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androidgesture

Difficulty in implementing gesture controls


I am trying to learn gesture detection in android apps. But apparently, on using onFling method, I am getting nothing in the logcat. I have implemented GestureDetector.OnGestureListener on the main class. I saw the example of gesture detection from here: https://developer.android.com/training/gestures/detector.html#detect

package com.persi.fragmenttester;
import android.content.Intent;
import android.support.v4.view.GestureDetectorCompat;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.GestureDetector;
import android.view.MotionEvent;

public class MainActivity extends AppCompatActivity implements GestureDetector.OnGestureListener,
        GestureDetector.OnDoubleTapListener{

    private GestureDetectorCompat mDetector;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        mDetector=new GestureDetectorCompat(this,this);
        mDetector.setOnDoubleTapListener(this);


    }


    @Override
    public boolean onSingleTapConfirmed(MotionEvent e) {
        return false;
    }

    @Override
    public boolean onDoubleTap(MotionEvent e) {
        Log.d("App",e.toString());
        return true;
    }

    @Override
    public boolean onDoubleTapEvent(MotionEvent e) {
        return false;
    }

    @Override
    public boolean onDown(MotionEvent e) {
        return false;
    }

    @Override
    public void onShowPress(MotionEvent e) {

    }

    @Override
    public boolean onSingleTapUp(MotionEvent e) {
        return false;
    }

    @Override
    public boolean onScroll(MotionEvent e1, MotionEvent e2, float distanceX, float distanceY) {
        return false;
    }

    @Override
    public void onLongPress(MotionEvent e) {
        Log.d("App",e.toString());

    }

    @Override
    public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX, float velocityY) {
        Log.d("App", "onFling: " + e1.toString() + e2.toString());
        return true;

    }
}

Solution

  • You need to override onTouchEvent()

    @Override
    public boolean onTouchEvent(MotionEvent event){
        if (this.mDetector.onTouchEvent(event)) {
            return true;
        }
        return super.onTouchEvent(event);
    }
    

    From the documentation:

    To make it possible for your GestureDetector object to receive events, you override the View or Activity's onTouchEvent() method, and pass along all observed events to the detector instance.