Input Method Editor (IME) support for text buttons

Original patch by @random (D765) with some minor work done by @campbell
and me.

At this place, I'd like call out a number of people who were involved and
deserve a big "Thank you!":
* At the first place @randon who developed and submitted the patch
* The Blendercn community which helped a lot with testing - espacially
* @yuzukyo, @leon_cheung and @kjym3
* @campbellbarton, @mont29 and @sergey for their help and advises during
* review
* @ton who realized the importance of this early on and asked me for
* reviewing

We are still not finished, as this is only the first part of the
implementaion, but there's more to come!

36 files changed, 602 insertions, 9 deletions

diff --git a/CMakeLists.txt b/CMakeLists.txt
index f2ffffeec31..4ee277b9248 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -318,6 +318,9 @@ mark_as_advanced(WITH_LIBMV_SCHUR_SPECIALIZATIONS)
 option(WITH_FREESTYLE     "Enable Freestyle (advanced edges rendering)" ON)
 
 # Misc
+if(WIN32)
+	option(WITH_INPUT_IME "Enable Input Method Editor (IME) for complex Asian character input" ON)
+endif()
 option(WITH_INPUT_NDOF "Enable NDOF input devices (SpaceNavigator and friends)" ${_init_INPUT_NDOF})
 option(WITH_RAYOPTIMIZATION	"Enable use of SIMD (SSE) optimizations for the raytracer" ON)
 option(WITH_OPENNL        "Enable use of Open Numerical Library" ON)
@@ -1151,6 +1154,10 @@ elseif(WIN32)
 
 		list(APPEND PLATFORM_LINKLIBS ws2_32 vfw32 winmm kernel32 user32 gdi32 comdlg32 advapi32 shfolder shell32 ole32 oleaut32 uuid psapi)
 
+		if(WITH_INPUT_IME)
+			list(APPEND PLATFORM_LINKLIBS imm32)
+		endif()
+
 		add_definitions(
 			-D_CRT_NONSTDC_NO_DEPRECATE
 			-D_CRT_SECURE_NO_DEPRECATE
@@ -1506,6 +1513,11 @@ elseif(WIN32)
 		endif()
 		
 		list(APPEND PLATFORM_LINKLIBS -lshell32 -lshfolder -lgdi32 -lmsvcrt -lwinmm -lmingw32 -lm -lws2_32 -lz -lstdc++ -lole32 -luuid -lwsock32 -lpsapi)
+
+		if(WITH_INPUT_IME)
+			list(APPEND PLATFORM_LINKLIBS -limm32)
+		endif()
+
 		set(PLATFORM_CFLAGS "-pipe -funsigned-char -fno-strict-aliasing")
 
 		if(WITH_MINGW64)
diff --git a/SConstruct b/SConstruct
index 4c2097f8879..4dacf89fcb0 100644
--- a/SConstruct
+++ b/SConstruct
@@ -266,6 +266,7 @@ if 'blenderlite' in B.targets:
     target_env_defs['WITH_BF_BOOLEAN'] = False
     target_env_defs['WITH_BF_REMESH'] = False
     target_env_defs['WITH_BF_PYTHON'] = False
+    target_env_defs['WITH_BF_IME'] = False
     target_env_defs['WITH_BF_3DMOUSE'] = False
     target_env_defs['WITH_BF_LIBMV'] = False
     target_env_defs['WITH_BF_FREESTYLE'] = False
diff --git a/build_files/scons/config/win32-mingw-config.py b/build_files/scons/config/win32-mingw-config.py
index 85aa72af19c..0fb84bfa4a5 100644
--- a/build_files/scons/config/win32-mingw-config.py
+++ b/build_files/scons/config/win32-mingw-config.py
@@ -170,6 +170,8 @@ BF_BOOST_LIBPATH = '${BF_BOOST}/lib'
 WITH_BF_RAYOPTIMIZATION = True
 BF_RAYOPTIMIZATION_SSE_FLAGS = ['-msse']
 
+WITH_BF_IME = True
+
 WITH_BF_OPENMP = True
 
 #CUDA
@@ -198,6 +200,9 @@ CC_WARN = [ '-Wall' ]
 
 LLIBS = ['-lshell32', '-lshfolder', '-lgdi32', '-lmsvcrt', '-lwinmm', '-lmingw32', '-lm', '-lws2_32', '-lz', '-lstdc++','-lole32','-luuid', '-lwsock32', '-lpsapi']
 
+if WITH_BF_IME:
+    LLIBS.append('-limm32')
+
 PLATFORM_LINKFLAGS = ['-Xlinker', '--stack=2097152']
 
 ## DISABLED, causes linking errors!
diff --git a/build_files/scons/config/win32-vc-config.py b/build_files/scons/config/win32-vc-config.py
index 967e9636fc2..d447a1ec08e 100644
--- a/build_files/scons/config/win32-vc-config.py
+++ b/build_files/scons/config/win32-vc-config.py
@@ -151,6 +151,8 @@ BF_OPENCOLLADA_INC = '${BF_OPENCOLLADA}/include/opencollada'
 BF_OPENCOLLADA_LIB = 'OpenCOLLADAStreamWriter OpenCOLLADASaxFrameworkLoader OpenCOLLADAFramework OpenCOLLADABaseUtils GeneratedSaxParser MathMLSolver xml pcre buffer ftoa'
 BF_OPENCOLLADA_LIBPATH = '${BF_OPENCOLLADA}/lib/opencollada'
 
+WITH_BF_IME = True
+
 WITH_BF_3DMOUSE = True
 
 WITH_BF_OPENMP = True
@@ -237,6 +239,9 @@ CXX_WARN = []
 
 LLIBS = ['ws2_32', 'vfw32', 'winmm', 'kernel32', 'user32', 'gdi32', 'comdlg32', 'advapi32', 'shfolder', 'shell32', 'ole32', 'oleaut32', 'uuid', 'psapi']
 
+if WITH_BF_IME:
+    LLIBS.append('imm32')
+
 PLATFORM_LINKFLAGS = ['/SUBSYSTEM:CONSOLE','/MACHINE:IX86','/STACK:2097152','/INCREMENTAL:NO', '/LARGEADDRESSAWARE', '/NODEFAULTLIB:msvcrt.lib', '/NODEFAULTLIB:msvcmrt.lib', '/NODEFAULTLIB:msvcurt.lib', '/NODEFAULTLIB:msvcrtd.lib']
 
