Added WinAPI Shim info

xpf/third-party-libraries.md

@@ -49,3 +49,157 @@ If you find that a control marked as `Fix In Progress` or `Untested` is mission-
 * **Unlisted Vendors**: The absence of a control vendor from our database doesn't indicate incompatibility. We encourage you to test any controls you need.
 * **Known Challenges**: Issues most commonly arise with controls that utilize GDI or WinForms components. 
 
+## WinAPI Shim APIs 
+
+Below is an overview of the Windows API (WinAPI) shims available in Avalonia XPF. These shims allow for native Windows functionality while maintaining cross-platform compatibility. Some APIs may not be fully implemented. 
+
+
+### Window Creation and Manipulation
+```csharp
+IntPtr CreateWindowEx(uint dwExStyle, void* lpClassName, void* lpWindowName, uint dwStyle, 
+    int x, int y, int nWidth, int nHeight, IntPtr hWndParent, IntPtr hMenu, 
+    IntPtr hInstance, IntPtr lpParam);
+IntPtr CreateWindowExW(uint dwExStyle, void* lpClassName, void* lpWindowName, uint dwStyle, 
+    int x, int y, int nWidth, int nHeight, IntPtr hWndParent, IntPtr hMenu, 
+    IntPtr hInstance, IntPtr lpParam);
+int GetWindowPlacement(IntPtr hWnd, IntPtr lpwndpl);
+int GetWindowRect(IntPtr hWnd, RECT* lpRect);
+int SetWindowPos(IntPtr hWnd, IntPtr hWndInsertAfter, int x, int y, int cx, int cy, int uFlags);
+int IsWindowEnabled(IntPtr hWnd);
+int IsWindowVisible(IntPtr hWnd);
+int IsWindow(IntPtr hWnd);
+```
+
+#### Window Properties and Attributes
+```csharp
+int GetWindowLong(IntPtr hWnd, int nIndex);
+int SetWindowLong(IntPtr hWnd, int nIndex, int newVal);
+IntPtr GetWindowLongPtr(IntPtr hWnd, int nIndex);
+IntPtr GetWindowLongPtrW(IntPtr hWnd, int nIndex);
+IntPtr SetWindowLongPtr(IntPtr hWnd, int nIndex, IntPtr newVal);
+IntPtr GetSystemMenu(IntPtr hWnd, int bRevert);
+int SetWindowDisplayAffinity(IntPtr hWnd, int* dwAffinity);
+int GetWindowInfo(IntPtr hwnd, WINDOWINFO* pwi);
+```
+
+### Device Context and Graphics
+```csharp
+IntPtr GetDC(IntPtr hWnd);
+IntPtr CreateCompatibleDC(IntPtr hdc);
+int DeleteDC(IntPtr hdc);
+int GetDeviceCaps(IntPtr hdc, int nIndex);
+int ReleaseDC(IntPtr hWnd, IntPtr hDC);
+IntPtr CreateRectRgn(int x1, int y1, int x2, int y2);
+IntPtr CreateRoundRectRgn(int x1, int y1, int x2, int y2, int cx, int cy);
+IntPtr CreateRectRgnIndirect(RECT* lprc);
+int DeleteObject(IntPtr obj);
+int SetWindowRgn(IntPtr hWnd, IntPtr hRgn, int bRedraw);
+```
+
+### DWM (Desktop Window Manager)
+```csharp
+int DwmIsCompositionEnabled(int* enabled);
+int DwmExtendFrameIntoClientArea(IntPtr hWnd, MARGINS* pMarInset);
+uint DwmGetWindowAttribute(IntPtr hwnd, int attribute, uint* pvAttribute, uint cbAttribute);
+uint DwmSetWindowAttribute(IntPtr hwnd, int attribute, uint* pvAttribute, uint cbAttribute);
+```
+
+### Monitor and Display
+```csharp
+IntPtr MonitorFromPoint(long point, uint dwFlags);
+IntPtr MonitorFromRect(IntPtr lprc, uint dwFlags);
+IntPtr MonitorFromWindow(IntPtr handle, uint flags);
+int GetMonitorInfo(IntPtr hMonitor, IntPtr lpmi);
+int EnumDisplayMonitors(IntPtr hdc, IntPtr lprcClip, IntPtr lpfnEnum, IntPtr data);
+int GetDpiForMonitor(IntPtr hMonitor, int dpiType, uint* dpiX, uint* dpiY);
+int GetDpiForWindow(IntPtr hWnd);
+```
+
+### Input Method Editor (IME)
+```csharp
+IntPtr ImmCreateContext();
+int ImmDestroyContext(IntPtr hIMC);
