Code in guide not working #1335
Description
I am following the guide at: https://docs.rs/conrod_core/0.69.0/conrod_core/guide/chapter_3/index.html.
There is a part where it says:
Not quite what we want, yet.
Up until that point, my code is:
#[macro_use] extern crate conrod;
extern crate find_folder;
use glium::Display;
use glium::glutin::{ContextBuilder, WindowBuilder, EventsLoop};
use glium::texture::Texture2d;
use conrod::backend::glium::glium::{self, Surface};
use conrod::backend::glium::Renderer;
use conrod::UiBuilder;
use conrod::{widget, Positionable, Colorable, Widget};
fn main() {
// boilerplate for creating a window
const WIDTH: u32 = 400;
const HEIGHT: u32 = 200;
// The EventsLoop is given to the Display.
let mut events_loop = EventsLoop::new();
let window = WindowBuilder::new().with_title("Hello Conrod").with_dimensions(WIDTH, HEIGHT);
let context = ContextBuilder::new().with_vsync(true); //.with_multisampling(4); // multisampling does not work (NoAvailablePixelFormat)
let display = Display::new(window, context, &events_loop).unwrap();
// create the UI
// UiBuilder receives the dimensions in its constuctor.
let mut ui = UiBuilder::new([WIDTH as f64, HEIGHT as f64]).build();
// load fonts
let assets = find_folder::Search::KidsThenParents(3, 5)
.for_folder("assets")
.unwrap();
let font_path = assets.join("fonts/MesloLGM-Regular.ttf");
ui.fonts.insert_from_file(font_path).unwrap();
// after building the ui we can add widgets. define a widget named text and
// keep track of it, so that it later can be given an id.
widget_ids!(struct Ids { text });
// generate all ids
let ids = Ids::new(ui.widget_id_generator());
// system needs this
let image_map = conrod::image::Map::<Texture2d>::new();
// conrod needs renderer
let mut renderer = Renderer::new(&display).unwrap();
// the main event loop
'main: loop {
// instantiate the widgets
let ui = &mut ui.set_widgets();
widget::Text::new("Hello World!")
.middle_of(ui.window)
.color(conrod::color::WHITE)
.font_size(32)
.set(ids.text, ui);
// Render the `Ui` and then display it on the screen.
if let Some(primitives) = ui.draw_if_changed() {
renderer.fill(&display, primitives, &image_map);
let mut target = display.draw();
target.clear_color(0.0, 1.0, 0.0, 1.0);
renderer.draw(&display, &mut target, &image_map).unwrap();
target.finish().unwrap();
}
}
}However, Rust complains, that it cannot borrow mutable the ui in the main loop at ui.draw_if_changed():
cannot borrow data in a dereference of `conrod::UiCell<'_>` as mutable (cannot borrow as mutable) [E0596]
trait `DerefMut` is required to modify through a dereference, but it is not implemented for `conrod::UiCell<'_>` [E0596]My dependencies are:
[dependencies]
conrod = {version="0.55.0", features=["glium", "winit"]}
find_folder = "0.3.0"My Rust version is:
$ rustc --version
rustc 1.41.1 (f3e1a954d 2020-02-24)Is the guide outdated, or am I doing something wrong?