Fix wrong node parameter widgets, attempt 3 at #2323 (#2334)

* WIP, for TrueDoctor to continue

* Expose first implementation type as default type in field metadata

* Cleanup

---------

Co-authored-by: Keavon Chambers <keavon@keavon.com>

node-graph/gcore/src/registry.rs

@@ -1,14 +1,13 @@
+use crate::transform::Footprint;
+use crate::{NodeIO, NodeIOTypes, Type};
+
+use dyn_any::DynAny;
+
 use std::collections::HashMap;
 use std::ops::Deref;
 use std::pin::Pin;
 use std::sync::{LazyLock, Mutex};
 
-use dyn_any::DynAny;
-
-use crate::transform::Footprint;
-use crate::NodeIO;
-use crate::NodeIOTypes;
-
 pub mod types {
 	/// 0% - 100%
 	pub type Percentage = f64;
@@ -47,6 +46,7 @@ pub struct FieldMetadata {
 	pub exposed: bool,
 	pub widget_override: RegistryWidgetOverride,
 	pub value_source: RegistryValueSource,
+	pub default_type: Option<Type>,
 	pub number_min: Option<f64>,
 	pub number_max: Option<f64>,
 	pub number_mode_range: Option<(f64, f64)>,

node-graph/node-macro/src/codegen.rs

@@ -117,6 +117,17 @@ pub(crate) fn generate_node_code(parsed: &ParsedNodeFn) -> syn::Result<TokenStre
 		})
 		.collect();
 
+	let default_types: Vec<_> = fields
+		.iter()
+		.map(|field| match field {
+			ParsedField::Regular { implementations, .. } => match implementations.first() {
+				Some(ty) => quote!(Some(concrete!(#ty))),
+				_ => quote!(None),
+			},
+			_ => quote!(None),
+		})
+		.collect();
+
 	let number_min_values: Vec<_> = fields
 		.iter()
 		.map(|field| match field {
@@ -292,6 +303,7 @@ pub(crate) fn generate_node_code(parsed: &ParsedNodeFn) -> syn::Result<TokenStre
 								description: #input_descriptions,
 								exposed: #exposed,
 								value_source: #value_sources,
+								default_type: #default_types,
 								number_min: #number_min_values,
 								number_max: #number_max_values,
 								number_mode_range: #number_mode_range_values,