swiftui_native/views/

materials.rs

//! Materials, Liquid Glass and theming.

use super::*;
use crate::abi;
use crate::resolve;
use core::ffi::c_void;
use crate::mangle;
mangle::modifier_types! {
    /// `.background(_: Material)`
    /// `ModifiedContent<AnyView, _BackgroundStyleModifier<Material>>`
    pub(crate) MATERIAL_BG_T = ty("_BackgroundStyleModifier").of(vec![ty("Material")]);
    /// `.background(_: AnyGradient)`
    /// `ModifiedContent<AnyView, _BackgroundStyleModifier<AnyGradient>>`
    pub(crate) GRADIENT_BG_T = ty("_BackgroundStyleModifier").of(vec![ty("AnyGradient")]);
    /// `.tint(_:)`
    /// `ModifiedContent<AnyView, _EnvironmentKeyWritingModifier<AnyShapeStyle?>>`
    pub(crate) TINT_T = ty("_EnvironmentKeyWritingModifier").of(vec![opt(ty("AnyShapeStyle"))]);
    /// `.preferredColorScheme(_:)`
    /// `ModifiedContent<AnyView, _PreferenceWritingModifier<PreferredColorSchemeKey>>`
    pub(crate) COLOR_SCHEME_T = ty("_PreferenceWritingModifier").of(vec![ty("PreferredColorSchemeKey")]);
    /// `.controlSize(_:)`
    /// `ModifiedContent<AnyView, _EnvironmentKeyWritingModifier<ControlSize>>`
    pub(crate) CONTROL_SIZE_T = ty("_EnvironmentKeyWritingModifier").of(vec![ty_enum("ControlSize")]);
    /// `.buttonStyle(.glass)`
    /// `ModifiedContent<AnyView, PrimitiveButtonStyleContainerModifier<GlassButtonStyle>>`
    pub(crate) GLASS_BUTTON_T = ty("PrimitiveButtonStyleContainerModifier").of(vec![ty("GlassButtonStyle")]);
    /// `.buttonStyle(.bordered)`
    /// `ModifiedContent<AnyView, PrimitiveButtonStyleContainerModifier<BorderedButtonStyle>>`
    pub(crate) BORDERED_BUTTON_T = ty("PrimitiveButtonStyleContainerModifier").of(vec![ty("BorderedButtonStyle")]);
    /// `.buttonStyle(.borderedProminent)`
    pub(crate) BORDERED_PROMINENT_T = ty("PrimitiveButtonStyleContainerModifier").of(vec![ty("BorderedProminentButtonStyle")]);
}






/// The blur materials SwiftUI exposes as `ShapeStyle`s.
#[derive(Clone, Copy, PartialEq, Eq, Debug)]
pub enum MaterialKind {
    UltraThin,
    Thin,
    Regular,
    Thick,
    UltraThick,
    Bar,
}

impl MaterialKind {
    pub(crate) fn getter(self) -> &'static core::ffi::CStr {
        match self {
            MaterialKind::UltraThin => c"$s7SwiftUI8MaterialV9ultraThinACvgZ",
            MaterialKind::Thin => c"$s7SwiftUI8MaterialV4thinACvgZ",
            MaterialKind::Regular => c"$s7SwiftUI8MaterialV7regularACvgZ",
            MaterialKind::Thick => c"$s7SwiftUI8MaterialV5thickACvgZ",
            MaterialKind::UltraThick => c"$s7SwiftUI8MaterialV10ultraThickACvgZ",
            MaterialKind::Bar => c"$s7SwiftUI8MaterialV3barACvgZ",
        }
    }
}

/// `SwiftUI.ColorScheme`, in declaration order.
#[derive(Clone, Copy, PartialEq, Eq, Debug)]
#[repr(u8)]
pub enum ColorScheme {
    Light = 0,
    Dark = 1,
}

/// `SwiftUI.ControlSize`, in declaration order.
#[derive(Clone, Copy, PartialEq, Eq, Debug)]
#[repr(u8)]
pub enum ControlSize {
    Mini = 0,
    Small = 1,
    Regular = 2,
    Large = 3,
    ExtraLarge = 4,
}

swift_statics! {
    /// `SwiftUI.Glass` — which Liquid Glass variant an effect uses.
    pub enum Glass {
        Regular = c"$s7SwiftUI5GlassV7regularACvgZ",
        Clear = c"$s7SwiftUI5GlassV5clearACvgZ",
        Identity = c"$s7SwiftUI5GlassV8identityACvgZ",
    }
}

