Add support for Notepad++

Closes #1.

Notepad.Extensions.Logging/LoggingBuilderExtensions.cs

@@ -1,4 +1,6 @@
-namespace Microsoft.Extensions.Logging
+using Notepad.Extensions.Logging;
+
+namespace Microsoft.Extensions.Logging
 {
     public static class LoggingBuilderExtensions
     {

Notepad.Extensions.Logging/NativeMethods.cs

@@ -2,7 +2,7 @@
 using System.Runtime.InteropServices;
 using System.Text;
 
-namespace Microsoft.Extensions.Logging
+namespace Notepad.Extensions.Logging
 {
     static class NativeMethods
     {
@@ -17,6 +17,11 @@ namespace Microsoft.Extensions.Logging
         [DllImport("User32.dll", CharSet = CharSet.Unicode, SetLastError = true)]
         public static extern IntPtr SendMessage(IntPtr hWnd, int Msg, IntPtr wParam, [MarshalAs(UnmanagedType.LPWStr)] string lParam);
 
+        public const int SCI_ADDTEXT = 2001;
+
+        [DllImport("User32.dll", CharSet = CharSet.Unicode, SetLastError = true)]
+        public static extern IntPtr SendMessage(IntPtr hWnd, int Msg, IntPtr wParam, IntPtr lParam);
+
         public delegate bool EnumWindowsDelegate(IntPtr hWnd, IntPtr lParam);
 
         [DllImport("user32.dll")]
@@ -24,5 +29,23 @@ namespace Microsoft.Extensions.Logging
 
         [DllImport("User32.dll")]
         public static extern int GetWindowText(IntPtr hWndParent, StringBuilder sb, int maxCount);
+
+        [DllImport("kernel32.dll", SetLastError = true)]
+        public static extern IntPtr VirtualAllocEx(IntPtr hProcess, IntPtr lpAddress, IntPtr dwSize, int flAllocationType, int flProtect);
+
+        public const int MEM_COMMIT = 0x00001000;
+        public const int MEM_RESERVE = 0x00002000;
+        public const int MEM_RELEASE = 0x8000;
+        public const int PAGE_READWRITE = 0x04;
+
+        [DllImport("kernel32.dll", SetLastError = true)]
+        [return: MarshalAs(UnmanagedType.Bool)]
+        public static extern bool VirtualFreeEx(IntPtr hProcess, IntPtr lpAddress, IntPtr dwSize, int dwFreeType);
+
+        [DllImport("User32.dll")]
+        public static extern int GetWindowThreadProcessId(IntPtr hWnd, out int lpdwProcessId);
+
+        [DllImport("kernel32.dll", SetLastError = true)]
+        public static extern int WriteProcessMemory(IntPtr hProcess, IntPtr lpBaseAddress, byte[] lpBuffer, IntPtr nSize, out IntPtr lpNumberOfBytesWritten);
     }
 }

Notepad.Extensions.Logging/Notepad.Extensions.Logging.csproj

@@ -10,6 +10,7 @@
     <RepositoryType>git</RepositoryType>
     <PackageLicenseExpression>Apache-2.0</PackageLicenseExpression>
     <GeneratePackageOnBuild>true</GeneratePackageOnBuild>
+    <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
   </PropertyGroup>
 
   <ItemGroup>

Notepad.Extensions.Logging/NotepadLogger.cs

@@ -1,9 +1,14 @@
 using System;
+using System.Buffers;
+using System.ComponentModel;
+using System.Diagnostics;
 using System.Runtime.InteropServices;
 using System.Text;
+using Microsoft.Extensions.Logging;
 using Microsoft.Extensions.ObjectPool;
+using static Notepad.Extensions.Logging.NativeMethods;
 
-namespace Microsoft.Extensions.Logging
+namespace Notepad.Extensions.Logging
 {
     class NotepadLogger : ILogger
     {
@@ -84,8 +89,55 @@ namespace Microsoft.Extensions.Logging
 
