[FancyZones] Child windows support (#16507)

src/modules/fancyzones/FancyZonesLib/WindowUtils.h

@@ -0,0 +1,30 @@
+#pragma once
+
+#include <Windows.h>
+
+#include "gdiplus.h"
+
+#include <string>
+#include <vector>
+
+namespace FancyZonesWindowUtils
+{
+    bool IsSplashScreen(HWND window);
+    bool IsWindowMaximized(HWND window) noexcept;
+    bool HasVisibleOwner(HWND window) noexcept;
+    bool IsStandardWindow(HWND window);
+    bool IsPopupWindow(HWND window) noexcept;
+    bool HasThickFrameAndMinimizeMaximizeButtons(HWND window) noexcept;
+    bool IsCandidateForZoning(HWND window);
+    bool IsProcessOfWindowElevated(HWND window); // If HWND is already dead, we assume it wasn't elevated
+    bool IsExcludedByUser(const std::wstring& processPath) noexcept;
+    bool IsExcludedByDefault(const std::wstring& processPath) noexcept;
+
+    void SwitchToWindow(HWND window) noexcept;
+    void SizeWindowToRect(HWND window, RECT rect) noexcept; // Parameter rect must be in screen coordinates (e.g. obtained from GetWindowRect)
+    void SaveWindowSizeAndOrigin(HWND window) noexcept;
+    void RestoreWindowSize(HWND window) noexcept;
+    void RestoreWindowOrigin(HWND window) noexcept;
+    void MakeWindowTransparent(HWND window);
+    RECT AdjustRectForSizeWindowToRect(HWND window, RECT rect, HWND windowOfRect) noexcept; // Parameter rect is in windowOfRect coordinates
+}