gtk-rs change widget appearance at runtime.
from Doods@infosec.pub to rust@programming.dev on 31 Oct 18:38
https://infosec.pub/post/19555901

It might be lack of sleep, but I can’t figure this out.

I have a Label, and I want its text to be red when it represents an error, and I want it be green when it represent “good to go”.

I found search result for C and maybe a solution for Python, but nothing for Rust.

I tried manually setting the css-classes property and running queue_draw(); it didn’t work.

I can have a gtk::Box or a Frame that I place where the Label should go, then declare two Labels, and use set_child() to switch between them, but that seems like an ugly solution.

Do you have a solution?

SOLVED:

I have to add a “.” before declaring a CSS “thing” for it to be considered a class.

Ex:

.overlay {
        background: rgba(60, 60, 60, 1);
        font-size: 25px;
}

instead of:

overlay {
        background: rgba(60, 60, 60, 1);
        font-size: 25px;)
}

Just use label.add_css_class(), label.remove_css_class() or label.set_css_classes() and make sure to properly load your CSS style sheets,

Source: the comment of d_k_bo@feddit.org

#rust

threaded - newest

Doods@infosec.pub on 31 Oct 18:44 next collapse

Before anyone suggests another library:

  • Iced and Egui both can’t handle Arabic, which is a deal breaker.
  • Iced takes forever to compile and iterate, maybe that’ll be fixed with dynamic linking.
  • Relm: I didn’t know it existed before I started this project.
  • Qt bindings: IDK I forgot Qt existed, I was always more of GNOME* guy.
  • I am already pretty deep into this project, and don’t want to learn something else for now.

* GNU Network Object something Environment

BB_C@programming.dev on 31 Oct 19:28 collapse

Use libcosmic 😑

No, but seriously… skip to the end.

Iced and Egui both can’t handle Arabic, which is a deal breaker.

Iced can handle Arabic shaping-wise when cosmic-text is used, but it can’t handle the direction (yet). If you only need it for the interface, a shit workaround would be to prefix all text with an RLM (RIGHT-TO-LEFT Mark). This would left-align all text of course.

Iced takes forever to compile and iterate, maybe that’ll be fixed with dynamic linking.

Fast iteration is already fixed by using cranelift in your release-dev profile (or whatever you want to call it), and mold as a linker. The binary will be slower, but iteration will be much much faster.

Okay, something helpful instead: Did you try asking in the rust:gnome.org matrix room mentioned in the project page?

Doods@infosec.pub on 01 Nov 05:41 collapse

If you only need it for the interface, a shit workaround would be to prefix all text with an RLM (RIGHT-TO-LEFT Mark).

Unfortunately no, I expect users to enter Arabic text as well.

Fast iteration is already fixed by using cranelift in your release-dev profile (or whatever you want to call it), and mold as a linker.

Maybe, I didn’t try that before, but I don’t expect Cranelift to match the speeds gtk-rs is currently giving me; Cranelift also doesn’t solve the problem of rust-analyzer acting crazy.

Okay, something helpful instead: Did you try asking in the rust:gnome.org matrix room mentioned in the project page?

No, I prefer public posts to prevent effort duplication, so much so that my mind started filtering out such things on project pages, but thanks for reminding me.

d_k_bo@feddit.org on 31 Oct 23:08 collapse

Just use label.add_css_class(), label.remove_css_class() or label.set_css_classes() and make sure to properly load your CSS style sheets, this is usually done by including them as a resource alongside .ui files and icons. If you are using libadwaita, you can also use its predefined style classes.

full example (requires nightly toolchain)

rust #!/usr/bin/env -S cargo +nightly -Zscript — [dependencies] gtk = { package = “gtk4”, version = “0.9.3”, features = [“v4_12”] } — use gtk::{glib, prelude::*}; const STYLESHEET: &str = r#" .green { color: green; } .red { color: red; } "#; fn main() -> glib::ExitCode { let app = gtk::Application::builder() .application_id(“org.example.HelloWorld”) .build(); app.connect_activate(|app| { let window = gtk::ApplicationWindow::builder() .application(app) .title(“Hello, World!”) .build(); // Stylesheets are usually bundled with application resources // and automatically loaded let css_provider = gtk::CssProvider::new(); css_provider.load_from_string(STYLESHEET); gtk::style_context_add_provider_for_display( &RootExt::display(&window), &css_provider, 0 ); let box_ = gtk::Box::new(gtk::Orientation::Vertical, 6); let label = gtk::Label::builder() .label(“Hello, World”) .css_classes([“green”].as_slice()) .build(); box_.append(&label); let button = gtk::Button::builder() .label(“Toggle Color”) .build(); box_.append(&button); button.connect_clicked(glib::clone!(#[weak] label, move |_| { if label.has_css_class(“red”) { label.add_css_class(“green”); label.remove_css_class(“red”); } else { label.add_css_class(“red”); label.remove_css_class(“green”); } })); window.set_child(Some(&box_)); window.present(); }); app.run() }

Doods@infosec.pub on 01 Nov 06:10 collapse

This is embarrassing, but when was it not?

I have to add a “.” before the name of a css class, I must learn my tools.

d_k_bo@feddit.org on 01 Nov 09:45 next collapse

Well, that’s CSS :D

Note that if you create a custom Widget class, you can set a CSS name, wich isn’t a CSS class and doesn’t use a leading dot.

Doods@infosec.pub on 01 Nov 14:50 collapse

you can set a CSS name, wich isn’t a CSS class and doesn’t use a leading dot.

Yeah that’s what I’ve been using all along.

zlatko@programming.dev on 01 Nov 10:10 collapse

I mean, it is not embarrassing for you. In the browser, the CSS’s “native platform”, you add classes, via the JavaScript API, without the dot. It’s not a stupid assumption.

To have to add the dot in the CSS class name seems a bit of an oversight in the gtkrs API.

d_k_bo@feddit.org on 01 Nov 12:41 collapse

I think you understood their comment wrong. In your code (e.g. label.add_css_class(“green”);) you don’t use a dot, but in the CSS stylesheet. It works the same as with HTML/JS/CSS.