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use super::*;
/// A length that is relative to the font size.
///
/// `1em` is the same as the font size.
#[derive(Default, Copy, Clone, Eq, PartialEq, Ord, PartialOrd)]
#[derive(Serialize, Deserialize)]
pub struct Em(N64);
impl Em {
/// The zero length.
pub fn zero() -> Self {
Self(N64::from(0.0))
}
/// The font size.
pub fn one() -> Self {
Self(N64::from(1.0))
}
/// Create an font-relative length.
pub fn new(em: f64) -> Self {
Self(N64::from(em))
}
/// Create font units at the given units per em.
pub fn from_units(units: impl Into<f64>, units_per_em: f64) -> Self {
Self(N64::from(units.into() / units_per_em))
}
/// Convert to a length at the given font size.
pub fn to_length(self, font_size: Length) -> Length {
self.get() * font_size
}
/// The number of em units.
pub fn get(self) -> f64 {
self.0.into()
}
/// Whether the length is zero.
pub fn is_zero(self) -> bool {
self.0 == 0.0
}
}
impl Debug for Em {
fn fmt(&self, f: &mut Formatter) -> fmt::Result {
write!(f, "{}em", self.get())
}
}
impl Neg for Em {
type Output = Self;
fn neg(self) -> Self {
Self(-self.0)
}
}
impl Add for Em {
type Output = Self;
fn add(self, other: Self) -> Self {
Self(self.0 + other.0)
}
}
sub_impl!(Em - Em -> Em);
impl Mul<f64> for Em {
type Output = Self;
fn mul(self, other: f64) -> Self {
Self(self.0 * other)
}
}
impl Mul<Em> for f64 {
type Output = Em;
fn mul(self, other: Em) -> Em {
other * self
}
}
impl Div<f64> for Em {
type Output = Self;
fn div(self, other: f64) -> Self {
Self(self.0 / other)
}
}
impl Div for Em {
type Output = f64;
fn div(self, other: Self) -> f64 {
self.get() / other.get()
}
}
assign_impl!(Em += Em);
assign_impl!(Em -= Em);
assign_impl!(Em *= f64);
assign_impl!(Em /= f64);
|
