glib: Add a Properties derive macro

The macro would simplify the creation of properties and generate
traits that can be used in ObjectImpl for now until further integration
with signals & the rest of GObject creation is figured out.

Author: ranfdev

glib-macros/Cargo.toml

@@ -26,3 +26,4 @@ proc-macro = true
 [dev-dependencies]
 glib = { path = "../glib" }
 trybuild2 = "1.0"
+once_cell = "1.9.0"

glib-macros/src/boxed_derive.rs

@@ -243,5 +243,15 @@ pub fn impl_boxed(input: &syn::DeriveInput) -> TokenStream {
                 ::std::boxed::Box::into_raw(::std::boxed::Box::new(self.clone())) as *mut _
             }
         }
+
+        impl #crate_ident::HasParamSpec for #name {
+            type ParamSpec = #crate_ident::ParamSpecBoxed;
+            type SetValue = Self;
+            type BuilderFn = fn(&str) -> #crate_ident::ParamSpecBoxedBuilder<Self>;
+
+            fn param_spec_builder() -> Self::BuilderFn {
+                |name| Self::ParamSpec::builder(name)
+            }
+        }
     }
 }

glib-macros/src/enum_derive.rs

@@ -189,5 +189,15 @@ pub fn impl_enum(input: &syn::DeriveInput) -> TokenStream {
                 }
             }
         }
+
+        impl #crate_ident::HasParamSpec for #name {
+            type ParamSpec = #crate_ident::ParamSpecEnum;
+            type SetValue = Self;
+            type BuilderFn = fn(&str, Self) -> #crate_ident::ParamSpecEnumBuilder<Self>;
+
+            fn param_spec_builder() -> Self::BuilderFn {
+                |name, default_value| Self::ParamSpec::builder_with_default(name, default_value)
+            }
+        }
     }
 }

glib-macros/src/lib.rs

@@ -9,6 +9,7 @@ mod error_domain_derive;
 mod flags_attribute;
 mod object_interface_attribute;
 mod object_subclass_attribute;
+mod properties;
 mod shared_boxed_derive;
 mod variant_derive;
 
@@ -819,7 +820,6 @@ pub fn variant_derive(input: TokenStream) -> TokenStream {
     let input = parse_macro_input!(input as DeriveInput);
     variant_derive::impl_variant(input)
 }
-
 #[proc_macro]
 pub fn cstr_bytes(item: TokenStream) -> TokenStream {
     syn::parse::Parser::parse2(
@@ -836,3 +836,92 @@ pub fn cstr_bytes(item: TokenStream) -> TokenStream {
     )
     .unwrap_or_else(|e| e.into_compile_error().into())
 }
+
+/// # Example
+/// ```
+/// use std::cell::RefCell;
+/// use std::marker::PhantomData;
+/// use std::sync::Mutex;
+/// use glib::prelude::*;
+/// use glib::subclass::prelude::*;
+/// use glib_macros::Properties;
+///
+/// #[derive(Default, Clone)]
+/// struct Author {
+///     name: String,
+///     nick: String,
+/// }
+///
+/// pub mod imp {
+///     use glib::{ParamSpec, Value};
+///     use std::rc::Rc;
+///
+///     use super::*;
+///
+///     #[derive(Properties, Default)]
+///     #[properties(wrapper_type = super::Foo)]
+///     pub struct Foo {
+///         #[property(get, set = Self::set_fizz)]
+///         fizz: RefCell<String>,
+///         #[property(name = "author-name", get, set, type = String, member = name)]
+///         #[property(name = "author-nick", get, set, type = String, member = nick)]
+///         author: RefCell<Author>,
+///         #[property(get, set, user_1, user_2, lax_validation)]
+///         custom_flags: RefCell<String>,
+///         #[property(get, set, builder().minimum(0).maximum(5))]
+///         numeric_builder: RefCell<u32>,
+///         #[property(get, set, builder('c'))]
+///         builder_with_required_param: RefCell<char>,
+///         #[property(get, set)]
+///         optional: RefCell<Option<String>>,
+///         #[property(get, set)]
+///         smart_pointer: Rc<RefCell<String>>,
+///     }
+///
+///     impl ObjectImpl for Foo {
+///         fn properties() -> &'static [ParamSpec] {
+///             Self::derived_properties()
+///         }
+///         fn set_property(
+///             &self,
+///             _id: usize,
+///             _value: &Value,
+///             _pspec: &ParamSpec,
+///         ) {
+///             Self::derived_set_property(self, _id, _value, _pspec).unwrap()
+///         }
+///         fn property(&self, _id: usize, _pspec: &ParamSpec) -> Value {
+///             Self::derived_property(self, _id, _pspec).unwrap()
+///         }
+///     }
+///
+///     #[glib::object_subclass]
+///     impl ObjectSubclass for Foo {
+///         const NAME: &'static str = "MyFoo";
+///         type Type = super::Foo;
+///     }
+///
+///     impl Foo {
+///         fn set_fizz(&self, value: String) {
+///             *self.fizz.borrow_mut() = format!("custom set: {}", value);
+///         }
+///     }
+/// }
+///
+/// glib::wrapper! {
+///     pub struct Foo(ObjectSubclass<imp::Foo>);
+/// }
+///
+/// fn main() {
+///   let myfoo: Foo = glib::object::Object::new(&[]);
+///
+///   myfoo.set_fizz("test value");
+///   assert_eq!(myfoo.fizz(), "custom set: test value".to_string());
+/// }
+/// ```
+#[allow(clippy::needless_doctest_main)]
+#[proc_macro_derive(Properties, attributes(properties, property))]
+pub fn derive_props(input: TokenStream) -> TokenStream {
+    let input = parse_macro_input!(input as properties::PropsMacroInput);
+    properties::impl_derive_props(input)
+}