feat: ensure windows overlap the taskbar when fullscreen

packages/wm-platform/src/com.rs

@@ -1,9 +1,12 @@
 use anyhow::Context;
 use windows::{
   core::{ComInterface, IUnknown, IUnknown_Vtbl, GUID, HRESULT},
-  Win32::System::Com::{
-    CoCreateInstance, CoInitializeEx, CoUninitialize, IServiceProvider,
-    CLSCTX_ALL, COINIT_APARTMENTTHREADED,
+  Win32::{
+    System::Com::{
+      CoCreateInstance, CoInitializeEx, CoUninitialize, IServiceProvider,
+      CLSCTX_ALL, CLSCTX_SERVER, COINIT_APARTMENTTHREADED,
+    },
+    UI::Shell::{ITaskbarList2, TaskbarList},
   },
 };
 
@@ -19,7 +22,11 @@ thread_local! {
   pub static COM_INIT: ComInit = ComInit::new();
 }
 
-pub struct ComInit();
+pub struct ComInit {
+  service_provider: Option<IServiceProvider>,
+  application_view_collection: Option<IApplicationViewCollection>,
+  taskbar_list: Option<ITaskbarList2>,
+}
 
 impl ComInit {
   /// Initializes COM on the current thread with apartment threading model.
@@ -34,7 +41,50 @@ impl ComInit {
     unsafe { CoInitializeEx(None, COINIT_APARTMENTTHREADED) }
       .expect("Unable to initialize COM.");
 
-    Self()
+    let service_provider = unsafe {
+      CoCreateInstance(&CLSID_IMMERSIVE_SHELL, None, CLSCTX_ALL)
+    }
+    .ok();
+
+    let application_view_collection = service_provider.as_ref().and_then(
+      |provider: &IServiceProvider| unsafe {
+        provider.QueryService(&IApplicationViewCollection::IID).ok()
+      },
+    );
+
+    let taskbar_list =
+      unsafe { CoCreateInstance(&TaskbarList, None, CLSCTX_SERVER) }.ok();
+
+    Self {
+      service_provider,
+      application_view_collection,
+      taskbar_list,
+    }
+  }
+
+  /// Returns an instance of `IServiceProvider`.
+  pub fn service_provider(&self) -> anyhow::Result<IServiceProvider> {
+    self
+      .service_provider
+      .clone()
+      .context("Unable to create `IServiceProvider` instance.")
+  }
+
+  /// Returns an instance of `IApplicationViewCollection`.
+  pub fn application_view_collection(
+    &self,
+  ) -> anyhow::Result<IApplicationViewCollection> {
+    self.application_view_collection.clone().context(
+      "Failed to query for `IApplicationViewCollection` instance.",
+    )
+  }
+
+  /// Returns an instance of `ITaskbarList2`.
+  pub fn taskbar_list(&self) -> anyhow::Result<ITaskbarList2> {
+    self
+      .taskbar_list
+      .clone()
+      .context("Unable to create `ITaskbarList2` instance.")
   }
 }
 
@@ -50,26 +100,6 @@ impl Drop for ComInit {
   }
 }
 
-/// Returns an instance of `IServiceProvider`.
-pub fn iservice_provider() -> anyhow::Result<IServiceProvider> {
-  COM_INIT.with(|_| unsafe {
-    CoCreateInstance(&CLSID_IMMERSIVE_SHELL, None, CLSCTX_ALL)
-      .context("Unable to create `IServiceProvider` instance.")
-  })
-}
-
-/// Returns an instance of `IApplicationViewCollection`.
-pub fn iapplication_view_collection(
-  provider: &IServiceProvider,
-) -> anyhow::Result<IApplicationViewCollection> {
-  COM_INIT.with(|_| {
-    unsafe { provider.QueryService(&IApplicationViewCollection::IID) }
-      .context(
-        "Failed to query for `IApplicationViewCollection` instance.",
-      )
-  })
-}
-
 /// Undocumented COM interface for Windows shell functionality.
 ///
 /// Note that filler methods are added to match the vtable layout.