/// Which primitive button style to apply.
#[derive(Clone, Copy, PartialEq, Eq, Debug)]
pub enum ButtonStyle {
    /// The Liquid Glass button style.
    Glass,
    Bordered,
    /// `.borderedProminent` — the filled, tinted button.
    BorderedProminent,
}

/// Read a static getter for a resilient struct, which returns indirectly in x8.
///
/// The buffer is sized by *stride*, not size: a callee may write the full
/// stride including tail padding, and a size-sized buffer overflows the
/// allocation. That corrupts the heap quietly and only crashes several
/// allocations later, a long way from the cause.
pub(crate) unsafe fn static_getter_indirect(
    getter: *const c_void,
    meta: *const c_void,
    _size: usize,
) -> Vec<u8> {
    let mut buf = vec![0u8; unsafe { abi::type_bytes(meta) }];
    unsafe {
        core::arch::asm!("blr {f}", f = in(reg) getter,
            in("x8") buf.as_mut_ptr(),
            in("x20") meta,
            lateout("x0") _, lateout("x1") _, lateout("x2") _, lateout("x3") _,
            lateout("x4") _, lateout("x5") _, lateout("x6") _, lateout("x7") _,
            lateout("x9") _, lateout("x10") _, lateout("x11") _, lateout("x12") _,
            lateout("x13") _, lateout("x14") _, lateout("x15") _, lateout("x16") _,
            lateout("x17") _, lateout("lr") _, lateout("x21") _, clobber_abi("C"),
        );
    }
    buf
}

/// `.background(_:ignoresSafeAreaEdges:)` with an arbitrary `ShapeStyle`.
///
///   x0 = @in style, x1 = Edge.Set, x2 = Self.Type, x3 = S.Type,
///   x4 = Self: View WT, x5 = S: ShapeStyle WT, x8 = @out, x20 = self
pub(crate) unsafe fn background_style(
    view: &ViewHandle,
    style: *mut u8,
    style_meta: *const c_void,
    style_wt: *const c_void,
    modifier: &ModifierType,
) -> ViewHandle {
    unsafe {
        let (_, _, size) = modifier.applied_to(view.meta);
        let mut result = vec![0u8; size];
        let this = view.value_ptr();
        core::arch::asm!("blr {f}", f = in(reg) resolve::bg_fn(),
            in("x0") style,
            in("x1") EDGE_SET_ALL, // ignoresSafeAreaEdges: .all
            in("x2") view.meta,
            in("x3") style_meta,
            in("x4") view.wt,
            in("x5") style_wt,
            in("x8") result.as_mut_ptr(),
            in("x20") this,
            lateout("x6") _, lateout("x7") _,
            lateout("x9") _, lateout("x10") _, lateout("x11") _, lateout("x12") _,
            lateout("x13") _, lateout("x14") _, lateout("x15") _, lateout("x16") _,
            lateout("x17") _, lateout("lr") _, lateout("x21") _, clobber_abi("C"),
        );
        wrap_modified(result, modifier, view)
    }
}

/// Apply `.background(_:)` with an `AnyGradient` — what `.indigo.gradient` is.
pub fn background_any_gradient(view: &ViewHandle, color: u64) -> ViewHandle {
    unsafe {
        let (mut value, meta, wt) = super::color_gradient(color);
        background_style(view, value.as_mut_ptr(), meta, wt, &GRADIENT_BG_T)
    }
}

/// A `Material`'s value, metadata and `ShapeStyle` witness.
///
/// What [`super::Shape::fill_style`] wants, for `Rectangle().fill(.regularMaterial)`
/// — the same material that `.background(_:)` takes, used as a fill instead.
pub fn material_parts(kind: MaterialKind) -> (Vec<u8>, *const c_void, *const c_void) {
    unsafe {
        let meta = abi::metadata0(resolve::material_ma());
        let value = static_getter_indirect(resolve::require(kind.getter()), meta, 0);
        (value, meta, resolve::material_shapestyle_wt())
    }
}

