Update make_widget! to use impl Self syntax

crates/kas-macros/src/args.rs

@@ -328,11 +328,14 @@ fn parse_impl(in_ident: Option<&Ident>, input: ParseStream) -> Result<ItemImpl>
             {
                 abort!(
                     self_ty.span(),
-                    format!("expected `Self` or `{0}` or `{0}<...>`", ident)
+                    format!(
+                        "expected `Self` or `{0}` or `{0}<...>` or `Trait for Self`, etc",
+                        ident
+                    )
                 );
             }
         } else {
-            abort!(self_ty.span(), "expected `Self`");
+            abort!(self_ty.span(), "expected `Self` or `Trait for Self`");
         }
     }
 
@@ -1187,7 +1190,7 @@ pub struct MakeWidget {
     // child widgets and data fields
     pub fields: Vec<WidgetField>,
     // impl blocks on the widget
-    pub impls: Vec<(Option<TypePath>, Vec<syn::ImplItem>)>,
+    pub impls: Vec<ItemImpl>,
 }
 
 impl Parse for MakeWidget {
@@ -1229,25 +1232,9 @@ impl Parse for MakeWidget {
             let _: Comma = content.parse()?;
         }
 
-        let mut impls = vec![];
+        let mut impls = Vec::new();
         while !input.is_empty() {
-            let _: Impl = input.parse()?;
-
-            let target = if input.peek(Brace) {
-                None
-            } else {
-                Some(input.parse::<TypePath>()?)
-            };
-
-            let content;
-            let _ = braced!(content in input);
-            let mut methods = vec![];
-
-            while !content.is_empty() {
-                methods.push(content.parse::<syn::ImplItem>()?);
-            }
-
-            impls.push((target, methods));
+            impls.push(parse_impl(None, input)?);
         }
 
         Ok(MakeWidget {

crates/kas-macros/src/lib.rs

@@ -650,9 +650,7 @@ pub fn widget(input: proc_macro::TokenStream) -> proc_macro::TokenStream {
 pub fn make_widget(input: proc_macro::TokenStream) -> proc_macro::TokenStream {
     let mut find_handler_ty_buf: Vec<(Ident, Type)> = vec![];
     // find type of handler's message; return None on error
-    let mut find_handler_ty = |handler: &Ident,
-                               impls: &Vec<(Option<TypePath>, Vec<syn::ImplItem>)>|
-     -> Option<Type> {
+    let mut find_handler_ty = |handler: &Ident, impls: &Vec<ItemImpl>| -> Option<Type> {
         // check the buffer in case we did this already
         for (ident, ty) in &find_handler_ty_buf {
             if ident == handler {
@@ -663,7 +661,10 @@ pub fn make_widget(input: proc_macro::TokenStream) -> proc_macro::TokenStream {
         let mut x: Option<(Ident, Type)> = None;
 
         for impl_block in impls {
-            for f in &impl_block.1 {
+            if impl_block.trait_.is_some() {
+                continue;
+            }
+            for f in &impl_block.items {
                 match f {
                     syn::ImplItem::Method(syn::ImplItemMethod { sig, .. })
                         if sig.ident == *handler =>
@@ -726,27 +727,27 @@ pub fn make_widget(input: proc_macro::TokenStream) -> proc_macro::TokenStream {
         let mut send = true;
         let mut msg = None;
         let msg_ident: Ident = parse_quote! { Msg };
-        for (name, body) in &args.impls {
-            if name == &Some(parse_quote! { Handler })
-                || name == &Some(parse_quote! { ::kas::Handler })
-            {
-                handle = false;
-
-                for item in body {
-                    match item {
-                        syn::ImplItem::Type(syn::ImplItemType {
-                            ref ident, ref ty, ..
-                        }) if *ident == msg_ident => {
-                            msg = Some(ty.clone());
-                            continue;
+        for impl_block in &args.impls {
+            if let Some((_, ref name, _)) = impl_block.trait_ {
+                if *name == parse_quote! { Handler } || *name == parse_quote! { ::kas::Handler } {
+                    handle = false;
+
+                    for item in &impl_block.items {
+                        match item {
+                            syn::ImplItem::Type(syn::ImplItemType {
+                                ref ident, ref ty, ..
+                            }) if *ident == msg_ident => {
+                                msg = Some(ty.clone());
+                                continue;
+                            }
+                            _ => (),
                         }
-                        _ => (),
                     }
+                } else if *name == parse_quote! { SendEvent }
+                    || *name == parse_quote! { ::kas::SendEvent }
+                {
+                    send = false;
                 }
-            } else if name == &Some(parse_quote! { SendEvent })
-                || name == &Some(parse_quote! { ::kas::SendEvent })
-            {
-                send = false;
             }
         }
 
