1 files changed, 51 insertions, 0 deletions
diff --git a/widget/windows/nsWindowTaskbarConcealer.h b/widget/windows/nsWindowTaskbarConcealer.h
new file mode 100644
index 0000000000..07c2691c52
--- /dev/null
+++ b/widget/windows/nsWindowTaskbarConcealer.h
@@ -0,0 +1,51 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef WIDGET_WINDOWS_NSWINDOWTASKBARCONCEALER_H_
+#define WIDGET_WINDOWS_NSWINDOWTASKBARCONCEALER_H_
+
+#include "nsWindow.h"
+#include "mozilla/Maybe.h"
+
+/**
+ * nsWindow::TaskbarConcealer
+ *
+ * Fullscreen-state (and, thus, taskbar-occlusion) manager.
+ */
+class nsWindow::TaskbarConcealer {
+ public:
+  // To be called when a window acquires focus. (Note that no action need be
+  // taken when focus is lost.)
+  static void OnFocusAcquired(nsWindow* aWin);
+
+  // To be called during or after a window's destruction. The corresponding
+  // nsWindow pointer is not needed, and will not be acquired or accessed.
+  static void OnWindowDestroyed(HWND aWnd);
+
+  // To be called when the Gecko-fullscreen state of a window changes.
+  static void OnFullscreenChanged(nsWindow* aWin, bool enteredFullscreen);
+
+  // To be called when the position of a window changes. (Performs its own
+  // batching; irrelevant movements will be cheap.)
+  static void OnWindowPosChanged(nsWindow* aWin);
+
+  // To be called when the cloaking state of any window changes. (Expects that
+  // all windows' internal cloaking-state mirror variables are up-to-date.)
+  static void OnCloakChanged();
+
+ private:
+  static void UpdateAllState(HWND destroyedHwnd = nullptr);
+
+  struct WindowState {
+    HMONITOR monitor;
+    bool isGkFullscreen;
+  };
+  static mozilla::Maybe<WindowState> GetWindowState(HWND);
+
+  static nsTHashMap<HWND, HMONITOR> sKnownWindows;
+  struct Impl;
+};
+
+#endif  // WIDGET_WINDOWS_NSWINDOWTASKBARCONCEALER_H_