Add IME Support for DX and XNA

Input/CompositionChangedEventArgs.cs

@@ -0,0 +1,12 @@
+// MonoGame.IMEHelper.Common
+//   Copyright (c) 2020 ryancheung
+
+using System;
+
+namespace Rampastring.XNAUI.Input;
+
+internal sealed class CompositionChangedEventArgs(string oldValue, string newValue) : EventArgs
+{
+    public string OldValue => oldValue;
+    public string NewValue => newValue;
+}

Input/IMEHandler.cs

@@ -0,0 +1,84 @@
+// MonoGame.IMEHelper.Common
+//   Copyright (c) 2020 ryancheung
+
+using System;
+
+using Microsoft.Xna.Framework;
+
+using Rampastring.XNAUI.PlatformSpecific;
+
+namespace Rampastring.XNAUI.Input;
+
+internal abstract class IMEHandler
+{
+    private string composition = string.Empty;
+
+    /// <summary>
+    /// Check if text composition is enabled currently.
+    /// </summary>
+    public abstract bool Enabled { get; protected set; }
+
+    /// <summary>
+    /// Composition String
+    /// </summary>
+    public virtual string Composition
+    {
+        get => composition;
+        protected set
+        {
+            string old = composition;
+            composition = value;
+            CompositionChanged?.Invoke(null, new(old, value));
+        }
+    }
+    /// <summary>
+    /// Caret position of the composition
+    /// </summary>
+    public virtual int CompositionCursorPos { get; protected set; }
+
+    /// <summary>
+    /// Invoked when the IMM service emit character input event.
+    /// </summary>
+    /// <seealso cref="StartTextComposition" />
+    /// <seealso cref="StopTextComposition" />
+    public event EventHandler<char> TextInput;
+    public event EventHandler<CompositionChangedEventArgs> CompositionChanged;
+
+    public static IMEHandler Create(Game game)
+    {
+#if !GL
+        return new WinFormsIMEHandler(game);
+#else
+        return new SdlIMEHandler(game);
+#endif
+    }
+
+    /// <summary>
+    /// Enable the system IMM service to support composited character input.
+    /// This should be called when you expect text input from a user and you support languages
+    /// that require an IME (Input Method Editor).
+    /// </summary>
+    /// <seealso cref="StopTextComposition" />
+    public abstract void StartTextComposition();
+
+    /// <summary>
+    /// Stop the system IMM service.
+    /// </summary>
+    /// <seealso cref="StartTextComposition" />
+    public abstract void StopTextComposition();
+
+    /// <summary>
+    /// Use this function to set the rectangle used to type Unicode text inputs if IME supported.
+    /// In SDL2, this method call gives the OS a hint for where to show the candidate text list,
+    /// since the OS doesn't know where you want to draw the text you received via SDL_TEXTEDITING event.
+    /// </summary>
+    public virtual void SetTextInputRect(in Rectangle rect)
+    { }
+
+    /// <summary>
+    /// Trigger a text input event.
+    /// </summary>
+    /// <param name="character"></param>
+    protected virtual void OnTextInput(char character)
+        => TextInput?.Invoke(this, character);
+}

PlatformSpecific/SdlIMEHandler.cs

@@ -0,0 +1,27 @@
+using Microsoft.Xna.Framework;
+
+using Rampastring.XNAUI.Input;
+
+namespace Rampastring.XNAUI.PlatformSpecific;
+
+/// <summary>
+/// Integrate IME to DesktopGL(SDL2) platform.
+/// </summary>
+/// <remarks>
+/// Note: We were unable to provide reliable input method support for
+/// SDL2 due to the lack of a way to be able to stabilize hooks for
+/// the SDL2 main loop.<br/>
+/// Perhaps this requires some changes in Monogame.
+/// </remarks>
+internal sealed class SdlIMEHandler(Game game) : IMEHandler
+{
+    public override bool Enabled { get => false; protected set => _ = value; }
+
+    public override void StartTextComposition()
+    {
+    }
+
+    public override void StopTextComposition()
+    {
+    }
+}

