Revise make_widget class spec

Author: dhardy

kas-gtk/examples/calculator.rs

@@ -31,7 +31,7 @@ enum Key {
 
 fn main() -> Result<(), kas_gtk::Error> {
     let buttons = make_widget!{
-        grid => Key;
+        container(grid) => Key;
         struct {
             #[widget(col = 0, row = 0)] _ = TextButton::new("clear", || Key::Clear),
             #[widget(col = 1, row = 0)] _ = TextButton::new("÷", || Key::Divide),
@@ -53,7 +53,7 @@ fn main() -> Result<(), kas_gtk::Error> {
         }
     };
     let content = make_widget!{
-        vertical => NoResponse;
+        container(vertical) => NoResponse;
         struct {
             // #[widget] state: Text = Text::from("0"),
             // #[widget] buf: Text = Text::new() ,

kas-gtk/examples/clock.rs

@@ -20,7 +20,7 @@ use kas::{SimpleWindow, Toolkit, TkWidget};
 
 fn main() -> Result<(), kas_gtk::Error> {
     let mut window = SimpleWindow::new(make_widget! {
-            vertical => NoResponse;
+            container(vertical) => NoResponse;
             struct {
                 #[widget] date: Text = Text::new(),
                 #[widget] time: Text = Text::new()

kas-gtk/examples/counter.rs

@@ -23,14 +23,14 @@ enum Message {
 
 fn main() -> Result<(), kas_gtk::Error> {
     let buttons = make_widget!(
-        horizontal => Message;
+        container(horizontal) => Message;
         struct {
             #[widget] _ = TextButton::new("−", || Message::Decr),
             #[widget] _ = TextButton::new("+", || Message::Incr),
         }
     );
     let window = SimpleWindow::new(make_widget!(
-        vertical => NoResponse;
+        container(vertical) => NoResponse;
         struct {
             #[widget] display: Text = Text::from("0"),
             #[widget(handler = handle_button)] buttons -> Message = buttons,

kas-gtk/examples/stopwatch.rs

@@ -17,7 +17,7 @@ use kas::display::Text;
 use kas::event::{NoResponse};
 use kas::macros::{NoResponse, make_widget};
 use kas::HasText;
-use kas::{Class, SimpleWindow, Toolkit, TkWidget, Window};
+use kas::{SimpleWindow, Toolkit, TkWidget, Window};
 
 #[derive(Debug, NoResponse)]
 enum Control {
@@ -34,11 +34,10 @@ fn make_window() -> Rc<RefCell<Window>> {
     }
 
     let stopwatch = make_widget! {
-        horizontal => NoResponse;
+        container(horizontal) => NoResponse;
         struct {
             #[widget] display: impl SetText = make_widget!{
-                single => NoResponse;
-                class = Class::Frame;
+                frame => NoResponse;
                 struct {
                     #[widget] display: Text = Text::from("0.000"),
                 }

kas-macros/src/args.rs

@@ -5,7 +5,7 @@
 
 use proc_macro2::{Punct, Spacing, Span, TokenStream, TokenTree};
 use quote::{quote, TokenStreamExt, ToTokens};
-use syn::{Data, DeriveInput, Expr, Fields, FieldsNamed, FieldsUnnamed, Generics, Ident, Index, Lit, Member, Path, TypeTraitObject, Type, TypePath, ImplItemMethod};
+use syn::{Data, DeriveInput, Expr, Fields, FieldsNamed, FieldsUnnamed, Generics, Ident, Index, Lit, Member, TypeTraitObject, Type, TypePath, ImplItemMethod};
 use syn::{parse_quote, braced, bracketed, parenthesized};
 use syn::parse::{Error, Parse, ParseStream, Result};
 use syn::token::{Brace, Colon, Comma, Eq, FatArrow, Impl, Paren, Pound, RArrow, Semi, Struct, Underscore, Where};
@@ -355,6 +355,11 @@ impl Parse for HandlerArgs {
     }
 }
 
+pub enum Class {
+    Container(Ident),
+    Frame,
+}
+
 pub enum ChildType {
     Fixed(Type),     // fixed type
     // Generic, optionally with specified handler response type,
@@ -370,10 +375,8 @@ pub struct WidgetField {
 }
 
 pub struct MakeWidget {
-    // layout direction
-    pub layout: Ident,
     // widget class
-    pub class: Option<Path>,
+    pub class: Class,
     // response type
     pub response: Type,
     // child widgets and data fields
@@ -384,23 +387,23 @@ pub struct MakeWidget {
 
 impl Parse for MakeWidget {
     fn parse(input: ParseStream) -> Result<Self> {
-        let layout: Ident = input.parse()?;
-        let _: FatArrow = input.parse()?;
+        let class_name: Ident = input.parse()?;
+        let class = if class_name == "container" {
+            let content;
+            let _ = parenthesized!(content in input);
+            let layout: Ident = content.parse()?;
+            Class::Container(layout)
+        } else if class_name == "frame" {
+            Class::Frame
+        } else {
+            return Err(Error::new(class_name.span(),
+                    "make_widget only supports the following classes: container, frame"));
+        };
 
+        let _: FatArrow = input.parse()?;
         let response: Type = input.parse()?;
         let _: Semi = input.parse()?;
 
-        // TODO: revise attributes?
-        let class = if input.peek(kw::class) {
-            let _: kw::class = input.parse()?;
-            let _: Eq = input.parse()?;
-            let class: Path = input.parse()?;
-            let _: Semi = input.parse()?;
-            Some(class)
-        } else {
-            None
-        };
-        
         let _: Struct = input.parse()?;
         let content;
         let _ = braced!(content in input);
@@ -436,7 +439,7 @@ impl Parse for MakeWidget {
             impls.push((target, methods));
         }
 
-        Ok(MakeWidget { layout, class, response, fields, impls })
+        Ok(MakeWidget { class, response, fields, impls })
     }
 }
 

kas-macros/src/lib.rs

@@ -20,7 +20,7 @@ use syn::{parse_quote, parse_macro_input};
 use syn::token::Comma;
 use syn::punctuated::Punctuated;
 
-use self::args::ChildType;
+use self::args::{Class, ChildType};
 
 #[cfg(not(feature = "cassowary"))] mod layout_extern;
 #[cfg(not(feature = "cassowary"))] use self::layout_extern as layout;
@@ -304,6 +304,11 @@ pub fn derive(input: proc_macro::TokenStream) -> proc_macro::TokenStream {
 
 /// Macro to create a widget with anonymous type
 /// 
+/// This macro supports widgets of the following classes:
+/// 
+/// -   Container
+/// -   Frame
+/// 
 /// This exists purely to save you some typing. You could instead make your own
 /// struct, derive `Widget` (with attributes to enable Core, Layout and Widget
 /// implementation), manually implement `event::Handler`, and instantiate an
@@ -312,10 +317,10 @@ pub fn derive(input: proc_macro::TokenStream) -> proc_macro::TokenStream {
 /// Syntax should match the following Backus-Naur Form:
 /// 
 /// ```bnf
-/// <input>     ::= <layout> "=>" <response> ";" <class_spec> <fields> ";" <funcs>
+/// <input>     ::= <class> "=>" <response> ";" <fields> ";" <funcs>
+/// <class>     ::= "container" "(" <layout> ")" | "frame"
 /// <layout>    ::= "single" | "horizontal" | "vertical" | "grid"
 /// <response>  ::= <type>
-/// <class_spec> ::= "" | "class" "=" <path> ";"
 /// <fields>    ::= "" | <field> | <field> "," <fields>
 /// <field>     ::= <w_attr> <opt_ident> <field_ty> = <expr>
 /// <opt_ident> ::= "_" | <ident>
@@ -454,9 +459,17 @@ pub fn make_widget(input: proc_macro::TokenStream) -> proc_macro::TokenStream {
     let mut handler_extra = Punctuated::<_, Comma>::new();
     let mut handler_clauses = Punctuated::<_, Comma>::new();
 
-    let layout = &args.layout;
     let response = &args.response;
 
+    let widget_args = match args.class {
+        Class::Container(layout) => quote!{
+            class = #c::Class::Container, layout = #layout
+        },
+        Class::Frame => quote!{
+            class = #c::Class::Frame
+        },
+    };
+    
     for (index, field) in args.fields.drain(..).enumerate() {
         let attr = &field.widget_attr;
 
@@ -545,12 +558,10 @@ pub fn make_widget(input: proc_macro::TokenStream) -> proc_macro::TokenStream {
         });
     };
 
-    let class = args.class.unwrap_or_else(|| parse_quote!{ #c::Class::Container });
-    
     // TODO: we should probably not rely on recursive macro expansion here!
     // (I.e. use direct code generation for Widget derivation, instead of derive.)
     let toks = (quote!{ {
-        #[widget(class = #class, layout = #layout)]
+        #[widget(#widget_args)]
         #[handler(response = #response, generics = < #handler_extra > #handler_where)]
         #[derive(Clone, Debug, #c::macros::Widget)]
         struct AnonWidget<#gen_ptrs> {