glib-macros: Add use_derived_properties macro

CHANGELOG.md

@@ -1,6 +1,8 @@
 # Change Log
 
 ## [Unreleased]
+Yuri Izmer:
+- glib-macros: Add `derived_properties` macro 
 
 ## [0.17.10]
 Ben Kimock:

glib-macros/src/derived_properties_attribute.rs

@@ -0,0 +1,79 @@
+// Take a look at the license at the top of the repository in the LICENSE file.
+
+use proc_macro2::TokenStream;
+use proc_macro_error::abort_call_site;
+use quote::quote;
+
+pub const WRONG_PLACE_MSG: &str =
+    "This macro should be used on `impl` block for `glib::ObjectImpl` trait";
+
+pub fn impl_derived_properties(input: &syn::ItemImpl) -> TokenStream {
+    let syn::ItemImpl {
+        attrs,
+        generics,
+        trait_,
+        self_ty,
+        items,
+        ..
+    } = input;
+
+    let trait_path = match &trait_ {
+        Some(path) => &path.1,
+        None => abort_call_site!(WRONG_PLACE_MSG),
+    };
+
+    let mut has_property = false;
+    let mut has_properties = false;
+    let mut has_set_property = false;
+
+    for item in items {
+        if let syn::ImplItem::Fn(method) = item {
+            let ident = &method.sig.ident;
+
+            if ident == "properties" {
+                has_properties = true;
+            } else if ident == "set_property" {
+                has_set_property = true;
+            } else if ident == "property" {
+                has_property = true;
+            }
+        }
+    }
+
+    let crate_ident = crate::utils::crate_ident_new();
+
+    let properties = quote!(
+        fn properties() -> &'static [#crate_ident::ParamSpec] {
+            Self::derived_properties()
+        }
+    );
+
+    let set_property = quote!(
+        fn set_property(&self, id: usize, value: &#crate_ident::Value, pspec: &#crate_ident::ParamSpec) {
+            Self::derived_set_property(self, id, value, pspec)
+        }
+    );
+
+    let property = quote!(
+        fn property(&self, id: usize, pspec: &#crate_ident::ParamSpec) -> #crate_ident::Value {
+            Self::derived_property(self, id, pspec)
+        }
+    );
+
+    let generated: Vec<_> = vec![
+        (has_properties, properties),
+        (has_set_property, set_property),
+        (has_property, property),
+    ]
+    .into_iter()
+    .filter_map(|(has_method, method)| (!has_method).then_some(method))
+    .collect();
+
+    quote!(
+        #(#attrs)*
+        impl #generics #trait_path for #self_ty {
+            #(#items)*
+            #(#generated)*
+        }
+    )
+}

glib-macros/src/lib.rs

@@ -3,6 +3,7 @@
 mod boxed_derive;
 mod clone;
 mod closure;
+mod derived_properties_attribute;
 mod downgrade_derive;
 mod enum_derive;
 mod error_domain_derive;
@@ -882,7 +883,7 @@
 ///
 /// ## Using Rust keywords as property names
 /// You might hit a roadblock when declaring properties with this macro because you want to use a name that happens to be a Rust keyword. This may happen with names like `loop`, which is a pretty common name when creating things like animation handlers.
 /// To use those names, you can make use of the raw identifier feature of Rust. Simply prefix the identifier name with `r#` in the struct declaration. Internally, those `r#`s are stripped so you can use its expected name in [`ObjectExt::property`] or within GtkBuilder template files.
 ///
 /// # Generated wrapper methods
 /// The following methods are generated on the wrapper type specified on `#[properties(wrapper_type = ...)]`:
@@ -942,7 +943,6 @@
 /// }
 ///
 /// pub mod imp {
-///     use glib::{ParamSpec, Value};
 ///     use std::rc::Rc;
 ///
 ///     use super::*;
@@ -966,18 +966,9 @@
 ///         #[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(id, value, pspec)
-///         }
-///         fn property(&self, id: usize, pspec: &ParamSpec) -> Value {
-///             self.derived_property(id, pspec)
-///         }
-///     }
+///     
+///     #[glib::derived_properties]
+///     impl ObjectImpl for Foo {}
 ///
 ///     #[glib::object_subclass]
 ///     impl ObjectSubclass for Foo {
@@ -1010,6 +1001,31 @@
     properties::impl_derive_props(input)
 }
 
