Scale from the center.
Scale from the right side
Do not apply any gravity
Scale from topmost downwards
Scale from the top right corner
Scale from the top left corner
Scale from the bottom upwards
Scale from the bottom right corner
Scale from the bottom left corner
Scale from the left side
Gravity of the scaling operations. When a gravity different than %CLUTTER_GRAVITY_NONE is used, an actor is scaled keeping the position of the specified portion at the same coordinates.