How to detect single touch as well as multi-touch

Question

I used the following code to detect the single finger touch and double finger touch. The code detects the double finger touch (when count==2).

I need to do some action on single touch also. If I touch the screen with one finger it doesn't go for the else part. What have I done wrong in this code?

@Override
public boolean onTouchEvent(MotionEvent event) {
    int action = event.getAction() & MotionEvent.ACTION_MASK;
    switch (action) {
        case MotionEvent.ACTION_POINTER_UP: {
            int count = event.getPointerCount();
            Log.v("count >>", count + "");
            if (count == 2) {
                // some action
            } else {
                Log.v("count not equal to 2", "not 2");
            }
            break;
        }
    }
    return true;
}

Update:

I used this code inside an Activity. I need to detect single touch, multitouch.

In my activity, I have two images, one on the left and one on the right. If I click the image some process has to do. If I use two fingers, I need to re-size the images, according to the scale-factor.

This is the code that I've used:

Updated:

package com.pinch.detect;

import java.io.BufferedInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.MalformedURLException;
import java.net.URL;
import java.net.URLConnection;

import android.app.Activity;
import android.content.Context;
import android.content.ContextWrapper;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.os.Bundle;
import android.util.FloatMath;
import android.util.Log;
import android.view.Display;
import android.view.MotionEvent;
import android.view.ScaleGestureDetector;
import android.view.View;
import android.view.ScaleGestureDetector.SimpleOnScaleGestureListener;
import android.view.View.OnClickListener;
import android.view.View.OnTouchListener;
import android.widget.ImageView;
import android.widget.TextView;
import android.widget.Toast;

public class PinchDetectorActivity extends Activity {
    TextView textGestureAction;
    ImageView img1, img2;
    static Bitmap bm, bm1;

    boolean multiTouch = false;
    Context context;
    float scaleFactor = 0.0f;
    float lastscale;
    int scr_width, scr_height;
    Display display;
    private ScaleGestureDetector scaleGestureDetector;

    /** Called when the activity is first created. */

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        textGestureAction = (TextView) findViewById(R.id.GestureAction);
        img1 = (ImageView) findViewById(R.id.img_left);
        img2 = (ImageView) findViewById(R.id.img_right);
        display = getWindowManager().getDefaultDisplay();

        scr_width = display.getWidth();
        scr_height = display.getHeight();
        Log.v("width >>", Integer.toString(scr_width));
        Log.v("height >>", Integer.toString(scr_height));

        bm = BitmapFactory.decodeResource(this.getResources(),
                R.drawable.fiction1);
        img1.setImageBitmap(bm);
        bm1 = BitmapFactory.decodeResource(this.getResources(),
                R.drawable.fiction2);
        img2.setImageBitmap(bm1);
        img1.setScaleType(ImageView.ScaleType.FIT_START);
        img2.setScaleType(ImageView.ScaleType.FIT_END);

        scaleGestureDetector = new ScaleGestureDetector(this,
                new MySimpleOnScaleGestureListener());



        img1.setOnTouchListener(new OnTouchListener(){

            @Override
            public boolean onTouch(View v, MotionEvent event) {
                // TODO Auto-generated method stub
                return false;
            }

        });
    }

    @Override
    public boolean onTouchEvent(MotionEvent event) {

        scaleGestureDetector.onTouchEvent(event);
        int index = event.getActionIndex();
        Log.v("Index value ",index+"");
        int action = event.getAction();

        if (index == 1) {
            multiTouch = true;
            System.out.println("mutli1");
        } else if (multiTouch == false) {
            System.out.println("single1");
            img1.setOnClickListener(new OnClickListener() {

                @Override
                public void onClick(View v) {
                    Log.v("clicked image1","img1>>>");
                }
            });
            img2.setOnClickListener(new OnClickListener() {

                @Override
                public void onClick(View v) { // TODO Auto-generated method
                    Log.v("clicked image2","img2>>>");
                }
            });
        }

         else if (action == MotionEvent.ACTION_MOVE && multiTouch) {
            System.out.println("mutli2");


            if (scaleFactor > 1) {

                Bitmap resizedbitmap = Bitmap.createScaledBitmap(bm,
                        scr_width / 2, scr_height, true);
                img1.setImageBitmap(resizedbitmap);
                Bitmap resizedbitmap1 = Bitmap.createScaledBitmap(bm1,
                        scr_width / 2, scr_height, true);
                img2.setImageBitmap(resizedbitmap1);
                Log.v("width >>", Integer.toString(scr_width));
                Log.v("height >>", Integer.toString(scr_height));

            } else if(scaleFactor<1){

                Log.v("width >>", Integer.toString(scr_width));
                Log.v("height >>", Integer.toString(scr_height));
                if (scr_width >= 640) {
                    Bitmap resizedbitmap = Bitmap.createScaledBitmap(bm,
                            scr_height + 90, scr_height, true);

                    img1.setImageBitmap(resizedbitmap);

                    Bitmap resizedbitmap1 = Bitmap.createScaledBitmap(bm1,
                            scr_height + 90, scr_height, true);

                    img2.setImageBitmap(resizedbitmap1);
                } else {
                    Bitmap resizedbitmap = Bitmap.createScaledBitmap(bm,
                            scr_height, scr_height + 30, true);

                    img1.setImageBitmap(resizedbitmap);

                    Bitmap resizedbitmap1 = Bitmap.createScaledBitmap(bm1,
                            scr_height, scr_height + 30, true);

                    img2.setImageBitmap(resizedbitmap1);
                }

            }



        } else if (action == MotionEvent.ACTION_MOVE && !multiTouch)
        {
            System.out.println("single2");
        }

        return super.onTouchEvent(event);

    }

    public class MySimpleOnScaleGestureListener extends
            SimpleOnScaleGestureListener {

        @Override
        public boolean onScale(ScaleGestureDetector detector) {
            // TODO Auto-generated method stub

            scaleFactor = detector.getScaleFactor();

            Log.v("scaleFactor >>>", scaleFactor + "");

            return true;
        }
    }

}

and my main.xml is

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:orientation="vertical"
    android:id="@+id/pinchlay" >


    <ImageView
        android:id="@+id/img_left"
        android:layout_width="320dp"
        android:layout_height="fill_parent"
        />

    <ImageView
        android:id="@+id/img_right"
        android:layout_width="320dp"
        android:layout_height="fill_parent"
        android:layout_alignParentRight="true"
        />

</RelativeLayout>

Answer 1

I cannot reproduce count==2 for single touch. It is 1 for me for single touch. Try debug your code on real device and see what you actually have.

Use event.getPointerId(i) along with event.getPointerCount() and see what these actual points of touch are.