super.dispatchTouchEvent(ev) return action cancel

Question

I want to add customer signature to my app and I used https://github.com/CoatedMoose/CustomViews/blob/master/library/src/com/coatedmoose/customviews/SignatureView.java and put it in my application and I used this method to pass event to signature View using this method

public boolean dispatchTouchEvent(MotionEvent ev) {
        super.dispatchTouchEvent(ev);
            return agreement_control.SignatureView.onTouchEvent(ev);
    }

but super.dispatchTouchEvent(ev); return Action cancel in ev

How can I avoid that ?

Note : when I touch signature View from the left upper corner and move my hand slowly to down I got the followings events

MotionEvent { action=ACTION_DOWN, id[0]=0, x[0]=15.0, y[0]=34.0, toolType[0]=TOOL_TYPE_FINGER, buttonState=0, metaState=0, flags=0x0, edgeFlags=0x0, pointerCount=1, historySize=0, eventTime=253599066, downTime=253599066, deviceId=2, source=0x1002 }

MotionEvent { action=ACTION_CANCEL, id[0]=0, x[0]=56.0, y[0]=834.0, toolType[0]=TOOL_TYPE_FINGER, buttonState=0, metaState=0, flags=0x0, edgeFlags=0x0, pointerCount=1, historySize=0, eventTime=253609229, downTime=253599066, deviceId=2, source=0x1002 }

I surprised why I got very large value of y