/// Apply `.background(_: Material)` — the blur materials.
pub fn background_material(view: &ViewHandle, kind: MaterialKind) -> ViewHandle {
    unsafe {
        // Material is resilient, so both its size and its static getters are
        // only knowable at runtime.
        let meta = abi::metadata0(resolve::material_ma());
        let mut value =
            static_getter_indirect(resolve::require(kind.getter()), meta, 0);
        background_style(
            view,
            value.as_mut_ptr(),
            meta,
            resolve::material_shapestyle_wt(),
            &MATERIAL_BG_T,
        )
    }
}

/// Apply `.glassEffect()` — Liquid Glass, in its default shape.
///
/// The result type is a `StaticIf<GlassEnabledPredicate, ...>`: SwiftUI picks
/// between the glass-modified view and the original at runtime depending on
/// whether the platform has Liquid Glass enabled.
pub fn glass_effect(view: &ViewHandle) -> ViewHandle {
    glass_effect_kind(view, Glass::Regular)
}

/// The same, with the variant named.
///
/// `Identity` is the no-op: it still builds the `StaticIf`, so the view's type
/// is the one a glass effect gives it, with nothing drawn. That is what makes
/// it usable as the "off" end of a condition without the two branches
/// disagreeing about their type.
pub fn glass_effect_kind(view: &ViewHandle, glass: Glass) -> ViewHandle {
    unsafe {
        let glass_meta = abi::metadata0(resolve::glass_ma());
        let mut glass = static_getter_indirect(
            glass.resolved(),
            glass_meta,
            0,
        );

        let shape_meta = abi::metadata0(resolve::glass_shape_ma());
        let shape_wt = abi::get_view_wt_for_proto(shape_meta, resolve::shape_proto());
        assert!(!shape_wt.is_null(), "DefaultGlassEffectShape: Shape");
        // `DefaultGlassEffectShape` is not zero-size and not all-zero: it holds
        // a `RoundedCornerStyle`, whose zero case is `.circular` while the
        // initialiser picks `.continuous`. Both render as a capsule at this
        // size, so only reflecting over the value shows the difference — call
        // the initialiser rather than assuming an empty buffer.
        let mut shape = vec![0u8; abi::type_bytes(shape_meta)];
        core::arch::asm!("blr {f}", f = in(reg) resolve::glass_shape_init(),
            in("x8") shape.as_mut_ptr(),
            in("x20") shape_meta,
            lateout("x0") _, lateout("x1") _, lateout("x2") _, lateout("x3") _,
            lateout("x4") _, lateout("x5") _, lateout("x6") _, lateout("x7") _,
            lateout("x9") _, lateout("x10") _, lateout("x11") _, lateout("x12") _,
            lateout("x13") _, lateout("x14") _, lateout("x15") _, lateout("x16") _,
            lateout("x17") _, lateout("lr") _, lateout("x21") _, clobber_abi("C"),
        );

        let (meta, wt, size) = glass_result_type(view.meta, view.wt);
        let mut result = vec![0u8; size];
        let this = view.value_ptr();
        // glassEffect<S: Shape>(_ glass: Glass, in shape: S)
        //   x0 = @in Glass, x1 = @in S, x2 = Self.Type, x3 = S.Type,
        //   x4 = Self: View WT, x5 = S: Shape WT, x8 = @out, x20 = self
        core::arch::asm!("blr {f}", f = in(reg) resolve::glass_effect_fn2(),
            in("x0") glass.as_mut_ptr(),
            in("x1") shape.as_mut_ptr(),
            in("x2") view.meta,
            in("x3") shape_meta,
            in("x4") view.wt,
            in("x5") shape_wt,
            in("x8") result.as_mut_ptr(),
            in("x20") this,
            lateout("x6") _, lateout("x7") _,
            lateout("x9") _, lateout("x10") _, lateout("x11") _, lateout("x12") _,
            lateout("x13") _, lateout("x14") _, lateout("x15") _, lateout("x16") _,
            lateout("x17") _, lateout("lr") _, lateout("x21") _, clobber_abi("C"),
        );
        wrap_owned(result, meta, wt)
    }
}