+IntPtr ImmGetContext(IntPtr hWnd);
+int ImmReleaseContext(IntPtr hWnd, IntPtr hIMC);
+IntPtr ImmAssociateContext(IntPtr hWnd, IntPtr hIMC);
+int ImmSetOpenStatus(IntPtr hIMC, int open);
+int ImmGetOpenStatus(IntPtr hIMC);
+int ImmGetCompositionString(IntPtr hIMC, int dwIndex, void* lpBuf, int dwBufLen);
+int ImmGetCompositionStringW(IntPtr hIMC, int dwIndex, void* lpBuf, int dwBufLen);
+int ImmSetCompositionFont(IntPtr hIMC, void* lf);
+int ImmSetCompositionFontW(IntPtr hIMC, void* lf);
+int ImmSetCompositionWindow(IntPtr hIMC, void* compform);
+int ImmSetCandidateWindow(IntPtr hIMC, void* candform);
+```
+
+### System Information and Settings
+```csharp
+int GetSysColor(int nIndex);
+int SystemParametersInfo(uint uiAction, uint uiParam, void* pvParam, uint fWinIni);
+int SystemParametersInfoW(uint uiAction, uint uiParam, void* pvParam, uint fWinIni);
+uint GetDoubleClickTime();
+int GetSystemMetrics(int index);
+int RtlGetVersion(RTL_OSVERSIONINFOW* lpVersionInformation);
+uint GetCaretBlinkTime();
+```
+
+### Clipboard and Shell
+```csharp
+int AddClipboardFormatListener(IntPtr hwnd);
+IntPtr SHGetFileInfo(void* pszPath, uint dwFileAttributes, SHFILEINFOA* psfi, 
+    uint cbFileInfo, uint uFlags);
+IntPtr SHGetFileInfoW(void* pszPath, uint dwFileAttributes, SHFILEINFOW* psfi, 
+    uint cbFileInfo, uint uFlags);
+```
+
+### Window Messages and Hooks
+```csharp
+IntPtr SendMessage(IntPtr hWnd, int uMsg, IntPtr wParam, IntPtr lParam);
+int PostMessage(IntPtr hWnd, int uMsg, IntPtr wParam, IntPtr lParam);
+IntPtr SetWindowsHookEx(int idHook, IntPtr lpfn, IntPtr hMod, uint dwThreadId);
+int UnhookWindowsHookEx(IntPtr hWnd);
+IntPtr DefWindowProc(IntPtr hWnd, uint msg, IntPtr wParam, IntPtr lParam);
+IntPtr DefWindowProcW(IntPtr hWnd, uint msg, IntPtr wParam, IntPtr lParam);
+```
+
+### File and Resource Management
+```csharp
+IntPtr LoadLibrary(void* lpLib);
+IntPtr LoadLibraryW(void* lpLib);
+int LoadString(IntPtr hInstance, uint uID, void* lpBuffer, int cchBufferMax);
+int LoadStringW(IntPtr hInstance, uint uID, void* lpBuffer, int cchBufferMax);
+IntPtr CreateFileMapping(IntPtr hFile, IntPtr lpFileMappingAttributes, uint flProtect, 
+    uint dwMaximumSizeHigh, uint dwMaximumSizeLow, char* lpName);
+IntPtr MapViewOfFile(IntPtr hFileMappingObject, uint dwDesiredAccess, uint dwFileOffsetHigh, 
+    uint dwFileOffsetLow, IntPtr dwNumberOfBytesToMap);
+int UnmapViewOfFile(IntPtr lpBaseAddress);
+int CloseHandle(IntPtr hObject);
+```
+
+### UI Elements
+```csharp
+int CreateCaret(IntPtr hWnd, IntPtr hBitmap, int width, int height);
+int ShowCaret(IntPtr hWnd);
+int HideCaret(IntPtr hWnd);
+int DestroyCaret();
+int SetCaretPos(int x, int y);
+uint TrackPopupMenuEx(IntPtr hmenu, uint fuFlags, int x, int y, IntPtr hwnd, IntPtr lptpm);
+```
+
+### Notes
+- Functions with 'W' suffix are Unicode versions
+- Many functions return non-zero value for success, zero for failure
+- IntPtr parameters typically represent handles (HWND, HDC, etc.)
+- void* parameters are typically used for strings or structures in unmanaged code
+
+### Usage Example
+```csharp
+// Example of getting window dimensions
+var hwnd = window.PlatformImpl.Handle.Handle;
+var rect = new RECT();
+if (GetWindowRect(hwnd, &rect) != 0)
+{
+    int width = rect.right - rect.left;
+    int height = rect.bottom - rect.top;
+}
+```