#![cfg_attr(not(debug_assertions), windows_subsystem = "windows")] // hide console window on Windows in release use eframe::egui; fn main() -> Result<(), eframe::Error> { env_logger::init(); // Log to stderr (if you run with `RUST_LOG=debug`). if cfg!(target_os = "macos") { eprintln!( "This example does not work on Mac! See https://github.com/emilk/egui/issues/1918" ); return Ok(()); } let options = eframe::NativeOptions { run_and_return: true, viewport: egui::ViewportBuilder::default().with_inner_size([320.0, 240.0]), ..Default::default() }; eprintln!("Starting first window…"); eframe::run_native( "First Window", options.clone(), Box::new(|_cc| Box::new(MyApp { has_next: true })), )?; std::thread::sleep(std::time::Duration::from_secs(2)); eprintln!("Starting second window…"); eframe::run_native( "Second Window", options.clone(), Box::new(|_cc| Box::new(MyApp { has_next: true })), )?; std::thread::sleep(std::time::Duration::from_secs(2)); eprintln!("Starting third window…"); eframe::run_native( "Third Window", options, Box::new(|_cc| Box::new(MyApp { has_next: false })), ) } struct MyApp { pub(crate) has_next: bool, } impl eframe::App for MyApp { fn update(&mut self, ctx: &egui::Context, _frame: &mut eframe::Frame) { egui::CentralPanel::default().show(ctx, |ui| { let label_text = if self.has_next { "When this window is closed the next will be opened after a short delay" } else { "This is the last window. Program will end when closed" }; ui.label(label_text); if ctx.os() == egui::os::OperatingSystem::Mac { ui.label("This example doesn't work on Mac!"); } if ui.button("Close").clicked() { eprintln!("Pressed Close button"); ui.ctx().send_viewport_cmd(egui::ViewportCommand::Close); } }); } }