 # # Todo
diff --git a/build_files/scons/config/win64-mingw-config.py b/build_files/scons/config/win64-mingw-config.py
index 0314ab13d07..f93be284813 100644
--- a/build_files/scons/config/win64-mingw-config.py
+++ b/build_files/scons/config/win64-mingw-config.py
@@ -170,6 +170,8 @@ BF_BOOST_LIBPATH = '${BF_BOOST}/lib'
 WITH_BF_RAYOPTIMIZATION = True
 BF_RAYOPTIMIZATION_SSE_FLAGS = ['-mmmx', '-msse', '-msse2']
 
+WITH_BF_IME = True
+
 WITH_BF_OPENMP = True
 
 #Freestyle
@@ -193,6 +195,9 @@ CC_WARN = [ '-Wall' ]
 
 LLIBS = ['-lshell32', '-lshfolder', '-lgdi32', '-lmsvcrt', '-lwinmm', '-lmingw32', '-lm', '-lws2_32', '-lz', '-lstdc++','-lole32','-luuid', '-lwsock32', '-lpsapi', '-lpthread']
 
+if WITH_BF_IME:
+    LLIBS.append('-limm32')
+
 PLATFORM_LINKFLAGS = ['-Xlinker', '--stack=2097152']
 
 ## DISABLED, causes linking errors!
diff --git a/build_files/scons/config/win64-vc-config.py b/build_files/scons/config/win64-vc-config.py
index 74d8c204963..b8e4f3d70fe 100644
--- a/build_files/scons/config/win64-vc-config.py
+++ b/build_files/scons/config/win64-vc-config.py
@@ -154,6 +154,8 @@ BF_OPENCOLLADA_INC = '${BF_OPENCOLLADA}/include/opencollada'
 BF_OPENCOLLADA_LIB = 'OpenCOLLADAStreamWriter OpenCOLLADASaxFrameworkLoader OpenCOLLADAFramework OpenCOLLADABaseUtils GeneratedSaxParser MathMLSolver xml pcre buffer ftoa'
 BF_OPENCOLLADA_LIBPATH = '${BF_OPENCOLLADA}/lib/opencollada'
 
+WITH_BF_IME = True
+
 WITH_BF_3DMOUSE = True
 
 WITH_BF_OPENMP = True
@@ -244,6 +246,9 @@ CXX_WARN = []
 
 LLIBS = ['ws2_32', 'vfw32', 'winmm', 'kernel32', 'user32', 'gdi32', 'comdlg32', 'advapi32', 'shfolder', 'shell32', 'ole32', 'oleaut32', 'uuid', 'psapi']
 
+if WITH_BF_IME:
+    LLIBS.append('imm32')
+
 PLATFORM_LINKFLAGS = ['/SUBSYSTEM:CONSOLE','/MACHINE:X64','/STACK:2097152','/OPT:NOREF','/INCREMENTAL:NO', '/NODEFAULTLIB:msvcrt.lib', '/NODEFAULTLIB:msvcmrt.lib', '/NODEFAULTLIB:msvcurt.lib', '/NODEFAULTLIB:msvcrtd.lib']
 
 BF_CYCLES_CUDA_ENV="C:\Program Files\Microsoft SDKs\Windows\v7.1\Bin\SetEnv.cmd"
diff --git a/build_files/scons/tools/btools.py b/build_files/scons/tools/btools.py
index cf9962d1bff..eb5036f9996 100644
--- a/build_files/scons/tools/btools.py
+++ b/build_files/scons/tools/btools.py
@@ -174,6 +174,7 @@ def validate_arguments(args, bc):
             'WITH_BF_CXX_GUARDEDALLOC',
             'WITH_BF_JEMALLOC', 'WITH_BF_STATICJEMALLOC', 'BF_JEMALLOC', 'BF_JEMALLOC_INC', 'BF_JEMALLOC_LIBPATH', 'BF_JEMALLOC_LIB', 'BF_JEMALLOC_LIB_STATIC',
             'BUILDBOT_BRANCH',
+            'WITH_BF_IME',
             'WITH_BF_3DMOUSE', 'WITH_BF_STATIC3DMOUSE', 'BF_3DMOUSE', 'BF_3DMOUSE_INC', 'BF_3DMOUSE_LIB', 'BF_3DMOUSE_LIBPATH', 'BF_3DMOUSE_LIB_STATIC',
             'WITH_BF_CYCLES', 'WITH_BF_CYCLES_CUDA_BINARIES', 'BF_CYCLES_CUDA_NVCC', 'BF_CYCLES_CUDA_NVCC', 'WITH_BF_CYCLES_CUDA_THREADED_COMPILE', 'BF_CYCLES_CUDA_ENV',
             'WITH_BF_OIIO', 'WITH_BF_STATICOIIO', 'BF_OIIO', 'BF_OIIO_INC', 'BF_OIIO_LIB', 'BF_OIIO_LIB_STATIC', 'BF_OIIO_LIBPATH',
@@ -507,6 +508,8 @@ def read_opts(env, cfg, args):
         (BoolVariable('WITH_BF_PLAYER', 'Build blenderplayer if true', False)),
         (BoolVariable('WITH_BF_NOBLENDER', 'Do not build blender if true', False)),
 
+        (BoolVariable('WITH_BF_IME', 'Enable Input Method Editor (IME) for complex Asian character input', False)),
+
         (BoolVariable('WITH_BF_3DMOUSE', 'Build blender with support of 3D mouses', False)),
         (BoolVariable('WITH_BF_STATIC3DMOUSE', 'Staticly link to 3d mouse library', False)),
         ('BF_3DMOUSE', '3d mouse library base path', ''),
diff --git a/intern/ghost/CMakeLists.txt b/intern/ghost/CMakeLists.txt
index 3ce269c2b4f..dc55a81b0d8 100644
--- a/intern/ghost/CMakeLists.txt
+++ b/intern/ghost/CMakeLists.txt
@@ -280,6 +280,16 @@ elseif(WIN32)
 		)
 	endif()
 
