SetWindowLongPtr on 32-bit

src/User32.Tests/User32Facts+HwndSubClass.cs

@@ -0,0 +1,116 @@
+// Copyright (c) All contributors. All rights reserved.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+
+using System;
+using System.Runtime.InteropServices;
+using PInvoke;
+
+/// <content>
+/// Contains the inner class <see cref="HwndSubClass"/>
+/// </content>
+public partial class User32Facts
+{
+    /// <summary>
+    /// Helper to subclass an HWND using SetWindowLongPtr
+    /// </summary>
+    private class HwndSubClass : IDisposable
+    {
+        /// <summary>
+        /// Keeps track of whether this instnace has been disposed, or not.
+        /// </summary>
+        private bool disposed = false;
+
+        /// <summary>
+        /// Initializes a new instance of the <see cref="HwndSubClass"/> class.
+        /// </summary>
+        /// <param name="hWnd">The HWND being subclassed</param>
+        internal HwndSubClass(IntPtr hWnd)
+        {
+            this.HWnd = hWnd;
+
+            unsafe
+            {
+                this.WindowProc = new User32.WndProc(this.HookProc);
+                this.WindowProcPointer = Marshal.GetFunctionPointerForDelegate(this.WindowProc);
+
+                this.OldWindowProcPointer =
+                    User32.SetWindowLongPtr(this.HWnd, User32.WindowLongIndexFlags.GWLP_WNDPROC, this.WindowProcPointer);
+            }
+        }
+
+        /// <summary>
+        /// Finalizes an instance of the <see cref="HwndSubClass"/> class.
+        /// </summary>
+        ~HwndSubClass()
+        {
+            this.Dispose(false);
+        }
+
+        /// <summary>
+        /// Event fired in response to every window message
+        /// </summary>
+        internal event EventHandler<WindowMessage> WindowMessage;
+
+        /// <summary>
+        /// Gets the new Window proceduce's address that has been replaced in the HWND
+        /// </summary>
+        internal IntPtr WindowProcPointer { get; }
+
+        /// <summary>
+        /// Gets the Window procedure delegate that has been used to subclass the supplied HWND
+        /// </summary>
+        internal User32.WndProc WindowProc { get; }
+
+        private IntPtr HWnd { get; set; }
+
+        /// <summary>
+        /// Gets or sets the original window procedures address. This will be replaced back
+        /// to the HWND when this instance of <see cref="HwndSubClass"/> is disposed
+        /// </summary>
+        private IntPtr OldWindowProcPointer { get; set; }
+
+        /// <summary>
+        /// Frees resources
+        /// </summary>
+        public void Dispose()
+        {
+            this.Dispose(true);
+            GC.SuppressFinalize(this);
+        }
+
+        /// <summary>
+        /// This is the replaces Window Procedure which will be used to track all window messages,
+        /// and generate events
+        /// </summary>
+        /// <param name="hWnd">The window handle</param>
+        /// <param name="msg">Message ID</param>
+        /// <param name="wParam">The wParam value</param>
+        /// <param name="lParam">The lParam value</param>
+        /// <returns>Message specific return value</returns>
+        internal unsafe IntPtr HookProc(IntPtr hWnd, User32.WindowMessage msg, void* wParam, void* lParam)
+        {
+            this.WindowMessage?.Invoke(this, new WindowMessage(msg, new IntPtr(wParam), new IntPtr(lParam)));
+            return User32.DefWindowProc(hWnd, msg, new IntPtr(wParam), new IntPtr(lParam));
+        }
+
+        /// <summary>
+        /// Cleanup - replaces the HWND with its original Window Procedure and marks this
+        /// instance of <see cref="HwndSubClass"/> as disposed.
+        /// </summary>
+        /// <param name="disposing">When true, indicates that this call is coming from a <see cref="Dispose()"/> call,
+        /// and when false, indicates that this call is coming from the finalizer</param>
+        protected virtual void Dispose(bool disposing)
+        {
+            if (!this.disposed)
+            {
+                this.disposed = true;
+                if (this.HWnd != IntPtr.Zero && this.OldWindowProcPointer != IntPtr.Zero)
+                {
+                    User32.SetWindowLongPtr(this.HWnd, User32.WindowLongIndexFlags.GWLP_WNDPROC, this.OldWindowProcPointer);
+                    this.HWnd = IntPtr.Zero;
+                    this.OldWindowProcPointer = IntPtr.Zero;
+                }
+            }
+        }
+    }
+}

src/User32.Tests/User32Facts+WindowMessage.cs

@@ -0,0 +1,45 @@
+// Copyright (c) All contributors. All rights reserved.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+
+using System;
+using PInvoke;
+
+/// <content>
+/// Contains the nested class <see cref="WindowMessage"/>
+/// </content>
+public partial class User32Facts
+{
+    /// <summary>
+    /// A simple wrapper representig a Window Message's payload
+    /// </summary>
+    private class WindowMessage
+    {
+        /// <summary>
+        /// Initializes a new instance of the <see cref="WindowMessage"/> class.
+        /// </summary>
+        /// <param name="msg">Window Message ID</param>
+        /// <param name="wParam">The wParam value</param>
+        /// <param name="lParam">The lparam value</param>
+        internal WindowMessage(User32.WindowMessage msg, IntPtr wParam, IntPtr lParam)
+        {
+            this.Message = msg;
+            this.WParam = wParam;
+            this.LParam = lParam;
+        }
+
+        /// <summary>
+        /// Gets the Window Message ID
+        /// </summary>
+        internal User32.WindowMessage Message { get; }
+
+        /// <summary>
+        /// Gets the wParam value
+        /// </summary>
+        internal IntPtr WParam { get; }
+
+        /// <summary>
+        /// Gets the lParam value
+        /// </summary>
+        internal IntPtr LParam { get; }
+    }
+}

src/User32.Tests/User32Facts.cs

@@ -5,7 +5,6 @@
 using System.Diagnostics;
 using System.IO;
 using System.Linq;
-using System.Runtime.InteropServices;
 using System.Threading;
 using PInvoke;
 using Xunit;
@@ -92,4 +91,58 @@ public void GetWindowTextHelper_WithNonzeroLastError()
             }
         }
     }
-}
+
+    /// <summary>
+    /// Validates that User32.SetWindowLongPtr works as intended.
+    /// SetWindowLongPtr is implemented as a call into User32.SetWindowLong on 32-bit platforms. This
+    /// test...
+    /// ... a. Creates a window
+    /// ... b. Subclasses it by calling SetWindowLongPtr.
+    ///          On 32-bit processes, it will indirectly call into SetWindowLong, and validate that our implementation is accurate.
+    ///     c. Wait a few seconds for window messages to appear in the new wndow procedure, and declare success as soon as the first message
+    ///         appears, which would indicate that the subclassing was successful.
+    /// </summary>
+    [Fact]
+    [STAThread]
+    public void SetWindowLongPtr_Test()
+    {
+        IntPtr hwnd = CreateWindow(
+            "static",
+            "Window",
+            WindowStyles.WS_BORDER | WindowStyles.WS_CAPTION | WindowStyles.WS_OVERLAPPED | WindowStyles.WS_VISIBLE,
+            0,
+            0,
+            100,
+            100,
+            IntPtr.Zero,
+            IntPtr.Zero,
+            Process.GetCurrentProcess().Handle,
+            IntPtr.Zero);
+
+        if (hwnd == IntPtr.Zero)
+        {
+            throw new Win32Exception();
+        }
+
+        SemaphoreSlim semaphore = new SemaphoreSlim(1, 1);
+
+        var hwndSubClass = new HwndSubClass(hwnd);
+        hwndSubClass.WindowMessage += (_, __) =>
+        {
+            semaphore.Release();
+        };
+
+        try
+        {
+            Assert.True(semaphore.Wait(TimeSpan.FromSeconds(5)));
+        }
+        finally
+        {
+            hwndSubClass.Dispose();
+            if (hwnd != IntPtr.Zero)
+            {
+                DestroyWindow(hwnd);
+            }
+        }
+    }
+}

