expected mutable reference `&mut egui::ui::Ui` found mutable reference `&mut Ui` should not be happening

Question

Here is the repo im using as a reference for adding a image: https://github.com/emilk/egui/blob/master/examples/retained_image/src/main.rs

Im getting this error when trying to draw a image to the screen on this line of code:

date_backdrop.show(ui);

"mismatched types expected mutable reference &mut egui::ui::Ui found mutable reference &mut Ui perhaps two different versions of crate egui are being used?"

dont understand how to fix this issue. still new to rust

here is my code:

use eframe::egui;
use egui_extras::RetainedImage;
struct InitView;


impl eframe::epi::App for InitView {
    fn name(&self) -> &str {
        "CheckIt"
    }
    
    fn update(&mut self,ctx: &eframe::egui::CtxRef,frame: &mut eframe::epi::Frame<'_>) {
        
        let date_backdrop = RetainedImage::from_image_bytes(
            "date_backdrop.png",
            include_bytes!("date_backdrop.png"),
        )
        .unwrap();
        
        //background color
        let frame = egui::containers::Frame {
            fill: egui::Color32::from_rgb(241, 233, 218),
            ..Default::default()
        };
        
        //main window
        egui::CentralPanel::default().frame(frame).show(ctx, |ui| {
            ui.heading("This is an image:");
            date_backdrop.show(ui);
           
        });
    }
}

fn main(){
    let app: InitView = InitView;
    let win_options = eframe::NativeOptions{
        initial_window_size: Some(egui::Vec2::new(386.0, 636.0)),
        always_on_top: true,
        resizable: false,
        ..Default::default()
    };
    eframe::run_native(Box::new(app), win_options);
}

Here is my Cargo.toml:

[package]
name = "checkit"
version = "0.1.0"
edition = "2021"

# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html

[dependencies]
eframe = "0.14.0"
image = { version = "0.24", default-features = false, features = ["png"] }
egui_extras = { version = "0.20.0", features = ["image"] }

What's in your `Cargo.toml`? – Cerberus Jan 17 '23 at 13:42 — Cerberus, Jan 17 '23 at 13:42
updated the post so you can see – Terrell-byte Jan 17 '23 at 13:44 — Terrell-byte, Jan 17 '23 at 13:44

score 1 · Accepted Answer · answered Jan 17 '23 at 13:56

As the error tells, you have two incompatible version of egui in the dependency tree: eframe 0.14 pulls in egui 0.14, while egui_extras 0.20 pulls in egui 0.20. When major version is 0, different minor versions are treated as incompatible, therefore the types from them are not interchangable.

As far as I can see, both eframe and egui_extras depend on the same minor version of egui as their own version, so you have to synchronize these two dependencies to use the same minor version. The easiest way is probably to bump eframe to 0.20.

expected mutable reference `&mut egui::ui::Ui` found mutable reference `&mut Ui` should not be happening

1 Answers1