+	if(WITH_INPUT_IME)
+		add_definitions(-DWITH_INPUT_IME)
+
+		list(APPEND SRC
+			intern/GHOST_ImeWin32.cpp
+
+			intern/GHOST_ImeWin32.h
+		)
+	endif()
+
 	if(WITH_INPUT_NDOF)
 		list(APPEND SRC
 			intern/GHOST_NDOFManagerWin32.cpp
diff --git a/intern/ghost/GHOST_C-api.h b/intern/ghost/GHOST_C-api.h
index 7b47f0526a2..c0f2651dd8b 100644
--- a/intern/ghost/GHOST_C-api.h
+++ b/intern/ghost/GHOST_C-api.h
@@ -897,6 +897,30 @@ extern int GHOST_UseNativePixels(void);
  */
 extern float GHOST_GetNativePixelSize(GHOST_WindowHandle windowhandle);
 
+/**
+ * Enable IME attached to the given window, i.e. allows user-input
+ * events to be dispatched to the IME.
+ * \param windowhandle Window handle of the caller
+ * \param x Requested x-coordinate of the rectangle
+ * \param y Requested y-coordinate of the rectangle
+ * \param w Requested width of the rectangle
+ * \param h Requested height of the rectangle
+ * \param complete Whether or not to complete the ongoing composition
+ * true:  Start a new composition
+ * false: Move the IME windows to the given position without finishing it.
+ */
+extern void GHOST_BeginIME(GHOST_WindowHandle windowhandle,
+                            GHOST_TInt32 x,
+                            GHOST_TInt32 y,
+                            GHOST_TInt32 w,
+                            GHOST_TInt32 h,
+                            int complete);
+/**
+ * Disable the IME attached to the given window, i.e. prohibits any user-input
+ * events from being dispatched to the IME.
+ * \param windowhandle The window handle of the caller
+ */
+extern void GHOST_EndIME(GHOST_WindowHandle windowhandle);
 
 #ifdef __cplusplus
 }
diff --git a/intern/ghost/GHOST_IWindow.h b/intern/ghost/GHOST_IWindow.h
index 71dc193a81b..3f8215dc7c2 100644
--- a/intern/ghost/GHOST_IWindow.h
+++ b/intern/ghost/GHOST_IWindow.h
@@ -331,6 +331,29 @@ public:
 
 	virtual float getNativePixelSize(void) = 0;
 
+#ifdef WITH_INPUT_IME
+	/**
+	 * Enable IME attached to the given window, i.e. allows user-input
+	 * events to be dispatched to the IME.
+	 * \param x Requested x-coordinate of the rectangle
+	 * \param y Requested y-coordinate of the rectangle
+	 * \param w Requested width of the rectangle
+	 * \param h Requested height of the rectangle
+	 * \param complete Whether or not to complete the ongoing composition
+	 * true:  Start a new composition
+	 * false: Move the IME windows to the given position without finishing it.
+	 */
+	virtual void beginIME(
+	        GHOST_TInt32 x, GHOST_TInt32 y,
+	        GHOST_TInt32 w, GHOST_TInt32 h,
+	        int completed) = 0;
+
+	/**
+	 * Disable the IME attached to the given window, i.e. prohibits any user-input
+	 * events from being dispatched to the IME.
+	 */
+	virtual void endIME() = 0;
+#endif /* WITH_INPUT_IME */
 	
 #ifdef WITH_CXX_GUARDEDALLOC
 	MEM_CXX_CLASS_ALLOC_FUNCS("GHOST:GHOST_IWindow")
diff --git a/intern/ghost/GHOST_Types.h b/intern/ghost/GHOST_Types.h
index 7333ba025a5..c4a7490c71c 100644
--- a/intern/ghost/GHOST_Types.h
+++ b/intern/ghost/GHOST_Types.h
@@ -190,6 +190,10 @@ typedef enum {
 
 	GHOST_kEventTimer,
 
+	GHOST_kEventImeCompositionStart,
+	GHOST_kEventImeComposition,
+	GHOST_kEventImeCompositionEnd,
+
 	GHOST_kNumEventTypes
 } GHOST_TEventType;
 
@@ -436,6 +440,22 @@ typedef struct {
 	GHOST_TEventDataPtr data;
 } GHOST_TEventDragnDropData;
 
+/** similar to wmImeData */
+typedef struct {
+	/** size_t */
+	GHOST_TUserDataPtr result_len, composite_len;
+	/** char * utf8 encoding */
+	GHOST_TUserDataPtr result, composite;
+	/** Cursor position in the IME composition. */
+	int cursor_position;
+	/** Represents the position of the beginning of the selection */
+	int target_start;
+	/** Represents the position of the end of the selection */
+	int target_end;
+	/** custom temporal data */
+	GHOST_TUserDataPtr tmp;
+} GHOST_TEventImeData;
+
 typedef struct {
 	int count;
 	GHOST_TUns8 **strings;
diff --git a/intern/ghost/SConscript b/intern/ghost/SConscript
index 5a4572c164d..a41fadf9ac7 100644
--- a/intern/ghost/SConscript
+++ b/intern/ghost/SConscript
@@ -154,6 +154,13 @@ if env['BF_GHOST_DEBUG']:
 else:
     sources.remove('intern' + os.sep + 'GHOST_EventPrinter.cpp')
 
+if env['WITH_BF_IME']:
+    if window_system in ('win32-vc', 'win32-mingw', 'win64-vc', 'win64-mingw'):
+        defs.append('WITH_INPUT_IME')
+    else:
+        sources.remove('intern' + os.sep + 'GHOST_ImeWin32.h')
+        sources.remove('intern' + os.sep + 'GHOST_ImeWin32.cpp')
+
 if env['WITH_BF_3DMOUSE']:
     defs.append('WITH_INPUT_NDOF')
 
diff --git a/intern/ghost/intern/GHOST_C-api.cpp b/intern/ghost/intern/GHOST_C-api.cpp
index 5a2e638f01a..0da77ac5e20 100644
--- a/intern/ghost/intern/GHOST_C-api.cpp
+++ b/intern/ghost/intern/GHOST_C-api.cpp
@@ -915,3 +915,21 @@ float GHOST_GetNativePixelSize(GHOST_WindowHandle windowhandle)
 	return 1.0f;
 }
 