src/User32/PublicAPI.Unshipped.txt

@@ -33,12 +33,12 @@ PInvoke.User32.SendMessageTimeoutFlags.SMTO_BLOCK = 1 -> PInvoke.User32.SendMess
 PInvoke.User32.SendMessageTimeoutFlags.SMTO_ERRORONEXIT = 32 -> PInvoke.User32.SendMessageTimeoutFlags
 PInvoke.User32.SendMessageTimeoutFlags.SMTO_NORMAL = 0 -> PInvoke.User32.SendMessageTimeoutFlags
 PInvoke.User32.SendMessageTimeoutFlags.SMTO_NOTIMEOUTIFNOTHUNG = 8 -> PInvoke.User32.SendMessageTimeoutFlags
-PInvoke.User32.WindowMessage.WM_DPICHANGED_AFTERPARENT = 739 -> PInvoke.User32.WindowMessage
-PInvoke.User32.WindowMessage.WM_DPICHANGED_BEFOREPARENT = 738 -> PInvoke.User32.WindowMessage
-PInvoke.User32.WindowMessage.WM_GETDPISCALEDSIZE = 740 -> PInvoke.User32.WindowMessage
 PInvoke.User32.WindowLongIndexFlags.GWLP_ID = PInvoke.User32.WindowLongIndexFlags.GWL_STYLE | PInvoke.User32.WindowLongIndexFlags.DWLP_DLGPROC -> PInvoke.User32.WindowLongIndexFlags
 PInvoke.User32.WindowLongIndexFlags.GWLP_USERDATA = -21 -> PInvoke.User32.WindowLongIndexFlags
 PInvoke.User32.WindowLongIndexFlags.GWLP_WNDPROC = PInvoke.User32.WindowLongIndexFlags.GWL_STYLE | PInvoke.User32.WindowLongIndexFlags.DWLP_DLGPROC | PInvoke.User32.WindowLongIndexFlags.DWLP_USER -> PInvoke.User32.WindowLongIndexFlags
+PInvoke.User32.WindowMessage.WM_DPICHANGED_AFTERPARENT = 739 -> PInvoke.User32.WindowMessage
+PInvoke.User32.WindowMessage.WM_DPICHANGED_BEFOREPARENT = 738 -> PInvoke.User32.WindowMessage
+PInvoke.User32.WindowMessage.WM_GETDPISCALEDSIZE = 740 -> PInvoke.User32.WindowMessage
 PInvoke.User32.mouse_eventFlags
 PInvoke.User32.mouse_eventFlags.MOUSEEVENTF_ABSOLUTE = 32768 -> PInvoke.User32.mouse_eventFlags
 PInvoke.User32.mouse_eventFlags.MOUSEEVENTF_HWHEEL = 4096 -> PInvoke.User32.mouse_eventFlags
@@ -52,13 +52,16 @@ PInvoke.User32.mouse_eventFlags.MOUSEEVENTF_RIGHTUP = 16 -> PInvoke.User32.mouse
 PInvoke.User32.mouse_eventFlags.MOUSEEVENTF_WHEEL = 2048 -> PInvoke.User32.mouse_eventFlags
 PInvoke.User32.mouse_eventFlags.MOUSEEVENTF_XDOWN = 128 -> PInvoke.User32.mouse_eventFlags
 PInvoke.User32.mouse_eventFlags.MOUSEEVENTF_XUP = 256 -> PInvoke.User32.mouse_eventFlags
+static PInvoke.User32.AdjustWindowRectEx(System.IntPtr lpRect, PInvoke.User32.WindowStyles dwStyle, bool bMenu, PInvoke.User32.WindowStylesEx dwExStyle) -> bool
 static PInvoke.User32.AdjustWindowRectExForDpi(System.IntPtr lpRect, PInvoke.User32.WindowStyles dwStyle, bool bMenu, PInvoke.User32.WindowStylesEx dwExStyle, int dpi) -> bool
 static PInvoke.User32.CreateWindowEx(PInvoke.User32.WindowStylesEx dwExStyle, short lpClassName, string lpWindowName, PInvoke.User32.WindowStyles dwStyle, int x, int y, int nWidth, int nHeight, System.IntPtr hWndParent, System.IntPtr hMenu, System.IntPtr hInstance, System.IntPtr lpParam) -> System.IntPtr
