fix(window): show the window buttons in full screen on macOS (#2015)

Native full screen moves a window's buttons into the bar revealed with the menu bar, and a project tab shown in its group's full-screen Space has none, so the title bar's slot for them stayed empty. The title bar now draws them there while the window fills the screen: close closes that project's tab, the green button leaves full screen, and minimize is disabled.

src-tauri/src/commands/mod.rs

@@ -431,6 +431,7 @@ pub fn builder() -> tauri_specta::Builder<tauri::Wry> {
         window::window_toggle_fullscreen,
         window::window_flash_taskbar,
         window::window_set_titlebar_height,
+        window::window_is_fullscreen,
         window_drag::window_start_drag,
         window::window_take_launch,
         window::window_close_context,

src-tauri/src/commands/window.rs

@@ -193,6 +193,20 @@ pub fn window_open_projects(
         .collect())
 }
 
+/// Whether this window fills the screen: in native full screen, or (macOS) shown in its window
+/// group's full-screen Space.
+#[tauri::command]
+#[specta::specta]
+pub fn window_is_fullscreen(window: WebviewWindow) -> bool {
+    #[cfg(target_os = "macos")]
+    {
+        use tauri::Manager;
+        crate::window_groups::in_fullscreen(window.app_handle(), &window)
+    }
+    #[cfg(not(target_os = "macos"))]
+    window.is_fullscreen().unwrap_or(false)
+}
+
 #[derive(Serialize, Deserialize, Type)]
 #[serde(rename_all = "camelCase")]
 pub struct CloseContext {

src-tauri/src/macos.rs

@@ -135,6 +135,7 @@ pub fn set_fullscreen_auxiliary(window: &WebviewWindow, host: Option<&WebviewWin
         if let Some(frame) = frame {
             native.setFrame_display(frame, true);
         }
+        target.state::<crate::state::AppState>().sink.emit(ide_core::IdeEvent::WindowFullscreenChanged);
     })
 }
 

src-tauri/src/titlebar.rs

@@ -12,11 +12,12 @@ use objc2::{
     runtime::ProtocolObject,
 };
 use objc2_app_kit::{
-    NSToolbar, NSWindow, NSWindowDidExitFullScreenNotification, NSWindowStyleMask, NSWindowToolbarStyle,
-    NSWindowWillEnterFullScreenNotification,
+    NSToolbar, NSWindow, NSWindowDidEnterFullScreenNotification, NSWindowDidExitFullScreenNotification,
+    NSWindowStyleMask, NSWindowToolbarStyle, NSWindowWillEnterFullScreenNotification,
 };
 use objc2_foundation::{NSNotificationCenter, NSObjectProtocol};
 use std::{cell::Cell, cell::RefCell, collections::HashMap, rc::Rc};
+use tauri::Manager;
 
 /// Unified compact (38pt) and unified (52pt) toolbars; pick the one closer to the web bar.
 const COMPACT_MAX_HEIGHT: f64 = 45.0;
@@ -55,7 +56,7 @@ impl Drop for Observer {
 
 struct Tracked {
     state: Rc<Fullscreen>,
-    _observers: [Observer; 2],
+    _observers: [Observer; 3],
 }
 
 thread_local! {
@@ -71,7 +72,7 @@ fn apply(window: &NSWindow, state: &Fullscreen) {
     }
 }
 
-fn track(window: &NSWindow) -> Tracked {
+fn track(window: &NSWindow, app: &tauri::AppHandle) -> Tracked {
     let state = Rc::new(Fullscreen::default());
     if window.styleMask().contains(NSWindowStyleMask::FullScreen) {
         state.will_enter();
@@ -79,11 +80,14 @@ fn track(window: &NSWindow) -> Tracked {
     let observe = |name, change: fn(&Fullscreen)| {
         let weak = Weak::new(window);
         let state = state.clone();
+        let app = app.clone();
         let block = block2::RcBlock::new(move |_| {
             change(&state);
             if let Some(window) = weak.load() {
                 apply(&window, &state);
             }
+            // The web title bar shows the window buttons itself in full screen.
+            app.state::<crate::state::AppState>().sink.emit(ide_core::IdeEvent::WindowFullscreenChanged);
         });
         let observer = unsafe {
             NSNotificationCenter::defaultCenter().addObserverForName_object_queue_usingBlock(
@@ -98,6 +102,7 @@ fn track(window: &NSWindow) -> Tracked {
     let observers = unsafe {
         [
             observe(NSWindowWillEnterFullScreenNotification, Fullscreen::will_enter),
+            observe(NSWindowDidEnterFullScreenNotification, Fullscreen::will_enter),
             observe(NSWindowDidExitFullScreenNotification, Fullscreen::did_exit),
         ]
     };
@@ -106,12 +111,13 @@ fn track(window: &NSWindow) -> Tracked {
 
 pub fn set_height(window: &tauri::WebviewWindow, height: f64) -> tauri::Result<()> {
     let label = window.label().to_owned();
+    let app = window.app_handle().clone();
     // with_webview runs on the AppKit thread.
     window.with_webview(move |webview| unsafe {
         let Some(mtm) = MainThreadMarker::new() else { return };
         let native = &*webview.ns_window().cast::<NSWindow>();
-        let state =
-            WINDOWS.with_borrow_mut(|windows| windows.entry(label).or_insert_with(|| track(native)).state.clone());
+        let state = WINDOWS
+            .with_borrow_mut(|windows| windows.entry(label).or_insert_with(|| track(native, &app)).state.clone());
         if native.toolbar().is_none() {
             let toolbar = NSToolbar::new(mtm);
             native.setToolbar(Some(&toolbar));