Qt Sensors - Accel Bubble

Overview
Writing a QML application that uses the Accelerometer QML sensors type requires the following steps:
Import the Sensors Declarative module.
import QtSensors 5.0
Add an Accelerometer QML type.
      Accelerometer {
          id: accel
          dataRate: 100
Use the 'active' property to start the sensor
          active:true
Move the bubble according to a factor of the accelerator sensor
          onReadingChanged: {
              var newX = (bubble.x + calcRoll(accel.reading.x, accel.reading.y, accel.reading.z) * .1)
              var newY = (bubble.y - calcPitch(accel.reading.x, accel.reading.y, accel.reading.z) * .1)
              if (isNaN(newX) || isNaN(newY))
                  return;
              if (newX < 0)
                  newX = 0
              if (newX > mainWindow.width - bubble.width)
                  newX = mainWindow.width - bubble.width
              if (newY < 18)
                  newY = 18
              if (newY > mainWindow.height - bubble.height)
                  newY = mainWindow.height - bubble.height
                  bubble.x = newX
                  bubble.y = newY
          }
Files: