom.
Learn to Set Margin of TextClock Using XML Attribute

Set Text in Uppercase or Lowercase

Follow steps below to set text in uppercase or lowercase programmatically as –

• Set Text in Uppercase

  We use textClock.isAllCaps attributes to set text in uppercase or normal. If it is true, text will be set in uppercase.

  textClock.text = "Hello Tutorialwing"
  textClock.isAllCaps = true
  

  In Above case, “Hello Tutorialwing” will be set in Uppercase to TextClock. So, text will be “HELLO TUTORIALWING”.

• By default, isAllCaps is false. So, whatever is written, text will be set as it is. For example,

  textClock.text = "Hello Tutorialwing"
  textClock.isAllCaps = false. // By default it is false. Written here for example.
  

  Above code will set text, “Hello Tutorialwing”, to TextClock without changing it to Uppercase.

  Actually, if isAllCaps is false, text is set as it is. It neither changes to uppercase nor lowercase.

  How do we set text in lowercase?

  Answer –

  • In xml file – write all the text in lowercase.
  • In kotlin file – take text as string. Then, convert it in lowercase. Then, set it to textClock.

Learn to Set Text in Uppercase or Lowercase Using XML Attribute

Set Size of Text in TextClock

Follow steps below to set size of TextClock programmatically using textClock.textSize attribute –

• Open res/values/dimens.xml file. Then, add below font-size in it –

  <dimen name="text_size">16sp</dimen>
  

• Now, using textClock.textSize attribute, we can set size of text dynamically as –

  textClock.textSize = resources.getDimension(R.dimen.text_margin)
  

Learn to Set Size of Text in TextClock Using XML Attribute

Set Style (Bold/italic) of Text in TextClock

We can set textStyle of TextClock programmatically as –

textClock.typeface = Typeface.DEFAULT_BOLD;

In above case, we have set textStyle as bold. So, text of TextClock will be displayed as bold letters.

If we want to preserve previous textStyle too, we can do it as –

textClock.setTypeface(textClock.typeface, Typeface.BOLD);

Learn to Set Typeface of TextClock Using XML Attribute

Set Letter Spacing of Text in TextClock

Follow steps below to set letter spacing of TextClock programmatically –

• Open res/values/dimens.xml file. Then, add below dimension in it –

  <dimen name="text_letter_spacing">1dp</dimen>
  

• We use textClock.letterSpacing attribute to set letter spacing of TextClock as below –

  textClock.letterSpacing = resources.getDimension(R.dimen.text_letter_spacing)
  

Learn to Set Letter Spacing of TextClock Using XML Attribute

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