Merge pull request #478 from kas-gui/work3

Remove input data from widget layout syntax items

Author: dhardy

crates/kas-macros/src/lib.rs

@@ -208,27 +208,33 @@ pub fn impl_scope(input: TokenStream) -> TokenStream {
 /// implementation of `Tile::nav_next`, with a couple of exceptions
 /// (where macro-time analysis is insufficient to implement this method).
 ///
-/// > [_Column_], [_Row_], [_List_] [_AlignedColumn_], [_AlignedRow_], [_Grid_], [_Float_], [_Frame_] :\
+/// > [_Column_], [_Row_], [_List_] [_AlignedColumn_], [_AlignedRow_], [_Grid_],
+/// > [_Float_], [_Frame_] :\
 /// >    These stand-alone macros are explicitly supported in this position.\
-///
+/// >
 /// > _Single_ :\
 /// >    `self` `.` _Member_\
-/// >    A named child: `self.foo` (more precisely, this matches any expression starting `self`, and uses `&mut (#expr)`)
+/// >    A named child: `self.foo` (more precisely, this matches any
+/// > expression starting `self`, and uses `&mut (#expr)`).
 /// >
 /// > _WidgetConstructor_ :\
 /// >    _Expr_\
-/// >    An expression yielding a widget, e.g. `Label::new("Hello world")`. The result must be an object of some type `W: Widget`.
+/// >    An expression yielding a widget, e.g.
+/// > `Label::new("Hello world")`. The result must be an object of some type
+/// > `W: Widget<Data = ()>`. This widget will be stored in a hidden field and
+/// > is accessible through `Tile::get_child` but does not receive input data.
 /// >
 /// > _LabelLit_ :\
 /// > &nbsp;&nbsp; _StrLit_\
-/// > &nbsp;&nbsp; A string literal generates a label widget, e.g. "Hello world". This is an internal type without text wrapping.
-/// >
+/// > &nbsp;&nbsp; A string literal generates a label widget, e.g. "Hello
+/// > world". This is an internal type without text wrapping.
+///
 /// Additional syntax rules (not layout items):
 ///
 /// > _Member_ :\
 /// > &nbsp;&nbsp; _Ident_ | _Index_\
 /// > &nbsp;&nbsp; The name of a struct field or an index into a tuple struct.
-/// >
+///
 /// ## Examples
 ///
 /// A simple example is the

crates/kas-macros/src/make_layout.rs

@@ -10,8 +10,8 @@ use proc_macro_error2::emit_error;
 use quote::{quote, quote_spanned, ToTokens, TokenStreamExt};
 use syn::parse::{Parse, ParseStream, Result};
 use syn::spanned::Spanned;
-use syn::{braced, bracketed, parenthesized, parse_quote, token};
-use syn::{Expr, Ident, LitStr, Member, Token, Type};
+use syn::{braced, bracketed, parenthesized, token};
+use syn::{Expr, Ident, LitStr, Member, Token};
 
 #[allow(non_camel_case_types)]
 mod kw {
@@ -21,24 +21,12 @@ mod kw {
     custom_keyword!(pack);
     custom_keyword!(column);
     custom_keyword!(row);
-    custom_keyword!(right);
-    custom_keyword!(left);
-    custom_keyword!(down);
-    custom_keyword!(up);
-    custom_keyword!(center);
-    custom_keyword!(stretch);
     custom_keyword!(frame);
     custom_keyword!(list);
     custom_keyword!(grid);
-    custom_keyword!(default);
-    custom_keyword!(top);
-    custom_keyword!(bottom);
     custom_keyword!(aligned_column);
     custom_keyword!(aligned_row);
     custom_keyword!(float);
-    custom_keyword!(px);
-    custom_keyword!(em);
-    custom_keyword!(map_any);
     custom_keyword!(with_direction);
     custom_keyword!(with_style);
     custom_keyword!(with_background);
@@ -48,15 +36,14 @@ mod kw {
 pub struct StorageFields {
     pub ty_toks: Toks,
     pub def_toks: Toks,
-    pub used_data_ty: bool,
 }
 
