Init commit

bread-theme/src/gtk.rs

@@ -0,0 +1,50 @@
+use gtk4::CssProvider;
+use std::cell::RefCell;
+use std::path::Path;
+
+/// Apply a CSS string to the default display at APPLICATION priority.
+/// Re-uses an existing provider if one is passed in (for SIGHUP reloads).
+pub fn apply_css(css: &str, provider: &RefCell<Option<CssProvider>>) {
+    let display = gtk4::gdk::Display::default().expect("no display");
+    let mut guard = provider.borrow_mut();
+    if let Some(p) = guard.as_ref() {
+        p.load_from_string(css);
+    } else {
+        let p = CssProvider::new();
+        p.load_from_string(css);
+        gtk4::style_context_add_provider_for_display(
+            &display,
+            &p,
+            gtk4::STYLE_PROVIDER_PRIORITY_APPLICATION,
+        );
+        *guard = Some(p);
+    }
+}
+
+/// Apply a user CSS override file at USER priority. Clears the provider if the
+/// file is absent so stale overrides don't persist across SIGHUP reloads.
+pub fn apply_user_css(path: &Path, provider: &RefCell<Option<CssProvider>>) {
+    let display = gtk4::gdk::Display::default().expect("no display");
+    let mut guard = provider.borrow_mut();
+    match std::fs::read_to_string(path) {
+        Ok(css) => {
+            if let Some(p) = guard.as_ref() {
+                p.load_from_string(&css);
+            } else {
+                let p = CssProvider::new();
+                p.load_from_string(&css);
+                gtk4::style_context_add_provider_for_display(
+                    &display,
+                    &p,
+                    gtk4::STYLE_PROVIDER_PRIORITY_USER,
+                );
+                *guard = Some(p);
+            }
+        }
+        Err(_) => {
+            if let Some(p) = guard.as_ref() {
+                p.load_from_string("");
+            }
+        }
+    }
+}