How to handle right-to-left and left-to-right swipe gestures on Android?

AndroidApps/ApplicationsMobile Development

This example demonstrates how do I handle right to left and left to right swipe gestures on android.

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.

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout 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: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="16sp"
      android:textStyle="bold"
      android:text="Swipe Left to right and Right to Left to detect Swipe Gesture"/>
</RelativeLayout>

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

import androidx.appcompat.app.AppCompatActivity;
import android.os.Bundle;
import android.widget.RelativeLayout;
import android.widget.Toast;
public class MainActivity extends AppCompatActivity {
   RelativeLayout layout;
   @Override
   protected void onCreate(Bundle savedInstanceState) {
      super.onCreate(savedInstanceState);
      setContentView(R.layout.activity_main);
      layout = findViewById(R.id.relativeLayout);
      layout.setOnTouchListener(new OnSwipeTouchListener(MainActivity.this) {
         @Override
         public void onSwipeLeft() {
            super.onSwipeLeft();
            Toast.makeText(MainActivity.this, "Swipe Left gesture detected", Toast.LENGTH_SHORT).show();
         }
         @Override
         public void onSwipeRight() {
            super.onSwipeRight();
            Toast.makeText(MainActivity.this, "Swipe Right gesture detected", Toast.LENGTH_SHORT).show();
         }
      });
   }
}

Step 4 − Create a java class (OnSwipeTouchListener.java) and add the following code −

import android.content.Context;
import android.view.GestureDetector;
import android.view.MotionEvent;
import android.view.View;
class OnSwipeTouchListener implements View.OnTouchListener {
   private GestureDetector gestureDetector;
   OnSwipeTouchListener(Context c) {
      gestureDetector = new GestureDetector(c, new GestureListener());
   }
   public boolean onTouch(final View view, final MotionEvent motionEvent) {
      return gestureDetector.onTouchEvent(motionEvent);
   }
   private final class GestureListener extends
   GestureDetector.SimpleOnGestureListener {
      private static final int SWIPE_THRESHOLD = 100;
      private static final int SWIPE_VELOCITY_THRESHOLD = 100;
      @Override
      public boolean onDown(MotionEvent e) {
         return true;
      }
      @Override
      public boolean onSingleTapUp(MotionEvent e) {
         onClick();
         return super.onSingleTapUp(e);
      }
      @Override
      public boolean onDoubleTap(MotionEvent e) {
         onDoubleClick();
         return super.onDoubleTap(e);
      }
      @Override
      public void onLongPress(MotionEvent e) {
         onLongClick();
         super.onLongPress(e);
      }
      @Override
      public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX, float velocityY) {
         try {
            float diffY = e2.getY() - e1.getY();
            float 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;
      }
   }
   public void onSwipeRight() {
   }
   public void onSwipeLeft() {
   }
   private void onSwipeUp() {
   }
   private void onSwipeDown() {
   }
   private void onClick() {
   }
   private void onDoubleClick() {
   }
   private void onLongClick() {
   }
}

Step 5 − Add the following code to androidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android" package="app.com.sample">
   <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 the android studio, open one of your project's activity files and click Run  icon from the toolbar. Select your mobile device as an option and then check your mobile device which will display your default screen −

Click here to download the project code.

raja
Azhar
Published on 26-Nov-2019 06:33:52
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