 static PInvoke.User32.CreateWindowEx(PInvoke.User32.WindowStylesEx dwExStyle, short lpClassName, string lpWindowName, PInvoke.User32.WindowStyles dwStyle, int x, int y, int nWidth, int nHeight, System.IntPtr hWndParent, System.IntPtr hMenu, System.IntPtr hInstance, void* lpParam) -> System.IntPtr
 static PInvoke.User32.GetNextWindow(System.IntPtr hWnd, PInvoke.User32.GetNextWindowCommands wCmd) -> System.IntPtr
 static PInvoke.User32.SetWindowLongPtr(System.IntPtr hWnd, PInvoke.User32.WindowLongIndexFlags nIndex, System.IntPtr dwNewLong) -> System.IntPtr
+static PInvoke.User32.SetWindowLongPtr(System.IntPtr hWnd, PInvoke.User32.WindowLongIndexFlags nIndex, void* dwNewLong) -> void*
 static PInvoke.User32.SystemParametersInfoForDpi(PInvoke.User32.SystemParametersInfoAction uiAction, int uiParam, System.IntPtr pvParam, PInvoke.User32.SystemParametersInfoFlags fWinIni, int dpi) -> bool
 static PInvoke.User32.mouse_event(PInvoke.User32.mouse_eventFlags dwFlags, int dx, int dy, int dwData, System.IntPtr dwExtraInfo) -> void
+static extern PInvoke.User32.AdjustWindowRectEx(PInvoke.RECT* lpRect, PInvoke.User32.WindowStyles dwStyle, bool bMenu, PInvoke.User32.WindowStylesEx dwExStyle) -> bool
 static extern PInvoke.User32.AdjustWindowRectExForDpi(PInvoke.RECT* lpRect, PInvoke.User32.WindowStyles dwStyle, bool bMenu, PInvoke.User32.WindowStylesEx dwExStyle, int dpi) -> bool
 static extern PInvoke.User32.AreDpiAwarenessContextsEqual(System.IntPtr dpiContextA, System.IntPtr dpiContextB) -> bool
 static extern PInvoke.User32.DestroyWindow(System.IntPtr hWnd) -> bool
@@ -82,7 +85,6 @@ static extern PInvoke.User32.SendMessageTimeout(System.IntPtr hWnd, PInvoke.User
 static extern PInvoke.User32.SetDialogControlDpiChangeBehavior(System.IntPtr hwnd, PInvoke.User32.DIALOG_CONTROL_DPI_CHANGE_BEHAVIORS mask, PInvoke.User32.DIALOG_CONTROL_DPI_CHANGE_BEHAVIORS values) -> bool
 static extern PInvoke.User32.SetDialogDpiChangeBehavior(System.IntPtr hDlg, PInvoke.User32.DIALOG_DPI_CHANGE_BEHAVIORS mask, PInvoke.User32.DIALOG_DPI_CHANGE_BEHAVIORS values) -> bool
 static extern PInvoke.User32.SetLastErrorEx(uint dwErrCode, uint dwType) -> void
-static extern PInvoke.User32.SetWindowLongPtr(System.IntPtr hWnd, PInvoke.User32.WindowLongIndexFlags nIndex, void* dwNewLong) -> void*
 static extern PInvoke.User32.SetProcessDpiAwarenessContext(System.IntPtr dpiAWarenessContext) -> bool
 static extern PInvoke.User32.SetThreadDpiAwarenessContext(System.IntPtr dpiContext) -> System.IntPtr
 static extern PInvoke.User32.SetThreadDpiHostingBehavior(PInvoke.User32.DPI_HOSTING_BEHAVIOR dpiHostingBehavior) -> PInvoke.User32.DPI_HOSTING_BEHAVIOR