Show Gtk GUI on HTTP request via Rocket.

huangapple
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英文:

Show Gtk GUI on HTTP request via Rocket

问题

正确的解决方法是确保GTK只在单个线程中初始化，以避免多线程冲突。您可以使用gtk::init函数在Rocket的启动函数中进行初始化，以确保GTK只在主线程中初始化一次。

修改您的main.rs如下所示：

  1. use gtk::prelude::*;
  2. use gtk::{Application, ApplicationWindow, Button};
  3. use rocket::{get, launch, routes, Build, Rocket};
  4. use std::sync::Mutex;
  6. // 使用Mutex确保只有一个线程在初始化GTK
  7. lazy_static::lazy_static! {
  8.     static ref GTK_INIT_MUTEX: Mutex<()> = Mutex::new(());
  9. }
  11. #[launch]
  12. fn rocket() -> Rocket<Build> {
  13.     // 初始化GTK
  14.     let _guard = GTK_INIT_MUTEX.lock().unwrap();
  15.     gtk::init().expect("Failed to initialize GTK");
  17.     rocket::build().mount("/", routes![do_get])
  18. }
  20. #[get("/")]
  21. fn do_get() -> String {
  22.     show_gui();
  23.     "Gui shown!".to_string()
  24. }
  26. fn show_gui() {
  27.     let application = Application::builder()
  28.         .application_id("com.example.FirstGtkApp")
  29.         .build();
  31.     application.connect_activate(|app| {
  32.         let window = ApplicationWindow::builder()
  33.             .application(app)
  34.             .title("First GTK Program")
  35.             .default_width(350)
  36.             .default_height(70)
  37.             .build();
  39.         let button = Button::with_label("Click me!");
  40.         button.connect_clicked(|_| {
  41.             eprintln!("Clicked!");
  42.         });
  43.         window.set_child(Some(&button));
  45.         window.show();
  46.     });
  48.     application.run();
  49. }

通过在Rocket启动函数中使用lazy_static库的Mutex来确保只有一个线程在初始化GTK。这将解决多线程冲突的问题，使您的程序能够在第二个请求时正常运行。

英文:

I want to show a Gtk Window upon a HTTP request to a Rocket server in my program.

Here's a MRE:

src/main.rs

  1. use gtk::prelude::*;
  2. use gtk::{Application, ApplicationWindow, Button};
  3. use gtk4 as gtk;
  4. use rocket::{get, launch, routes, Build, Rocket};
  6. #[launch]
  7. fn rocket() -&gt; Rocket&lt;Build&gt; {
  8.     rocket::build().mount(&quot;/&quot;, routes![do_get])
  9. }
  11. #[get(&quot;/&quot;)]
  12. fn do_get() -&gt; String {
  13.     show_gui();
  14.     &quot;Gui shown!&quot;.to_string()
  15. }
  17. fn show_gui() {
  18.     let application = Application::builder()
  19.         .application_id(&quot;com.example.FirstGtkApp&quot;)
  20.         .build();
  22.     application.connect_activate(|app| {
  23.         let window = ApplicationWindow::builder()
  24.             .application(app)
  25.             .title(&quot;First GTK Program&quot;)
  26.             .default_width(350)
  27.             .default_height(70)
  28.             .build();
  30.         let button = Button::with_label(&quot;Click me!&quot;);
  31.         button.connect_clicked(|_| {
  32.             eprintln!(&quot;Clicked!&quot;);
  33.         });
  34.         window.set_child(Some(&amp;button));
  36.         window.show();
  37.     });
  39.     application.run();
  40. }

Cargo.toml

  1. [package]
  2. name = &quot;gui&quot;
  3. version = &quot;0.1.0&quot;
  4. edition = &quot;2021&quot;
  6. # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
  8. [dependencies]
  9. gtk4 = &quot;0.6.6&quot;
  10. rocket = { version = &quot;0.5.0-rc.3&quot;, features = [&quot;json&quot;] }

