fix(windows): fix tray event window showing up on click, closes #506 (#…

…507)

* fix(windows): fix tray event window showing up on click, closes #506

* changefile

* change file

* changefile content

.changes/tray-ghost-window.md

@@ -0,0 +1,5 @@
+---
+"tao": "patch"
+---
+
+On Windows, fix a ghost window appearing occasionally when clicking the tray icon.

src/platform_impl/windows/system_tray.rs

@@ -72,10 +72,18 @@ impl SystemTrayBuilder {
       RegisterClassW(&wnd_class);
 
       let hwnd = CreateWindowExW(
-        Default::default(),
+        WS_EX_NOACTIVATE | WS_EX_TRANSPARENT | WS_EX_LAYERED |
+        // WS_EX_TOOLWINDOW prevents this window from ever showing up in the taskbar, which
+        // we want to avoid. If you remove this style, this window won't show up in the
+        // taskbar *initially*, but it can show up at some later point. This can sometimes
+        // happen on its own after several hours have passed, although this has proven
+        // difficult to reproduce. Alternatively, it can be manually triggered by killing
+        // `explorer.exe` and then starting the process back up.
+        // It is unclear why the bug is triggered by waiting for several hours.
+        WS_EX_TOOLWINDOW,
         PCWSTR(class_name.as_ptr()),
-        "tao_system_tray_window",
-        WS_OVERLAPPEDWINDOW,
+        PCWSTR::default(),
+        WS_OVERLAPPED,
         CW_USEDEFAULT,
         0,
         CW_USEDEFAULT,