+#ifdef WITH_INPUT_IME
+
+void GHOST_BeginIME(GHOST_WindowHandle windowhandle,
+                    GHOST_TInt32 x, GHOST_TInt32 y,
+                    GHOST_TInt32 w, GHOST_TInt32 h,
+                    int complete)
+{
+	GHOST_IWindow *window = (GHOST_IWindow *) windowhandle;
+	window->beginIME(x, y, w, h, complete);
+}
+
+void GHOST_EndIME(GHOST_WindowHandle windowhandle)
+{
+	GHOST_IWindow *window = (GHOST_IWindow *) windowhandle;
+	window->endIME();
+}
+
+#endif  /* WITH_INPUT_IME */
diff --git a/intern/ghost/intern/GHOST_SystemWin32.cpp b/intern/ghost/intern/GHOST_SystemWin32.cpp
index 3b793fda968..4247c4f31ce 100644
--- a/intern/ghost/intern/GHOST_SystemWin32.cpp
+++ b/intern/ghost/intern/GHOST_SystemWin32.cpp
@@ -792,6 +792,15 @@ GHOST_Event *GHOST_SystemWin32::processWindowEvent(GHOST_TEventType type, GHOST_
 	return new GHOST_Event(system->getMilliSeconds(), type, window);
 }
 
+#ifdef WITH_INPUT_IME
+GHOST_Event *GHOST_SystemWin32::processImeEvent(GHOST_TEventType type, GHOST_IWindow *window, GHOST_TEventImeData *data)
+{
+	GHOST_System *system = (GHOST_System *)getSystem();
+	return new GHOST_EventIME(system->getMilliSeconds(), type, window, data);
+}
+#endif
+
+
 GHOST_TSuccess GHOST_SystemWin32::pushDragDropEvent(
         GHOST_TEventType eventType,
         GHOST_TDragnDropTypes draggedObjectType,
@@ -904,6 +913,7 @@ LRESULT WINAPI GHOST_SystemWin32::s_wndProc(HWND hwnd, UINT msg, WPARAM wParam,
 
 	LRESULT lResult = 0;
 	GHOST_SystemWin32 *system = ((GHOST_SystemWin32 *)getSystem());
+	GHOST_EventManager *eventManager = system->getEventManager();
 	GHOST_ASSERT(system, "GHOST_SystemWin32::s_wndProc(): system not initialized");
 
 	if (hwnd) {
@@ -912,8 +922,13 @@ LRESULT WINAPI GHOST_SystemWin32::s_wndProc(HWND hwnd, UINT msg, WPARAM wParam,
 			switch (msg) {
 				// we need to check if new key layout has AltGr
 				case WM_INPUTLANGCHANGE:
+				{
 					system->handleKeyboardChange();
+#ifdef WITH_INPUT_IME
+					window->getImeInput()->SetInputLanguage();
+#endif
 					break;
+				}
 				////////////////////////////////////////////////////////////////////////
 				// Keyboard events, processed
 				////////////////////////////////////////////////////////////////////////
@@ -949,6 +964,56 @@ LRESULT WINAPI GHOST_SystemWin32::s_wndProc(HWND hwnd, UINT msg, WPARAM wParam,
 					}
 					break;
 				}
+#ifdef WITH_INPUT_IME
+				////////////////////////////////////////////////////////////////////////
+				// IME events, processed, read more in GHOST_IME.h
+				////////////////////////////////////////////////////////////////////////
+				case WM_IME_SETCONTEXT:
+				{
+					window->getImeInput()->SetInputLanguage();
+					window->getImeInput()->CreateImeWindow(window->getHWND());
+					window->getImeInput()->CleanupComposition(window->getHWND());
+					window->getImeInput()->CheckFirst(window->getHWND());
+					break;
+				}
+				case WM_IME_STARTCOMPOSITION:
+				{
+					eventHandled = true;
+					/* remove input event before start comp event, avoid redundant input */
+					eventManager->removeTypeEvents(GHOST_kEventKeyDown, window);
+					window->getImeInput()->CreateImeWindow(window->getHWND());
+					window->getImeInput()->ResetComposition(window->getHWND());
+					event = processImeEvent(
+					        GHOST_kEventImeCompositionStart,
+					        window,
+					        &window->getImeInput()->eventImeData);
+					break;
+				}
+				case WM_IME_COMPOSITION:
+				{
+					eventHandled = true;
+					window->getImeInput()->UpdateImeWindow(window->getHWND());
+					window->getImeInput()->UpdateInfo(window->getHWND());
+					event = processImeEvent(
+					        GHOST_kEventImeComposition,
+					        window,
+					        &window->getImeInput()->eventImeData);
+					break;
+				}
+				case WM_IME_ENDCOMPOSITION:
+				{
+					eventHandled = true;
+					/* remove input event after end comp event, avoid redundant input */
+					eventManager->removeTypeEvents(GHOST_kEventKeyDown, window);
+					window->getImeInput()->ResetComposition(window->getHWND());
+					window->getImeInput()->DestroyImeWindow(window->getHWND());
+					event = processImeEvent(
+					        GHOST_kEventImeCompositionEnd,
+					        window,
+					        &window->getImeInput()->eventImeData);
+					break;
+				}
+#endif /* WITH_INPUT_IME */
 				////////////////////////////////////////////////////////////////////////
 				// Keyboard events, ignored
 				////////////////////////////////////////////////////////////////////////
diff --git a/intern/ghost/intern/GHOST_SystemWin32.h b/intern/ghost/intern/GHOST_SystemWin32.h
index 79fed06c6a5..cb3b8ee3cfc 100644
--- a/intern/ghost/intern/GHOST_SystemWin32.h
+++ b/intern/ghost/intern/GHOST_SystemWin32.h
@@ -307,6 +307,15 @@ protected:
 	static GHOST_Event *processWindowEvent(GHOST_TEventType type, GHOST_IWindow *window);
 