/// The concrete type behind a `-> some View`, with its `View` witness and size.
///
/// Cached, and it was not. Every opaque-returning modifier — most of them — came
/// through here and paid two `dlsym`s, a metadata instantiation and a
/// conformance search, on every view built. Swift pays that once per site and
/// keeps the answer in a `…Md` word; this keeps it in a map, because the
/// substitutions are not always fixed at the site — a modifier generic over its
/// style resolves a different type for each style it is handed.
///
/// The key is the descriptor plus its substitutions, all of them already
/// resolved pointers, in a fixed array so a lookup allocates nothing.
/// # Safety
/// `oret` must be an opaque type descriptor, and `subst` must be the whole
/// generic signature's substitutions in declaration order — parameters, then
/// conformances. One missing entry reads the next off the end of the slice.
pub unsafe fn opaque_result_type(
    oret: *const c_void,
    subst: &[*const c_void],
) -> (*const c_void, *const c_void, usize) {
    use std::collections::HashMap;
    use std::sync::{Mutex, OnceLock};

    /// Descriptor, then substitutions. Eight is the longest list this crate
    /// builds; the assert says so rather than truncating quietly into a key that
    /// collides with a shorter one.
    type Key = [usize; 9];
    assert!(subst.len() < 9, "opaque substitution list longer than the cache key");
    let mut key: Key = [0; 9];
    key[0] = oret as usize;
    for (slot, p) in key[1..].iter_mut().zip(subst) {
        *slot = *p as usize;
    }

    static CACHE: OnceLock<Mutex<HashMap<Key, super::Resolved>>> = OnceLock::new();
    let cache = CACHE.get_or_init(|| Mutex::new(HashMap::new()));
    if let Ok(map) = cache.lock() {
        if let Some(&(m, w, n)) = map.get(&key) {
            return (m as *const c_void, w as *const c_void, n);
        }
    }

    unsafe {
        type GetMeta =
            unsafe extern "C" fn(usize, *const c_void, *const c_void, usize) -> *const c_void;
        type GetConf = unsafe extern "C" fn(*const c_void, *const c_void, usize) -> *const c_void;
        // Resolved once. These were two `dlsym` calls per modifier.
        static SYMS: OnceLock<(usize, usize)> = OnceLock::new();
        let (meta_fn, conf_fn) = *SYMS.get_or_init(|| {
            (
                libc::dlsym((-2isize) as *mut c_void, c"swift_getOpaqueTypeMetadata".as_ptr())
                    as usize,
                libc::dlsym((-2isize) as *mut c_void, c"swift_getOpaqueTypeConformance2".as_ptr())
                    as usize,
            )
        });
        let get_meta: GetMeta = core::mem::transmute(meta_fn as *const c_void);
        let get_conf: GetConf = core::mem::transmute(conf_fn as *const c_void);

        let meta = get_meta(0, subst.as_ptr() as *const c_void, oret, 0);
        assert!(!meta.is_null(), "opaque result metadata");
        let wt = get_conf(subst.as_ptr() as *const c_void, oret, 1);
        assert!(!wt.is_null(), "opaque result View conformance");
        let n = abi::type_bytes(meta);
        if let Ok(mut map) = cache.lock() {
            map.insert(key, (meta as usize, wt as usize, n));
        }
        (meta, wt, n)
    }
}

/// Resolve `glassEffect`'s opaque result type.
pub(crate) unsafe fn glass_result_type(
    recv_meta: *const c_void,
    recv_wt: *const c_void,
) -> (*const c_void, *const c_void, usize) {
    unsafe {
        let oret = resolve::require(
            c"$s7SwiftUI4ViewPAAE11glassEffect_2inQrAA5GlassV_qd__tAA5ShapeRd__lFQOMQ",
        );
        let shape_meta = abi::metadata0(resolve::glass_shape_ma());
        let shape_wt = abi::get_view_wt_for_proto(shape_meta, resolve::shape_proto());
        // An opaque return is a function of `Self`; describing it as `AnyView`
        // while the call passes a concrete receiver sizes the result for a type
        // that was never built.
        let subst: [*const c_void; 4] = [recv_meta, shape_meta, recv_wt, shape_wt];
        type GetMeta = unsafe extern "C" fn(usize, *const c_void, *const c_void, usize) -> *const c_void;
        type GetConf = unsafe extern "C" fn(*const c_void, *const c_void, usize) -> *const c_void;
        let get_meta: GetMeta = core::mem::transmute(libc::dlsym(
            (-2isize) as *mut c_void, c"swift_getOpaqueTypeMetadata".as_ptr()));
        let get_conf: GetConf = core::mem::transmute(libc::dlsym(
            (-2isize) as *mut c_void, c"swift_getOpaqueTypeConformance2".as_ptr()));
        let meta = get_meta(0, subst.as_ptr() as *const c_void, oret, 0);
        assert!(!meta.is_null(), "glassEffect opaque metadata");
        let wt = get_conf(subst.as_ptr() as *const c_void, oret, 1);
        assert!(!wt.is_null(), "glassEffect opaque View conformance");
        (meta, wt, abi::type_bytes(meta))
    }
}

