refactor: don't directly call the win32 open/savedialog impls.

instead call them through a "cross-platform" wrapper.

VTTiny/Editor/Native/FileDialog.cs

@@ -0,0 +1,38 @@
+namespace VTTiny.Editor.Native
+{
+    /// <summary>
+    /// This is the multiplatform wrapper for the open/save file dialog functionality.
+    /// It just calls back into the platform-specific implementations.
+    /// 
+    /// NOTE: So far the only FileDialog implementation we have is for Win32.
+    ///       PRs to improve that are welcome.
+    /// </summary>
+    public static class FileDialog
+    {
+        /// <summary>
+        /// Show an open file dialog.
+        /// </summary>
+        /// <returns>The path to the opened file, or nothing.</returns>
+        public static string OpenFile()
+        {
+#if ARCH_WINDOWS
+            return Win32.FileDialog.OpenFile();
+#else
+            throw new System.NotImplementedException($"OpenFile() is not yet supported on {System.Runtime.InteropServices.RuntimeInformation.OSDescription}!");
+#endif
+        }
+
+        /// <summary>
+        /// Show a save file dialog.
+        /// </summary>
+        /// <returns>The path to the saved file, or nothing.</returns>
+        public static string SaveFile()
+        {
+#if ARCH_WINDOWS
+            return Win32.FileDialog.SaveFile();
+#else
+            throw new System.NotImplementedException($"SaveFile() is not yet supported on {System.Runtime.InteropServices.RuntimeInformation.OSDescription}!");
+#endif
+        }
+    }
+}

VTTiny/Editor/Native/Win32/FileDialog.cs

@@ -4,11 +4,8 @@ namespace VTTiny.Editor.Native.Win32
 {
     /// <summary>
     /// This class wraps the Win32 methods for opening open/save file dialog boxes.
-    /// 
-    /// NOTE: So far this is the only FileDialog implementation we have, it'd be nice to have more cross platform solutions.
-    ///       PRs welcome.
     /// </summary>
-    public static class FileDialog
+    internal static class FileDialog
     {
         private const string COMDLG_LIBRARY_NAME = "comdlg32";
 

VTTiny/Editor/UI/Menu/FileMenuCategory.cs

@@ -1,5 +1,5 @@
 using System;
-using VTTiny.Editor.Native.Win32;
+using VTTiny.Editor.Native;
 using VTTiny.Scenery;
 
 namespace VTTiny.Editor.UI

VTTiny/VTTiny.csproj

@@ -5,6 +5,19 @@
     <TargetFramework>net6.0</TargetFramework>
     <Authors>prefetcher</Authors>
     <Product />
+    <IsWindows Condition="'$([System.Runtime.InteropServices.RuntimeInformation]::IsOSPlatform($([System.Runtime.InteropServices.OSPlatform]::Windows)))' == 'true'">true</IsWindows>
+    <IsMacOS Condition="'$([System.Runtime.InteropServices.RuntimeInformation]::IsOSPlatform($([System.Runtime.InteropServices.OSPlatform]::OSX)))' == 'true'">true</IsMacOS>
+    <IsLinux Condition="'$([System.Runtime.InteropServices.RuntimeInformation]::IsOSPlatform($([System.Runtime.InteropServices.OSPlatform]::Linux)))' == 'true'">true</IsLinux> 
+  </PropertyGroup>
+
+  <PropertyGroup Condition="'$(IsWindows)'=='true'">
+    <DefineConstants>ARCH_WINDOWS</DefineConstants>
+  </PropertyGroup>
+  <PropertyGroup Condition="'$(IsMacOS)'=='true'">
+    <DefineConstants>ARCH_MACOS</DefineConstants>
+  </PropertyGroup>
+  <PropertyGroup Condition="'$(IsLinux)'=='true'">
+    <DefineConstants>ARCH_LINUX</DefineConstants>
   </PropertyGroup>
 
   <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug|AnyCPU'">