gdk4/
drag_surface.rs

1// Take a look at the license at the top of the repository in the LICENSE file.
2
3use std::{boxed::Box as Box_, mem::transmute};
4
5use glib::{
6    signal::{connect_raw, SignalHandlerId},
7    translate::*,
8};
9
10use crate::{ffi, prelude::*, DragSurface, DragSurfaceSize};
11
12mod sealed {
13    pub trait Sealed {}
14    impl<T: super::IsA<super::DragSurface>> Sealed for T {}
15}
16
17// rustdoc-stripper-ignore-next
18/// Trait containing manually implemented methods of
19/// [`DragSurface`](crate::DragSurface).
20pub trait DragSurfaceExtManual: sealed::Sealed + IsA<DragSurface> {
21    #[cfg(feature = "v4_12")]
22    #[cfg_attr(docsrs, doc(cfg(feature = "v4_12")))]
23    #[doc(alias = "compute-size")]
24    fn connect_compute_size<F: Fn(&DragSurface, &mut DragSurfaceSize) + 'static>(
25        &self,
26        f: F,
27    ) -> SignalHandlerId {
28        unsafe extern "C" fn compute_size_trampoline<
29            F: Fn(&DragSurface, &mut DragSurfaceSize) + 'static,
30        >(
31            this: *mut ffi::GdkDragSurface,
32            size: *mut ffi::GdkDragSurfaceSize,
33            f: glib::ffi::gpointer,
34        ) {
35            let f: &F = &*(f as *const F);
36            f(
37                &from_glib_borrow(this),
38                &mut *(size as *mut DragSurfaceSize),
39            )
40        }
41        unsafe {
42            let f: Box_<F> = Box_::new(f);
43            connect_raw(
44                self.as_ptr() as *mut _,
45                b"compute-size\0".as_ptr() as *const _,
46                Some(transmute::<*const (), unsafe extern "C" fn()>(
47                    compute_size_trampoline::<F> as *const (),
48                )),
49                Box_::into_raw(f),
50            )
51        }
52    }
53}
54
55impl<O: IsA<DragSurface>> DragSurfaceExtManual for O {}