padding property
Padding around the button's content.
When null, the native button keeps the style's own insets. A side set to 0 also keeps the style's inset on that side.
On iOS and macOS, the top and bottom padding apply to a button with a label, and its height grows to fit the label and that padding (at least minHeight, or 44). An icon-only button is sized by width and minHeight.
Implementation
final EdgeInsets? padding;