@@ -855,24 +856,12 @@ pub fn make_widget(input: proc_macro::TokenStream) -> proc_macro::TokenStream {
         });
     }
 
-    let (impl_generics, ty_generics, where_clause) = args.generics.split_for_impl();
+    let (impl_generics, _, where_clause) = args.generics.split_for_impl();
 
     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 #impl_generics #target AnonWidget #ty_generics #where_clause {
-                #contents
-            }
+            #impl_block
         });
     }
 
@@ -886,9 +875,9 @@ pub fn make_widget(input: proc_macro::TokenStream) -> proc_macro::TokenStream {
             struct AnonWidget #impl_generics #where_clause {
                 #field_toks
             }
-        }
 
-        #impls
+            #impls
+        }
 
         AnonWidget {
             #field_val_toks

examples/calculator.rs

@@ -70,7 +70,7 @@ fn main() -> Result<(), kas::shell::Error> {
             #[widget(col = 2, row = 4)]
             _ = TextButton::new_msg("&.", Key::Char('.')),
         }
-        impl kas::WidgetConfig {
+        impl kas::WidgetConfig for Self {
             fn configure(&mut self, mgr: &mut Manager) {
                 // Enable key bindings without Alt held:
                 mgr.enable_alt_bypass(true);
@@ -85,7 +85,7 @@ fn main() -> Result<(), kas::shell::Error> {
             #[widget(use_msg = handle_button)] buttons -> Key = buttons,
             calc: Calculator = Calculator::new(),
         }
-        impl {
+        impl Self {
             fn handle_button(&mut self, mgr: &mut Manager, msg: Key) {
                 if self.calc.handle(msg) {
                     *mgr |= self.display.set_string(self.calc.display());

examples/counter.rs

@@ -25,7 +25,7 @@ fn main() -> Result<(), kas::shell::Error> {
             ],
             count: i32 = 0,
         }
-        impl {
+        impl Self {
             fn handle_button(&mut self, mgr: &mut Manager, incr: i32) {
                 self.count += incr;
                 *mgr |= self.display.set_string(self.count.to_string());

examples/custom-theme.rs

@@ -139,7 +139,7 @@ fn main() -> Result<(), kas::shell::Error> {
             struct {
                 #[widget(use_msg = handler)] _ = widgets,
             }
-            impl {
+            impl Self {
                 fn handler(&mut self, _: &mut Manager, item: Item) {
                     match item {
                         Item::White => BACKGROUND.with(|b| b.set(Rgba::WHITE)),

examples/data-list-view.rs

@@ -214,7 +214,7 @@ fn main() -> Result<(), kas::shell::Error> {
             #[widget] _ = TextButton::new_msg("↓↑", Control::Dir),
             n: usize = 3,
         }
-        impl {
+        impl Self {
             fn activate(&mut self, _: &mut Manager, n: usize) -> Control {
                 self.n = n;
                 Control::Set(n)
@@ -253,7 +253,7 @@ fn main() -> Result<(), kas::shell::Error> {
                 #[widget(use_msg = set_radio)] list: ScrollBars<MyList> =
                     ScrollBars::new(list).with_bars(false, true),
             }
-            impl {
+            impl Self {
                 fn control(&mut self, mgr: &mut Manager, control: Control) {
                     match control {
                         Control::Set(len) => {

examples/data-list.rs

@@ -113,7 +113,7 @@ fn main() -> Result<(), kas::shell::Error> {
             #[widget] _ = TextButton::new_msg("↓↑", Control::Dir),
             n: usize = 3,
         }
-        impl {
+        impl Self {
             fn activate(&mut self, _: &mut Manager, n: usize) -> Control {
                 self.n = n;
                 Control::Set(n)
@@ -154,7 +154,7 @@ fn main() -> Result<(), kas::shell::Error> {
                 #[widget] _ = Filler::maximize(),
                 active: usize = 0,
             }
-            impl {
+            impl Self {
                 fn control(&mut self, mgr: &mut Manager, control: Control) {
                     match control {
                         Control::Set(len) => {