         static void WriteToNotepad(string message)
         {
-            IntPtr hwnd = WindowFinder.FindNotepadWindow();
+            var (kind, hwnd) = WindowFinder.FindNotepadWindow();
-            NativeMethods.SendMessage(hwnd, NativeMethods.EM_REPLACESEL, (IntPtr)1, message);
+            switch (kind)
+            {
+                case WindowKind.Notepad:
+                        SendMessage(hwnd, EM_REPLACESEL, (IntPtr)1, message);
+                    break;
+
+                case WindowKind.NotepadPlusPlus:
+                    {
+                        WriteToNotepadPlusPlus(hwnd, message);
+                        break;
+                    }
+            }
+        }
+
+        unsafe static void WriteToNotepadPlusPlus(IntPtr hwnd, string message)
+        {
+            var dataLength = Encoding.UTF8.GetByteCount(message);
+
+            //
+            // HERE BE DRAGONS
+            // We need to copy the message into Notepad++'s memory so that it can read it.
+            // Look away now, before its too late.
+            // 
+ 
+            var threadID = GetWindowThreadProcessId(hwnd, out var remoteProcessId);
+            using var remoteProcess = Process.GetProcessById(remoteProcessId);
+            var mem = VirtualAllocEx(remoteProcess.Handle, IntPtr.Zero, (IntPtr)dataLength, MEM_COMMIT | MEM_RESERVE, PAGE_READWRITE);
+            if (mem == IntPtr.Zero) throw new Win32Exception();
+
+            try
+            {
+                var data = ArrayPool<byte>.Shared.Rent(dataLength);
+                try
+                {
+                    var idx = Encoding.UTF8.GetBytes(message, 0, message.Length, data, 0);
+
+                    WriteProcessMemory(remoteProcess.Handle, mem, data, (IntPtr)dataLength, out var bytesWritten);
+                    SendMessage(hwnd, SCI_ADDTEXT, (IntPtr)dataLength, mem);
+                }
+                finally
+                {
+                    ArrayPool<byte>.Shared.Return(data);
+                }
+            }
+            finally
+            {
+                VirtualFreeEx(remoteProcess.Handle, IntPtr.Zero, IntPtr.Zero, MEM_RELEASE);
+            }
         }
     }
 }

Notepad.Extensions.Logging/NotepadLoggerProvider.cs

@@ -1,7 +1,8 @@
 using System.Text;
+using Microsoft.Extensions.Logging;
 using Microsoft.Extensions.ObjectPool;
 
-namespace Microsoft.Extensions.Logging
+namespace Notepad.Extensions.Logging
 {
     class NotepadLoggerProvider : ILoggerProvider
     {

Notepad.Extensions.Logging/NullDisposable.cs

@@ -1,6 +1,6 @@
 using System;
 
-namespace Microsoft.Extensions.Logging
+namespace Notepad.Extensions.Logging
 {
     class NullDisposable : IDisposable
     {

Notepad.Extensions.Logging/WindowFinder.cs

@@ -3,23 +3,25 @@ using System.ComponentModel;
 using System.Text;
 using System.Text.RegularExpressions;
 
-namespace Microsoft.Extensions.Logging
+namespace Notepad.Extensions.Logging
 {
     static class WindowFinder
     {
-        public static IntPtr FindNotepadWindow()
+
+        public static (WindowKind kind, IntPtr hwnd) FindNotepadWindow()
         {
             sb ??= new StringBuilder(4096);
 
             try
             {
                 FindMainWindow();
-                return handle;
+                return (windowKind, handle);
             }
             finally
             {
                 handle = IntPtr.Zero;
                 sb.Clear();
+                windowKind = WindowKind.Invalid;
             }
         }
 
@@ -41,6 +43,12 @@ namespace Microsoft.Extensions.Logging
 
             WindowFinder.handle = hWnd;
 
+            if (sb.Length > 0 && sb[0] == '*')
+            {
+                // Notepad and Notepad++ both mark dirty documents by adding a leading asterisk to the window name.
+                sb.Remove(0, 1);
+            }
+
             if (IsKnownNotepadWindow(sb.ToString()))
             {
                 return false;
@@ -51,6 +59,9 @@ namespace Microsoft.Extensions.Logging
         [ThreadStatic]
         static IntPtr handle;
 
+        [ThreadStatic]
+        static WindowKind windowKind;
+
         [ThreadStatic]
         static StringBuilder sb;
 
@@ -61,14 +72,15 @@ namespace Microsoft.Extensions.Logging
             switch (titleText)
             {
                 case "Untitled - Notepad":
-                case "*Untitled - Notepad":
+                    windowKind = WindowKind.Notepad;
                     handle = NativeMethods.FindWindowEx(handle, IntPtr.Zero, "EDIT", null);
                     return true;
             }
 
             if (notepadPlusPlusRegex.IsMatch(titleText))
             {
-                handle = NativeMethods.FindWindowEx(handle, IntPtr.Zero, "SysTabControl32", null);
+                windowKind = WindowKind.NotepadPlusPlus;
+                handle = NativeMethods.FindWindowEx(handle, IntPtr.Zero, "Scintilla", null);
                 return true;
             }
 

Notepad.Extensions.Logging/WindowKind.cs

@@ -0,0 +1,9 @@
+namespace Notepad.Extensions.Logging
+{
+    public enum WindowKind
+    {
+        Invalid,
+        Notepad,
+        NotepadPlusPlus
+    }
+}