When the item is not visible, the width and height are not valid,
resulting in wrong output values

Signed-off-by: Patrick José Pereira <patrickelectric@gmail.com>

Signed-off-by: Patrick José Pereira <patrickelectric@gmail.com>

This allows you to arm

- Positions are bounded to rectangle
- No longer re-centers if thumbs go outside bounds
- ThumbPad moves to meet first thumb position, this prevents
inadvertent movement as you put your thumb down