OrientationEventListener on Android to get current rotation degree
Strangely, it's not possible to get current rotation angle in android directly, except for getting the fixed 4 rotation modes: 0, 90, 180, 270. In order to get precise rotation degrees instead of rotation modes, OrientationEventListener can be used. Once it's implemented, you can get the rotation degree in onOrientationChanged(). It's a lot easier than manipulating values from all the sensors like gyroscope, accelerator, etc.