Kotlin - How to handle swipe Gesture in Android Application?
Implement swipe right functionality in Android using Kotlin with this tutorial, covering how to handle swipe gestures effectively in your app.
Published February 21, 2020
In this post we are going to learn how to hanlde swipe Gesture in Android
Let's Start
Step 1: Create a new project in Android Studio, go to File ⇒ New Project and fill all required details to create a new project
Step 2: Updated Activity xml file with below code
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="https://schemas.android.com/apk/res/android"
xmlns:tools="https://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:padding="4dp"
android:id="@+id/relativeLayout"
tools:context=".MainActivity">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textAlignment="center"
android:layout_centerInParent="true"
android:textSize="18sp"
android:textStyle="bold"
android:padding="16dp"
android:lineSpacingExtra="2dp"
android:textColor="@color/colorPrimary"
android:text="Swipe Left to right and Right to Left to detect Swipe Gesture"/>
</RelativeLayout>
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Step 3: Create class and add below code
package com.rrtutors.androidsamples.guestures
import android.content.Context
import android.view.GestureDetector
import android.view.MotionEvent
import android.view.View
import com.rrtutors.androidsamples.guestures.OnSwipeTouchListener.GestureListener
public abstract class OnSwipeTouchListener() :View.OnTouchListener{
constructor(c: Context) : this() {
gestureDetector = GestureDetector(c, GestureListener())
}
private var gestureDetector: GestureDetector?=null;
override fun onTouch(v: View?, event: MotionEvent?): Boolean {
return gestureDetector?.onTouchEvent(event)!!;
}
inner class GestureListener: GestureDetector.OnGestureListener{
private val SWIPE_THRESHOLD = 100
private val SWIPE_VELOCITY_THRESHOLD = 100
override fun onShowPress(e: MotionEvent?) {
}
override fun onSingleTapUp(e: MotionEvent?): Boolean {
//onSingleTapUp(e)
return true;
}
override fun onDown(e: MotionEvent?): Boolean {
return true;
}
override fun onFling(e1: MotionEvent?, e2: MotionEvent?, velocityX: Float, velocityY: Float): Boolean {
try {
val diffY = e2?.getY()!! - e1?.getY()!!
val diffX = e2.getX() - e1.getX()
if (Math.abs(diffX) > Math.abs(diffY)) {
if (Math.abs(diffX) > SWIPE_THRESHOLD && Math.abs(velocityX) > SWIPE_VELOCITY_THRESHOLD) {
if (diffX > 0) {
onSwipeRight()
} else {
onSwipeLeft()
}
}
} else {
if (Math.abs(diffY) > SWIPE_THRESHOLD && Math.abs(velocityY) > SWIPE_VELOCITY_THRESHOLD) {
if (diffY > 0) {
onSwipeDown()
} else {
onSwipeUp()
}
}
}
} catch (exception: Exception) {
exception.printStackTrace()
}
return false
}
override fun onScroll(e1: MotionEvent?, e2: MotionEvent?, distanceX: Float, distanceY: Float): Boolean {
return true;
}
override fun onLongPress(e: MotionEvent?) {
}
}
abstract fun onSwipeRight();
abstract fun onSwipeLeft();
private fun onSwipeUp() {}
private fun onSwipeDown() {}
private fun onClick() {}
private fun onDoubleClick() {}
private fun onLongClick() {}
}
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Step 4: Update Activity file with below code
package com.rrtutors.androidsamples.guestures
import androidx.appcompat.app.AppCompatActivity
import android.os.Bundle
import android.widget.Toast
import com.rrtutors.androidsamples.MainActivity
import com.rrtutors.androidsamples.R
import kotlinx.android.synthetic.main.activity_guesture.*
class GuestureActivity : AppCompatActivity() {
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_guesture)
relativeLayout.setOnTouchListener(object : OnSwipeTouchListener(this@GuestureActivity){
override fun onSwipeRight() {
Toast.makeText(this@GuestureActivity, "Swipe Right gesture detected", Toast.LENGTH_SHORT).show();
}
override fun onSwipeLeft() {
Toast.makeText(this@GuestureActivity, "Swipe Left gesture detected", Toast.LENGTH_SHORT).show();
}
})
}
}
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Step 5: Let's run application
