osui/src/macros.rs

#[macro_export]
macro_rules! event {
    ($name:ident) => {
        #[derive(Debug, Clone)]
        pub struct $name;

        impl $crate::extensions::Event for $name {
            fn as_any(&self) -> &dyn std::any::Any {
                self
            }
        }
    };

    ($name:ident {$($inner:tt)*}) => {
        #[derive(Debug, Clone)]
        pub struct $name {
            $($inner)*
        }

        impl $crate::extensions::Event for $name {
            fn as_any(&self) -> &dyn std::any::Any {
                self
            }
        }
    };

    ($name:ident ($($inner:tt)*)) => {
        #[derive(Debug, Clone)]
        pub struct $name ($($inner)*);

        impl $crate::extensions::Event for $name {
            fn as_any(&self) -> &dyn std::any::Any {
                self
            }
        }
    };
}

#[macro_export]
macro_rules! component {
    ($name:ident) => {
        #[derive(Debug, Clone)]
        pub struct $name;

        impl $crate::widget::Component for $name {
            fn as_any(&self) -> &dyn std::any::Any {
                self
            }

            fn as_any_mut(&mut self) -> &mut dyn std::any::Any {
                self
            }
        }
    };

    ($name:ident {$($inner:tt)*}) => {
        #[derive(Debug, Clone)]
        pub struct $name {
            $($inner)*
        }

        impl $crate::widget::Component for $name {
            fn as_any(&self) -> &dyn std::any::Any {
                self
            }

            fn as_any_mut(&mut self) -> &mut dyn std::any::Any {
                self
            }
        }
    };

    ($name:ident ($($inner:tt)*)) => {
        #[derive(Debug, Clone)]
        pub struct $name ($($inner)*);

        impl $crate::widget::Component for $name {
            fn as_any(&self) -> &dyn std::any::Any {
                self
            }

            fn as_any_mut(&mut self) -> &mut dyn std::any::Any {
                self
            }
        }
    };
}

/// Macro to create an event handler closure that calls a method on `self`
///
/// This macro automates the pattern of capturing `self` as a raw pointer,
/// then passing an event to a method on `self` inside an unsafe closure.
///
/// # Parameters
/// - `$self_ty`: The self type.
/// - `$self`: The instance variable (usually `self`) to call the method on.
/// - `$events`: The event source which has an `.on` method to register the handler.
/// - `$method`: The method name on `self` to call when an event occurs.
///
/// # Usage
/// ```rust
/// event_handler!(self, events, on_keypress);
/// ```
///
/// This expands roughly to:
/// ```rust
/// let self_ref = self as *mut Self;
/// events.on(move |event| unsafe { (*self_ref).on_keypress(event) });
/// ```
///
/// # Safety
/// This macro uses `unsafe` code because it dereferences a raw pointer inside the closure.
/// Ensure that the `self` reference lives at least as long as the closure to avoid undefined behavior.
///
/// # Why use raw pointers here?
/// Often, event handlers require `'static` closures, but `self` is a stack reference.
/// Capturing `self` directly is not possible, so this workaround uses a raw pointer.
#[macro_export]
macro_rules! event_handler {
    ($self_ty:ty, $self:ident, $events:ident, $method:ident) => {{
        let self_ref = $self as *mut $self_ty;
        $events.on(move |es, e| unsafe { (*self_ref).$method(es, e) });
    }};
}

#[macro_export]
macro_rules! transform {
    ($($f:ident: $v:expr),* $(,)?) => {{
        let mut t = Transform::new();
        $(t.$f = $v.into();)*
        t
    }};
}

#[macro_export]
macro_rules! rsx {
    ($($inner:tt)*) => {{
        let mut r = $crate::frontend::Rsx(Vec::new());

        $crate::rsx_inner! { r, $($inner)* };

        r
    }};
}

#[macro_export]
macro_rules! rsx_inner {
    // static
    ($r:expr, $(@$comp:expr;)* static $s:literal $($rest:tt)*) => {
        let w = $crate::widget::StaticWidget::new(Box::new(format!($s)));
        $(w.component($comp);)*
        $r.create_element_static(w, $crate::frontend::Rsx(Vec::new()));
        $crate::rsx_inner! { $r, $($rest)* };
    };

    ($r:expr, $(@$comp:expr;)* $(%$dep:ident)* $s:literal $($rest:tt)*) => {
        $r.create_element({ $(let $dep = $dep.clone();)* move || {
            $crate::widget::WidgetLoad::new(format!($s)) $(.component($comp))*
        } }, vec![$(Box::new($dep.clone())),*], $crate::frontend::Rsx(Vec::new()));
        $crate::rsx_inner! { $r, $($rest)* };
    };

    // static
    ($r:expr, $(@$comp:expr;)* static $name:path { $($inner:tt)* } ($($e:expr),*) $($rest:tt)*) => {
        let w = $crate::widget::StaticWidget::new(Box::new(<$name>::new($($e),*)));
        $(w.component($comp);)*
        $r.create_element_static(w, $crate::frontend::Rsx(Vec::new()));
        $crate::rsx_inner! { $r, $($rest)* };
    };

    // static
    ($r:expr, $(@$comp:expr;)* static $name:path { $($inner:tt)* } $($rest:tt)*) => {
        let w = $crate::widget::StaticWidget::new(Box::new(<$name>::new()));
        $(w.component($comp);)*
        $r.create_element_static(w, $crate::frontend::Rsx(Vec::new()));
        $crate::rsx_inner! { $r, $($rest)* };
    };

    ($r:expr, $(@$comp:expr;)* $(%$dep:ident)* $name:path { $($inner:tt)* } ($($e:expr),*) $($rest:tt)*) => {
        $r.create_element({ $(let $dep = $dep.clone();)* move || {
            $crate::widget::WidgetLoad::new(<$name>::new($($e),*)) $(.component($comp))*
        } }, vec![$(Box::new($dep.clone())),*], $crate::rsx!{ $($inner)* });
        $crate::rsx_inner! { $r, $($rest)* };
    };

    ($r:expr, $(@$comp:expr;)* $(%$dep:ident)* $name:path { $($inner:tt)* } $($rest:tt)*) => {
        $r.create_element({ $(let $dep = $dep.clone();)* move || {
            $crate::widget::WidgetLoad::new(<$name>::new()) $(.component($comp))*
        } }, vec![$(Box::new($dep.clone())),*], $crate::rsx!{ $($inner)* });
        $crate::rsx_inner! { $r, $($rest)* };
    };

    ($r:expr, $expand:ident => ($($inner:tt)*) $($rest:tt)*) => {
        $r.expand(&mut $expand($($inner)*));
        $crate::rsx_inner! { $r, $($rest)* };
    };

    ($r:expr,) => {};
}