[Rotate] command performs view rotation by mouse dragging with left button down.
One dragging, that is, the mouse movement from the instance of mouse button
press to the instance of mouse button release is the command operation and the
commnad is terminated when the mouse button is released. After the command is
invoked, the pressing of left button changes the mouse cursor to .
Dragging with the cursor shape, view rotation is applied and the view rotation
is confirmed.
Another dynamic way to rotate view other than this command is: