gdk4/toplevel.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::*, Toplevel, ToplevelSize};
11
12mod sealed {
13 pub trait Sealed {}
14 impl<T: super::IsA<super::Toplevel>> Sealed for T {}
15}
16
17// rustdoc-stripper-ignore-next
18/// Trait containing manually implemented methods of
19/// [`Toplevel`](crate::Toplevel).
20pub trait ToplevelExtManual: sealed::Sealed + IsA<Toplevel> {
21 /// Emitted when the size for the surface needs to be computed, when
22 /// it is present.
23 ///
24 /// This signal will normally be emitted during or after a call to
25 /// [`ToplevelExt::present()`][crate::prelude::ToplevelExt::present()], depending on the configuration
26 /// received by the windowing system. It may also be emitted at any
27 /// other point in time, in response to the windowing system
28 /// spontaneously changing the configuration of the toplevel surface.
29 ///
30 /// It is the responsibility of the toplevel user to handle this signal
31 /// and compute the desired size of the toplevel, given the information
32 /// passed via the [`ToplevelSize`][crate::ToplevelSize] object. Failing to do so
33 /// will result in an arbitrary size being used as a result.
34 /// ## `size`
35 /// a [`ToplevelSize`][crate::ToplevelSize]
36 fn connect_compute_size<F: Fn(&Toplevel, &mut ToplevelSize) + 'static>(
37 &self,
38 f: F,
39 ) -> SignalHandlerId {
40 unsafe extern "C" fn compute_size_trampoline<
41 F: Fn(&Toplevel, &mut ToplevelSize) + 'static,
42 >(
43 this: *mut ffi::GdkToplevel,
44 size: *mut ffi::GdkToplevelSize,
45 f: glib::ffi::gpointer,
46 ) {
47 let f: &F = &*(f as *const F);
48 f(&from_glib_borrow(this), &mut *(size as *mut ToplevelSize))
49 }
50 unsafe {
51 let f: Box_<F> = Box_::new(f);
52 connect_raw(
53 self.as_ptr() as *mut _,
54 b"compute-size\0".as_ptr() as *const _,
55 Some(transmute::<*const (), unsafe extern "C" fn()>(
56 compute_size_trampoline::<F> as *const (),
57 )),
58 Box_::into_raw(f),
59 )
60 }
61 }
62}
63
64impl<O: IsA<Toplevel>> ToplevelExtManual for O {}