How to detect shake events in Kotlin?

Kotlin Apps/ApplicationsMobile Development

This example demonstrates how to detect shake events in Kotlin.

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 − Add the following code to res/layout/activity_main.xml.

Example

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout 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"
   android:orientation="vertical"
   android:padding="8dp"
   tools:context=".MainActivity">
   <TextView
      android:id="@+id/textView"
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:layout_marginTop="50dp"
      android:padding="8dp"
      android:text="Tutorials Point"
      android:textColor="@color/colorPrimaryDark"
      android:textSize="48sp"
      android:textStyle="bold" />
   <TextView
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:text="Shake the phone to detect to shake event.."
      android:textSize="24sp"
   android:textStyle="bold" />
</LinearLayout>

Step 3 − Add the following code to src/MainActivity.kt

Example

import android.content.Context
import android.hardware.Sensor
import android.hardware.SensorEvent
import android.hardware.SensorEventListener
import android.hardware.SensorManager
import android.os.Bundle
import android.widget.Toast
import androidx.appcompat.app.AppCompatActivity
import java.util.*
import kotlin.math.sqrt
class MainActivity : AppCompatActivity() {
   private var sensorManager: SensorManager? = null
   private var acceleration = 0f
   private var currentAcceleration = 0f
   private var lastAcceleration = 0f
   override fun onCreate(savedInstanceState: Bundle?) {
      super.onCreate(savedInstanceState)
      setContentView(R.layout.activity_main)
      sensorManager = getSystemService(Context.SENSOR_SERVICE) as SensorManager
      Objects.requireNonNull(sensorManager)!!.registerListener(sensorListener, sensorManager!!
      .getDefaultSensor(Sensor.TYPE_ACCELEROMETER), SensorManager.SENSOR_DELAY_NORMAL)
      acceleration = 10f
      currentAcceleration = SensorManager.GRAVITY_EARTH
      lastAcceleration = SensorManager.GRAVITY_EARTH
   }
   private val sensorListener: SensorEventListener = object : SensorEventListener {
      override fun onSensorChanged(event: SensorEvent) {
         val x = event.values[0]
         val y = event.values[1]
         val z = event.values[2]
         lastAcceleration = currentAcceleration
         currentAcceleration = sqrt((x * x + y * y + z * z).toDouble()).toFloat()
         val delta: Float = currentAcceleration - lastAcceleration
         acceleration = acceleration * 0.9f + delta
         if (acceleration > 12) {
            Toast.makeText(applicationContext, "Shake event detected", Toast.LENGTH_SHORT).show()
         }
      }
      override fun onAccuracyChanged(sensor: Sensor, accuracy: Int) {}
   }
   override fun onResume() {
      sensorManager?.registerListener(sensorListener, sensorManager!!.getDefaultSensor(
         Sensor .TYPE_ACCELEROMETER), SensorManager.SENSOR_DELAY_NORMAL
      )
      super.onResume()
   }
   override fun onPause() {
      sensorManager!!.unregisterListener(sensorListener)
      super.onPause()
   }
}

Step 4 − Add the following code to androidManifest.xml

Example

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android" package="app.com.q13">
   <application
      android:allowBackup="true"
      android:icon="@mipmap/ic_launcher"
      android:label="@string/app_name"
      android:roundIcon="@mipmap/ic_launcher_round"
      android:supportsRtl="true"
      android:theme="@style/AppTheme">
      <activity android:name=".MainActivity">
         <intent-filter>
            <action android:name="android.intent.action.MAIN" />
            <category android:name="android.intent.category.LAUNCHER" />
         </intent-filter>
      </activity>
   </application>
</manifest>

Let's try to run your application. I assume you have connected your actual Android Mobile device with your computer. To run the app from android studio, open one of your project's activity files and click the Run icon from the toolbar. Select your mobile device as an option and then check your mobile device which will display your default screen

NOTE: Try this on your own device for the best result.

raja
Published on 23-May-2020 15:17:05
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