 #[derive(Debug)]
 pub struct Tree(Layout);
 impl Tree {
-    pub fn storage_fields(&self, children: &mut Vec<Child>, data_ty: &Type) -> StorageFields {
+    pub fn storage_fields(&self, children: &mut Vec<Child>) -> StorageFields {
         let mut fields = StorageFields::default();
-        self.0.append_fields(&mut fields, children, data_ty);
+        self.0.append_fields(&mut fields, children);
         fields
     }
 
@@ -138,7 +125,6 @@ enum Layout {
     Float(LayoutList<()>),
     Grid(Ident, GridDimensions, LayoutList<CellInfo>),
     Label(Ident, LitStr),
-    MapAny(Box<Layout>, MapAny),
 }
 
 #[derive(Debug)]
@@ -148,6 +134,7 @@ struct ExprMember {
     member: Member,
 }
 
+#[allow(unused)]
 #[derive(Debug)]
 enum Direction {
     Left,
@@ -192,20 +179,17 @@ impl Layout {
 
         loop {
             if let Ok(dot_token) = input.parse::<Token![.]>() {
-                if input.peek(kw::map_any) {
-                    let map_any = MapAny::parse(dot_token, input)?;
-                    layout = Layout::MapAny(Box::new(layout), map_any);
-                } else if input.peek(kw::align) {
+                if input.peek(kw::align) {
                     let align = Align::parse(dot_token, input)?;
                     layout = Layout::Align(Box::new(layout), align);
                 } else if input.peek(kw::pack) {
                     let pack = Pack::parse(dot_token, input, core_gen)?;
                     layout = Layout::Pack(Box::new(layout), pack);
                 } else if let Ok(ident) = input.parse::<Ident>() {
                     let note_msg = if matches!(&layout, &Layout::Frame(_, _, _, _)) {
-                        "supported methods on layout objects: `map_any`, `align`, `pack`, `with_style`, `with_background`"
+                        "supported methods on layout objects: `align`, `pack`, `with_style`, `with_background`"
                     } else {
-                        "supported methods on layout objects: `map_any`, `align`, `pack`"
+                        "supported methods on layout objects: `align`, `pack`"
                     };
                     emit_error!(
                         ident, "method not supported here";
@@ -484,24 +468,7 @@ impl ToTokens for ExprMember {
 
 impl Parse for Direction {
     fn parse(input: ParseStream) -> Result<Self> {
-        let lookahead = input.lookahead1();
-        if lookahead.peek(kw::right) {
-            let _: kw::right = input.parse()?;
-            Ok(Direction::Right)
-        } else if lookahead.peek(kw::down) {
-            let _: kw::down = input.parse()?;
-            Ok(Direction::Down)
-        } else if lookahead.peek(kw::left) {
-            let _: kw::left = input.parse()?;
-            Ok(Direction::Left)
-        } else if lookahead.peek(kw::up) {
-            let _: kw::up = input.parse()?;
-            Ok(Direction::Up)
-        } else if lookahead.peek(Token![self]) {
-            Ok(Direction::Expr(input.parse()?))
-        } else {
-            Err(lookahead.error())
-        }
+        Ok(Direction::Expr(input.parse()?))
     }
 }
 
@@ -524,24 +491,6 @@ impl ToTokens for Direction {
     }
 }
 
-#[derive(Debug)]
-#[allow(unused)]
-struct MapAny {
-    pub dot_token: Token![.],
-    pub kw: kw::map_any,
-    pub paren_token: token::Paren,
-}
-impl MapAny {
-    fn parse(dot_token: Token![.], input: ParseStream) -> Result<Self> {
-        let _content;
-        Ok(MapAny {
-            dot_token,
-            kw: input.parse()?,
-            paren_token: parenthesized!(_content in input),
-        })
-    }
-}
-
 #[derive(Debug)]
 #[allow(unused)]
 struct Align {
@@ -612,10 +561,10 @@ impl Pack {
 }
 
 impl Layout {
-    fn append_fields(&self, fields: &mut StorageFields, children: &mut Vec<Child>, data_ty: &Type) {
+    fn append_fields(&self, fields: &mut StorageFields, children: &mut Vec<Child>) {
         match self {
             Layout::Align(layout, _) => {
-                layout.append_fields(fields, children, data_ty);
+                layout.append_fields(fields, children);
             }
             Layout::Single(_) => (),
             Layout::Pack(layout, pack) => {
@@ -626,18 +575,17 @@ impl Layout {
                 fields
                     .def_toks
                     .append_all(quote! { #stor: Default::default(), });
-                layout.append_fields(fields, children, data_ty);
+                layout.append_fields(fields, children);
             }
             Layout::Widget(ident, expr) => {
                 children.push(Child::new_core(ident.clone().into()));
                 fields
                     .ty_toks
-                    .append_all(quote! { #ident: Box<dyn ::kas::Widget<Data = #data_ty>>, });
+                    .append_all(quote! { #ident: Box<dyn ::kas::Widget<Data = ()>>, });
                 let span = expr.span();
                 fields
                     .def_toks
                     .append_all(quote_spanned! {span=> #ident: Box::new(#expr), });
-                fields.used_data_ty = true;
             }
             Layout::Frame(stor, layout, _, _) => {
                 fields
@@ -646,7 +594,7 @@ impl Layout {
                 fields
                     .def_toks
                     .append_all(quote! { #stor: Default::default(), });
-                layout.append_fields(fields, children, data_ty);
+                layout.append_fields(fields, children);
             }
             Layout::List(stor, _, LayoutList(list)) => {
                 fields
@@ -660,12 +608,12 @@ impl Layout {
                     quote! { #stor: ::kas::layout::FixedRowStorage<#len>, }
                 });
                 for item in list {
-                    item.layout.append_fields(fields, children, data_ty);
+                    item.layout.append_fields(fields, children);
                 }
             }
             Layout::Float(LayoutList(list)) => {
                 for item in list {
-                    item.layout.append_fields(fields, children, data_ty);
+                    item.layout.append_fields(fields, children);
                 }
             }
             Layout::Grid(stor, dim, LayoutList(list)) => {
@@ -678,42 +626,18 @@ impl Layout {
                     .append_all(quote! { #stor: Default::default(), });
 
                 for item in list {
-                    item.layout.append_fields(fields, children, data_ty);
+                    item.layout.append_fields(fields, children);
                 }
             }
             Layout::Label(ident, text) => {
                 children.push(Child::new_core(ident.clone().into()));
                 let span = text.span();
-                if *data_ty == syn::parse_quote! { () } {
-                    fields
-                        .ty_toks
-                        .append_all(quote! { #ident: ::kas::hidden::StrLabel, });
-                    fields.def_toks.append_all(
-                        quote_spanned! {span=> #ident: ::kas::hidden::StrLabel::new(#text), },
-                    );
-                } else {
-                    fields.ty_toks.append_all(
-                        quote! { #ident: ::kas::hidden::MapAny<#data_ty, ::kas::hidden::StrLabel>, },
-                    );
-                    fields.def_toks.append_all(
-                        quote_spanned! {span=> #ident: ::kas::hidden::MapAny::new(::kas::hidden::StrLabel::new(#text)), },
-                    );
-                    fields.used_data_ty = true;
-                }
-            }
-            Layout::MapAny(layout, map_any) => {
-                let start = children.len();
-                layout.append_fields(fields, children, &parse_quote! { () });
-                let map_expr: Expr = parse_quote! { &() };
-                for child in &mut children[start..] {
-                    if let Some(ref expr) = child.data_binding {
-                        if *expr != map_expr {
-                            emit_error!(map_any.kw, "invalid data type mapping")
-                        }
-                    } else {
-                        child.data_binding = Some(map_expr.clone());
-                    }
-                }
+                fields
+                    .ty_toks
+                    .append_all(quote! { #ident: ::kas::hidden::StrLabel, });
+                fields.def_toks.append_all(
+                    quote_spanned! {span=> #ident: ::kas::hidden::StrLabel::new(#text), },
+                );
             }
         }
     }
@@ -764,7 +688,6 @@ impl Layout {
             Layout::Label(stor, _) => {
                 quote! { layout::Visitor::single(&mut #core_path.#stor) }
             }
-            Layout::MapAny(layout, _) => return layout.generate(core_path),
         })
     }
 
@@ -777,10 +700,9 @@ impl Layout {
         output: &mut Vec<usize>,
     ) -> std::result::Result<(), (Span, &'static str)> {
         match self {
-            Layout::Align(layout, _)
-            | Layout::Pack(layout, _)
-            | Layout::Frame(_, layout, _, _)
-            | Layout::MapAny(layout, _) => layout.nav_next(children, output),
+            Layout::Align(layout, _) | Layout::Pack(layout, _) | Layout::Frame(_, layout, _, _) => {
+                layout.nav_next(children, output)
+            }
             Layout::Single(m) => {
                 for (i, child) in children.enumerate() {
                     if let ChildIdent::Field(ref ident) = child.ident {

crates/kas-macros/src/widget.rs

@@ -184,7 +184,7 @@ pub fn widget(attr_span: Span, mut args: WidgetArgs, scope: &mut Scope) -> Resul
 
             let mut stor_defs = Default::default();
             if let Some(Layout { ref tree, .. }) = args.layout {
-                stor_defs = tree.storage_fields(&mut children, &data_ty);
+                stor_defs = tree.storage_fields(&mut children);
             }
             if !stor_defs.ty_toks.is_empty() {
                 let name = format!("_{name}CoreTy");
@@ -796,11 +796,6 @@ pub fn impl_widget(
                 ChildIdent::Field(ident) => quote! { self.#ident },
                 ChildIdent::CoreField(ident) => quote! { #core_path.#ident },
             };
-            // TODO: incorrect or unconstrained data type of child causes a poor error
-            // message here. Add a constaint like this (assuming no mapping fn):
-            // <#ty as WidgetNode::Data> == Self::Data
-            // But this is unsupported: rust#20041
-            // predicates.push(..);
 
             get_mut_rules.append_all(if let Some(ref data) = child.data_binding {
                 quote! { #i => closure(#path.as_node(#data)), }

crates/kas-macros/src/widget_args.rs

@@ -238,7 +238,7 @@ impl Child {
         Child {
             ident: ChildIdent::CoreField(ident),
             attr_span: None,
-            data_binding: None,
+            data_binding: Some(syn::parse_quote! { &() }),
         }
     }
 }

crates/kas-widgets/src/combobox.rs

@@ -29,7 +29,7 @@ impl_scope! {
     /// when selected. If a handler is specified via [`Self::with`] or
     /// [`Self::with_msg`] then this message is passed to the handler and not emitted.
     #[widget {
-        layout = frame!(row! [self.label, self.mark])
+        layout = frame!(row! [self.label, Mark::new(MarkStyle::Point(Direction::Down))])
             .with_style(FrameStyle::Button)
             .align(AlignHints::CENTER);
         navigable = true;
@@ -40,8 +40,6 @@ impl_scope! {
         #[widget(&())]
         label: Label<String>,
         #[widget(&())]
-        mark: Mark,
-        #[widget(&())]
         popup: Popup<AdaptEvents<Column<Vec<MenuEntry<V>>>>>,
         active: usize,
         opening: bool,
@@ -233,7 +231,6 @@ impl<A, V: Clone + Debug + Eq + 'static> ComboBox<A, V> {
         ComboBox {
             core: Default::default(),
             label,
-            mark: Mark::new(MarkStyle::Point(Direction::Down)),
             popup: Popup::new(
                 AdaptEvents::new(Column::new(entries)).on_messages(|cx, _, _| {
                     if let Some(_) = cx.try_peek::<V>() {

examples/gallery.rs

@@ -107,12 +107,13 @@ fn widgets() -> Box<dyn Widget<Data = AppData>> {
     let popup_edit_box = impl_anon! {
         #[widget{
             layout = row! [
-                format_data!(data: &Data, "{}", &data.text),
-                Button::label_msg("&Edit", MsgEdit).map_any(),
+                self.text,
+                Button::label_msg("&Edit", MsgEdit),
             ];
         }]
         struct {
             core: widget_core!(),
+            #[widget] text: Text<Data, String> = format_data!(data: &Data, "{}", &data.text),
             #[widget(&())] popup: Popup<TextEdit> = Popup::new(TextEdit::new("", true), Direction::Down),
         }
         impl Events for Self {