cxx-qt-gen: share QSignal free namespace generation in naming module

Related to KDAB#577

crates/cxx-qt-gen/src/generator/cpp/externcxxqt.rs

@@ -4,7 +4,10 @@
 // SPDX-License-Identifier: MIT OR Apache-2.0
 
 use crate::{
-    generator::cpp::signal::generate_cpp_free_signal,
+    generator::{
+        cpp::signal::generate_cpp_free_signal,
+        naming::namespace::namespace_externcxxqt_with_qobject_namespace,
+    },
     parser::{externcxxqt::ParsedExternCxxQt, mappings::ParsedCxxMappings},
     CppFragment,
 };
@@ -27,18 +30,15 @@ pub fn generate(
     for block in blocks {
         for signal in &block.signals {
             // Build a namespace that includes any namespace for the T
-            let ident_namespace = if let Some(namespace) = cxx_mappings
-                .namespaces
-                .get(&signal.qobject_ident.to_string())
-            {
-                format!("::{namespace}")
-            } else {
-                "".to_owned()
-            };
+            let namespace = namespace_externcxxqt_with_qobject_namespace(
+                cxx_mappings
+                    .namespaces
+                    .get(&signal.qobject_ident.to_string()),
+            );
 
             out.push(GeneratedCppExternCxxQtBlocks {
                 method: generate_cpp_free_signal(signal, cxx_mappings)?,
-                namespace: format!("rust::cxxqtgen1::externcxxqt{ident_namespace}"),
+                namespace,
             });
         }
     }

crates/cxx-qt-gen/src/generator/naming/namespace.rs

@@ -38,6 +38,16 @@ pub fn namespace_combine_ident(namespace: &str, ident: &Ident) -> String {
     format!("{namespace}::{ident}")
 }
 
+/// Build the externcxxqt namespace combined with the given qobject_namespace
+pub fn namespace_externcxxqt_with_qobject_namespace(qobject_namespace: Option<&String>) -> String {
+    let mut free_namespace = vec!["rust::cxxqtgen1::externcxxqt"];
+    if let Some(qobject_namespace) = qobject_namespace {
+        free_namespace.push(qobject_namespace);
+    }
+
+    free_namespace.join("::")
+}
+
 /// For a given base namespace and QObject ident generate the internal namespace
 ///
 /// The base namespace could be from the module bridge or from the QObject

crates/cxx-qt-gen/src/generator/rust/signals.rs

@@ -7,7 +7,10 @@ use std::collections::BTreeMap;
 
 use crate::{
     generator::{
-        naming::{qobject::QObjectName, signals::QSignalName},
+        naming::{
+            namespace::namespace_externcxxqt_with_qobject_namespace, qobject::QObjectName,
+            signals::QSignalName,
+        },
         rust::{
             externcxxqt::GeneratedExternCxxQt, fragment::RustFragmentPair,
             qobject::GeneratedRustQObject,
@@ -38,20 +41,12 @@ pub fn generate_rust_free_signal(
     let on_ident_rust = idents.on_name;
     let original_method = &signal.method;
 
-    // TODO: share this in the naming module with generator/cpp
-    let connect_namespace = {
-        // Build a namespace that includes any namespace for the T
-        let ident_namespace = if let Some(namespace) = cxx_mappings
+    // Build a namespace that includes any namespace for the T
+    let connect_namespace = namespace_externcxxqt_with_qobject_namespace(
+        cxx_mappings
             .namespaces
-            .get(&signal.qobject_ident.to_string())
-        {
-            format!("::{namespace}")
-        } else {
-            "".to_owned()
-        };
-
-        format!("rust::cxxqtgen1::externcxxqt{ident_namespace}")
-    };
+            .get(&signal.qobject_ident.to_string()),
+    );
 
     let parameters_cxx: Vec<FnArg> = signal
         .parameters