/// Apply `.tint(_:)`.
pub fn tint(view: &ViewHandle, c: crate::Color) -> ViewHandle {
    unsafe {
        let (_, _, size) = TINT_T.applied_to(view.meta);
        let mut result = vec![0u8; size];
        let this = view.value_ptr();
        // Optional<Color> is one class reference; nil is a null pointer.
        let mut style: u64 = color_value(c.r, c.g, c.b, c.a);
        // tint<S: ShapeStyle>(_: S?)
        //   x0 = @in S?, x1 = Self.Type, x2 = S.Type,
        //   x3 = Self: View WT, x4 = S: ShapeStyle WT
        core::arch::asm!("blr {f}", f = in(reg) resolve::tint_fn(),
            in("x0") &mut style as *mut u64,
            in("x1") view.meta,
            in("x2") resolve::color_meta(),
            in("x3") view.wt,
            in("x4") resolve::color_shapestyle_wt(),
            in("x8") result.as_mut_ptr(),
            in("x20") this,
            lateout("x5") _, lateout("x6") _, lateout("x7") _,
            lateout("x9") _, lateout("x10") _, lateout("x11") _, lateout("x12") _,
            lateout("x13") _, lateout("x14") _, lateout("x15") _, lateout("x16") _,
            lateout("x17") _, lateout("lr") _, lateout("x21") _, clobber_abi("C"),
        );
        wrap_modified(result, &TINT_T, view)
    }
}

/// Apply `.tint(_:)` through the `Color?` overload.
///
/// `View.tint` has two: one generic over `ShapeStyle`, which [`tint`] calls and
/// which yields `_EnvironmentKeyWritingModifier<AnyShapeStyle?>`, and one taking
/// a plain `Color?`, which yields `…<Color?>`. Swift picks the second for
/// `.tint(.white)`, so a reference written that way disagrees with the first on
/// both type and value.
pub fn tint_color(view: &ViewHandle, color: u64) -> ViewHandle {
    unsafe {
        super::opaque_modifier(
            resolve::tint_color_fn(),
            resolve::tint_color_oret(),
            view,
            &[color],
            [0.0; 4],
        )
    }
}

/// Apply `.tint(_:)` to a `Color` that is already built — one of SwiftUI's
/// named colours, which no set of components spells.
pub fn tint_value(view: &ViewHandle, tint: u64) -> ViewHandle {
    unsafe {
        let (_, _, size) = TINT_T.applied_to(view.meta);
        let mut result = vec![0u8; size];
        let this = view.value_ptr();
        // Optional<Color> is one class reference; nil is a null pointer.
        let mut style: u64 = tint;
        // tint<S: ShapeStyle>(_: S?)
        //   x0 = @in S?, x1 = Self.Type, x2 = S.Type,
        //   x3 = Self: View WT, x4 = S: ShapeStyle WT
        core::arch::asm!("blr {f}", f = in(reg) resolve::tint_fn(),
            in("x0") &mut style as *mut u64,
            in("x1") view.meta,
            in("x2") resolve::color_meta(),
            in("x3") view.wt,
            in("x4") resolve::color_shapestyle_wt(),
            in("x8") result.as_mut_ptr(),
            in("x20") this,
            lateout("x5") _, lateout("x6") _, lateout("x7") _,
            lateout("x9") _, lateout("x10") _, lateout("x11") _, lateout("x12") _,
            lateout("x13") _, lateout("x14") _, lateout("x15") _, lateout("x16") _,
            lateout("x17") _, lateout("lr") _, lateout("x21") _, clobber_abi("C"),
        );
        wrap_modified(result, &TINT_T, view)
    }
}