packages/wm-platform/src/native_window.rs

@@ -10,18 +10,14 @@ use windows::{
       DWMWA_WINDOW_CORNER_PREFERENCE, DWMWCP_DEFAULT, DWMWCP_DONOTROUND,
       DWMWCP_ROUND, DWMWCP_ROUNDSMALL,
     },
-    System::{
-      Com::{CoCreateInstance, CLSCTX_SERVER},
-      Threading::{
-        OpenProcess, QueryFullProcessImageNameW, PROCESS_NAME_WIN32,
-        PROCESS_QUERY_LIMITED_INFORMATION,
-      },
+    System::Threading::{
+      OpenProcess, QueryFullProcessImageNameW, PROCESS_NAME_WIN32,
+      PROCESS_QUERY_LIMITED_INFORMATION,
     },
     UI::{
       Input::KeyboardAndMouse::{
         SendInput, INPUT, INPUT_0, INPUT_MOUSE, MOUSEINPUT,
       },
-      Shell::{ITaskbarList, TaskbarList},
       WindowsAndMessaging::{
         EnumWindows, GetClassNameW, GetLayeredWindowAttributes, GetWindow,
         GetWindowLongPtrW, GetWindowRect, GetWindowTextW,
@@ -47,7 +43,7 @@ use wm_common::{
   Rect, RectDelta, WindowState,
 };
 
-use super::{iapplication_view_collection, iservice_provider, COM_INIT};
+use super::COM_INIT;
 
 /// Magic number used to identify programmatic mouse inputs from our own
 /// process.
@@ -664,9 +660,8 @@ impl NativeWindow {
   }
 
   pub fn set_cloaked(&self, cloaked: bool) -> anyhow::Result<()> {
-    COM_INIT.with(|_| -> anyhow::Result<()> {
-      let view_collection =
-        iapplication_view_collection(&iservice_provider()?)?;
+    COM_INIT.with(|com_init| -> anyhow::Result<()> {
+      let view_collection = com_init.application_view_collection()?;
 
       let mut view = None;
       unsafe { view_collection.get_view_for_hwnd(self.handle, &mut view) }
@@ -691,9 +686,8 @@ impl NativeWindow {
     &self,
     visible: bool,
   ) -> anyhow::Result<()> {
-    COM_INIT.with(|_| -> anyhow::Result<()> {
-      let taskbar_list: ITaskbarList =
-        unsafe { CoCreateInstance(&TaskbarList, None, CLSCTX_SERVER)? };
+    COM_INIT.with(|com_init| -> anyhow::Result<()> {
+      let taskbar_list = com_init.taskbar_list()?;
 
       if visible {
         unsafe { taskbar_list.AddTab(HWND(self.handle))? };
@@ -814,6 +808,22 @@ impl NativeWindow {
     Ok(())
   }
 
+  /// Marks the window as fullscreen.
+  ///
+  /// Causes the native Windows taskbar to be moved to the bottom of the
+  /// z-order when this window is active.
+  pub fn mark_fullscreen(&self, fullscreen: bool) -> anyhow::Result<()> {
+    COM_INIT.with(|com_init| -> anyhow::Result<()> {
+      let taskbar_list = com_init.taskbar_list()?;
+
+      unsafe {
+        taskbar_list.MarkFullscreenWindow(HWND(self.handle), fullscreen)
+      }?;
+
+      Ok(())
+    })
+  }
+
   pub fn set_z_order(&self, z_order: &ZOrder) -> anyhow::Result<()> {
     let z_order = match z_order {
       ZOrder::TopMost => HWND_TOPMOST,

packages/wm/src/commands/general/platform_sync.rs

@@ -165,6 +165,7 @@ fn windows_to_bring_to_front(
   Ok(windows_to_bring_to_front)
 }
 
+#[allow(clippy::too_many_lines)]
 fn redraw_containers(
   focused_container: &Container,
   state: &mut WmState,
@@ -278,6 +279,25 @@ fn redraw_containers(
       warn!("Failed to set window position: {}", err);
     }
 
+    // Whether the window is either transitioning to or from fullscreen.
+    // TODO: This check can be improved since `prev_state` can be
+    // fullscreen without it needing to be marked as not fullscreen.
+    let is_transitioning_fullscreen =
+      match (window.prev_state(), window.state()) {
+        (Some(_), WindowState::Fullscreen(s)) if !s.maximized => true,
+        (Some(WindowState::Fullscreen(_)), _) => true,
+        _ => false,
+      };
+
+    if is_transitioning_fullscreen {
+      if let Err(err) = window.native().mark_fullscreen(matches!(
+        window.state(),
+        WindowState::Fullscreen(_)
+      )) {
+        warn!("Failed to mark window as fullscreen: {}", err);
+      }
+    }
+
     // Skip setting taskbar visibility if the window is hidden (has no
     // effect). Since cloaked windows are normally always visible in the
     // taskbar, we only need to set visibility if `show_all_in_taskbar` is