Question

I have an activity with a layout contains an ImageView and TextView. ImageView TextvVew are for showing the image and the name of the person respectively. I need to swap from right to left and the other way around with respect to users finger gesture. Same time, the name and the image must be changed accordingly.
Is there a way to implement this? It would be great if anyone would be able to let me know a tutorial written on this as I’m new to Android development.

Thank you.

I tried following ways but it does not detect any gesture.

MyGroupActivity.java

import goldenOld.pkg.R;
import android.app.Activity;
import android.os.Bundle;
import android.view.GestureDetector.OnGestureListener;
import android.view.GestureDetector.SimpleOnGestureListener;
import android.view.MotionEvent;
import android.widget.Toast;

public class MyGroupActivity extends Activity implements OnGestureListener{

private static final int SWIPE_MIN_DISTANCE = 120;
private static final int SWIPE_MAX_OFF_PATH = 250;
private static final int SWIPE_THRESHOLD_VELOCITY = 200;

/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);  
    setContentView(R.layout.tab_mygroup);
}

public boolean onDown(MotionEvent arg0) {
    // TODO Auto-generated method stub
    return false;
}

public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX,
        float velocityY) {
    Toast mToast2 =  Toast.makeText(getApplicationContext(), "Fling", Toast.LENGTH_SHORT);
    mToast2.show();
    try {
        if (Math.abs(e1.getY() - e2.getY()) > SWIPE_MAX_OFF_PATH)
            return false;
        // right to left swipe
        if(e1.getX() - e2.getX() > SWIPE_MIN_DISTANCE && Math.abs(velocityX) > SWIPE_THRESHOLD_VELOCITY) {
            Toast.makeText(getApplicationContext(), "Left Swipe", Toast.LENGTH_SHORT).show();
        }  else if (e2.getX() - e1.getX() > SWIPE_MIN_DISTANCE && Math.abs(velocityX) > SWIPE_THRESHOLD_VELOCITY) {
            Toast.makeText(getApplicationContext(), "Right Swipe", Toast.LENGTH_SHORT).show();
        }
        else if(e1.getY() - e2.getY() > SWIPE_MIN_DISTANCE && Math.abs(velocityX) > SWIPE_THRESHOLD_VELOCITY) {
            Toast.makeText(getApplicationContext(), "Swipe up", Toast.LENGTH_SHORT).show();
        }  else if (e2.getY() - e1.getY() > SWIPE_MIN_DISTANCE && Math.abs(velocityX) > SWIPE_THRESHOLD_VELOCITY) {
            Toast.makeText(getApplicationContext(), "Swipe down", Toast.LENGTH_SHORT).show();
        }
    } catch (Exception e) {
        // nothing
        Toast mToast =  Toast.makeText(getApplicationContext(), "Exception", Toast.LENGTH_SHORT);
        mToast.show();
    }

    return true;

}

public void onLongPress(MotionEvent arg0) {
    Toast mToast =  Toast.makeText(getApplicationContext(), "Long Press", Toast.LENGTH_SHORT);
    mToast.show();
}

public boolean onScroll(MotionEvent arg0, MotionEvent arg1, float arg2,
        float arg3) {
    // TODO Auto-generated method stub
    return false;
}

public void onShowPress(MotionEvent arg0) {
    // TODO Auto-generated method stub

}

public boolean onSingleTapUp(MotionEvent arg0) {
    Toast mToast =  Toast.makeText(getApplicationContext(), "Single Tap", Toast.LENGTH_SHORT);
    mToast.show();
    return true;
}

public class MyGestureDetector extends SimpleOnGestureListener {

    private static final int SWIPE_MIN_DISTANCE = 120;
    private static final int SWIPE_MAX_OFF_PATH = 250;
    private static final int SWIPE_THRESHOLD_VELOCITY = 200;
    @Override
    public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX, float velocityY) {
        Toast mToast =  Toast.makeText(getApplicationContext(), "Fling", Toast.LENGTH_SHORT);
        mToast.show();
        try {
            if (Math.abs(e1.getY() - e2.getY()) > SWIPE_MAX_OFF_PATH)
                return false;

            if(e1.getX() - e2.getX() > SWIPE_MIN_DISTANCE && Math.abs(velocityX) > SWIPE_THRESHOLD_VELOCITY) {
                //do what you want on left swipe
            }  else if (e2.getX() - e1.getX() > SWIPE_MIN_DISTANCE && Math.abs(velocityX) > SWIPE_THRESHOLD_VELOCITY) {
                //do what you want on right swipe
            }
        } catch (Exception e) {
            // nothing
        }
        return false;
    }

    public boolean onSingleTapUp(MotionEvent arg0) {
        Toast mToast =  Toast.makeText(getApplicationContext(), "Single Tap", Toast.LENGTH_SHORT);
        mToast.show();
        return true;
    }

}

}

Answer 1

You will have to use gesture detector for your purpose. See the following examples:

• http://www.ceveni.com/2009/08/android-gestures-detection-sample-code.html
• http://www.vogella.de/articles/AndroidGestures/article.html
• http://www.hascode.com/2010/05/creating-a-simple-gesture-app-with-android/

Also note that onFling() is the callback method which will be called when your activity detects any gesture. So here only you will have to write your logic of detecting which direction user is swiping.