From 67b43f86f357201940e18fe9188ef91c2e35394e Mon Sep 17 00:00:00 2001
From: Siegfried Pammer <siegfriedpammer@gmail.com>
Date: Thu, 10 May 2012 21:30:07 +0200
Subject: [PATCH] improve IME support

---
 .../Editing/ImeNativeWrapper.cs               | 18 ++++++++++++
 .../Editing/ImeSupport.cs                     | 29 +++++++++++++++++--
 .../TextEditorOptions.cs                      |  2 +-
 3 files changed, 46 insertions(+), 3 deletions(-)

diff --git a/src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Editing/ImeNativeWrapper.cs b/src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Editing/ImeNativeWrapper.cs
index 4a1f38e92c..1e81993239 100644
--- a/src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Editing/ImeNativeWrapper.cs
+++ b/src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Editing/ImeNativeWrapper.cs
@@ -16,6 +16,7 @@ using ICSharpCode.AvalonEdit;
 using ICSharpCode.AvalonEdit.Document;
 using ICSharpCode.AvalonEdit.Rendering;
 using ICSharpCode.AvalonEdit.Utils;
+using Draw = System.Drawing;
 
 namespace ICSharpCode.AvalonEdit.Editing
 {
@@ -70,7 +71,9 @@ namespace ICSharpCode.AvalonEdit.Editing
 		const int CPS_CANCEL = 0x4;
 		const int NI_COMPOSITIONSTR = 0x15;
 		const int GCS_COMPSTR = 0x0008;
+		
 		public const int WM_IME_COMPOSITION = 0x10F;
+		public const int WM_INPUTLANGCHANGE = 0x51;
 		
 		[DllImport("imm32.dll")]
 		static extern IntPtr ImmAssociateContext(IntPtr hWnd, IntPtr hIMC);
@@ -85,6 +88,12 @@ namespace ICSharpCode.AvalonEdit.Editing
 		[DllImport("imm32.dll")]
 		[return: MarshalAs(UnmanagedType.Bool)]
 		static extern bool ImmSetCompositionWindow(IntPtr hIMC, ref CompositionForm form);
+		[DllImport("imm32.dll")]
+		[return: MarshalAs(UnmanagedType.Bool)]
+		static extern bool ImmSetCompositionFont(IntPtr hIMC, ref LOGFONT font);
+		[DllImport("imm32.dll")]
+		[return: MarshalAs(UnmanagedType.Bool)]
+		static extern bool ImmGetCompositionFont(IntPtr hIMC, out LOGFONT font);
 		
 		public static IntPtr AssociateContext(HwndSource source, IntPtr hIMC)
 		{
@@ -132,6 +141,15 @@ namespace ICSharpCode.AvalonEdit.Editing
 			return ImmSetCompositionWindow(hIMC, ref form);
 		}
 		
+		public static bool SetCompositionFont(HwndSource source, IntPtr hIMC, TextArea textArea)
+		{
+			if (textArea == null)
+				throw new ArgumentNullException("textArea");
+//			LOGFONT font = new LOGFONT();
+//			ImmGetCompositionFont(hIMC, out font);
+			return false;
+		}
+		
 		static Rect GetBounds(this TextView textView)
 		{
 			Point location = textView.TranslatePoint(new Point(0,0), textView);
diff --git a/src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Editing/ImeSupport.cs b/src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Editing/ImeSupport.cs
index 5e3082b0dd..934c546210 100644
--- a/src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Editing/ImeSupport.cs
+++ b/src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Editing/ImeSupport.cs
@@ -34,9 +34,17 @@ namespace ICSharpCode.AvalonEdit.Editing
 			InputMethod.SetIsInputMethodSuspended(this.textArea, true);
 			textArea.GotKeyboardFocus += TextAreaGotKeyboardFocus;
 			textArea.LostKeyboardFocus += TextAreaLostKeyboardFocus;
+			textArea.OptionChanged += TextAreaOptionChanged;
 			currentContext = IntPtr.Zero;
 			previousContext = IntPtr.Zero;
 		}
+
+		void TextAreaOptionChanged(object sender, PropertyChangedEventArgs e)
+		{
+			if (e.PropertyName == "EnableImeSupport" && textArea.IsKeyboardFocusWithin) {
+				CreateContext();
+			}
+		}
 		
 		public void Dispose()
 		{
@@ -66,10 +74,20 @@ namespace ICSharpCode.AvalonEdit.Editing
 				return;
 			if (e.OriginalSource != this.textArea)
 				return;
+			CreateContext();
+		}
+
+		void CreateContext()
+		{
+			if (this.textArea == null)
+				return;
+			if (!textArea.Options.EnableImeSupport)
+				return;
 			hwndSource = (HwndSource)PresentationSource.FromVisual(this.textArea);
 			if (hwndSource != null) {
 				currentContext = ImeNativeWrapper.GetContext(hwndSource);
 				previousContext = ImeNativeWrapper.AssociateContext(hwndSource, currentContext);
+//				ImeNativeWrapper.SetCompositionFont(hwndSource, currentContext, textArea);
 				hwndSource.AddHook(WndProc);
 			}
 		}
@@ -85,8 +103,15 @@ namespace ICSharpCode.AvalonEdit.Editing
 		
 		IntPtr WndProc(IntPtr hWnd, int msg, IntPtr wParam, IntPtr lParam, ref bool handled)
 		{
-			if (msg == ImeNativeWrapper.WM_IME_COMPOSITION)
-				UpdateCompositionWindow();
+			switch (msg) {
+				case ImeNativeWrapper.WM_INPUTLANGCHANGE:
+					ClearContext();
+					CreateContext();
+					break;
+				case ImeNativeWrapper.WM_IME_COMPOSITION:
+					UpdateCompositionWindow();
+					break;
+			}
 			return IntPtr.Zero;
 		}
 		
diff --git a/src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/TextEditorOptions.cs b/src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/TextEditorOptions.cs
index 95ee2498c7..897fcbcf45 100644
--- a/src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/TextEditorOptions.cs
+++ b/src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/TextEditorOptions.cs
@@ -382,7 +382,7 @@ namespace ICSharpCode.AvalonEdit
 			}
 		}
 		
-		bool enableImeSupport;
+		bool enableImeSupport = true;
 		
 		/// <summary>
 		/// Gets/Sets whether the support for Input Method Editors (IME)