However, upon the second request, my program panics:

  1. $ cargo run
  2.    Compiling gui v0.1.0 (/home/neumann/gui)
  3.     Finished dev [unoptimized + debuginfo] target(s) in 2.54s
  4.      Running `target/debug/gui`
  5. &#128295; Configured for debug.
  6.    &gt;&gt; address: 127.0.0.1
  7.    &gt;&gt; port: 8000
  8.    &gt;&gt; workers: 12
  9.    &gt;&gt; max blocking threads: 512
  10.    &gt;&gt; ident: Rocket
  11.    &gt;&gt; IP header: X-Real-IP
  12.    &gt;&gt; limits: bytes = 8KiB, data-form = 2MiB, file = 1MiB, form = 32KiB, json = 1MiB, msgpack = 1MiB, string = 8KiB
  13.    &gt;&gt; temp dir: /tmp
  14.    &gt;&gt; http/2: true
  15.    &gt;&gt; keep-alive: 5s
  16.    &gt;&gt; tls: disabled
  17.    &gt;&gt; shutdown: ctrlc = true, force = true, signals = [SIGTERM], grace = 2s, mercy = 3s
  18.    &gt;&gt; log level: normal
  19.    &gt;&gt; cli colors: true
  20. &#128236; Routes:
  21.    &gt;&gt; (do_get) GET /
  22. &#128225; Fairings:
  23.    &gt;&gt; Shield (liftoff, response, singleton)
  24. &#128737;️ Shield:
  25.    &gt;&gt; X-Content-Type-Options: nosniff
  26.    &gt;&gt; Permissions-Policy: interest-cohort=()
  27.    &gt;&gt; X-Frame-Options: SAMEORIGIN
  28. &#128640; Rocket has launched from http://127.0.0.1:8000
  29. GET / text/html:
  30.    &gt;&gt; Matched: (do_get) GET /
  31.    &gt;&gt; Outcome: Success
  32.    &gt;&gt; Response succeeded.
  33. GET / text/html:
  34.    &gt;&gt; Matched: (do_get) GET /
  35. thread &#39;rocket-worker-thread&#39; panicked at &#39;Attempted to initialize GTK from two different threads.&#39;, /home/neumann/.cargo/registry/src/index.crates.io-6f17d22bba15001f/gtk4-0.6.6/src/rt.rs:95:9
  36. note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
  37.    &gt;&gt; Handler do_get panicked.
  38.    &gt;&gt; This is an application bug.
  39.    &gt;&gt; A panic in Rust must be treated as an exceptional event.
  40.    &gt;&gt; Panicking is not a suitable error handling mechanism.
  41.    &gt;&gt; Unwinding, the result of a panic, is an expensive operation.
  42.    &gt;&gt; Panics will degrade application performance.
  43.    &gt;&gt; Instead of panicking, return `Option` and/or `Result`.
  44.    &gt;&gt; Values of either type can be returned directly from handlers.
  45.    &gt;&gt; A panic is treated as an internal server error.
  46.    &gt;&gt; Outcome: Failure
  47.    &gt;&gt; No 500 catcher registered. Using Rocket default.
  48.    &gt;&gt; Response succeeded.

What is the correct way to resolve this issue?