examples/filter-list.rs

@@ -64,7 +64,7 @@ fn main() -> Result<(), kas::shell::Error> {
                     >> =
                     ScrollBars::new(FilterListView::new(data, filter)),
             }
-            impl {
+            impl Self {
                 fn set_selection_mode(&mut self, mgr: &mut Manager, mode: SelectionMode) {
                     *mgr |= self.list.set_selection_mode(mode);
                 }

examples/gallery.rs

@@ -176,7 +176,7 @@ fn main() -> Result<(), kas::shell::Error> {
             #[widget(use_msg = edit)] edit = TextButton::new_msg("&Edit", ()),
             future: Option<Future<Option<String>>> = None,
         }
-        impl {
+        impl Self {
             fn edit(&mut self, mgr: &mut Manager, _: ()) {
                 if self.future.is_none() {
                     let text = self.label.get_string();
@@ -192,7 +192,7 @@ fn main() -> Result<(), kas::shell::Error> {
                 }
             }
         }
-        impl Handler {
+        impl Handler for Self {
             type Msg = VoidMsg;
             fn handle(&mut self, mgr: &mut Manager, event: Event) -> Response<Self::Msg> {
                 match event {
@@ -267,7 +267,7 @@ fn main() -> Result<(), kas::shell::Error> {
             #[widget(row=12, col=0)] _ = Label::new("Child window"),
             #[widget(row=12, col=1)] _ = popup_edit_box,
         }
-        impl {
+        impl Self {
             fn handle_slider(&mut self, _: &mut Manager, msg: i32) -> Item {
                 Item::Slider(msg)
             }
@@ -300,7 +300,7 @@ fn main() -> Result<(), kas::shell::Error> {
                     for<W: Widget<Msg = Item>> ScrollBarRegion<W> =
                         ScrollBarRegion::new(widgets),
             }
-            impl {
+            impl Self {
                 fn menu(&mut self, mgr: &mut Manager, msg: Menu) {
                     match msg {
                         Menu::Theme(name) => {

examples/markdown.rs

@@ -51,7 +51,7 @@ It also supports lists:
                     ScrollBarRegion::new(Label::new(Markdown::new(doc)?)),
                 #[widget(row=1, col=1, use_msg=update)] _ = TextButton::new_msg("&Update", ()),
             }
-            impl {
+            impl Self {
                 fn update(&mut self, mgr: &mut Manager, _: ()) {
                     let text = match Markdown::new(self.editor.get_str()) {
                         Ok(text) => text,

examples/splitter.rs

@@ -41,7 +41,7 @@ fn main() -> Result<(), kas::shell::Error> {
                 #[widget(use_msg = handle_button)] buttons -> Message = buttons,
                 #[widget] panes: RowSplitter<EditField> = panes,
             }
-            impl {
+            impl Self {
                 fn handle_button(&mut self, mgr: &mut Manager, msg: Message) {
                     match msg {
                         Message::Decr => {

examples/stopwatch.rs

@@ -27,7 +27,7 @@ fn make_window() -> Box<dyn kas::Window> {
             saved: Duration = Duration::default(),
             start: Option<Instant> = None,
         }
-        impl {
+        impl Self {
             fn reset(&mut self, mgr: &mut Manager, _: ()) {
                 self.saved = Duration::default();
                 self.start = None;
@@ -43,12 +43,12 @@ fn make_window() -> Box<dyn kas::Window> {
                 }
             }
         }
-        impl kas::WidgetConfig {
+        impl kas::WidgetConfig for Self {
             fn configure(&mut self, mgr: &mut Manager) {
                 mgr.enable_alt_bypass(true);
             }
         }
-        impl Handler {
+        impl Handler for Self {
             type Msg = VoidMsg;
             fn handle(&mut self, mgr: &mut Manager, event: Event) -> Response<VoidMsg> {
                 match event {

examples/sync-counter.rs

@@ -28,7 +28,7 @@ fn main() -> Result<(), kas::shell::Error> {
                     TextButton::new_msg("+", 1),
                 ],
             }
-            impl {
+            impl Self {
                 fn update(&mut self, mgr: &mut Manager, msg: i32) {
                     self.counter.update_value(mgr, |v| v + msg);
                 }