How to get a texture to fill available space in a window?

[pozix604]

I'm trying to figure out how to get egui to scale a texture to fill the available space in a window taking into account other items that are in the window.

Below, I generate a texture in code and sandwich it between a heading and a label. I'd like for the texture to scale to fill the available window if I resize the window, while keeping the label and heading visible. I know I can specify the exact width and height of the texture, so one way is to manually account for all widgets in the window and do the math. Is there a better way to do this?

use eframe::egui::*;
use eframe::*;

fn generate_random_image(width: usize, height: usize, offset: usize) -> Vec<u8> {
    (0..(width * height)).map(|i| if (offset + i) % 17 == 0 { 0 } else { 0xff }).collect()
}

struct Application {
    texture: TextureHandle,
}

impl Application {
    fn new(cc: &CreationContext<'_>) -> Self {
        let raw = generate_random_image(128, 128, 0);
        let img = ColorImage::from_gray([128, 128], &raw);
        let texture = cc.egui_ctx.load_texture("noise", img, TextureOptions::NEAREST);
        Self { texture }
    }
}

impl App for Application {
    fn update(&mut self, ctx: &eframe::egui::Context, frame: &mut eframe::Frame) {
        CentralPanel::default().show(ctx, |ui| {
            ui.vertical(|ui| {
                ui.heading("Textures");
                let width = ui.max_rect().width();
                let height = ui.max_rect().height();
                ui.add(Image::new(egui::load::SizedTexture::new(
                    self.texture.id(),
                    Vec2::new(width, height),
                )));
                ui.label("A label at the bottom");
            });
        });
    }
}

fn main() {
    run_native(
        "Textures",
        NativeOptions {
            viewport: ViewportBuilder::default().with_inner_size([512.0, 512.0]),
            ..Default::default()
        },
        Box::new(|cc| Ok(Box::new(Application::new(cc)))),
    )
    .unwrap();
}