[niepce] npc-engine: bind LibMetadata with cxx

[Hubert Figuière <hub src gnome org>]

commit d32fbbafda03df55a6615c4f227590d58b34f607
Author: Hubert Figuière <hub figuiere net>
Date:   Sat Oct 15 22:19:43 2022 -0400

    npc-engine: bind LibMetadata with cxx

 crates/npc-engine/build.rs              | 1 +
 crates/npc-engine/src/db/libmetadata.rs | 9 ++++-----
 crates/npc-engine/src/lib.rs            | 8 +++++++-
 src/niepce/ui/gridviewmodule.cpp        | 2 +-
 src/rust_bindings.hpp                   | 2 +-
 5 files changed, 14 insertions(+), 8 deletions(-)
---
diff --git a/crates/npc-engine/build.rs b/crates/npc-engine/build.rs
index 6ce29916..98867eda 100644
--- a/crates/npc-engine/build.rs
+++ b/crates/npc-engine/build.rs
@@ -33,6 +33,7 @@ fn main() {
             .exclude_item("Keyword")
             .exclude_item("Label")
             .exclude_item("LibFile")
+            .exclude_item("LibMetadata")
             // Ensure these are opaque as generics are still a problem.
             .exclude_item("NiepcePropertySet")
             .exclude_item("NiepcePropertyBag")
diff --git a/crates/npc-engine/src/db/libmetadata.rs b/crates/npc-engine/src/db/libmetadata.rs
index a61b4715..38642e9a 100644
--- a/crates/npc-engine/src/db/libmetadata.rs
+++ b/crates/npc-engine/src/db/libmetadata.rs
@@ -74,6 +74,10 @@ impl LibMetadata {
         }
     }
 
+    pub fn id(&self) -> LibraryId {
+        self.id
+    }
+
     pub fn serialize_inline(&self) -> String {
         self.xmp.serialize_inline()
     }
@@ -292,11 +296,6 @@ impl FromDb for LibMetadata {
     }
 }
 
-#[no_mangle]
-pub extern "C" fn engine_libmetadata_get_id(meta: &LibMetadata) -> LibraryId {
-    meta.id
-}
-
 #[no_mangle]
 pub extern "C" fn engine_libmetadata_to_properties(
     meta: &LibMetadata,
diff --git a/crates/npc-engine/src/lib.rs b/crates/npc-engine/src/lib.rs
index 3e73af00..7cbad7ec 100644
--- a/crates/npc-engine/src/lib.rs
+++ b/crates/npc-engine/src/lib.rs
@@ -104,7 +104,7 @@ pub extern "C" fn eng_property_bag_set_value(
     b.set_value(key.into(), v.clone())
 }
 
-use crate::db::{Keyword, Label, LibFile};
+use crate::db::{Keyword, Label, LibFile, LibMetadata};
 
 #[cxx::bridge(namespace = "eng")]
 mod ffi {
@@ -161,4 +161,10 @@ mod ffi {
     }
 
     impl Box<LibFile> {}
+
+    extern "Rust" {
+        type LibMetadata;
+
+        fn id(&self) -> i64;
+    }
 }
diff --git a/src/niepce/ui/gridviewmodule.cpp b/src/niepce/ui/gridviewmodule.cpp
index 1aef8204..1746291b 100644
--- a/src/niepce/ui/gridviewmodule.cpp
+++ b/src/niepce/ui/gridviewmodule.cpp
@@ -61,7 +61,7 @@ GridViewModule::on_lib_notification(const eng::LibNotification &ln)
         auto lm = engine_library_notification_get_libmetadata(&ln);
         DBG_OUT("received metadata");
         if (lm) {
-            m_metapanecontroller->display(engine_libmetadata_get_id(lm), lm);
+            m_metapanecontroller->display(lm->id(), lm);
         } else {
             ERR_OUT("Invalid LibMetadata (nullptr)");
         }
diff --git a/src/rust_bindings.hpp b/src/rust_bindings.hpp
index 6608efa8..9539c612 100644
--- a/src/rust_bindings.hpp
+++ b/src/rust_bindings.hpp
@@ -38,6 +38,7 @@ typedef fwk::PropertyValue PropertyValue;
 typedef fwk::RgbColour RgbColour;
 typedef eng::Label Label;
 typedef eng::LibFile LibFile;
+typedef eng::LibMetadata LibMetadata;
 typedef eng::Keyword Keyword;
 struct NiepcePropertyBag;
 struct NiepcePropertySet;
@@ -69,7 +70,6 @@ using NiepcePropertyIdx = ffi::NiepcePropertyIdx;
 typedef ffi::LibraryId library_id_t; // XXX change this to LibraryId
 typedef ffi::FileStatus FileStatus;
 typedef ffi::LibFolder LibFolder;
-typedef ffi::LibMetadata LibMetadata;
 typedef ffi::Managed Managed;
 typedef ffi::LibNotification LibNotification;
 typedef ffi::NotificationType NotificationType;