KeyboardNavigationHandler constructor.
The keyboard shortcuts are the following :
- space bar : Stop all animations when an event is received
- + : zoom in the camera
- - : zoom out the camera
- Left arrow : pan the camera left
- shift + left arrow : rotate the camera counterclockwise
- Right arrow : pan the camera right
- shift + right arrow : rotate the camera clockwise
- Up arrow : pan the camera up
- shift + up arrow : rotate the camera up
- Down arrow : pan the camera down
- shift + down arrow : rotate the camera down