feat: introduce App::run_return (#12668)

* Introduce `run_return`

* Fix compile error

* Clone web_context

* Refactor to Result API

* Fix clippy

* Impl mock runtime

* Make it desktop-only

* Add changelog entry

* Fix compile error

* Make it semver compatible

* Extend changelog entry

* Undo semver-hack

* Reduce diff

* Remove unnecessary mut

* Make it take `self` by value

* Reduce diff

* Undo diff hack

* Make everything cfg(desktop)

* Rename vars to reduce diff

* Fix clippy

* Extract make_event_handler

* Reduce diff

* Deprecate `App::run_return`

* Update changelog

* Fix compile errors

* Accept reference

* Create event handler first

* Update example

* Update manifest

* Fix example

* Fix example docs

* Call `setup` only upon Ready

* Update changelog entry

* Update docs

* Update changelog

* Add platform-specific note

* update docs

* run_return on mobile

* Apply suggestions from code review

* remove change file

---------

Co-authored-by: Lucas Nogueira <lucas@tauri.app>

examples/run-iteration/README.md

@@ -1,3 +0,0 @@
-# Run Iteration Example
-
-To execute run the following on the root directory of the repository: `cargo run --example run-iteration`.

examples/run-return/README.md

@@ -0,0 +1,3 @@
+# Run Return Example
+
+To execute run the following on the root directory of the repository: `cargo run --example run-return`.

examples/run-return/main.rs

@@ -4,23 +4,18 @@
 
 #![cfg_attr(not(debug_assertions), windows_subsystem = "windows")]
 
-use tauri::Manager;
-
 fn main() {
-  let mut app = tauri::Builder::default()
+  let app = tauri::Builder::default()
     .build(tauri::generate_context!(
-      "../../examples/run-iteration/tauri.conf.json"
+      "../../examples/run-return/tauri.conf.json"
     ))
     .expect("error while building tauri application");
 
-  loop {
-    app.run_iteration(|_app, _event| {
-      //println!("{:?}", _event);
-    });
+  let exit_code = app.run_return(|_app, _event| {
+    //println!("{:?}", _event);
+  });
 
-    if app.webview_windows().is_empty() {
-      app.cleanup_before_exit();
-      break;
-    }
-  }
+  println!("I run after exit");
+
+  std::process::exit(exit_code);
 }

examples/run-return/tauri.conf.json

@@ -1,6 +1,6 @@
 {
   "$schema": "../../crates/tauri-schema-generator/schemas/config.schema.json",
-  "productName": "RunIteration",
+  "productName": "RunReturn",
   "version": "0.1.0",
   "identifier": "com.tauri.dev",
   "build": {