feat(theme): add dynamic theming

src/view/styles/mod.rs

@@ -1,14 +1,25 @@
 use adw::gdk::Display;
-use gtk4 as gtk;
 
 use gtk::{
-    style_context_add_provider_for_display, CssProvider, STYLE_PROVIDER_PRIORITY_APPLICATION,
+    style_context_add_provider_for_display, CssProvider, STYLE_PROVIDER_PRIORITY_APPLICATION, Settings
 };
 
-pub fn load_css() {
+pub fn load_css(settings: &Settings) {
     let style_provider = CssProvider::new();
 
-    style_provider.load_from_string(include_str!("base.css"));
+    let theme = settings.gtk_theme_name();
+
+    match theme {
+        Some(theme_type) => {
+            let theme_string = theme_type.to_string();
+            if theme_string.contains("dark") || settings.is_gtk_application_prefer_dark_theme() {
+                style_provider.load_from_string(include_str!("base_dark.css"));
+            } else {
+                style_provider.load_from_string(include_str!("base_light.css"));
+            }
+        },
+        None => eprintln!("Theme hasn't been determined."),
+    }
 
     style_context_add_provider_for_display(
         &Display::default().expect("Could not connect to a display"),

src/view/ui.rs

@@ -1,7 +1,6 @@
 use crate::model::builder_traits::*;
 
 use adw::HeaderBar;
-use gtk4 as gtk;
 
 use gtk::{prelude::*, StackTransitionType::SlideLeftRight, *};
 
@@ -19,7 +18,14 @@ use crate::view::{
 use super::{components::MenuActions, styles::load_css};
 
 pub fn ui(application: &adw::Application) {
-    load_css();
+
+    let default_settings = Settings::default();
+
+    if let Some(settings) = default_settings {
+        settings.connect_gtk_application_prefer_dark_theme_notify(load_css);
+        settings.connect_gtk_theme_name_notify(load_css);
+        load_css(&settings);
+    }
 
     let hamming_code = Box::builder()
         .orientation(Orientation::Vertical)
@@ -30,7 +36,7 @@ pub fn ui(application: &adw::Application) {
 
     let info_bar = InfoBar::builder()
         .set_text_label("Sample text")
-        .set_button_icon("close")
+        .set_button_icon("window-close-symbolic")
         .build();
 
     hamming_code::hamming_code_page(&hamming_code);