requiredWidth

Declare the width of the content to be exactly width. The incoming measurement Constraints will not override this value. If the content chooses a size that does not satisfy the incoming Constraints, the parent layout will be reported a size coerced in the Constraints, and the position of the content will be automatically offset to be centered on the space assigned to the child by the parent layout under the assumption that Constraints were respected.

See requiredWidthIn and requiredSizeIn to set a size range. See width to set a preferred width, which is only respected when the incoming constraints allow it.