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#![recursion_limit = "128"]
#![feature(proc_macro_diagnostic)]
extern crate proc_macro;
mod args;
use proc_macro2::{Span, TokenStream};
use quote::{quote, TokenStreamExt};
use std::fmt::Write;
use syn::punctuated::Punctuated;
use syn::spanned::Spanned;
use syn::token::Comma;
use syn::{parse_macro_input, parse_quote};
use syn::{DeriveInput, FnArg, Ident, ImplItemMethod, Type, TypePath};
use self::args::ChildType;
mod layout;
#[proc_macro_derive(Widget, attributes(core, widget, handler, layout_data))]
pub fn derive(input: proc_macro::TokenStream) -> proc_macro::TokenStream {
let mut ast = parse_macro_input!(input as DeriveInput);
let args = match args::read_attrs(&mut ast) {
Ok(w) => w,
Err(err) => return err.to_compile_error().into(),
};
let (impl_generics, ty_generics, where_clause) = ast.generics.split_for_impl();
let name = &ast.ident;
let core = args.core;
let count = args.children.len();
let mut get_rules = quote! {};
let mut get_mut_rules = quote! {};
let mut walk_rules = quote! {};
let mut walk_mut_rules = quote! {};
for (i, child) in args.children.iter().enumerate() {
let ident = &child.ident;
get_rules.append_all(quote! { #i => Some(&self.#ident), });
get_mut_rules.append_all(quote! { #i => Some(&mut self.#ident), });
walk_rules.append_all(quote! { self.#ident.walk(f); });
walk_mut_rules.append_all(quote! { self.#ident.walk_mut(f); });
}
let mut toks = quote! {
impl #impl_generics kas::WidgetCore
for #name #ty_generics #where_clause
{
fn core_data(&self) -> &kas::CoreData {
&self.#core
}
fn core_data_mut(&mut self) -> &mut kas::CoreData {
&mut self.#core
}
fn as_widget(&self) -> &dyn kas::Widget { self }
fn as_widget_mut(&mut self) -> &mut dyn kas::Widget { self }
fn len(&self) -> usize {
#count
}
fn get(&self, _index: usize) -> Option<&dyn kas::Widget> {
match _index {
#get_rules
_ => None
}
}
fn get_mut(&mut self, _index: usize) -> Option<&mut dyn kas::Widget> {
match _index {
#get_mut_rules
_ => None
}
}
fn walk(&self, f: &mut dyn FnMut(&dyn kas::Widget)) {
#walk_rules
f(self);
}
fn walk_mut(&mut self, f: &mut dyn FnMut(&mut dyn kas::Widget)) {
#walk_mut_rules
f(self);
}
}
};
if let Some(ref layout) = args.widget.layout {
let (fns, dt) = match layout::derive(&args.children, layout, &args.layout_data) {
Ok(res) => res,
Err(err) => return err.to_compile_error().into(),
};
toks.append_all(quote! {
impl #impl_generics kas::Widget
for #name #ty_generics #where_clause
{
#fns
}
impl #impl_generics kas::LayoutData
for #name #ty_generics #where_clause
{
#dt
}
});
}
if let Some(handler) = args.handler {
let msg = handler.msg;
let mut generics = ast.generics.clone();
if !handler.generics.params.is_empty() {
if !generics.params.empty_or_trailing() {
generics.params.push_punct(Default::default());
}
generics.params.extend(handler.generics.params.into_pairs());
}
if let Some(h_clauses) = handler.generics.where_clause {
if let Some(ref mut clauses) = generics.where_clause {
if !clauses.predicates.empty_or_trailing() {
clauses.predicates.push_punct(Default::default());
}
clauses.predicates.extend(h_clauses.predicates.into_pairs());
} else {
generics.where_clause = Some(h_clauses);
}
}
let (impl_generics, _, where_clause) = generics.split_for_impl();
let mut ev_to_num = TokenStream::new();
let mut ev_to_coord = TokenStream::new();
for child in args.children.iter() {
let ident = &child.ident;
let handler = if let Some(ref h) = child.args.handler {
quote! { r.try_into().unwrap_or_else(|msg| self.#h(_tk, msg)) }
} else {
quote! { r.into() }
};
ev_to_num.append_all(quote! {
if id <= self.#ident.id() {
let r = self.#ident.handle(_tk, addr, event);
#handler
} else
});
ev_to_coord.append_all(quote! {
if self.#ident.rect().contains(coord) {
let r = self.#ident.handle(_tk, addr, event);
#handler
} else
});
}
let handler = if args.children.is_empty() {
quote! {}
} else {
quote! {
fn handle(&mut self, _tk: &mut dyn kas::TkWindow, addr: kas::event::Address, event: kas::event::Event)
-> kas::event::Response<Self::Msg>
{
use kas::{WidgetCore, event::{Event, Response}};
match addr {
kas::event::Address::Id(id) => {
#ev_to_num {
debug_assert!(id == self.id(), "Handler::handle: bad WidgetId");
Response::Unhandled(event)
}
}
kas::event::Address::Coord(coord) => {
#ev_to_coord {
kas::event::Manager::handle_generic(self, _tk, event)
}
}
}
}
}
};
toks.append_all(quote! {
impl #impl_generics kas::event::Handler
for #name #ty_generics #where_clause
{
type Msg = #msg;
#handler
}
});
};
toks.into()
}
#[proc_macro]
pub fn make_widget(input: proc_macro::TokenStream) -> proc_macro::TokenStream {
let mut find_handler_ty_buf: Vec<(Ident, Type)> = vec![];
