Zoom image in android

package com.example.testproject;
import com.example.testproject.R;

import android.annotation.SuppressLint;
import android.app.Activity;
import android.graphics.PointF;
import android.os.Bundle;
import android.util.FloatMath;
import android.util.Log;
import android.view.MotionEvent;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.View.OnTouchListener;
import android.widget.Button;
import android.widget.LinearLayout;

@SuppressLint("NewApi")
public class PinchZoom extends Activity {
 View mainView = null;

 // Remember some things for zooming
 PointF start = new PointF();
 PointF mid = new PointF();

 float oldDist = 1f;
 PointF oldDistPoint = new PointF();

 public static String TAG = "ZOOM";

 static final int NONE = 0;
 static final int DRAG = 1;
 static final int ZOOM = 2;
 int mode = NONE;

 @Override
 public void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  setContentView(R.layout.zoom );
  mainView = (LinearLayout) findViewById(R.id.lytMain);

  Button buttonZoomOut = (Button) findViewById(R.id.btnZoomOut);
  Button buttonNormal = (Button) findViewById(R.id.btnZoom);
  Button buttonZoomIn = (Button) findViewById(R.id.btnZoomIn);

  buttonZoomOut.setOnClickListener(new OnClickListener() {
   @Override
   public void onClick(View v) {
    zoom(0.5f, 0.5f, new PointF(0, 0));
   }
  });
  buttonNormal.setOnClickListener(new OnClickListener() {
   @Override
   public void onClick(View v) {
    zoom(1f, 1f, new PointF(0, 0));
   }
  });
  buttonZoomIn.setOnClickListener(new OnClickListener() {
   @Override
   public void onClick(View v) {
    zoom(2f, 2f, new PointF(0, 0));
   }
  });

  mainView.setOnTouchListener(new OnTouchListener() {
   @Override
   public boolean onTouch(View v, MotionEvent event) {
    Log.d(TAG, "mode=DRAG");
    switch (event.getAction() & MotionEvent.ACTION_MASK) {
    case MotionEvent.ACTION_DOWN:
     start.set(event.getX(), event.getY());
     Log.d(TAG, "mode=DRAG");
     mode = DRAG;

     break;
    case MotionEvent.ACTION_POINTER_DOWN:
     oldDist = spacing(event);
     oldDistPoint = spacingPoint(event);
     Log.d(TAG, "oldDist=" + oldDist);
     if (oldDist > 10f) {
      midPoint(mid, event);
      mode = ZOOM;
      Log.d(TAG, "mode=ZOOM");
     }
     System.out.println("current time :" + System.currentTimeMillis());
     break;// return !gestureDetector.onTouchEvent(event);
    case MotionEvent.ACTION_UP:
    case MotionEvent.ACTION_POINTER_UP:
     Log.d(TAG, "mode=NONE");
     mode = NONE;
     break;
    case MotionEvent.ACTION_MOVE:
     if (mode == DRAG) {

     } else if (mode == ZOOM) {
      PointF newDist = spacingPoint(event);
      float newD = spacing(event);
      Log.e(TAG, "newDist=" + newDist);
      float[] old = new float[9];
      float[] newm = new float[9];
      Log.e(TAG, "x=" + old[0] + ":&:" + old[2]);
      Log.e(TAG, "y=" + old[4] + ":&:" + old[5]);
      float scale = newD / oldDist;
      float scalex = newDist.x / oldDistPoint.x;
      float scaley = newDist.y / oldDistPoint.y;
      zoom(scale, scale, start);
     }
     break;
    }
    return true;
   }
  });
 }

 /**
  * zooming is done from here
  */
 @SuppressLint("NewApi")
public void zoom(Float scaleX, Float scaleY, PointF pivot) {
  mainView.setPivotX(pivot.x);
  mainView.setPivotY(pivot.y);
  mainView.setScaleX(scaleX);
  mainView.setScaleY(scaleY);
 }

 /**
  * space between the first two fingers
  */
 private float spacing(MotionEvent event) {
  // ...
  float x = event.getX(0) - event.getX(1);
  float y = event.getY(0) - event.getY(1);
  return FloatMath.sqrt(x * x + y * y);
 }

 private PointF spacingPoint(MotionEvent event) {
  PointF f = new PointF();
  f.x = event.getX(0) - event.getX(1);
  f.y = event.getY(0) - event.getY(1);
  return f;
 }

 /**
  * the mid point of the first two fingers
  */
 private void midPoint(PointF point, MotionEvent event) {
  // ...
  float x = event.getX(0) + event.getX(1);
  float y = event.getY(0) + event.getY(1);
  point.set(x / 2, y / 2);
 }
}

Other Links
========
http://stackoverflow.com/questions/13398288/image-zoom-issue-with-universal-image-loader-and-view-pager