From 0dec5058bf8854419e66925b091416b9a7bcf8c7 Mon Sep 17 00:00:00 2001
From: Siegfried Pammer <siegfriedpammer@gmail.com>
Date: Wed, 13 Mar 2013 20:09:49 +0100
Subject: [PATCH] fixed IME: IME context is properly restored when returning
 from a toolbar or button.

---
 .../Editing/ImeNativeWrapper.cs               | 30 ++++---------------
 .../Editing/ImeSupport.cs                     | 21 +++++++------
 .../Editing/TextArea.cs                       |  4 +--
 3 files changed, 20 insertions(+), 35 deletions(-)

diff --git a/src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Editing/ImeNativeWrapper.cs b/src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Editing/ImeNativeWrapper.cs
index d8d0de240c..b978d7b26b 100644
--- a/src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Editing/ImeNativeWrapper.cs
+++ b/src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Editing/ImeNativeWrapper.cs
@@ -76,21 +76,15 @@ namespace ICSharpCode.AvalonEdit.Editing
 		public const int WM_IME_SETCONTEXT = 0x281;
 		public const int WM_INPUTLANGCHANGE = 0x51;
 		
-//		[DllImport("imm32.dll")]
-//		public static extern IntPtr ImmCreateContext();
-//
-//		[DllImport("imm32.dll")]
-//		[return: MarshalAs(UnmanagedType.Bool)]
-//		public static extern bool ImmDestroyContext(IntPtr hIMC);
-		
-//		[DllImport("imm32.dll")]
-//		public static extern IntPtr ImmAssociateContext(IntPtr hWnd, IntPtr hIMC);
-		
 		[DllImport("imm32.dll")]
-		static extern IntPtr ImmGetContext(IntPtr hWnd);
+		public static extern IntPtr ImmAssociateContext(IntPtr hWnd, IntPtr hIMC);
+		[DllImport("imm32.dll")]
+		internal static extern IntPtr ImmGetContext(IntPtr hWnd);
+		[DllImport("imm32.dll")]
+		internal static extern IntPtr ImmGetDefaultIMEWnd(IntPtr hWnd);
 		[DllImport("imm32.dll")]
 		[return: MarshalAs(UnmanagedType.Bool)]
-		static extern bool ImmReleaseContext(IntPtr hWnd, IntPtr hIMC);
+		internal static extern bool ImmReleaseContext(IntPtr hWnd, IntPtr hIMC);
 		[DllImport("imm32.dll")]
 		[return: MarshalAs(UnmanagedType.Bool)]
 		static extern bool ImmNotifyIME(IntPtr hIMC, int dwAction, int dwIndex, int dwValue = 0);
@@ -124,18 +118,6 @@ namespace ICSharpCode.AvalonEdit.Editing
 			return ImmNotifyIME(hIMC, NI_COMPOSITIONSTR, CPS_CANCEL);
 		}
 		
-		public static IntPtr GetContext(HwndSource source)
-		{
-			if (source == null)
-				return IntPtr.Zero;
-			return ImmGetContext(source.Handle);
-		}
-		
-		public static bool ReleaseContext(HwndSource source, IntPtr hIMC)
-		{
-			return source != null && hIMC != IntPtr.Zero && ImmReleaseContext(source.Handle, hIMC);
-		}
-		
 		public static bool SetCompositionWindow(HwndSource source, IntPtr hIMC, TextArea textArea)
 		{
 			if (textArea == null)
diff --git a/src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Editing/ImeSupport.cs b/src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Editing/ImeSupport.cs
index 10fa063524..23c3c41c36 100644
--- a/src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Editing/ImeSupport.cs
+++ b/src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Editing/ImeSupport.cs
@@ -24,7 +24,8 @@ namespace ICSharpCode.AvalonEdit.Editing
 	{
 		readonly TextArea textArea;
 		IntPtr currentContext;
-		//IntPtr previousContext;
+		IntPtr previousContext;
+		IntPtr defaultImeWnd;
 		HwndSource hwndSource;
 		
 		public ImeSupport(TextArea textArea)
@@ -47,16 +48,16 @@ namespace ICSharpCode.AvalonEdit.Editing
 		void ClearContext()
 		{
 			if (hwndSource != null) {
-				//ImeNativeWrapper.AssociateContext(hwndSource, previousContext);
-				//ImeNativeWrapper.ImmDestroyContext(currentContext);
-				ImeNativeWrapper.ReleaseContext(hwndSource, currentContext);
+				ImeNativeWrapper.ImmAssociateContext(hwndSource.Handle, previousContext);
+				ImeNativeWrapper.ImmReleaseContext(defaultImeWnd, currentContext);
 				currentContext = IntPtr.Zero;
+				defaultImeWnd = IntPtr.Zero;
 				hwndSource.RemoveHook(WndProc);
 				hwndSource = null;
 			}
 		}
 		
-		public void OnGotFocus(KeyboardFocusChangedEventArgs e)
+		public void OnGotKeyboardFocus(KeyboardFocusChangedEventArgs e)
 		{
 			CreateContext();
 		}
@@ -68,9 +69,11 @@ namespace ICSharpCode.AvalonEdit.Editing
 				return;
 			hwndSource = (HwndSource)PresentationSource.FromVisual(this.textArea);
 			if (hwndSource != null) {
-				//currentContext = ImeNativeWrapper.ImmCreateContext();
-				//previousContext = ImeNativeWrapper.AssociateContext(hwndSource, currentContext);
-				currentContext = ImeNativeWrapper.GetContext(hwndSource);
+				defaultImeWnd = ImeNativeWrapper.ImmGetDefaultIMEWnd(IntPtr.Zero);
+				currentContext = ImeNativeWrapper.ImmGetContext(defaultImeWnd);
+				previousContext = ImeNativeWrapper.ImmAssociateContext(hwndSource.Handle, currentContext);
+				Debug.Assert(hwndSource != null);
+				Debug.Assert(currentContext != null);
 				hwndSource.AddHook(WndProc);
 				// UpdateCompositionWindow() will be called by the caret becoming visible
 				
@@ -83,7 +86,7 @@ namespace ICSharpCode.AvalonEdit.Editing
 			}
 		}
 		
-		public void OnLostFocus(KeyboardFocusChangedEventArgs e)
+		public void OnLostKeyboardFocus(KeyboardFocusChangedEventArgs e)
 		{
 			if (e.OldFocus == textArea && currentContext != IntPtr.Zero)
 				ImeNativeWrapper.NotifyIme(currentContext);
diff --git a/src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Editing/TextArea.cs b/src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Editing/TextArea.cs
index 3eaffdedc9..31607759f8 100644
--- a/src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Editing/TextArea.cs
+++ b/src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Editing/TextArea.cs
@@ -758,7 +758,7 @@ namespace ICSharpCode.AvalonEdit.Editing
 		{
 			base.OnGotKeyboardFocus(e);
 			// First activate IME, then show caret
-			ime.OnGotFocus(e);
+			ime.OnGotKeyboardFocus(e);
 			caret.Show();
 		}
 		
@@ -767,7 +767,7 @@ namespace ICSharpCode.AvalonEdit.Editing
 		{
 			base.OnLostKeyboardFocus(e);
 			caret.Hide();
-			ime.OnLostFocus(e);
+			ime.OnLostKeyboardFocus(e);
 		}
 		#endregion