Splashscreen

If your webpage could take some time to load, or if you need to run an initialization procedure in Rust before displaying your main window, a splashscreen could improve the loading experience for the user.

Setup

First, create a splashscreen.html in your distDir that contains the HTML code for a splashscreen. Then, update your tauri.conf.json like so:

"windows": [
  {
    "title": "Tauri App",
    "width": 800,
    "height": 600,
    "resizable": true,
    "fullscreen": false,
+   "visible": false // Hide the main window by default
  },
  // Add the splashscreen window
+ {
+   "width": 400,
+   "height": 200,
+   "decorations": false,
+   "url": "splashscreen.html",
+   "label": "splashscreen"
+ }
]

Now, your main window will be hidden and the splashscreen window will show when your app is launched. Next, you'll need a way to close the splashscreen and show the main window when your app is ready. How you do this depends on what you are waiting for before closing the splashscreen.

Waiting for Webpage

If you are waiting for your web code, you'll want to create a close_splashscreen command.

src-tauri/main.rs

use tauri::Manager;
// Create the command:
#[tauri::command]
fn close_splashscreen(window: tauri::Window) {
  // Close splashscreen
  if let Some(splashscreen) = window.get_window("splashscreen") {
    splashscreen.close().unwrap();
  }
  // Show main window
  window.get_window("main").unwrap().show().unwrap();
}

// Register the command:
fn main() {
  tauri::Builder::default()
    // Add this line
    .invoke_handler(tauri::generate_handler![close_splashscreen])
    .run(tauri::generate_context!())
    .expect("failed to run app");
}

Then, you can call it from your JS:

// With the Tauri API npm package:
import { invoke } from '@tauri-apps/api/tauri'
// With the Tauri global script:
const invoke = window.__TAURI__.invoke

document.addEventListener('DOMContentLoaded', () => {
  // This will wait for the window to load, but you could
  // run this function on whatever trigger you want
  invoke('close_splashscreen')
})

Waiting for Rust

If you are waiting for Rust code to run, put it in the setup function handler so you have access to the App instance:

src-tauri/main.rs

use tauri::Manager;
fn main() {
  tauri::Builder::default()
    .setup(|app| {
      let splashscreen_window = app.get_window("splashscreen").unwrap();
      let main_window = app.get_window("main").unwrap();
      // we perform the initialization code on a new task so the app doesn't freeze
      tauri::async_runtime::spawn(async move {
        // initialize your app here instead of sleeping :)
        println!("Initializing...");
        std::thread::sleep(std::time::Duration::from_secs(2));
        println!("Done initializing.");

        // After it's done, close the splashscreen and display the main window
        splashscreen_window.close().unwrap();
        main_window.show().unwrap();
      });
      Ok(())
    })
    .run(tauri::generate_context!())
    .expect("failed to run app");
}