 	/**
+	 * Creates a IME event.
+	 * \param type		The type of event to create.
+	 * \param window		The window receiving the event (the active window).
+	 * \param data		IME data.
+	 * \return The event created.
+	 */
+	static GHOST_Event *processImeEvent(GHOST_TEventType type, GHOST_IWindow *window, GHOST_TEventImeData *data);
+
+	/**
 	 * Handles minimum window size.
 	 * \param minmax	The MINMAXINFO structure.
 	 */
diff --git a/intern/ghost/intern/GHOST_Window.h b/intern/ghost/intern/GHOST_Window.h
index 15b81998aab..ac31c54666b 100644
--- a/intern/ghost/intern/GHOST_Window.h
+++ b/intern/ghost/intern/GHOST_Window.h
@@ -295,6 +295,22 @@ public:
 		return 1.0f;
 	}
 
+#ifdef WITH_INPUT_IME
+	virtual void beginIME(GHOST_TInt32 x,
+	                      GHOST_TInt32 y,
+	                      GHOST_TInt32 w,
+	                      GHOST_TInt32 h,
+	                      int completed)
+	{
+		/* do nothing temporarily if not in windows */
+	}
+
+	virtual void endIME()
+	{
+		/* do nothing temporarily if not in windows */
+	}
+#endif /* WITH_INPUT_IME */
+
 protected:
 	/**
 	 * Tries to install a rendering context in this window.
diff --git a/intern/ghost/intern/GHOST_WindowWin32.cpp b/intern/ghost/intern/GHOST_WindowWin32.cpp
index 64ea7192616..4e384881f2c 100644
--- a/intern/ghost/intern/GHOST_WindowWin32.cpp
+++ b/intern/ghost/intern/GHOST_WindowWin32.cpp
@@ -1050,3 +1050,16 @@ GHOST_TSuccess GHOST_WindowWin32::endProgressBar()
 	return GHOST_kFailure;
 }
 
+
+#ifdef WITH_INPUT_IME
+void GHOST_WindowWin32::beginIME(GHOST_TInt32 x, GHOST_TInt32 y, GHOST_TInt32 w, GHOST_TInt32 h, int completed)
+{
+	this->getImeInput()->BeginIME(this->getHWND(),	GHOST_Rect(x, y - h , x, y), (bool)completed);
+}
+
+
+void GHOST_WindowWin32::endIME()
+{
+	this->getImeInput()->EndIME(this->getHWND());
+}
+#endif /* WITH_INPUT_IME */
diff --git a/intern/ghost/intern/GHOST_WindowWin32.h b/intern/ghost/intern/GHOST_WindowWin32.h
index 7b12d8c583e..c4575d0f9b0 100644
--- a/intern/ghost/intern/GHOST_WindowWin32.h
+++ b/intern/ghost/intern/GHOST_WindowWin32.h
@@ -39,6 +39,9 @@
 
 #include "GHOST_Window.h"
 #include "GHOST_TaskbarWin32.h"
+#ifdef WITH_INPUT_IME
+#  include "GHOST_ImeWin32.h"
+#endif
 
 #include <wintab.h>
 #define PACKETDATA  (PK_BUTTONS | PK_NORMAL_PRESSURE | PK_ORIENTATION | PK_CURSOR)
@@ -253,6 +256,17 @@ public:
 	/** if the window currently resizing */
 	bool m_inLiveResize;
 
+#ifdef WITH_INPUT_IME
+	GHOST_ImeWin32 *getImeInput() {return &m_imeImput;}
+
+	virtual void beginIME(
+	        GHOST_TInt32 x, GHOST_TInt32 y,
+	        GHOST_TInt32 w, GHOST_TInt32 h,
+	        int completed);
+
+	virtual void endIME();
+#endif /* WITH_INPUT_IME */
+
 private:
 
 	/**
@@ -339,6 +353,11 @@ private:
 
 	/** Hwnd to parent window */
 	GHOST_TEmbedderWindowID m_parentWindowHwnd;
+
+#ifdef WITH_INPUT_IME
+	/** Handle input method editors event */
+	GHOST_ImeWin32 m_imeImput;
+#endif
 };
 
 #endif // __GHOST_WINDOWWIN32_H__
diff --git a/source/blender/blenloader/intern/readfile.c b/source/blender/blenloader/intern/readfile.c
index ac903c7a8d2..0950edac46a 100644
--- a/source/blender/blenloader/intern/readfile.c
+++ b/source/blender/blenloader/intern/readfile.c
@@ -5677,6 +5677,9 @@ static void direct_link_windowmanager(FileData *fd, wmWindowManager *wm)
 		win->eventstate = NULL;
 		win->curswin = NULL;
 		win->tweak = NULL;
+#ifdef WIN32
+		win->ime_data = NULL;
+#endif
 		
 		BLI_listbase_clear(&win->queue);
 		BLI_listbase_clear(&win->handlers);
diff --git a/source/blender/editors/include/UI_interface.h b/source/blender/editors/include/UI_interface.h
index 42f67379dfd..2251f3fd0e4 100644
--- a/source/blender/editors/include/UI_interface.h
+++ b/source/blender/editors/include/UI_interface.h
@@ -313,6 +313,7 @@ void UI_draw_box_shadow(unsigned char alpha, float minx, float miny, float maxx,
 void UI_draw_roundbox_gl_mode(int mode, float minx, float miny, float maxx, float maxy, float rad);
 void UI_draw_roundbox_shade_x(int mode, float minx, float miny, float maxx, float maxy, float rad, float shadetop, float shadedown);
 void UI_draw_roundbox_shade_y(int mode, float minx, float miny, float maxx, float maxy, float rad, float shadeLeft, float shadeRight);
+void UI_draw_text_underline(int pos_x, int pos_y, int len, int height);
 
 /* state for scrolldrawing */
 #define UI_SCROLL_PRESSED       (1 << 0)
diff --git a/source/blender/editors/interface/CMakeLists.txt b/source/blender/editors/interface/CMakeLists.txt
index b921d17104c..972eca747b9 100644
--- a/source/blender/editors/interface/CMakeLists.txt
+++ b/source/blender/editors/interface/CMakeLists.txt
@@ -71,6 +71,12 @@ if(WITH_PYTHON)
 	add_definitions(-DWITH_PYTHON)
 endif()
 
+if(WIN32)
+	if(WITH_INPUT_IME)
+		add_definitions(-DWITH_INPUT_IME)
+	endif()
+endif()
+
 add_definitions(${GL_DEFINITIONS})
 
 blender_add_lib(bf_editor_interface "${SRC}" "${INC}" "${INC_SYS}")
diff --git a/source/blender/editors/interface/SConscript b/source/blender/editors/interface/SConscript
index 303ab7ff286..5af8bba5a9f 100644
--- a/source/blender/editors/interface/SConscript
+++ b/source/blender/editors/interface/SConscript
@@ -48,6 +48,10 @@ incs = [
 
 defs = env['BF_GL_DEFINITIONS']
 
+if env['OURPLATFORM'] in ('win32-vc', 'win32-mingw', 'win64-vc', 'win64-mingw'):
+    if env['WITH_BF_IME']:
+        defs.append('WITH_INPUT_IME')
+
 if env['WITH_BF_INTERNATIONAL']:
     defs.append('WITH_INTERNATIONAL')
 
diff --git a/source/blender/editors/interface/interface.c b/source/blender/editors/interface/interface.c
index 92017e7a967..4cbb02c4dd5 100644
--- a/source/blender/editors/interface/interface.c
+++ b/source/blender/editors/interface/interface.c
@@ -209,6 +209,11 @@ void ui_window_to_region(const ARegion *ar, int *x, int *y)
 	*y -= ar->winrct.ymin;
 }
 
+void ui_region_to_window(const ARegion *ar, int *x, int *y)
+{
+	*x += ar->winrct.xmin;
+	*y += ar->winrct.ymin;
+}
 /* ******************* block calc ************************* */
 
 void ui_block_translate(uiBlock *block, int x, int y)
diff --git a/source/blender/editors/interface/interface_draw.c b/source/blender/editors/interface/interface_draw.c
index 4dd952f0753..bcd9b9a5547 100644
--- a/source/blender/editors/interface/interface_draw.c
+++ b/source/blender/editors/interface/interface_draw.c
@@ -395,6 +395,12 @@ void UI_draw_roundbox(float minx, float miny, float maxx, float maxy, float rad)
 	ui_draw_anti_roundbox(GL_POLYGON, minx, miny, maxx, maxy, rad, roundboxtype & UI_RB_ALPHA);
 }
 
+void UI_draw_text_underline(int pos_x, int pos_y, int len, int height)
+{
+	int ofs_y = 4 * U.pixelsize;
+	glRecti(pos_x, pos_y - ofs_y, pos_x + len, pos_y - ofs_y + (height * U.pixelsize));
+}
+
 /* ************** SPECIAL BUTTON DRAWING FUNCTIONS ************* */
 
 void ui_draw_but_IMAGE(ARegion *UNUSED(ar), uiBut *but, uiWidgetColors *UNUSED(wcol), const rcti *rect)
diff --git a/source/blender/editors/interface/interface_handlers.c b/source/blender/editors/interface/interface_handlers.c
index 3a312808cee..b39c786fba7 100644
--- a/source/blender/editors/interface/interface_handlers.c
+++ b/source/blender/editors/interface/interface_handlers.c
@@ -87,6 +87,10 @@
 #include "WM_api.h"
 #include "WM_types.h"
 
+#ifdef WITH_INPUT_IME
+#  include "wm_window.h"
+#endif
+
 /* place the mouse at the scaled down location when un-grabbing */
 #define USE_CONT_MOUSE_CORRECT
 /* support dragging toggle buttons */
@@ -2425,8 +2429,50 @@ static bool ui_textedit_copypaste(uiBut *but, uiHandleButtonData *data, const in
 	return changed;
 }
 
+#ifdef WITH_INPUT_IME
+/* enable ime, and set up uibut ime data */
+static void ui_textedit_ime_begin(wmWindow *win, uiBut *UNUSED(but))
+{
+	/* XXX Is this really needed? */
+	int x, y;
+
+	/* enable IME and position to cursor, it's a trick */
+	x = win->eventstate->x;
+	/* flip y and move down a bit, prevent the IME panel cover the edit button */
+	y = win->eventstate->y - 12;
+
+	wm_window_IME_begin(win, x, y, 0, 0, true);
+}
+
+/* disable ime, and clear uibut ime data */
+static void ui_textedit_ime_end(wmWindow *win, uiBut *UNUSED(but))
+{
+	wm_window_IME_end(win);
+}
+
+void ui_but_ime_reposition(uiBut *but, int x, int y, bool complete)
+{
+	BLI_assert(but->active);
+
+	ui_region_to_window(but->active->region, &x, &y);
+	wm_window_IME_begin(but->active->window, x, y - 4, 0, 0, complete);
+}
+
+/* should be ui_but_ime_data_get */
+wmIMEData *ui_but_get_ime_data(uiBut *but)
+{
+	if (but->active && but->active->window) {
+		return but->active->window->ime_data;
+	}
+	else {
+		return NULL;
+	}
+}
+#endif  /* WITH_INPUT_IME */
+
 static void ui_textedit_begin(bContext *C, uiBut *but, uiHandleButtonData *data)
 {
+	wmWindow *win = CTX_wm_window(C);
 	int len;
 
 	if (data->str) {
@@ -2482,12 +2528,18 @@ static void ui_textedit_begin(bContext *C, uiBut *but, uiHandleButtonData *data)
 	but->flag &= ~UI_BUT_REDALERT;
 
 	ui_but_update(but);
-	
-	WM_cursor_modal_set(CTX_wm_window(C), BC_TEXTEDITCURSOR);
+
+	WM_cursor_modal_set(win, BC_TEXTEDITCURSOR);
+
+#ifdef WITH_INPUT_IME
+	ui_textedit_ime_begin(win, but);
+#endif
 }
 
 static void ui_textedit_end(bContext *C, uiBut *but, uiHandleButtonData *data)
 {
+	wmWindow *win = CTX_wm_window(C);
+
 	if (but) {
 		if (ui_but_is_utf8(but)) {
 			int strip = BLI_utf8_invalid_strip(but->editstr, strlen(but->editstr));
@@ -2518,7 +2570,11 @@ static void ui_textedit_end(bContext *C, uiBut *but, uiHandleButtonData *data)
 		but->pos = -1;
 	}
 	
