Swipe Refresh Layout example kotlin in android

Pull to Swipe Refresh Layout is a gesture that is being used in a lot of popular apps, apps where content updates are frequent, like news, social media e.t.c. In Android development this gesture it’s called ‘Swipe to Refresh‘

Methods are:

– setOnRefreshListener(OnRefreshListener): adds a listener to let other parts of the code know when refreshing begins.
– setRefreshing(boolean): enables or disables progress visibility.
– isRefreshing(): checks whether the view is refreshing.
– setColorScheme(): it receive four different colors that will be used to colorize the animation.

MainActivity.kt

package com.cfsuman.kotlinexamples

import android.graphics.Color
import android.support.v7.app.AppCompatActivity
import android.os.Bundle
import android.os.Handler
import kotlinx.android.synthetic.main.activity_main.*
import java.util.*


class MainActivity : AppCompatActivity() {

    private lateinit var mRandom:Random
    private lateinit var mHandler: Handler
    private lateinit var mRunnable:Runnable

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

        // Initialize a new Random instance
        mRandom = Random()

        // Initialize the handler instance
        mHandler = Handler()


        // Set an on refresh listener for swipe refresh layout
        swipe_refresh_layout.setOnRefreshListener {
            // Initialize a new Runnable
            mRunnable = Runnable {
                // Update the text view text with a random number
                text_view.text = "Refresh and get random number ${mRandom.nextInt(500)}"

                // Change the text view text color with a random color
                text_view.setTextColor(randomHSVColor())

                // Hide swipe to refresh icon animation
                swipe_refresh_layout.isRefreshing = false
            }

            // Execute the task after specified time
            mHandler.postDelayed(
                    mRunnable,
                    (randomInRange(1,5)*1000).toLong() // Delay 1 to 5 seconds
            )
        }
   }



    // Custom method to generate random HSV color
    fun randomHSVColor(): Int {
        // Generate a random hue value between 0 to 360
        val hue = mRandom.nextInt(361)
        // We make the color depth full
        val saturation = 1.0f
        // We make a full bright color
        val value = 1.0f
        // We avoid color transparency
        val alpha = 255
        // Finally, generate the color
        // Return the color
        return Color.HSVToColor(alpha, floatArrayOf(hue.toFloat(), saturation, value))
    }


    // Custom method to get a random number from the provided range
    private fun randomInRange(min:Int, max:Int):Int{
        // Define a new Random class
        val r = Random()

        // Get the next random number within range
        // Including both minimum and maximum number
        return r.nextInt((max - min) + 1) + min;
    }
}

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<android.support.v4.widget.SwipeRefreshLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:id="@+id/swipe_refresh_layout"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="#edf9ee"
    >
    <TextView
        android:id="@+id/text_view"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:gravity="center"
        android:text="Swipe to refresh me"
        android:textSize="50sp"
        />
</android.support.v4.widget.SwipeRefreshLayout>

Output