Pinvoke X11 instead of calling xdotool

Author: FaithBeam

README.md

@@ -24,14 +24,6 @@ Anything that can install .NET 8 should be able to run YMouseButtonControl
 | Ubuntu               | 20.04+      |
 | macOS                | 12.0+       |
 
-##  Linux Recommended Software
-
-* xdotool (x11 only)
-  * ```sudo apt install xdotool```
-  * This is used to retrieve the foreground window name
-
-If you don't install xdotool or use wayland, every window will match when doing a mouse press.
-
 ## Build
 
 ### Requirements

YMouseButtonControl.Linux/Services/CurrentWindowServiceX11.cs

@@ -1,4 +1,4 @@
-using System.Diagnostics;
+using System.Runtime.InteropServices;
 using YMouseButtonControl.Core.Services.Processes;
 
 namespace YMouseButtonControl.Linux.Services;
@@ -7,36 +7,93 @@ public class CurrentWindowServiceX11 : ICurrentWindowService
 {
     public string ForegroundWindow => GetForegroundWindow();
 
-    private string GetForegroundWindow()
+    private static string GetForegroundWindow()
     {
-        var startInfo = new ProcessStartInfo
+        var display = X11.XOpenDisplay(nint.Zero);
+        if (display == nint.Zero)
         {
-            FileName = "/bin/bash",
-            Arguments = "-c \"xdotool getwindowfocus getwindowpid\"",
-            RedirectStandardOutput = true,
-        };
-        using var xdoProc = new Process();
-        xdoProc.StartInfo = startInfo;
-        xdoProc.Start();
-        var pid = xdoProc.StandardOutput.ReadToEnd().TrimEnd();
-        xdoProc.WaitForExit();
-
-        if (string.IsNullOrWhiteSpace(pid))
+            throw new Exception("Error opening display");
+        }
+
+        try
+        {
+            var pid = GetForegroundWindowPid(display);
+            if (pid is null)
+            {
+                return "";
+            }
+
+            return GetPathFromPid(pid) ?? "";
+        }
+        finally
+        {
+            X11.XCloseDisplay(display);
+        }
+    }
+
+    private static string? GetPathFromPid(int? pid)
+    {
+        var fi = new FileInfo($"/proc/{pid}/exe");
+        return fi.LinkTarget;
+    }
+
+    private static unsafe int? GetForegroundWindowPid(nint display)
+    {
+        var root = X11.XDefaultRootWindow(display);
+        var prop = X11.XInternAtom(display, Marshal.StringToHGlobalAnsi("_NET_ACTIVE_WINDOW"), 0);
+        var pidProp = X11.XInternAtom(display, Marshal.StringToHGlobalAnsi("_NET_WM_PID"), 1);
+
+        if (X11.XGetWindowProperty(display, root, prop, 0, sizeof(ulong), 0, 0,
+                out _, out _, out _,
+                out _, out var outProp) != 0 || outProp == nint.Zero)
         {
-            return "";
+            return null;
         }
 
-        startInfo = new ProcessStartInfo
+        var activeWindow = *(nint*)outProp;
+        X11.XFree(outProp);
+
+        if (X11.XGetWindowProperty(display, activeWindow, pidProp, 0, sizeof(int), 0, 0, out _, out _, out _, out _,
+                out var prop2) != 0 || prop2 == nint.Zero)
         {
-            FileName = "/bin/bash",
-            Arguments = $"-c \"ls -l /proc/{pid}/exe\"",
-            RedirectStandardOutput = true,
-        };
-        using var proc = new Process();
-        proc.StartInfo = startInfo;
-        proc.Start();
-        var path = proc.StandardOutput.ReadToEnd().Split("-> ")[1].Trim();
-        proc.WaitForExit();
-        return path;
+            return null;
+        }
+
+        var pid = *(int*)prop2;
+        X11.XFree(prop2);
+        return pid;
     }
 }
+
+internal static partial class X11
+{
+    [LibraryImport("libX11.so")]
+    internal static partial int XFree(nint data);
+
+    [LibraryImport("libX11.so")]
+    internal static partial nint XOpenDisplay(nint display);
+
+    [LibraryImport("libX11.so")]
+    internal static partial void XCloseDisplay(nint display);
+
+    [LibraryImport("libX11.so")]
+    internal static partial nint XDefaultRootWindow(nint display);
+
+    [LibraryImport("libX11.so")]
+    internal static partial nint XInternAtom(nint display, nint atomName, int onlyIfExists);
+
+    [LibraryImport("libX11.so")]
+    internal static partial int XGetWindowProperty(
+        IntPtr display,
+        IntPtr window,
+        IntPtr property,
+        long longOffset,
+        long longLength,
+        int delete,
+        ulong reqType,
+        out ulong actualTypeReturn,
+        out int actualFormatReturn,
+        out ulong nItemsReturn,
+        out ulong bytesAfterReturn,
+        out IntPtr propReturn);
+}

YMouseButtonControl.Linux/YMouseButtonControl.Linux.csproj

@@ -5,6 +5,7 @@
         <ImplicitUsings>enable</ImplicitUsings>
         <Nullable>enable</Nullable>
         <LangVersion>default</LangVersion>
+        <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
     </PropertyGroup>
 
     <PropertyGroup Condition=" '$(Configuration)' == 'Debug' ">

YMouseButtonControl/DependencyInjection/ServicesBootstrapper.cs

@@ -55,25 +55,7 @@ private static void RegisterLinuxServices(IServiceCollection services)
             .AddScoped<IBackgroundTasksRunner, Linux.Services.BackgroundTasksRunner>();
         if (Environment.GetEnvironmentVariable("XDG_SESSION_TYPE") == "x11")
         {
-            var startInfo = new ProcessStartInfo
-            {
-                FileName = "/bin/bash",
-                Arguments = "-c \"xdotool\"",
-                RedirectStandardOutput = true,
-                RedirectStandardError = true,
-            };
-            using var proc = new Process();
-            proc.StartInfo = startInfo;
-            proc.Start();
-            proc.WaitForExit();
-            if (proc.ExitCode == 1)
-            {
-                services.AddScoped<ICurrentWindowService, Linux.Services.CurrentWindowServiceX11>();
-            }
-            else
-            {
-                services.AddScoped<ICurrentWindowService, Linux.Services.CurrentWindowService>();
-            }
+            services.AddScoped<ICurrentWindowService, Linux.Services.CurrentWindowServiceX11>();
         }
         else
         {
@@ -99,4 +81,4 @@ private static void RegisterMacOsServices(IServiceCollection services)
             .AddScoped<ICurrentWindowService, MacOS.Services.CurrentWindowService>()
             .AddScoped<IBackgroundTasksRunner, MacOS.Services.BackgroundTasksRunner>();
     }
-}
+}