-	WM_cursor_modal_restore(CTX_wm_window(C));
+	WM_cursor_modal_restore(win);
+
+#ifdef WITH_INPUT_IME
+	ui_textedit_ime_end(win, but);
+#endif
 }
 
 static void ui_textedit_next_but(uiBlock *block, uiBut *actbut, uiHandleButtonData *data)
@@ -2583,6 +2639,14 @@ static void ui_do_but_textedit(bContext *C, uiBlock *block, uiBut *but, uiHandle
 	int retval = WM_UI_HANDLER_CONTINUE;
 	bool changed = false, inbox = false, update = false;
 
+#ifdef WITH_INPUT_IME
+	wmWindow *win = CTX_wm_window(C);
+	wmIMEData *ime_data = win->ime_data;
+	bool is_ime_composing = ime_data && ime_data->is_ime_composing;
+#else
+	bool is_ime_composing = false;
+#endif
+
 	switch (event->type) {
 		case MOUSEMOVE:
 		case MOUSEPAN:
@@ -2603,6 +2667,12 @@ static void ui_do_but_textedit(bContext *C, uiBlock *block, uiBut *but, uiHandle
 		case RIGHTMOUSE:
 		case ESCKEY:
 			if (event->val == KM_PRESS) {
+#ifdef WITH_INPUT_IME
+				/* skips button handling since it is not wanted */
+				if (is_ime_composing) {
+					break;
+				}
+#endif
 				data->cancel = true;
 				data->escapecancel = true;
 				button_activate_state(C, but, BUTTON_STATE_EXIT);
@@ -2660,7 +2730,7 @@ static void ui_do_but_textedit(bContext *C, uiBlock *block, uiBut *but, uiHandle
 		}
 	}
 
-	if (event->val == KM_PRESS) {
+	if (event->val == KM_PRESS && !is_ime_composing) {
 		switch (event->type) {
 			case VKEY:
 			case XKEY:
@@ -2776,7 +2846,15 @@ static void ui_do_but_textedit(bContext *C, uiBlock *block, uiBut *but, uiHandle
 				break;
 		}
 
-		if ((event->ascii || event->utf8_buf[0]) && (retval == WM_UI_HANDLER_CONTINUE)) {
+		if ((event->ascii || event->utf8_buf[0]) &&
+		    (retval == WM_UI_HANDLER_CONTINUE)
+#ifdef WITH_INPUT_IME
+		    &&
+		    !is_ime_composing &&
+		    !WM_event_is_ime_switch(event)
+#endif
+		    )
+		{
 			char ascii = event->ascii;
 			const char *utf8_buf = event->utf8_buf;
 
@@ -2811,6 +2889,25 @@ static void ui_do_but_textedit(bContext *C, uiBlock *block, uiBut *but, uiHandle
 			update = true;
 	}
 
+#ifdef WITH_INPUT_IME
+	if (event->type == WM_IME_COMPOSITE_START || event->type == WM_IME_COMPOSITE_EVENT) {
+		changed = true;
+
+		if (event->type == WM_IME_COMPOSITE_START && but->selend > but->selsta) {
+			ui_textedit_delete_selection(but, data);
+		}
+		if (event->type == WM_IME_COMPOSITE_EVENT && ime_data->result_len) {
+			ui_textedit_type_buf(
+			        but, data,
+			        ime_data->str_result,
+			        ime_data->result_len);
+		}
+	}
+	else if (event->type == WM_IME_COMPOSITE_END) {
+		changed = true;
+	}
+#endif
+
 	if (changed) {
 		/* only update when typing for TAB key */
 		if (update && data->interactive) {
diff --git a/source/blender/editors/interface/interface_intern.h b/source/blender/editors/interface/interface_intern.h
index 328822e47ef..2c3a239b2a2 100644
--- a/source/blender/editors/interface/interface_intern.h
+++ b/source/blender/editors/interface/interface_intern.h
@@ -433,6 +433,7 @@ extern void ui_block_to_window_rctf(const struct ARegion *ar, uiBlock *block, rc
 extern void ui_window_to_block_fl(const struct ARegion *ar, uiBlock *block, float *x, float *y);
 extern void ui_window_to_block(const struct ARegion *ar, uiBlock *block, int *x, int *y);
 extern void ui_window_to_region(const ARegion *ar, int *x, int *y);
+extern void ui_region_to_window(const struct ARegion *ar, int *x, int *y);
 
 extern double ui_but_value_get(uiBut *but);
 extern void ui_but_value_set(uiBut *but, double value);
@@ -627,6 +628,11 @@ void ui_panel_menu(struct bContext *C, ARegion *ar, Panel *pa);
 uiBut *ui_but_find_old(uiBlock *block_old, const uiBut *but_new);
 uiBut *ui_but_find_new(uiBlock *block_old, const uiBut *but_new);
 
+#ifdef WITH_INPUT_IME
+void ui_but_ime_reposition(uiBut *but, int x, int y, bool complete);
+struct wmIMEData *ui_but_get_ime_data(uiBut *but);
+#endif
+
 /* interface_widgets.c */
 void ui_draw_anti_tria(float x1, float y1, float x2, float y2, float x3, float y3);
 void ui_draw_anti_roundbox(int mode, float minx, float miny, float maxx, float maxy, float rad, bool use_alpha);
diff --git a/source/blender/editors/interface/interface_widgets.c b/source/blender/editors/interface/interface_widgets.c
index c9def075666..d6c51b6b220 100644
--- a/source/blender/editors/interface/interface_widgets.c
+++ b/source/blender/editors/interface/interface_widgets.c
@@ -59,6 +59,10 @@
 
 #include "interface_intern.h"
 
+#ifdef WITH_INPUT_IME
+#  include "WM_types.h"
+#endif
+
 /* icons are 80% of height of button (16 pixels inside 20 height) */
 #define ICON_SIZE_FROM_BUTRECT(rect) (0.8f * BLI_rcti_size_y(rect))
 
@@ -1232,6 +1236,50 @@ static void ui_text_clip_right_label(uiFontStyle *fstyle, uiBut *but, const rcti
 		BLF_disable(fstyle->uifont_id, BLF_KERNING_DEFAULT);
 }
 
