fix: bring hidden or covered bubbles back every minute

Another always-on-top window, or a shell action that hid ours, could
leave a bubble covered or hidden until restart. The fullscreen check
thread now shows every ready bubble again and puts it back at the top of
the always-on-top band once a minute, unless the user or a fullscreen
app has them hidden. Windows re-asserts HWND_TOPMOST without activating;
other platforms drop and re-set always-on-top.

README.md

@@ -45,6 +45,8 @@ self-updater are all written from scratch against the same public APIs
   expires and after an update was applied
 - Auto-hide when a fullscreen app is in the foreground (games, video,
   presentations) — reappears when you leave fullscreen
+- Every minute, shown bubbles are put back on top, so another
+  always-on-top window can't keep them covered or hidden
 
 ## Who this is for
 

src/bubble.rs

@@ -489,6 +489,45 @@ pub fn apply(app: &AppHandle, action: Action) {
     }
 }
 
+/// Show every ready bubble again and put it back on top, unless the
+/// bubbles are meant to be hidden. Another always-on-top window, or a shell
+/// action that hid ours, can otherwise leave a bubble covered or hidden for
+/// good. A bubble still waiting for its page is left to the ready handshake.
+/// Visibility is read on the main thread, after any hide queued before.
+pub fn bring_back(app: &AppHandle) {
+    let handle = app.clone();
+    let queued = app.run_on_main_thread(move || {
+        let shows = runtime_of(&handle).is_some_and(|r| r.with_state(|s| s.visibility.shows()));
+        if !shows {
+            return;
+        }
+        for (_, window) in windows(&handle) {
+            if with_pending(|p| p.contains_key(window.label())) {
+                continue;
+            }
+            show(&window);
+            raise(&window);
+        }
+    });
+    if let Err(err) = queued {
+        log::warn!("bubble bring-back could not reach the main thread: {err}");
+    }
+}
+
+fn raise(window: &WebviewWindow) {
+    #[cfg(windows)]
+    let result = platform::windows::raise_topmost(window).map_err(|e| e.to_string());
+    // Re-setting the same level is a no-op, so drop it and set it again.
+    #[cfg(not(windows))]
+    let result = window
+        .set_always_on_top(false)
+        .and_then(|()| window.set_always_on_top(true))
+        .map_err(|e| e.to_string());
+    if let Err(err) = result {
+        log::warn!("{} not raised: {err}", window.label());
+    }
+}
+
 /// Make every bubble ignore the mouse, or take it again.
 pub fn set_click_through(app: &AppHandle, ignore: bool) {
     let handle = app.clone();

src/fullscreen.rs

@@ -2,10 +2,13 @@
 //! fullscreen window of another process is in the foreground, and hides the
 //! bubbles while one is. They come back without activation when it leaves,
 //! unless the user hid them in the meantime.
+//!
+//! The same thread brings the bubbles back every minute while they should
+//! show, in case another window covered or hid them.
 
 use std::io;
 use std::sync::Arc;
-use std::time::Duration;
+use std::time::{Duration, Instant};
 
 use crate::core::visibility::Event;
 use crate::platform::{self, FullscreenCheck};
@@ -14,13 +17,21 @@ use crate::runtime::Runtime;
 /// How often the foreground window is checked.
 pub const CHECK_INTERVAL: Duration = Duration::from_millis(1500);
 
+/// How often shown bubbles are brought back on top.
+pub const BRING_BACK_INTERVAL: Duration = Duration::from_secs(60);
+
 /// Start the check thread. It runs until the process starts exiting.
 pub fn spawn(runtime: Arc<Runtime>) -> io::Result<()> {
     std::thread::Builder::new()
         .name("fullscreen".into())
         .spawn(move || {
+            let mut last_bring_back = Instant::now();
             while !runtime.is_exiting() {
                 tick(&runtime);
+                if last_bring_back.elapsed() >= BRING_BACK_INTERVAL {
+                    last_bring_back = Instant::now();
+                    runtime.bring_back_bubbles();
+                }
                 std::thread::sleep(CHECK_INTERVAL);
             }
         })

src/platform/windows.rs

@@ -28,9 +28,9 @@ use windows::Win32::UI::Shell::{
 use windows::Win32::UI::WindowsAndMessaging::{
     GetClassNameW, GetForegroundWindow, GetWindowLongPtrW, GetWindowRect, GetWindowThreadProcessId,
     IsIconic, IsWindowVisible, MessageBoxW, SetForegroundWindow, SetWindowLongPtrW, SetWindowPos,
-    ShowWindow, GWL_EXSTYLE, GWL_STYLE, MA_NOACTIVATE, MB_ICONERROR, MB_OK, MB_SETFOREGROUND,
-    SWP_FRAMECHANGED, SWP_NOACTIVATE, SWP_NOMOVE, SWP_NOSIZE, SWP_NOZORDER, SW_HIDE,
-    SW_SHOWNOACTIVATE, WM_DISPLAYCHANGE, WM_EXITSIZEMOVE, WM_MOUSEACTIVATE, WM_NCDESTROY,
+    ShowWindow, GWL_EXSTYLE, GWL_STYLE, HWND_TOPMOST, MA_NOACTIVATE, MB_ICONERROR, MB_OK,
+    MB_SETFOREGROUND, SWP_FRAMECHANGED, SWP_NOACTIVATE, SWP_NOMOVE, SWP_NOSIZE, SWP_NOZORDER,
+    SW_HIDE, SW_SHOWNOACTIVATE, WM_DISPLAYCHANGE, WM_EXITSIZEMOVE, WM_MOUSEACTIVATE, WM_NCDESTROY,
     WM_SETTINGCHANGE, WS_EX_NOACTIVATE, WS_EX_TOOLWINDOW,
 };
 
@@ -293,6 +293,26 @@ pub fn show_no_activate(window: &tauri::WebviewWindow) -> io::Result<()> {
     Ok(())
 }
 
+/// Put a bubble back at the top of the always-on-top band, above any
+/// topmost window that came after it, without activating it.
+pub fn raise_topmost(window: &tauri::WebviewWindow) -> io::Result<()> {
+    let hwnd = hwnd_of(window)?;
+    // SAFETY: `hwnd` is a live window of this process; nothing moves,
+    // resizes or activates.
+    unsafe {
+        SetWindowPos(
+            hwnd,
+            Some(HWND_TOPMOST),
+            0,
+            0,
+            0,
+            0,
+            SWP_NOMOVE | SWP_NOSIZE | SWP_NOACTIVATE,
+        )
+    }
+    .map_err(io::Error::from)
+}
+
 /// Hide a bubble (see [`show_no_activate`]).
 pub fn hide(window: &tauri::WebviewWindow) -> io::Result<()> {
     let hwnd = hwnd_of(window)?;

src/runtime.rs

@@ -506,6 +506,12 @@ impl Runtime {
         bubble::set_click_through(&self.ui.app, ignore);
     }
 
+    /// Show the bubbles again and put them back on top, unless they are
+    /// meant to be hidden.
+    pub fn bring_back_bubbles(&self) {
+        bubble::bring_back(&self.ui.app);
+    }
+
     /// Apply a visibility event to every bubble. A user show or hide is
     /// also saved as `widget_visible`.
     pub fn apply_visibility(&self, event: visibility::Event) {