gtk4/subclass/
drawing_area.rs

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// Take a look at the license at the top of the repository in the LICENSE file.

// rustdoc-stripper-ignore-next
//! Traits intended for subclassing [`DrawingArea`].

use glib::translate::*;

use crate::{ffi, prelude::*, subclass::prelude::*, DrawingArea};

pub trait DrawingAreaImpl: WidgetImpl + ObjectSubclass<Type: IsA<DrawingArea>> {
    fn resize(&self, width: i32, height: i32) {
        self.parent_resize(width, height)
    }
}

pub trait DrawingAreaImplExt: DrawingAreaImpl {
    fn parent_resize(&self, width: i32, height: i32) {
        unsafe {
            let data = Self::type_data();
            let parent_class = data.as_ref().parent_class() as *mut ffi::GtkDrawingAreaClass;
            if let Some(f) = (*parent_class).resize {
                f(
                    self.obj().unsafe_cast_ref::<DrawingArea>().to_glib_none().0,
                    width,
                    height,
                )
            }
        }
    }
}

impl<T: DrawingAreaImpl> DrawingAreaImplExt for T {}

unsafe impl<T: DrawingAreaImpl> IsSubclassable<T> for DrawingArea {
    fn class_init(class: &mut glib::Class<Self>) {
        Self::parent_class_init::<T>(class);

        let klass = class.as_mut();
        klass.resize = Some(drawing_area_resize::<T>);
    }
}

unsafe extern "C" fn drawing_area_resize<T: DrawingAreaImpl>(
    ptr: *mut ffi::GtkDrawingArea,
    width: i32,
    height: i32,
) {
    let instance = &*(ptr as *mut T::Instance);
    let imp = instance.imp();

    imp.resize(width, height)
}