+#ifdef WITH_INPUT_IME
+static void widget_draw_text_ime_underline(
+        uiFontStyle *fstyle, uiWidgetColors *wcol, uiBut *but, const rcti *rect,
+        const wmIMEData *ime_data, const char *drawstr)
+{
+	int ofs_x, width;
+	int rect_x = BLI_rcti_size_x(rect);
+	int sel_start = ime_data->sel_start, sel_end = ime_data->sel_end;
+
+	if (drawstr[0] != 0) {
+		if (but->pos >= but->ofs) {
+			ofs_x = BLF_width(fstyle->uifont_id, drawstr + but->ofs, but->pos - but->ofs);
+		}
+		else {
+			ofs_x = 0;
+		}
+
+		width = BLF_width(fstyle->uifont_id, drawstr + but->ofs,
+		                  ime_data->composite_len + but->pos - but->ofs);
+
+		glColor4ubv((unsigned char *)wcol->text);
+		UI_draw_text_underline(rect->xmin + ofs_x, rect->ymin + 6 * U.pixelsize, min_ii(width, rect_x - 2) - ofs_x, 1);
+
+		/* draw the thick line */
+		if (sel_start != -1 && sel_end != -1) {
+			sel_end -= sel_start;
+			sel_start += but->pos;
+
+			if (sel_start >= but->ofs) {
+				ofs_x = BLF_width(fstyle->uifont_id, drawstr + but->ofs, sel_start - but->ofs);
+			}
+			else {
+				ofs_x = 0;
+			}
+
+			width = BLF_width(fstyle->uifont_id, drawstr + but->ofs,
+			                  sel_end + sel_start - but->ofs);
+
+			UI_draw_text_underline(rect->xmin + ofs_x, rect->ymin + 6 * U.pixelsize, min_ii(width, rect_x - 2) - ofs_x, 2);
+		}
+	}
+}
+#endif  /* WITH_INPUT_IME */
+
 static void widget_draw_text(uiFontStyle *fstyle, uiWidgetColors *wcol, uiBut *but, rcti *rect)
 {
 	int drawstr_left_len = UI_MAX_DRAW_STR;
@@ -1239,6 +1287,10 @@ static void widget_draw_text(uiFontStyle *fstyle, uiWidgetColors *wcol, uiBut *b
 	const char *drawstr_right = NULL;
 	bool use_right_only = false;
 
+#ifdef WITH_INPUT_IME
+	const wmIMEData *ime_data;
+#endif
+
 	UI_fontstyle_set(fstyle);
 	
 	if (but->editstr || (but->drawflag & UI_BUT_TEXT_LEFT))
@@ -1266,13 +1318,30 @@ static void widget_draw_text(uiFontStyle *fstyle, uiWidgetColors *wcol, uiBut *b
 			/* max length isn't used in this case,
 			 * we rely on string being NULL terminated. */
 			drawstr_left_len = INT_MAX;
-			drawstr = but->editstr;
+
+#ifdef WITH_INPUT_IME
+			/* FIXME, IME is modifying 'const char *drawstr! */
+			ime_data = ui_but_get_ime_data(but);
+
+			if (ime_data && ime_data->composite_len) {
+				/* insert composite string into cursor pos */
+				BLI_snprintf((char *)drawstr, UI_MAX_DRAW_STR, "%s%s%s",
+				             but->editstr, ime_data->str_composite,
+				             but->editstr + but->pos);
+			}
+			else
+#endif
+			{
+				drawstr = but->editstr;
+			}
 		}
 	}
 
 
-	/* text button selection and cursor */
+	/* text button selection, cursor, composite underline */
 	if (but->editstr && but->pos != -1) {
+		int but_pos_ofs;
+		int tx, ty;
 
 		/* text button selection */
 		if ((but->selend - but->selsta) > 0) {
@@ -1298,18 +1367,44 @@ static void widget_draw_text(uiFontStyle *fstyle, uiWidgetColors *wcol, uiBut *b
 		}
 
 		/* text cursor */
+		but_pos_ofs = but->pos;
+
+#ifdef WITH_INPUT_IME
+		/* if is ime compositing, move the cursor */
+		if (ime_data && ime_data->composite_len && ime_data->cursor_pos != -1) {
+			but_pos_ofs += ime_data->cursor_pos;
+		}
+#endif
+
 		if (but->pos >= but->ofs) {
 			int t;
 			if (drawstr[0] != 0) {
-				t = BLF_width(fstyle->uifont_id, drawstr + but->ofs, but->pos - but->ofs);
+				t = BLF_width(fstyle->uifont_id, drawstr + but->ofs, but_pos_ofs - but->ofs);
 			}
 			else {
 				t = 0;
 			}
 
 			glColor3f(0.20, 0.6, 0.9);
-			glRecti(rect->xmin + t, rect->ymin + 2, rect->xmin + t + 2, rect->ymax - 2);
+
+			tx = rect->xmin + t + 2;
+			ty = rect->ymin + 2;
+
+			/* draw cursor */
+			glRecti(rect->xmin + t, ty, tx, rect->ymax - 2);
 		}
+
+#ifdef WITH_INPUT_IME
+		if (ime_data && ime_data->composite_len) {
+			/* ime cursor following */
+			if (but->pos >= but->ofs) {
+				ui_but_ime_reposition(but, tx + 5, ty + 3, false);
+			}
+
+			/* composite underline */
+			widget_draw_text_ime_underline(fstyle, wcol, but, rect, ime_data, drawstr);
+		}
+#endif
 	}
 	
 	if (fstyle->kerning == 1)
diff --git a/source/blender/makesdna/DNA_windowmanager_types.h b/source/blender/makesdna/DNA_windowmanager_types.h
index 73a70b48712..1a0562ae8c5 100644
--- a/source/blender/makesdna/DNA_windowmanager_types.h
+++ b/source/blender/makesdna/DNA_windowmanager_types.h
@@ -165,6 +165,13 @@ enum {
 	WM_INIT_KEYMAP = (1<<1),
 };
 
+/* IME is win32 only! */
+#ifndef WIN32
+#  ifdef __GNUC__
+#    define ime_data ime_data __attribute__ ((deprecated))
+#  endif
+#endif
+
 /* the savable part, rest of data is local in ghostwinlay */
 typedef struct wmWindow {
 	struct wmWindow *next, *prev;
@@ -197,6 +204,10 @@ typedef struct wmWindow {
 
 	struct wmGesture *tweak;      /* internal for wm_operators.c */
 
+	/* