Single class for opening files

Author: ds5678

AssetRipper.NativeDialogs.Example/Program.cs

@@ -17,7 +17,7 @@ static async Task Main(string[] args)
 		}
 		else if (arguments.OpenFiles)
 		{
-			string[]? files = await OpenFilesDialog.OpenFilesAsync();
+			string[]? files = await OpenFileDialog.OpenFilesAsync();
 			if (files is null || files.Length == 0)
 			{
 				Console.WriteLine("No files selected.");

AssetRipper.NativeDialogs/OpenFileDialog.cs

@@ -110,4 +110,111 @@ public static class OpenFileDialog
 			return Task.FromResult<string?>(null);
 		}
 	}
+
+	public static Task<string[]?> OpenFilesAsync()
+	{
+		if (OperatingSystem.IsWindows())
+		{
+			return OpenFilesAsyncWindows();
+		}
+		else if (OperatingSystem.IsMacOS())
+		{
+			return OpenFilesAsyncMacOS();
+		}
+		else if (OperatingSystem.IsLinux())
+		{
+			return OpenFilesAsyncLinux();
+		}
+		else
+		{
+			return Task.FromResult<string[]?>(null);
+		}
+	}
+
+	[SupportedOSPlatform("windows")]
+	private unsafe static Task<string[]?> OpenFilesAsyncWindows()
+	{
+		// https://learn.microsoft.com/en-us/windows/win32/api/commdlg/ns-commdlg-openfilenamew
+
+		char[] buffer = ArrayPool<char>.Shared.Rent(ushort.MaxValue + 1); // Should be enough for the overwhelming majority of cases.
+		new Span<char>(buffer).Clear();
+
+		string filter = "All Files\0*.*\0\0";
+
+		fixed (char* bufferPtr = buffer)
+		fixed (char* filterPtr = filter)
+		{
+			OPENFILENAMEW ofn = default;
+			ofn.lStructSize = (uint)Unsafe.SizeOf<OPENFILENAMEW>();
+			ofn.hwndOwner = default; // No owner window.
+			ofn.lpstrFile = bufferPtr;
+			ofn.nMaxFile = (uint)buffer.Length;
+			ofn.lpstrFilter = filterPtr;
+			ofn.nFilterIndex = 1; // The first pair of strings has an index value of 1.
+			ofn.Flags = OFN.OFN_PATHMUSTEXIST | OFN.OFN_FILEMUSTEXIST | OFN.OFN_ALLOWMULTISELECT | OFN.OFN_EXPLORER;
+			if (Windows.GetOpenFileNameW(&ofn) && buffer[^1] == 0)
+			{
+				List<string> files = [];
+
+				int directoryLength = Array.IndexOf(buffer, '\0');
+				string directory = new(buffer, 0, directoryLength);
+
+				int startIndex = directoryLength + 1;
+				while (startIndex < buffer.Length && buffer[startIndex] != '\0')
+				{
+					int endIndex = Array.IndexOf(buffer, '\0', startIndex);
+					string fileName = new(buffer, startIndex, endIndex - startIndex);
+					files.Add(Path.Combine(directory, fileName));
+					startIndex = endIndex + 1; // Move to the next file name
+				}
+
+				ArrayPool<char>.Shared.Return(buffer);
+				if (files.Count > 0)
+				{
+					return Task.FromResult<string[]?>(files.ToArray());
+				}
+				else
+				{
+					// If a single file was selected, the system appends it to the directory path.
+					return Task.FromResult<string[]?>([directory]);
+				}
+			}
+		}
+
+		ArrayPool<char>.Shared.Return(buffer);
+		return Task.FromResult<string[]?>(null);
+	}
+
+	[SupportedOSPlatform("macos")]
+	private static async Task<string[]?> OpenFilesAsyncMacOS()
+	{
+		ReadOnlySpan<string> arguments =
+		[
+			"-e", "set theFiles to choose file with multiple selections allowed",
+			"-e", "set filePaths to {}",
+			"-e", "repeat with aFile in theFiles",
+			"-e", "set end of filePaths to POSIX path of aFile",
+			"-e", "end repeat",
+			"-e", "set text item delimiters to \":\"",
+			"-e", "return filePaths as string",
+		];
+		string? output = await ProcessExecutor.TryRun("osascript", arguments);
+		if (string.IsNullOrEmpty(output))
+		{
+			return null; // User canceled the dialog
+		}
+		return output.Split(':');
+	}
+
+	[SupportedOSPlatform("linux")]
+	private static async Task<string[]?> OpenFilesAsyncLinux()
+	{
+		// Todo: proper Linux implementation
+		string? path = await OpenFileDialog.OpenFileAsync();
+		if (string.IsNullOrEmpty(path))
+		{
+			return null; // User canceled the dialog
+		}
+		return [path];
+	}
 }