Create An Android SeekBar Programmatically in Kotlin

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

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

Output

Tutorialwing Android Dynamic SeekBar Output Android SeekBar Programmatically in Kotlin

Tutorialwing Android Dynamic SeekBar Output

Getting Started

We can define android SeekBar widget as below –

Android seekBar is an extension of progressBar that have draggable thumb. User can drag the thumb back and forth to set current progress value.

Now, how do we use SeekBar 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 DynamicSeekBar. 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 SeekBar 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 SeekBar 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">DynamicSeekBar</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 SeekBar Dynamically and add it into this LinearLayout having id rootContainer.

4. Create Android SeekBar programmatically in Kotlin

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

package com.tutorialwing.dynamicseekbar

import androidx.appcompat.app.AppCompatActivity
import android.os.Bundle
import android.view.ViewGroup
import android.widget.LinearLayout
import android.widget.SeekBar
import android.widget.Toast
import com.tutorialwing.dynamicseekbar.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)

		setupSeekBar()
	}

	private fun setupSeekBar() {
		val seekBar = SeekBar(this)
		val layoutParams = LinearLayout.LayoutParams(
			ViewGroup.LayoutParams.MATCH_PARENT,
			ViewGroup.LayoutParams.WRAP_CONTENT
		)
		layoutParams.setMargins(30, 30, 30, 30)
		seekBar.layoutParams = layoutParams

		// Add SeekBar to LinearLayout
		binding.rootContainer.addView(seekBar)

		seekBar.setOnSeekBarChangeListener(object : SeekBar.OnSeekBarChangeListener {
			override fun onProgressChanged(seekBar: SeekBar, progress: Int, fromUser: Boolean) {
				// Write code to perform some action when progress is changed.
			}

			override fun onStartTrackingTouch(seekBar: SeekBar) {
				// Write code to perform some action when touch is started.
			}

			override fun onStopTrackingTouch(seekBar: SeekBar) {
				// Write code to perform some action when touch is stopped.
				Toast.makeText(
					this@MainActivity,
					"Progress is " + seekBar.progress + "%",
					Toast.LENGTH_SHORT
				).show()
			}
		})
	}
}

In MainActivity.kt file, we have created a seekBar widget programmatically. Then, we have added this seekbar widget into linearLayout, having id rootContainer. At last, we have set a listener to show a toast message whenever there is a change in progress of the seekbar i.e. position of the thumb of the seekBar.

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

Tutorialwing Android Dynamic SeekBar Output Android SeekBar Programmatically in Kotlin

Tutorialwing Android Dynamic SeekBar Output

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

Set Id of SeekBar

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

    seekBar.id = R.id.seekBar_ID  // SeekBar
    

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

Learn to Set ID of SeekBar Using XML Attribute

Set Width and Height of SeekBar

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

seekBar.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 SeekBar 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 SeekBar Using XML Attribute

Set Padding of SeekBar

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

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

Learn to Set Padding of SeekBar Using XML Attribute

Set Margin of SeekBar

Follow steps below to set margin of SeekBar 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 SeekBar 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)
    seekBar.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 SeekBar.

Learn to Set Margin of SeekBar Using XML Attribute

Set Background of SeekBar

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

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

Learn to Set Background of SeekBar Using XML Attribute

Set Visibility of SeekBar

We can set visibility of SeekBar programmatically as –

seekBar.visibility = View.VISIBLE

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

Set Text of SeekBar

Follow steps below to set text of SeekBar 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 SeekBar dynamically, in MainActivity.kt file, as –
    seekBar.text = getString(R.string.click_on_me)
    

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

Learn to Set Text of SeekBar Using XML Attribute

Set Color of Text of SeekBar

Follow steps below to set color of text of SeekBar 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 SeekBar dynamically, in MainActivity.kt file, as –
    val textColor = ContextCompat.getColor(this, R.color.black)
    seekBar.setTextColor(textColor)
    

    Here, we used setTextColor() method to set color of SeekBar of seekBar.

Learn to Set Color of SeekBar Using XML Attribute

Set Gravity of SeekBar

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

seekBar.gravity = Gravity.CENTER

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

seekBar.gravity = Gravity.CENTER_HORIZONTAL or Gravity.BOTTOM

Here, we have applied multiple gravity values, in Kotlin, to SeekBar. In above case, text will be aligned as horizontally centered to bottom.
Learn to Set Margin of SeekBar 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 seekBar.isAllCaps attributes to set text in uppercase or normal. If it is true, text will be set in uppercase.

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

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

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

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

    Above code will set text, “Hello Tutorialwing”, to SeekBar 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 seekBar.

Learn to Set Text in Uppercase or Lowercase Using XML Attribute

Set Size of Text in SeekBar

Follow steps below to set size of SeekBar programmatically using seekBar.textSize attribute –

  • Open res/values/dimens.xml file. Then, add below font-size in it –
    <dimen name="text_size">16sp</dimen>
    
  • Now, using seekBar.textSize attribute, we can set size of text dynamically as –

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

Learn to Set Size of Text in SeekBar Using XML Attribute

Set Style (Bold/italic) of Text in SeekBar

We can set textStyle of SeekBar programmatically as –

seekBar.typeface = Typeface.DEFAULT_BOLD;

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

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

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

Learn to Set Typeface of SeekBar Using XML Attribute

Set Letter Spacing of Text in SeekBar

Follow steps below to set letter spacing of SeekBar programmatically –

  • Open res/values/dimens.xml file. Then, add below dimension in it –
    <dimen name="text_letter_spacing">1dp</dimen>
    
  • We use seekBar.letterSpacing attribute to set letter spacing of SeekBar as below –

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

Learn to Set Letter Spacing of SeekBar Using XML Attribute

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

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