monorepo/fitnesstrax/app/src/components/singleton.rs

/*
Copyright 2024, Savanni D'Gerinel <savanni@luminescent-dreams.com>

This file is part of FitnessTrax.

FitnessTrax is free software: you can redistribute it and/or modify it under the terms of the GNU
General Public License as published by the Free Software Foundation, either version 3 of the
License, or (at your option) any later version.

FitnessTrax is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without
even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
General Public License for more details.

You should have received a copy of the GNU General Public License along with FitnessTrax. If not, see <https://www.gnu.org/licenses/>.
*/

//! A Widget container for a single components
use glib::Object;
use gtk::{prelude::*, subclass::prelude::*};
use std::cell::RefCell;

pub struct SingletonPrivate {
    widget: RefCell<gtk::Widget>,
}

impl Default for SingletonPrivate {
    fn default() -> Self {
        Self {
            widget: RefCell::new(gtk::Label::new(None).upcast()),
        }
    }
}

#[glib::object_subclass]
impl ObjectSubclass for SingletonPrivate {
    const NAME: &'static str = "Singleton";
    type Type = Singleton;
    type ParentType = gtk::Box;
}

impl ObjectImpl for SingletonPrivate {}
impl WidgetImpl for SingletonPrivate {}
impl BoxImpl for SingletonPrivate {}

glib::wrapper! {
    /// The Singleton component contains exactly one child widget. The swap function makes it easy
    /// to handle the job of swapping that child out for a different one.
    pub struct Singleton(ObjectSubclass<SingletonPrivate>) @extends gtk::Box, gtk::Widget;
}

impl Default for Singleton {
    fn default() -> Self {
        let s: Self = Object::builder().build();

        s.append(&*s.imp().widget.borrow());

        s
    }
}

impl Singleton {
    pub fn swap(&self, new_widget: &impl IsA<gtk::Widget>) {
        let new_widget = new_widget.clone().upcast();
        self.remove(&*self.imp().widget.borrow());
        self.append(&new_widget);
        *self.imp().widget.borrow_mut() = new_widget;
    }
}

pub trait SingletonImpl: WidgetImpl + BoxImpl {}
unsafe impl<T: SingletonImpl> IsSubclassable<T> for Singleton {}