BF Layout

BFH_CENTER	Centered horizontally.
BFH_LEFT	Aligned to the left.
BFH_RIGHT	Aligned to the right.
BFH_FIT	Fit horizontally. BFH_LEFT | BFH_RIGHT.
BFH_SCALE	Scale horizontally if there is more space.
BFH_SCALEFIT	Scale fit horizontally. BFH_SCALE | BFH_FIT.
BFH_MASK	Masks out flags.

BFV_CENTER	Centered vertically.
BFV_TOP	Aligned to the top.
BFV_BOTTOM	Aligned to the bottom.
BFV_FIT	Fit. BFV_BOTTOM | BFV_TOP.
BFV_SCALE	Scale vertically if there is more space.
BFV_SCALEFIT	Scale fit vertically. BFV_SCALE | BFV_FIT.
BFV_MASK	Masks out flags.