gtk: Add SectionModel subclassing support

Author: bilelmoussaoui

gtk4/src/subclass/mod.rs

@@ -68,6 +68,9 @@ pub mod root;
 pub mod scale;
 pub mod scale_button;
 pub mod scrollable;
+#[cfg(any(feature = "v4_12", docsrs))]
+#[cfg_attr(docsrs, doc(cfg(feature = "v4_12")))]
+pub mod section_model;
 pub mod selection_model;
 pub mod shortcut_manager;
 pub mod sorter;
@@ -150,6 +153,9 @@ pub mod prelude {
     pub use super::scale::{ScaleImpl, ScaleImplExt};
     pub use super::scale_button::{ScaleButtonImpl, ScaleButtonImplExt};
     pub use super::scrollable::{ScrollableImpl, ScrollableImplExt};
+    #[cfg(any(feature = "v4_12", docsrs))]
+    #[cfg_attr(docsrs, doc(cfg(feature = "v4_12")))]
+    pub use super::section_model::{SectionModelImpl, SectionModelImplExt};
     pub use super::selection_model::{SelectionModelImpl, SelectionModelImplExt};
     pub use super::shortcut_manager::{ShortcutManagerImpl, ShortcutManagerImplExt};
     pub use super::sorter::{SorterImpl, SorterImplExt};

gtk4/src/subclass/section_model.rs

@@ -0,0 +1,72 @@
+// Take a look at the license at the top of the repository in the LICENSE file.
+
+// rustdoc-stripper-ignore-next
+//! Traits intended for implementing the [`SectionModel`](crate::SectionModel) interface.
+
+use crate::{prelude::*, subclass::prelude::*, SectionModel};
+use glib::translate::*;
+
+pub trait SectionModelImpl: ListModelImpl {
+    #[doc(alias = "get_section")]
+    fn section(&self, position: u32) -> (u32, u32) {
+        self.parent_section(position)
+    }
+}
+
+mod sealed {
+    pub trait Sealed {}
+    impl<T: super::SectionModelImplExt> Sealed for T {}
+}
+
+pub trait SectionModelImplExt: sealed::Sealed + ObjectSubclass {
+    fn parent_section(&self, position: u32) -> (u32, u32) {
+        unsafe {
+            let type_data = Self::type_data();
+            let parent_iface = type_data.as_ref().parent_interface::<SectionModel>()
+                as *const ffi::GtkSectionModelInterface;
+
+            let func = (*parent_iface)
+                .get_section
+                .expect("no parent \"get_section\" implementation");
+
+            let mut start = std::mem::MaybeUninit::uninit();
+            let mut end = std::mem::MaybeUninit::uninit();
+            func(
+                self.obj()
+                    .unsafe_cast_ref::<SectionModel>()
+                    .to_glib_none()
+                    .0,
+                position,
+                start.as_mut_ptr(),
+                end.as_mut_ptr(),
+            );
+            (start.assume_init(), end.assume_init())
+        }
+    }
+}
+
+impl<T: SectionModelImpl> SectionModelImplExt for T {}
+
+unsafe impl<T: SectionModelImpl> IsImplementable<T> for SectionModel {
+    fn interface_init(iface: &mut glib::Interface<Self>) {
+        let iface = iface.as_mut();
+
+        assert_initialized_main_thread!();
+
+        iface.get_section = Some(model_get_section::<T>);
+    }
+}
+
+unsafe extern "C" fn model_get_section<T: SectionModelImpl>(
+    model: *mut ffi::GtkSectionModel,
+    position: u32,
+    startptr: *mut libc::c_uint,
+    endptr: *mut libc::c_uint,
+) {
+    let instance = &*(model as *mut T::Instance);
+    let imp = instance.imp();
+
+    let (start, end) = imp.section(position);
+    *startptr = start;
+    *endptr = end;
+}