Set Custom Range for Android SeekBar

In our previous tutorial : Android SeekBar – Kotlin Example, we have learnt to use a SeekBar. By observation, you might have found that the default range is [0,100].

In this tutorial, we will learn to set a custom range to progress of Seekbar.

The following diagram illustrates the minimum, maximum and step value for a SeekBar.

Android SeekBar Set Range

Consider that you require a range of [MIN, MAX] with a STEP value. Following two statements will set the custom range for SeekBar.

seekbar.setMax( (MAX - MIN) / STEP );

  onProgressChanged {
	double progress_custom = MIN + (progress * STEP);
  }
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Android SeekBar Set Custom Range – Kotlin Example

We shall modify MainActivity.kt of the Android Application that we created in our previous tutorial, : Android SeekBar – Kotlin Example.

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context="com.tutorialkart.seekbarexample.MainActivity">

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:gravity="center"
        android:orientation="vertical">

        <TextView
            android:id="@+id/progress"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="- -"
            android:padding="20dp"/>
        <TextView
            android:id="@+id/seekbarStatus"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="- -"
            android:padding="20dp"/>

        <SeekBar
            android:id="@+id/seekbar"
            android:layout_width="match_parent"
            android:padding="15dp"
            android:layout_height="wrap_content" />

    </LinearLayout>

</android.support.constraint.ConstraintLayout>

MainActivity.kt

package com.tutorialkart.seekbarexample

import android.os.Build
import android.support.v7.app.AppCompatActivity
import android.os.Bundle
import android.widget.SeekBar
import android.widget.SeekBar.OnSeekBarChangeListener
import android.widget.TextView
import kotlinx.android.synthetic.main.activity_main.*

class MainActivity : AppCompatActivity(),OnSeekBarChangeListener {

    private var progressView: TextView? = null
    private var seekbarStatusView: TextView? = null
    private var seekbarView: SeekBar? = null

    // SeekBar Range
    var MIN = 10
    var MAX = 160
    var STEP = 5

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)

        progressView = this.progress
        seekbarStatusView = this.seekbarStatus

        seekbarView = this.seekbar
        // set max to seekbar
        seekbarView!!.max = (MAX - MIN) / STEP

        seekbarView!!.setOnSeekBarChangeListener(this)

    }

    override fun onProgressChanged(seekBar: SeekBar, progress: Int,
                                   fromUser: Boolean) {
        val progress_custom = MIN + ( progress * STEP )
        progressView!!.text = progress_custom.toString()
        seekbarStatusView!!.text = "Tracking Touch"
    }

    override fun onStartTrackingTouch(seekBar: SeekBar) {
        seekbarStatusView!!.text = "Started Tracking Touch"
    }

    override fun onStopTrackingTouch(seekBar: SeekBar) {
        seekbarStatusView!!.text = "Stopped Tracking Touch"
    }
}

Output

Android SeekBar Set Custom Range - Kotlin Example

Conclusion

In this Android Tutorial – Android SeekBar Set Custom Range, we have learnt to set custom range, [MIN, MAX] and STEP for SeekBar.