PlatformSpecific/WinFormsIMEHandler.cs

@@ -0,0 +1,42 @@
+using ImeSharp;
+
+using Microsoft.Xna.Framework;
+
+using Rampastring.XNAUI.Input;
+
+namespace Rampastring.XNAUI.PlatformSpecific;
+
+/// <summary>
+/// Integrate IME to XNA framework.
+/// </summary>
+internal class WinFormsIMEHandler : IMEHandler
+{
+    public override bool Enabled
+    {
+        get => InputMethod.Enabled;
+        protected set => InputMethod.Enabled = value;
+    }
+
+    public WinFormsIMEHandler(Game game)
+    {
+        InputMethod.Initialize(game.Window.Handle);
+        InputMethod.TextInputCallback = OnTextInput;
+        InputMethod.TextCompositionCallback = (compositionText, cursorPosition, _, _, _, _) =>
+        {
+            Composition = compositionText.ToString();
+            CompositionCursorPos = cursorPosition;
+        };
+    }
+
+
+    public override void StartTextComposition()
+        => Enabled = true;
+
+
+    public override void StopTextComposition()
+        => Enabled = false;
+
+
+    public override void SetTextInputRect(in Rectangle rect)
+        => InputMethod.SetTextInputRect(rect.X, rect.Y, rect.Width, rect.Height);
+}

Rampastring.XNAUI.csproj

@@ -121,6 +121,17 @@
     <Compile Remove="Input\KeyboardEventArgs.cs" />
     <Compile Remove="Input\KeyboardEventInput.cs" />
   </ItemGroup>
+  <ItemGroup Condition="$(Configuration.Contains('GL'))">
+    <!--Remove WinForm-->
+    <Compile Remove="PlatformSpecific\WinFormsIMEHandler.cs" />
+    <None Include="PlatformSpecific\WinFormsIMEHandler.cs" />
+  </ItemGroup>
+  <ItemGroup Condition="!$(Configuration.Contains('GL'))">
+    <!--Remove SDL-->
+    <Compile Remove="PlatformSpecific\SdlIMEHandler.cs" />
+    <None Include="PlatformSpecific\SdlIMEHandler.cs" />
+    <PackageReference Include="ImeSharp" Version="1.2.5" />
+  </ItemGroup>
   <ItemGroup>
     <None Include="README.md" Pack="true" PackagePath="\" />
   </ItemGroup>

WindowManager.cs

@@ -27,6 +27,7 @@ namespace Rampastring.XNAUI;
 public class WindowManager : DrawableGameComponent
 {
     private const int XNA_MAX_TEXTURE_SIZE = 2048;
+    internal IMEHandler IMEHandler { get; }
 
     /// <summary>
     /// Creates a new WindowManager.
@@ -35,6 +36,7 @@ public class WindowManager : DrawableGameComponent
     /// <param name="graphics">The game's GraphicsDeviceManager.</param>
     public WindowManager(Game game, GraphicsDeviceManager graphics) : base(game)
     {
+        IMEHandler = IMEHandler.Create(game);
         this.graphics = graphics;
     }
 
@@ -768,8 +770,8 @@ public override void Draw(GameTime gameTime)
             Game.Window.ClientBounds.Width - (SceneXPosition * 2), Game.Window.ClientBounds.Height - (SceneYPosition * 2)), Color.White);
 
 #if DEBUG
-        Renderer.DrawString("Active control " + activeControlName, 0, Vector2.Zero, Color.Red, 1.0f);
-
+        Renderer.DrawString("Active control: " + activeControlName, 0, Vector2.Zero, Color.Red, 1.0f);
+        Renderer.DrawString("IME Status: " + (IMEHandler.Enabled ? "Enabled" : "Disabled"), 0, new Vector2(0, 16), Color.Red, 1.0f);
 #endif
         if (Cursor.Visible)
             Cursor.Draw(gameTime);