android kotlin - Custom horizontal progress bar

MainActivity.kt


package com.example.jetpack

import android.os.Bundle
import android.os.Handler
import android.os.Looper
import android.widget.Button
import android.widget.ProgressBar
import android.widget.TextView
import androidx.appcompat.app.AppCompatActivity
import kotlin.random.Random


class MainActivity : AppCompatActivity() {
    var progressStatus = 0
    var handler = Handler(Looper.getMainLooper())

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)
        
        // Get the widgets reference from XML layout
        val button = findViewById<Button>(R.id.button)
        val textView = findViewById<TextView>(R.id.textView)
        val progressBar = findViewById<ProgressBar>(R.id.progressBar)


        button.setOnClickListener {
            button.isEnabled = false

            // set up progress bar on initial stage
            progressBar.progress = 0
            progressStatus = 0

            // generate random number of files to download
            val filesToDownload= Random.nextInt(10,200)

            // set up max value for progress bar
            progressBar.max = filesToDownload

            Thread(Runnable {
                while (progressStatus < filesToDownload){
                    // update progress status
                    progressStatus +=1

                    // sleep the thread for 200 milliseconds
                    Thread.sleep(200)

                    // update the progress bar
                    handler.post {
                        progressBar.progress = progressStatus

                        // calculate the percentage
                        var percentage = ((progressStatus.toDouble()
                                / filesToDownload) * 100).toInt()

                        // update the text view
                        textView.text = "Downloaded $progressStatus of " +
                                "$filesToDownload files ($percentage%)"

                        if (progressStatus == filesToDownload){
                            button.isEnabled = true
                        }
                    }
                }
            }).start()
        }
    }
}

res/drawable/progressbar_states.xml


<?xml version="1.0" encoding="utf-8"?>
<layer-list xmlns:android="http://schemas.android.com/apk/res/android">
    <item android:id="@+id/background">
            <shape android:shape="line">
                <stroke
                    android:width="3dp"
                    android:dashWidth="20dp"
                    android:dashGap="7dp"
                    android:color="#FFEB3B"
                    />
            </shape>
    </item>

    <item android:id="@+id/progress">
        <clip android:clipOrientation="horizontal" android:gravity="start">
            <shape android:shape="line">
                <stroke
                    android:width="3dp"
                    android:dashWidth="20dp"
                    android:dashGap="7dp"
                    android:color="#2196F3"
                    />
            </shape>
        </clip>
    </item>
</layer-list>

activity_main.xml


<?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:id="@+id/constraintLayout"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">

    <com.google.android.material.textview.MaterialTextView
        android:id="@+id/textView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginStart="16dp"
        android:layout_marginTop="8dp"
        android:padding="24dp"
        android:text="Stats"
        android:textAppearance="@style/TextAppearance.MaterialComponents.Headline6"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

    <com.google.android.material.button.MaterialButton
        android:id="@+id/button"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop="8dp"
        android:text="Start Task"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/progressBar" />

    <ProgressBar
        android:id="@+id/progressBar"
        style="?android:attr/progressBarStyleHorizontal"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_marginStart="8dp"
        android:layout_marginTop="12dp"
        android:layout_marginEnd="8dp"
        android:progressDrawable="@drawable/progressbar_states"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintHorizontal_bias="0.498"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/textView" />

</androidx.constraintlayout.widget.ConstraintLayout>