title: Android ImageView zoom, rotate, position change prob
body: <p>I am using a the following code for a image, which will rotate, zoom in-out with pinch. User can make its position by dragging it. </p>
  
  <p><strong>activity_img_match.xml</strong></p>
  
  <pre><code>&lt;FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
      xmlns:tools="http://schemas.android.com/tools"
          android:layout_width="match_parent"
          android:layout_height="match_parent"
          android:layout_weight="1"
          android:background="@drawable/brokenbone"
          android:gravity="center_vertical|center_horizontal" &gt;
  
          &lt;ImageView
              android:id="@+id/bonestruct"
              android:layout_width="fill_parent"
              android:layout_height="fill_parent"
              android:scaleType="matrix"
              android:src="@drawable/bone" /&gt;
      &lt;/FrameLayout&gt;
  </code></pre>
  
  <p><strong>ImgMatchActivity.java</strong></p>
  
  <pre><code>    public class ImgMatchActivity extends Activity implements OnTouchListener {
  
      private static final String TAG = "Touch";
      // These matrices will be used to move and zoom image
      Matrix matrix = new Matrix();
      Matrix savedMatrix = new Matrix();
      Matrix savedMatrix2 = new Matrix();
  
      // We can be in one of these 3 states
      static final int NONE = 0;
      static final int DRAG = 1;
      static final int ZOOM = 2;
      private static final float MAX_ZOOM = 5.0f;
      private static final float MIN_ZOOM = 0.15f;
      int mode = NONE;
  
      // Remember some things for zooming
      PointF start = new PointF();
      PointF mid = new PointF();
      float oldDist = 1f;
  
      @Override
      public void onCreate(Bundle savedInstanceState) {
          super.onCreate(savedInstanceState);
          setContentView(R.layout.activity_img_match);
  
          ImageView bonestruct = (ImageView) findViewById(R.id.bonestruct);
          bonestruct.setOnTouchListener(this);
  
      }
  
      @Override
      public boolean onCreateOptionsMenu(Menu menu) {
          // Inflate the menu; this adds items to the action bar if it is present.
          getMenuInflater().inflate(R.menu.activity_img_match, menu);
          return true;
      }
  
      public boolean onTouch(View selectedView, MotionEvent event) {
          // TODO Auto-generated method stub
          ImageView view = (ImageView) selectedView;
          int rotation = 25;
          // Dump touch event to log
          dumpEvent(event);
  
          // Handle touch events here...
          switch (event.getAction() &amp; MotionEvent.ACTION_MASK) {
          case MotionEvent.ACTION_DOWN:
              savedMatrix.set(matrix);
              start.set(event.getX(), event.getY());
              Log.d(TAG, "mode=DRAG");
              mode = DRAG;
              break;
  
          case MotionEvent.ACTION_POINTER_DOWN:
              oldDist = spacing(event);
              Log.d(TAG, "oldDist=" + oldDist);
              if (oldDist &gt; 10f) {
                  savedMatrix.set(matrix);
                  midPoint(mid, event);
                  mode = ZOOM;
                  Log.d(TAG, "mode=ZOOM");
              }
              break;
  
          case MotionEvent.ACTION_UP:
  
              mode = NONE;
              Log.d(TAG, "mode=NONE");
              savedMatrix.set(matrix);
              //matrix.postRotate(90);
  
              break;
  
          case MotionEvent.ACTION_MOVE:
              if (mode == DRAG) {
                  // ...
                  matrix.set(savedMatrix);
                  matrix.postTranslate(event.getX() - start.x, event.getY()
                          - start.y);
              } else if (mode == ZOOM) {
                  float newDist = spacing(event);
                  Log.d(TAG, "newDist=" + newDist);
                  if (newDist &gt; 10f) {
                      matrix.set(savedMatrix);
                      float scale = newDist / oldDist;
                      matrix.postScale(scale, scale, mid.x, mid.y);
                  }
              }
              break;
          }
  
          view.setImageMatrix(matrix);
          fixing();
          view.setImageMatrix(savedMatrix2);
  
          return true; // indicate event was handled
  
      }
  
      public void fixing() {
  
          float[] value = new float[9];
          matrix.getValues(value);
  
          float[] savedValue = new float[9];
          savedMatrix.getValues(savedValue);
  
          WindowManager mWinMgr = (WindowManager) getApplicationContext().getSystemService(Context.WINDOW_SERVICE);
          int width = mWinMgr.getDefaultDisplay().getWidth();
          int height = mWinMgr.getDefaultDisplay().getHeight();
  
          Drawable d = this.getResources().getDrawable(R.drawable.bone);
          if (d == null)
              return;
          int imageWidth = d.getIntrinsicWidth();
          int imageHeight = d.getIntrinsicHeight();
          int scaleWidth = (int) (imageWidth * value[0]);
          int scaleHeight = (int) (imageHeight * value[4]);
  
          // don't let the image go outside
          if (value[2] &gt; width - 1)
              value[2] = width - 10;
          else if (value[5] &gt; height - 1)
              value[5] = height - 10;
          else if (value[2] &lt; -(scaleWidth - 1))
              value[2] = -(scaleWidth - 10);
          else if (value[5] &lt; -(scaleHeight - 1))
              value[5] = -(scaleHeight - 10);
  
          //Log.d("value[0]", "value[0]: "+value[0]);
          //Log.d("value[4]", "value[4]: "+value[4]);
  
          // maximum zoom ratio: MAX
          if (value[0] &gt; MAX_ZOOM || value[4] &gt; MAX_ZOOM) {
              value[0] = MAX_ZOOM;
              value[4] = MAX_ZOOM;
              // value[2] = savedValue[2];
              // value[5] = savedValue[5];
          }
  
          // minimum zoom ratio: MIN
          /*if (value[0] &lt; MIN_ZOOM || value[4] &lt; MIN_ZOOM) {
              value[0] = MIN_ZOOM;
              value[4] = MIN_ZOOM;
              // value[2] = savedValue[2];
              // value[5] = savedValue[5];
          }*/
  
          matrix.setValues(value);
          savedMatrix2.set(matrix);
      }
  
      /** Show an event in the LogCat view, for debugging */
      private void dumpEvent(MotionEvent event) {
          String names[] = { "DOWN", "UP", "MOVE", "CANCEL", "OUTSIDE",
                  "POINTER_DOWN", "POINTER_UP", "7?", "8?", "9?" };
          StringBuilder sb = new StringBuilder();
          int action = event.getAction();
          int actionCode = action &amp; MotionEvent.ACTION_MASK;
          sb.append("event ACTION_").append(names[actionCode]);
          if (actionCode == MotionEvent.ACTION_POINTER_DOWN
                  || actionCode == MotionEvent.ACTION_POINTER_UP) {
              sb.append("(pid ").append(
                      action &gt;&gt; MotionEvent.ACTION_POINTER_ID_SHIFT);
              sb.append(")");
          }
          sb.append("[");
          for (int i = 0; i &lt; event.getPointerCount(); i++) {
              sb.append("#").append(i);
              sb.append("(pid ").append(event.getPointerId(i));
              sb.append(")=").append((int) event.getX(i));
              sb.append(",").append((int) event.getY(i));
              if (i + 1 &lt; event.getPointerCount())
                  sb.append(";");
          }
          sb.append("]");
          Log.d(TAG, sb.toString());
      }
  
      /** Determine the 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);
      }
  
      /** 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);
      }
  
  }
  </code></pre>
  
  <p>Now I can drag the image, zoom it-out by pinch action. But there is no rotation at all. How to get the rotation action and get rotation angle? </p>