+/// This macro is shorteng for:
+///
+/// ```ignore
+///     fn properties() -> &'static [glib::ParamSpec] {
+///         Self::derived_properties()
+///     }
+///     fn set_property(&self, id: usize, value: &glib::Value, pspec: &glib::ParamSpec) {
+///         self.derived_set_property(id, value, pspec)
+///     }
+///     fn property(&self, id: usize, pspec: &glib::ParamSpec) -> glib::Value {
+///         self.derived_property(id, pspec)
+///     }
+/// ```
+///
+/// for ObjectImpl trait implementation
+#[proc_macro_attribute]
+#[proc_macro_error]
+pub fn derived_properties(_attr: TokenStream, item: TokenStream) -> TokenStream {
+    use proc_macro_error::abort_call_site;
+    match syn::parse::<syn::ItemImpl>(item) {
+        Ok(input) => derived_properties_attribute::impl_derived_properties(&input).into(),
+        Err(_) => abort_call_site!(derived_properties_attribute::WRONG_PLACE_MSG),
+    }
+}
+
 /// # Example
 /// ```
 /// use glib::prelude::*;

glib-macros/tests/properties.rs

@@ -11,8 +11,6 @@ mod base {
     use std::marker::PhantomData;
 
     pub mod imp {
-        use glib::{ParamSpec, Value};
-
         use super::*;
 
         #[derive(Properties, Default)]
@@ -24,17 +22,8 @@ mod base {
             not_overridden: PhantomData<u32>,
         }
 
-        impl ObjectImpl for Base {
-            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)
-            }
-            fn property(&self, id: usize, _pspec: &ParamSpec) -> Value {
-                Self::derived_property(self, id, _pspec)
-            }
-        }
+        #[glib::derived_properties]
+        impl ObjectImpl for Base {}
 
         #[glib::object_subclass]
         impl ObjectSubclass for Base {
@@ -90,7 +79,6 @@ mod foo {
     }
 
     pub mod imp {
-        use glib::{ParamSpec, Value};
         use std::rc::Rc;
 
         use super::*;
@@ -166,25 +154,16 @@ mod foo {
             construct_only_custom_setter: OnceCell<Option<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)
-            }
-            fn property(&self, id: usize, _pspec: &ParamSpec) -> Value {
-                Self::derived_property(self, id, _pspec)
-            }
-        }
-
         #[glib::object_subclass]
         impl ObjectSubclass for Foo {
             const NAME: &'static str = "MyFoo";
             type Type = super::Foo;
             type ParentType = Base;
         }
 
+        #[glib::derived_properties]
+        impl ObjectImpl for Foo {}
+
         impl Foo {
             fn set_author_name(&self, value: String) {
                 self.author.borrow_mut().name = value;
@@ -417,10 +396,7 @@ mod kw_names {
         use glib::ObjectExt;
         use std::cell::Cell;
 
-        use glib::{
-            subclass::{prelude::ObjectImpl, types::ObjectSubclass},
-            ParamSpec, Value,
-        };
+        use glib::subclass::{prelude::ObjectImpl, types::ObjectSubclass};
         use glib_macros::Properties;
 
         #[derive(Properties, Default)]
@@ -461,17 +437,8 @@ mod kw_names {
             type Type = super::KwNames;
         }
 
-        impl ObjectImpl for KwNames {
-            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)
-            }
-            fn property(&self, id: usize, _pspec: &ParamSpec) -> Value {
-                Self::derived_property(self, id, _pspec)
-            }
-        }
+        #[glib::derived_properties]
+        impl ObjectImpl for KwNames {}
     }
 
     glib::wrapper! {

glib/src/lib.rs

@@ -10,8 +10,8 @@
 #[doc(hidden)]
 pub use glib_macros::cstr_bytes;
 pub use glib_macros::{
-    clone, closure, closure_local, flags, object_interface, object_subclass, Boxed, Downgrade,
-    Enum, ErrorDomain, Properties, SharedBoxed, ValueDelegate, Variant,
+    clone, closure, closure_local, derived_properties, flags, object_interface, object_subclass,
+    Boxed, Downgrade, Enum, ErrorDomain, Properties, SharedBoxed, ValueDelegate, Variant,
 };
 pub use gobject_ffi;
 #[doc(hidden)]
@@ -131,7 +131,7 @@
 mod convert;
 pub use self::convert::*;
 mod enums;
 mod functions;
 pub use self::functions::*;
 mod key_file;
 pub mod prelude;