title: drag, zoom imageview without matrix android
body: <p>i need a solution for implement drag and zoom , routate ImageView around screen onTouch event without using matrix.
  i searched a lot but all answers done it with matrix and because i have multi objects in screen matrix is not suitable for me, i want drag and zoom ImageView object not matrix in the ImageView, after some try i implement a class that drag view fine but in zoom it disturb, thanks if someone can help me and sorry for bad language skills and if i have misspelling.</p>
  
  <pre><code>package com.example.painting1;
  
  import android.graphics.PointF;
  import android.util.FloatMath;
  import android.view.MotionEvent;
  import android.view.View;
  import android.view.View.OnTouchListener;
  import android.widget.ImageView;
  
  public class Drag implements OnTouchListener {
  
      ImageView img;
  
      // We can be in one of these 3 states
      private static final int NONE = 0;
      private static final int DRAG = 1;
      private static final int ZOOM = 2;
  
      private int mode = NONE;
  
      private PointF mid = new PointF();
  
      PointF DownPT = new PointF(); // Record Mouse Position When Pressed Down
      PointF StartPT = new PointF(); // Record Start Position of 'img'
  
      float oldDist = 1f;
  
      public Drag( ImageView img ) {
          // TODO Auto-generated constructor stub
          this.img = img;
          img.setOnTouchListener(this);
      }
  
          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);
          }
  
          /**
           * Calculate 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);
          }
  
          @Override
              public boolean onTouch(View v, MotionEvent event)
              {
                  int evid = event.getAction();
                  int moid = MotionEvent.ACTION_MASK;
  
                  switch (evid &amp; moid)
                  {
                      case MotionEvent.ACTION_MOVE :
  
                         if (mode == DRAG) {                      
                                  PointF mv = new PointF( event.getX() - DownPT.x, event.getY() - DownPT.y);
                                  img.setX((int)(StartPT.x+mv.x));
                                  img.setY((int)(StartPT.y+mv.y));
                                  StartPT = new PointF( img.getX(), img.getY() );
                          }
  
                           else if (mode == ZOOM) {
                                      float newDist = spacing(event);
                                      if (newDist &gt; 10f) {
                                          //matrix.set(savedMatrix);
                                          float scale = (newDist / oldDist);
                                          //matrix.postScale(scale, scale, mid.x, mid.y);
  
                                          img.layout((int)scale, (int)scale, (int)mid.x, (int)mid.y);
  
                                          img.setScaleX(scale);
                                          img.setScaleY(scale);
                                      }
                           }
  
                          break;
  
                      case MotionEvent.ACTION_DOWN :
  
                          mode = DRAG;
  
                          DownPT.x = event.getX();
                          DownPT.y = event.getY();
                          StartPT = new PointF( img.getX(), img.getY() );
                          break;
                      case MotionEvent.ACTION_UP :
                          // Nothing have to do
                      case MotionEvent.ACTION_POINTER_UP :
                              mode = NONE;
                          break;
  
                      case MotionEvent.ACTION_POINTER_DOWN :
  
                          oldDist = spacing(event);
                          if (oldDist &gt; 10f) {
                              //savedMatrix.set(matrix);
                              midPoint(mid, event);
                              mode = ZOOM;
                          }
                          break;
                      default :
                          break;
                  }
                  return true;
          }
  }
  </code></pre>