/// Apply `.preferredColorScheme(_:)` — light or dark for this subtree.
pub fn preferred_color_scheme(view: &ViewHandle, scheme: ColorScheme) -> ViewHandle {
    unsafe {
        let (_, _, size) = COLOR_SCHEME_T.applied_to(view.meta);
        // ColorScheme is resilient, so the optional is passed by pointer.
        let mut buf = [scheme as u8];
        let r = abi::call_modifier(resolve::color_scheme_fn(), view.value_ptr(), view.meta, view.wt,
            &[buf.as_mut_ptr() as u64],
            [0.0; 4],
            size,
        );
        wrap_modified(r, &COLOR_SCHEME_T, view)
    }
}

/// Apply `.controlSize(_:)`.
pub fn control_size(view: &ViewHandle, size_kind: ControlSize) -> ViewHandle {
    unsafe {
        let (_, _, size) = CONTROL_SIZE_T.applied_to(view.meta);
        let mut buf = [size_kind as u8];
        let r = abi::call_modifier(resolve::control_size_fn(), view.value_ptr(), view.meta, view.wt,
            &[buf.as_mut_ptr() as u64],
            [0.0; 4],
            size,
        );
        wrap_modified(r, &CONTROL_SIZE_T, view)
    }
}

/// Apply `.buttonStyle(_:)` to a subtree.
pub fn button_style(view: &ViewHandle, style: ButtonStyle) -> ViewHandle {
    unsafe {
        let (accessor, init, modifier) = match style {
            ButtonStyle::Glass => {
                (resolve::glass_button_ma(), resolve::glass_button_init(), &GLASS_BUTTON_T)
            }
            ButtonStyle::Bordered => {
                (resolve::bordered_button_ma(), resolve::bordered_button_init(), &BORDERED_BUTTON_T)
            }
            ButtonStyle::BorderedProminent => (
                resolve::bordered_prominent_ma(),
                resolve::bordered_prominent_init(),
                &BORDERED_PROMINENT_T,
            ),
        };
        let style_meta = abi::metadata0(accessor);
        let style_wt =
            abi::get_view_wt_for_proto(style_meta, resolve::primitive_button_style_proto());
        assert!(!style_wt.is_null(), "button style: PrimitiveButtonStyle");

        // The styles are resilient structs, so `init()` writes through x8.
        let mut value = vec![0u8; abi::type_bytes(style_meta)];
        core::arch::asm!("blr {f}", f = in(reg) init,
            in("x8") value.as_mut_ptr(),
            in("x20") style_meta,
            lateout("x0") _, lateout("x1") _, lateout("x2") _, lateout("x3") _,
            lateout("x4") _, lateout("x5") _, lateout("x6") _, lateout("x7") _,
            lateout("x9") _, lateout("x10") _, lateout("x11") _, lateout("x12") _,
            lateout("x13") _, lateout("x14") _, lateout("x15") _, lateout("x16") _,
            lateout("x17") _, lateout("lr") _, lateout("x21") _, clobber_abi("C"),
        );

        let (_, _, size) = modifier.applied_to(view.meta);
        let mut result = vec![0u8; size];
        let this = view.value_ptr();
        // buttonStyle<S: PrimitiveButtonStyle>(_: S)
        //   x0 = @in S, x1 = Self.Type, x2 = S.Type,
        //   x3 = Self: View WT, x4 = S: PrimitiveButtonStyle WT
        core::arch::asm!("blr {f}", f = in(reg) resolve::button_style_fn(),
            in("x0") value.as_mut_ptr(),
            in("x1") view.meta,
            in("x2") style_meta,
            in("x3") view.wt,
            in("x4") style_wt,
            in("x8") result.as_mut_ptr(),
            in("x20") this,
            lateout("x5") _, lateout("x6") _, lateout("x7") _,
            lateout("x9") _, lateout("x10") _, lateout("x11") _, lateout("x12") _,
            lateout("x13") _, lateout("x14") _, lateout("x15") _, lateout("x16") _,
            lateout("x17") _, lateout("lr") _, lateout("x21") _, clobber_abi("C"),
        );
        wrap_modified(result, modifier, view)
    }
}