android - Whenever I try to rotate imageview, it only rotates on axis -

so have been attempting create program can drag, zoom , rotate photo. big problem seem running whenever try rotate photo, rotates along corner, rather around center. means try rotate image, leaves fingers.

another big problem have every time touch 2 fingers, image resets being upright, instead of angle held when touched it.

@override protected void ondraw(canvas canvas) {       canvas.save();     //if(mode==drag)     canvas.translate(mposx, mposy);     if (myscale.isinprogress()) {         canvas.scale(mscalefactor, mscalefactor, myscale.getfocusx(), myscale.getfocusy());     }     else{         canvas.scale(mscalefactor, mscalefactor, mlastgesturex, mlastgesturey);     }      if (myscale.isinprogress()) {         canvas.rotate(degrees, myscale.getfocusx(), myscale.getfocusy());     }     else{         canvas.rotate(degrees, mlastgesturex, mlastgesturey);     }     //canvas.setmatrix(matrix);     //setimagematrix(matrix);     super.ondraw(canvas);     canvas.restore();     //canvas.drawbitmap(,matrix,new paint()); }              @override public boolean ontouchevent(motionevent event) {     super.ontouchevent(event);     if(event.getpointercount()>1){          myscale.ontouchevent(event);     }     switch (event.getaction() & motionevent.action_mask){             case motionevent.action_down: {                 savedmatrix.set(matrix);                  final float x = event.getx();                 final float y = event.gety();                 mode=drag;                 // remember started                 mlasttouchx = x;                 mlasttouchy = y;                 mactivepointerid = event.getpointerid(0);                 lastevent = null;                 break;             }         case motionevent.action_pointer_down: {             olddist = spacing(event);             //savedmatrix.set(matrix);             //midpoint(mid, event);             log.d("touchresponse: ", "mode=zoom");             final float gx = myscale.getfocusx();             final float gy = myscale.getfocusy();             mlastgesturex=gx;             mlastgesturey=gy;             mode=zoom;             lastevent = new float[4];             lastevent[0] = event.getx(0);             lastevent[1] = event.getx(1);             lastevent[2] = event.gety(0);             lastevent[3] = event.gety(1);             d = rotation(event);             break;         }               case motionevent.action_move: {                 final int pointerindex = event.findpointerindex(mactivepointerid);                 final float x = event.getx(pointerindex);                 final float y = event.gety(pointerindex);                   // calculate distance moved              if(!myscale.isinprogress()&&mode==drag){                     // move object                 float dx = x-mlasttouchx;                 float dy = y-mlasttouchy;                     mposx+=dx;                      mposy+=dy;                       // remember touch position next move event                       // invalidate request redraw                     invalidate();              }                 mlasttouchx = x;                 mlasttouchy = y;                 if(event.getpointercount()==2){                     if (lastevent!=null){                     newrot=rotation(event);                     degrees = newrot-d;                      }                  }                 invalidate();                 break;              }          case motionevent.action_up: {          }           case motionevent.action_pointer_up: {             // extract index of pointer left touch sensor\             mode=none;             mode = none;             lastevent = null;             final int pointerindex = (event.getaction() & motionevent.action_pointer_index_mask)                     >> motionevent.action_pointer_index_shift;             final int pointerid = event.getpointerid(pointerindex);             if (pointerid == mactivepointerid) {                 // our active pointer going up. choose new                 // active pointer , adjust accordingly.                 final int newpointerindex = pointerindex == 0 ? 1 : 0;                 mlasttouchx = event.getx(newpointerindex);                 mlasttouchy = event.gety(newpointerindex);                 mactivepointerid = event.getpointerid(newpointerindex);             }             invalidate();              break;         }          }      return true; }                 //this method ripped tutoriaql 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 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); }  private class scalelistener extends scalegesturedetector.simpleonscalegesturelistener {     @override     public boolean onscale(scalegesturedetector detector) {          mscalefactor *= detector.getscalefactor();          // don't let object small or large.         mscalefactor = math.max(0.1f, math.min(mscalefactor, 10.0f));           //matrix=temp;          invalidate();         return true;     } }  private float rotation(motionevent event) {     double delta_x = (event.getx(0) - event.getx(1));     double delta_y = (event.gety(0) - event.gety(1));     double radians = math.atan2(delta_y, delta_x);     //if (constant.trace) log.d("rotation ~~~~~~~~~~~~~~~~~", delta_x+" ## "+delta_y+" ## "+radians+" ## "     //        +math.todegrees(radians));     log.d("rotation ~~~~~~~~~~~~~~~~~", delta_x+" ## "+delta_y+" ## "+radians+" ## "             +math.todegrees(radians));     return (float) math.todegrees(radians); } 

if want rotate around center, need translate center first. set new origin center of image, , rotate rotates around origin.