答案1

得分: 1

以下是您提供的代码的翻译：

  1. 根据 @Jmb 的提示，我提出了以下解决方案，适用于我：
  3. ```rust
  4. #![allow(clippy::let_underscore_untyped, clippy::no_effect_underscore_binding)]
  5. use gtk4::prelude::*;
  6. use gtk4::{Application, ApplicationWindow, Button};
  7. use rocket::{get, launch, routes, Build, Rocket, State};
  8. use std::sync::mpsc::{sync_channel, SyncSender};
  9. use std::thread;
  11. #[launch]
  12. fn rocket() -> Rocket<Build> {
  13.     let sender = gtk_spawn();
  14.     rocket::build().manage(sender).mount("/", routes![do_get])
  15. }
  17. #[allow(clippy::needless_pass_by_value)]
  18. #[get("/")]
  19. fn do_get(sender: &State<SyncSender<&'static str>>) -> String {
  20.     sender.send("show").expect("无法发送到线程");
  21.     "Gui 显示！".to_string()
  22. }
  24. #[must_use]
  25. pub fn gtk_spawn() -> SyncSender<&'static str> {
  26.     let (sender, receiver) = sync_channel::<&'static str>(32);
  27.     thread::spawn(move || {
  28.         while matches!(receiver.recv().expect("无法接收消息"), "show") {
  29.             show_gui();
  30.         }
  31.     });
  32.     sender
  33. }
  35. fn show_gui() {
  36.     let application = Application::builder()
  37.         .application_id("com.example.FirstGtkApp")
  38.         .build();
  40.     application.connect_activate(|app| {
  41.         let window = ApplicationWindow::builder()
  42.             .application(app)
  43.             .title("第一个 GTK 程序")
  44.             .default_width(350)
  45.             .default_height(70)
  46.             .build();
  48.         let button = Button::with_label("点击我！");
  49.         button.connect_clicked(|_| {
  50.             eprintln!("点击了！");
  51.         });
  52.         window.set_child(Some(&button));
  54.         window.show();
  55.     });
  57.     application.run();
  58. }
英文:

Based on @Jmb's hint I came up with the following solution, that works for me:

  1. #![allow(clippy::let_underscore_untyped, clippy::no_effect_underscore_binding)]
  2. use gtk4::prelude::*;
  3. use gtk4::{Application, ApplicationWindow, Button};
  4. use rocket::{get, launch, routes, Build, Rocket, State};
  5. use std::sync::mpsc::{sync_channel, SyncSender};
  6. use std::thread;
  8. #[launch]
  9. fn rocket() -&gt; Rocket&lt;Build&gt; {
  10.     let sender = gtk_spawn();
  11.     rocket::build().manage(sender).mount(&quot;/&quot;, routes![do_get])
  12. }
  14. #[allow(clippy::needless_pass_by_value)]
  15. #[get(&quot;/&quot;)]
  16. fn do_get(sender: &amp;State&lt;SyncSender&lt;&amp;&#39;static str&gt;&gt;) -&gt; String {
  17.     sender.send(&quot;show&quot;).expect(&quot;cannot send to thread&quot;);
  18.     &quot;Gui shown!&quot;.to_string()
  19. }
  21. #[must_use]
  22. pub fn gtk_spawn() -&gt; SyncSender&lt;&amp;&#39;static str&gt; {
  23.     let (sender, receiver) = sync_channel::&lt;&amp;&#39;static str&gt;(32);
  24.     thread::spawn(move || {
  25.         while matches!(receiver.recv().expect(&quot;could not receive message&quot;), &quot;show&quot;) {
  26.             show_gui();
  27.         }
  28.     });
  29.     sender
  30. }
  32. fn show_gui() {
  33.     let application = Application::builder()
  34.         .application_id(&quot;com.example.FirstGtkApp&quot;)
  35.         .build();
  37.     application.connect_activate(|app| {
  38.         let window = ApplicationWindow::builder()
  39.             .application(app)
  40.             .title(&quot;First GTK Program&quot;)
  41.             .default_width(350)
  42.             .default_height(70)
  43.             .build();
  45.         let button = Button::with_label(&quot;Click me!&quot;);
  46.         button.connect_clicked(|_| {
  47.             eprintln!(&quot;Clicked!&quot;);
  48.         });
  49.         window.set_child(Some(&amp;button));
  51.         window.show();
  52.     });
  54.     application.run();
  55. }

huangapple
  • 本文由 发表于 2023年7月6日 17:47:01
  • 转载请务必保留本文链接：https://go.coder-hub.com/76627546.html
  • gtk
  • rust
  • rust-rocket
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