use crate::*;

/// Use whole drawing area along one or both axes.
///
/// ```
/// # fn doctest_layout_full () -> Result<(), Box<dyn std::error::Error>> {
/// use tengri::{Layout, Draw, XYWH};
/// let area = XYWH(0u16, 0, 80, 25);
/// assert_eq!("1".layout(area)?,           Some(XYWH(0u16, 0,  1,  1)));
/// assert_eq!("1".full_w().layout(area)?,  Some(XYWH(0u16, 0, 80,  1)));
/// assert_eq!("1".full_h().layout(area)?,  Some(XYWH(0u16, 0,  1, 25)));
/// assert_eq!("1".full_wh().layout(area)?, Some(XYWH(0u16, 0, 80, 25)));
/// # Ok(()) }
/// ```
pub enum Full<T: Screen, I: Draw<T>> {
    __(PhantomData<T>),
    W(I),
    H(I),
    WH(I),
}
impl_draw!(<T: Screen, I: Draw<T>,>|self: Full<T, I>, to: T|{
    let XYWH(x0, y0, w0, h0) = to.area();
    match self {
        Self::W(item) => if let Some(XYWH(_, y, _, h)) = item.layout(to.area())? {
            to.clip(XYWH(x0, y, w0, h), |to|item.draw(to))
        } else {
            Ok(None)
        },
        Self::H(item) => if let Some(XYWH(x, _, w, _)) = item.layout(to.area())? {
            to.clip(XYWH(x, y0, w, h0), |to|item.draw(to))
        } else {
            Ok(None)
        },
        Self::WH(item) => if let Some(XYWH(..)) = item.layout(to.area())? {
            to.clip(XYWH(x0, y0, w0, h0), |to|item.draw(to))
        } else {
            Ok(None)
        },
        _ => unreachable!(),
    }
});