WindowsAPI.cs

/*  AeroShot - Transparent screenshot utility for Windows
    Copyright (C) 2021 Cvolton
    Copyright (C) 2015 toe_head2001
    Copyright (C) 2012 Caleb Joseph

    AeroShot is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    AeroShot is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>. */

using System;
using System.Drawing;
using System.Runtime.InteropServices;
using System.Text;

namespace AeroShot
{
    internal delegate bool CallBackPtr(IntPtr hwnd, int lParam);

    [StructLayout(LayoutKind.Sequential)]
    internal struct WindowsRect
    {
        internal int Left;
        internal int Top;
        internal int Right;
        internal int Bottom;

        internal WindowsRect(int x)
        {
            Left = x;
            Top = x;
            Right = x;
            Bottom = x;
        }
    }

    [StructLayout(LayoutKind.Sequential)]
    internal struct WindowsMargins
    {
        internal int LeftWidth;
        internal int RightWidth;
        internal int TopHeight;
        internal int BottomHeight;

        internal WindowsMargins(int left, int right, int top, int bottom)
        {
            LeftWidth = left;
            RightWidth = right;
            TopHeight = top;
            BottomHeight = bottom;
        }
    }

    [StructLayout(LayoutKind.Sequential)]
    internal struct BitmapInfo
    {
        public Int32 biSize;
        public Int32 biWidth;
        public Int32 biHeight;
        public Int16 biPlanes;
        public Int16 biBitCount;
        public Int32 biCompression;
        public Int32 biSizeImage;
        public Int32 biXPelsPerMeter;
        public Int32 biYPelsPerMeter;
        public Int32 biClrUsed;
        public Int32 biClrImportant;
    }

    [StructLayout(LayoutKind.Sequential)]
    internal struct IconInfoStruct
    {
        internal bool fIcon;
        internal Int32 xHotspot;
        internal Int32 yHotspot;
        internal IntPtr hbmMask;
        internal IntPtr hbmColor;
    }

    [StructLayout(LayoutKind.Sequential)]
    internal struct CursorInfoStruct
    {
        internal Int32 cbSize;
        internal Int32 flags;
        internal IntPtr hCursor;
        internal PointStruct ptScreenPos;
    }

    [StructLayout(LayoutKind.Sequential)]
    internal struct PointStruct
    {
        internal int X;
        internal int Y;
    }

    internal enum DwmWindowAttribute
    {
        NonClientRenderingEnabled = 1,
        NonClientRenderingPolicy,
        TransitionsForceDisabled,
        AllowNonClientPaint,
        CaptionButtonBounds,
        NonClientRtlLayout,
        ForceIconicRepresentation,
        Flip3DPolicy,
        ExtendedFrameBounds,
        HasIconicBitmap,
        DisallowPeek,
        ExcludedFromPeek,
        Last
    }

    internal static class WindowsApi
    {
        // Safe method of calling dwmapi.dll, for versions of Windows lower than Vista
        internal static int DwmGetWindowAttribute(IntPtr hWnd, DwmWindowAttribute dwAttribute, ref WindowsRect pvAttribute, int cbAttribute)
        {
            IntPtr dwmDll = LoadLibrary("dwmapi.dll");
            if (dwmDll == IntPtr.Zero)
                return Marshal.GetLastWin32Error();
            IntPtr dwmFunction = GetProcAddress(dwmDll, "DwmGetWindowAttribute");
            if (dwmFunction == IntPtr.Zero)
                return Marshal.GetLastWin32Error();
            var call = (DwmGetWindowAttributeDelegate)Marshal.GetDelegateForFunctionPointer(dwmFunction, typeof(DwmGetWindowAttributeDelegate));
            int result = call(hWnd, dwAttribute, ref pvAttribute, cbAttribute);
            FreeLibrary(dwmDll);
            return result;
        }

        internal struct DWM_COLORIZATION_PARAMS
        {
            public uint clrColor;
            public uint clrAfterGlow;
            public uint nIntensity;
            public uint clrAfterGlowBalance;
            public uint clrBlurBalance;
            public uint clrGlassReflectionIntensity;
            public bool fOpaque;
        }

        internal enum DeviceCap
        {
            VERTRES = 10,
            DESKTOPVERTRES = 117,

            // http://pinvoke.net/default.aspx/gdi32/GetDeviceCaps.html
        }

        [DllImport("user32.dll")]
        internal static extern IntPtr FindWindow(string lpClassName, string lpWindowName);

        [DllImport("user32.dll")]
        internal static extern bool SetForegroundWindow(IntPtr hWnd);

        [DllImport("user32.dll")]
        internal static extern bool ShowWindow(IntPtr hWnd, int nCmdShow);

        [DllImport("user32.dll")]
        internal static extern bool SetWindowPos(IntPtr hWnd, IntPtr hWndInsertAfter, int x, int y, int width, int height, uint uFlags);

        [DllImport("user32.dll")]
        internal static extern bool GetWindowRect(IntPtr hWnd, ref WindowsRect rect);
        [DllImport("user32.dll")]
        internal static extern long GetWindowLong(IntPtr hWnd, int nIndex);

