gtk4/subclass/
drawing_area.rs

1// Take a look at the license at the top of the repository in the LICENSE file.
2
3// rustdoc-stripper-ignore-next
4//! Traits intended for subclassing [`DrawingA£rea`](crate::DrawingA£rea).
5
6use glib::translate::*;
7
8use crate::{ffi, prelude::*, subclass::prelude::*, DrawingArea};
9
10pub trait DrawingAreaImpl: DrawingAreaImplExt + WidgetImpl {
11    fn resize(&self, width: i32, height: i32) {
12        self.parent_resize(width, height)
13    }
14}
15
16mod sealed {
17    pub trait Sealed {}
18    impl<T: super::DrawingAreaImplExt> Sealed for T {}
19}
20pub trait DrawingAreaImplExt: sealed::Sealed + ObjectSubclass {
21    fn parent_resize(&self, width: i32, height: i32) {
22        unsafe {
23            let data = Self::type_data();
24            let parent_class = data.as_ref().parent_class() as *mut ffi::GtkDrawingAreaClass;
25            if let Some(f) = (*parent_class).resize {
26                f(
27                    self.obj().unsafe_cast_ref::<DrawingArea>().to_glib_none().0,
28                    width,
29                    height,
30                )
31            }
32        }
33    }
34}
35
36impl<T: DrawingAreaImpl> DrawingAreaImplExt for T {}
37
38unsafe impl<T: DrawingAreaImpl> IsSubclassable<T> for DrawingArea {
39    fn class_init(class: &mut glib::Class<Self>) {
40        Self::parent_class_init::<T>(class);
41
42        let klass = class.as_mut();
43        klass.resize = Some(drawing_area_resize::<T>);
44    }
45}
46
47unsafe extern "C" fn drawing_area_resize<T: DrawingAreaImpl>(
48    ptr: *mut ffi::GtkDrawingArea,
49    width: i32,
50    height: i32,
51) {
52    let instance = &*(ptr as *mut T::Instance);
53    let imp = instance.imp();
54
55    imp.resize(width, height)
56}