let mut find_handler_ty = |handler: &Ident,
impls: &Vec<(Option<TypePath>, Vec<ImplItemMethod>)>|
-> Option<Type> {
for (ident, ty) in &find_handler_ty_buf {
if ident == handler {
return Some(ty.clone());
}
}
let mut x: Option<(Ident, Type)> = None;
for impl_block in impls {
for f in &impl_block.1 {
if f.sig.ident == *handler {
if let Some(x) = x {
handler
.span()
.unwrap()
.error("multiple methods with this name")
.emit();
x.0.span()
.unwrap()
.error("first method with this name")
.emit();
f.sig
.ident
.span()
.unwrap()
.error("second method with this name")
.emit();
return None;
}
if f.sig.inputs.len() != 3 {
f.sig.span()
.unwrap()
.error("handler functions must have signature: fn handler(&mut self, tk: &mut dyn TkWindow, msg: T)")
.emit();
return None;
}
let arg = f.sig.inputs.last().unwrap();
let ty = match arg {
FnArg::Typed(arg) => (*arg.ty).clone(),
_ => panic!("expected typed argument"),
};
x = Some((f.sig.ident.clone(), ty));
}
}
}
if let Some(x) = x {
find_handler_ty_buf.push((handler.clone(), x.1.clone()));
Some(x.1)
} else {
handler
.span()
.unwrap()
.error("no methods with this name found")
.emit();
None
}
};
let mut args = parse_macro_input!(input as args::MakeWidget);
let mut name_buf = String::with_capacity(32);
let mut field_toks = quote! {
#[core] core: kas::CoreData,
#[layout_data] layout_data: <Self as kas::LayoutData>::Data,
};
let mut field_val_toks = quote! {
core: Default::default(),
layout_data: Default::default(),
};
let mut debug_fields = TokenStream::new();
let mut gen_tys = Punctuated::<_, Comma>::new();
let mut gen_ptrs = Punctuated::<_, Comma>::new();
let mut handler_extra = Punctuated::<_, Comma>::new();
let mut handler_clauses = Punctuated::<_, Comma>::new();
let msg = &args.msg;
let layout = args.layout;
let widget_args = quote! { layout = #layout };
for (index, field) in args.fields.drain(..).enumerate() {
let attr = field.widget_attr;
let ident = match &field.ident {
Some(ref ident) => ident.clone(),
None => {
name_buf.clear();
name_buf
.write_fmt(format_args!("mw_anon_{}", index))
.unwrap();
Ident::new(&name_buf, Span::call_site())
}
};
let ty: Type = match field.ty {
ChildType::Fixed(ty) => ty.clone(),
ChildType::Generic(gen_msg, gen_bound) => {
name_buf.clear();
name_buf.write_fmt(format_args!("MWAnon{}", index)).unwrap();
let ty = Ident::new(&name_buf, Span::call_site());
gen_tys.push(ty.clone());
if let Some(ref wattr) = attr {
if let Some(tyr) = gen_msg {
handler_clauses.push(quote! { #ty: kas::event::Handler<Msg = #tyr> });
} else {
if let Some(ref handler) = wattr.args.handler {
if let Some(ty_bound) = find_handler_ty(handler, &args.impls) {
handler_clauses
.push(quote! { #ty: kas::event::Handler<Msg = #ty_bound> });
} else {
return quote! {}.into();
}
} else {
name_buf.push_str("R");
let tyr = Ident::new(&name_buf, Span::call_site());
handler_extra.push(tyr.clone());
handler_clauses.push(quote! { #ty: kas::event::Handler<Msg = #tyr> });
handler_clauses.push(quote! { #msg: From<#tyr> });
}
}
if let Some(mut bound) = gen_bound {
bound.bounds.push(parse_quote! { kas::Widget });
gen_ptrs.push(quote! { #ty: #bound });
} else {
gen_ptrs.push(quote! { #ty: kas::Widget });
}
} else {
gen_ptrs.push(quote! { #ty });
}
Type::Path(TypePath {
qself: None,
path: ty.into(),
})
}
};
let value = &field.value;
field_toks.append_all(quote! { #attr #ident: #ty, });
field_val_toks.append_all(quote! { #ident: #value, });
debug_fields
.append_all(quote! { write!(f, ", {}: {:?}", stringify!(#ident), self.#ident)?; });
}
let handler_where = if handler_clauses.is_empty() {
quote! {}
} else {
quote! { where #handler_clauses }
};
let mut impls = quote! {};
for impl_block in args.impls {
let mut contents = TokenStream::new();
for method in impl_block.1 {
contents.append_all(std::iter::once(method));
}
let target = if let Some(t) = impl_block.0 {
quote! { #t for }
} else {
quote! {}
};
impls.append_all(quote! {
impl<#gen_ptrs> #target AnonWidget<#gen_tys> {
#contents
}
});
}
let toks = (quote! { {
#[widget(#widget_args)]
#[handler(msg = #msg, generics = < #handler_extra > #handler_where)]
#[derive(Clone, Debug, kas::macros::Widget)]
struct AnonWidget<#gen_ptrs> {
#field_toks
}
#impls
AnonWidget {
#field_val_toks
}
} })
.into();
toks
}
#[proc_macro_derive(VoidMsg)]
pub fn derive_empty_msg(input: proc_macro::TokenStream) -> proc_macro::TokenStream {
let ast = parse_macro_input!(input as DeriveInput);
let (impl_generics, ty_generics, where_clause) = ast.generics.split_for_impl();
let name = &ast.ident;
let toks = quote! {
impl #impl_generics From<kas::event::VoidMsg>
for #name #ty_generics #where_clause
{
fn from(_: kas::event::VoidMsg) -> Self {
unreachable!()
}
}
};
toks.into()
}