        [DllImport("user32.dll")]
        internal static extern IntPtr GetWindow(IntPtr hWnd, uint uCmd);

        [DllImport("user32.dll")]
        internal static extern int GetWindowText(IntPtr hWnd, StringBuilder lpString, int nMaxCount);

        [DllImport("user32.dll")]
        internal static extern int GetWindowTextLength(IntPtr hWnd);

        [DllImport("user32.dll")]
        internal static extern IntPtr GetForegroundWindow();

        [DllImport("user32.dll")]
        public static extern bool GetCursorInfo(out CursorInfoStruct pci);

        [DllImport("user32.dll")]
        public static extern IntPtr DestroyIcon(IntPtr hIcon);

        [DllImport("user32.dll")]
        public static extern IntPtr CopyIcon(IntPtr hIcon);

        [DllImport("user32.dll")]
        public static extern bool GetIconInfo(IntPtr hIcon, out IconInfoStruct piconinfo);

        [DllImport("user32.dll")]
        internal static extern bool RegisterHotKey(IntPtr hWnd, int id, int fsModifiers, int vlc);

        [DllImport("user32.dll")]
        internal static extern bool UnregisterHotKey(IntPtr hWnd, int id);

        [DllImport("user32.dll")]
        internal static extern bool SystemParametersInfo(uint uiAction, uint uiParam, ref int pvParam, uint fWinIni);

        [DllImport("user32.dll")]
        internal static extern bool SystemParametersInfo(uint uiAction, uint uiParam, uint pvParam, uint fWinIni);

        [DllImport("user32.dll", SetLastError = true)]
        [return: MarshalAs(UnmanagedType.Bool)]
        internal static extern bool SystemParametersInfo(uint uiAction, uint uiParam, bool pvParam, uint fWinIni);

        [DllImport("user32.dll")]
        internal static extern bool RedrawWindow(IntPtr hWnd, IntPtr lpRectUpdate, IntPtr hrgnUpdate, UInt32 flags);

        [DllImport("user32.dll")]
        internal static extern int GetDpiForWindow(IntPtr hWnd);

        [DllImport("dwmapi.dll")]
        internal static extern int DwmIsCompositionEnabled(out bool enabled);

        [DllImport("dwmapi.dll", EntryPoint = "#127", PreserveSig = false)]
        internal static extern void DwmGetColorizationParameters(out DWM_COLORIZATION_PARAMS parameters);

        [DllImport("dwmapi.dll", EntryPoint = "#131", PreserveSig = false)]
        internal static extern void DwmSetColorizationParameters(ref DWM_COLORIZATION_PARAMS parameters, bool unknown);

        [DllImport("dwmapi.dll", PreserveSig = false)]
        public static extern void DwmEnableComposition(bool bEnable);

        [DllImport("dwmapi.dll", PreserveSig = false)]
        public static extern void DwmGetColorizationColor(out uint ColorizationColor, [MarshalAs(UnmanagedType.Bool)]out bool ColorizationOpaqueBlend);

        [DllImport("dwmapi.dll", EntryPoint = "#104")]
        public static extern int DwmpSetColorization(UInt32 ColorizationColor, bool ColorizationOpaqueBlend, UInt32 Opacity);

        [DllImport("gdi32.dll")]
        internal static extern bool BitBlt(IntPtr hdcDest, int xDest, int yDest, int wDest, int hDest, IntPtr hdcSource, int xSrc, int ySrc, CopyPixelOperation rop);

        [DllImport("gdi32.dll")]
        internal static extern IntPtr CreateDC(string lpszDriver, string lpszDevice, string lpszOutput, int lpInitData);

        [DllImport("gdi32.dll")]
        internal static extern IntPtr DeleteDC(IntPtr hDc);

        [DllImport("gdi32.dll")]
        internal static extern int SaveDC(IntPtr hdc);

        [DllImport("gdi32.dll")]
        internal static extern IntPtr DeleteObject(IntPtr hDc);

        [DllImport("gdi32.dll")]
        internal static extern IntPtr CreateCompatibleBitmap(IntPtr hdc, int nWidth, int nHeight);

        [DllImport("gdi32.dll")]
        internal static extern IntPtr CreateCompatibleDC(IntPtr hdc);

        [DllImport("gdi32.dll")]
        internal static extern IntPtr SelectObject(IntPtr hdc, IntPtr bmp);

        [DllImport("kernel32.dll", SetLastError = true)]
        private static extern bool FreeLibrary(IntPtr hModule);

        [DllImport("kernel32.dll", SetLastError = true)]
        private static extern IntPtr LoadLibrary(string dllToLoad);

        [DllImport("kernel32.dll", SetLastError = true)]
        private static extern IntPtr GetProcAddress(IntPtr hModule, string procedureName);

        [UnmanagedFunctionPointer(CallingConvention.Cdecl)]
        private delegate int DwmGetWindowAttributeDelegate(IntPtr hWnd, DwmWindowAttribute dwAttribute, ref WindowsRect pvAttribute, int cbAttribute);
    }
}