android - Issue trying to detect swipe to change views in ViewFlipper -

i'm trying implement swipe detection change views in viewflipper. i've used code shown below, copied there.

while ontouch triggered when touching viewflipper, onfling event never triggered.

anybody can help? what's best way detect swipe?

thanks

public class homeactivity extends activity {         viewflipper viewflipper;      private gesturedetector gesturedetector;      private animation slideleftin, slideleftout, sliderightin, sliderightout;      @override     protected void oncreate(bundle savedinstancestate) {         super.oncreate(savedinstancestate);          setcontentview(r.layout.home);                 linearlayout home = (linearlayout) findviewbyid(r.id.home);          // gesture detection         gesturedetector = new gesturedetector(new mygesturedetector());          // info popup         imageview btn_open_popup = (imageview) findviewbyid(r.id.btn_popup);          slideleftin = animationutils.loadanimation(this, r.anim.slide_left_in);         slideleftout = animationutils.loadanimation(this, r.anim.slide_left_out);         sliderightin = animationutils.loadanimation(this, r.anim.slide_right_in);         sliderightout = animationutils.loadanimation(this, r.anim.slide_right_out);          // compute size according density         float density = getresources().getdisplaymetrics().density;         final int width = (int) (295.0f * density);         final int height = (int) (307.0f * density);                   btn_open_popup.setonclicklistener(new view.onclicklistener() {             public void onclick(view v) {                  layoutinflater inflater = (layoutinflater) homeactivity.this.getsystemservice(context.layout_inflater_service);                  view popup_container = inflater.inflate(r.layout.popup_container,null, false);                  final popupwindow pw = new popupwindow(popup_container, width, height, true);                  pw.showatlocation(findviewbyid(r.id.home), gravity.center, 0,0);                      imageview btn_close_popup = (imageview) popup_container.findviewbyid(r.id.btn_close_popup);                 btn_close_popup.setalpha(120);                  btn_close_popup.setonclicklistener(new view.onclicklistener() {                     public void onclick(view v) {                         pw.dismiss();                     }                 });                  // set swipe listener viewflipper                 viewflipper=(viewflipper)popup_container.findviewbyid(r.id.popup_flipper);                 viewflipper.setontouchlistener(new ontouchlistener() {                      public boolean ontouch(view v, motionevent event) {                         if (gesturedetector.ontouchevent(event)) {                             return true;                         } else {                             return false;                         }                     }                 });             }         });               }          class mygesturedetector extends simpleongesturelistener {          private static final int swipe_min_distance = 120;         private static final int swipe_max_off_path = 250;         private static final int swipe_threshold_velocity = 200;          public boolean onfling(motionevent e1, motionevent e2, float velocityx, float velocityy) {             system.out.println(" in onfling() :: ");             if (math.abs(e1.gety() - e2.gety()) > swipe_max_off_path)                 return false;             if (e1.getx() - e2.getx() > swipe_min_distance                     && math.abs(velocityx) > swipe_threshold_velocity) {                 viewflipper.setinanimation(sliderightin);                 viewflipper.setoutanimation(slideleftout);                 viewflipper.shownext();             } else if (e2.getx() - e1.getx() > swipe_min_distance                     && math.abs(velocityx) > swipe_threshold_velocity) {                 viewflipper.setinanimation(slideleftin);                 viewflipper.setoutanimation(sliderightout);                 viewflipper.showprevious();             }             return super.onfling(e1, e2, velocityx, velocityy);         }     }      }