From b82b6566f1a0f5f0cbd9c0f5fca6b8702d85ebe8 Mon Sep 17 00:00:00 2001
From: Ashley Wulber <ashley@system76.com>
Date: Sun, 21 May 2023 23:15:08 -0400
Subject: [PATCH] refactor(cosmic-config-derive): add support for types with
 generic parameters

---
 Cargo.toml                      |  1 +
 cosmic-config-derive/src/lib.rs | 20 ++++++++++++++++++--
 cosmic-config/Cargo.toml        |  2 +-
 cosmic-config/src/lib.rs        |  6 +++---
 4 files changed, 23 insertions(+), 6 deletions(-)

diff --git a/Cargo.toml b/Cargo.toml
index 0879d0f9..acccb0ff 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -29,6 +29,7 @@ cosmic-panel-config = {git = "https://github.com/pop-os/cosmic-panel", optional
 sctk = { package = "smithay-client-toolkit", git = "https://github.com/Smithay/client-toolkit", optional = true, rev = "389a4f2" }
 slotmap = "1.0.6"
 fraction = "0.13.0"
+cosmic-config = { path = "cosmic-config" }
 
 [target.'cfg(unix)'.dependencies]
 freedesktop-icons = "0.2.2"
diff --git a/cosmic-config-derive/src/lib.rs b/cosmic-config-derive/src/lib.rs
index 5f9c25e0..36370d75 100644
--- a/cosmic-config-derive/src/lib.rs
+++ b/cosmic-config-derive/src/lib.rs
@@ -1,6 +1,6 @@
 use proc_macro::TokenStream;
 use quote::quote;
-use syn;
+use syn::{self, parse_quote};
 
 #[proc_macro_derive(CosmicConfigEntry)]
 pub fn cosmic_config_entry_derive(input: TokenStream) -> TokenStream {
@@ -14,6 +14,7 @@ pub fn cosmic_config_entry_derive(input: TokenStream) -> TokenStream {
 
 fn impl_cosmic_config_entry_macro(ast: &syn::DeriveInput) -> TokenStream {
     let name = &ast.ident;
+    let generics = &ast.generics;
 
     // Get the fields of the struct
     let fields = match ast.data {
@@ -42,8 +43,23 @@ fn impl_cosmic_config_entry_macro(ast: &syn::DeriveInput) -> TokenStream {
         }
     });
 
+    // Get the existing where clause or create a new one if it doesn't exist
+    let mut where_clause = ast
+        .generics
+        .where_clause
+        .clone()
+        .unwrap_or_else(|| parse_quote!(where));
+
+    // Add your additional constraints to the where clause
+    // Here, we add the constraint 'T: Debug' to all generic parameters
+    for param in ast.generics.params.iter() {
+        where_clause
+            .predicates
+            .push(parse_quote!(#param: ::std::default::Default + ::serde::Serialize + ::serde::de::DeserializeOwned));
+    }
+
     let gen = quote! {
-        impl CosmicConfigEntry for #name {
+        impl #generics CosmicConfigEntry for #name #generics #where_clause {
             fn write_entry(&self, config: &Config) -> Result<(), cosmic_config::Error> {
                 #(#write_each_config_field)*
                 Ok(())
diff --git a/cosmic-config/Cargo.toml b/cosmic-config/Cargo.toml
index 5bf94df1..7393fafc 100644
--- a/cosmic-config/Cargo.toml
+++ b/cosmic-config/Cargo.toml
@@ -6,7 +6,7 @@ edition = "2021"
 [features]
 default = ["macro", "subscription"]
 macro = ["cosmic-config-derive"]
-subscription = ["iced", "iced_futures"]
+subscription = ["iced_futures"]
 
 [dependencies]
 atomicwrites = "0.4.0"
diff --git a/cosmic-config/src/lib.rs b/cosmic-config/src/lib.rs
index 57dfef95..cfcea1e8 100644
--- a/cosmic-config/src/lib.rs
+++ b/cosmic-config/src/lib.rs
@@ -1,7 +1,7 @@
 #[cfg(feature = "subscription")]
-use iced::subscription;
-#[cfg(feature = "subscription")]
 use iced_futures::futures::channel::mpsc;
+#[cfg(feature = "subscription")]
+use iced_futures::subscription;
 use notify::{RecommendedWatcher, Watcher};
 use serde::{de::DeserializeOwned, Serialize};
 use std::{
@@ -277,7 +277,7 @@ pub enum ConfigUpdate<T> {
 
 pub trait CosmicConfigEntry
 where
-    Self: Sized + Default,
+    Self: Sized,
 {
     fn write_entry(&self, config: &Config) -> Result<(), crate::Error>;
     fn get_entry(config: &Config) -> Result<Self, (Vec<crate::Error>, Self)>;