Preview
class PreviewViewMeteringPointFactory(display: Display, cameraInfo: <Error class: unknown class>, resolution: Size?, scaleType: <Error class: unknown class>, viewWidth: Int, viewHeight: Int)
Implement the MeteringPointFactory for PreviewView by DisplayOrientedMeteringPointFactory.
The width / height in DisplayOrientedMeteringPointFactory defines area (0, 0) - (width, height) which represents the full preview surface. The (x, y) passed to createPoint() must be in this coordinate system.
However, in PreviewView, the preview could be cropped or letterbox/pillarbox depending on the scaleType. Thus we need to adjust two things for DisplayOrientedMeteringPointFactory. (1) Calculate the new width/height of factory based on the FIT/FULL scaleType to make it represent the full preview (2) Add offset to the (x, y) in convertPoint based on the BEGIN/CENTER/END scaleType.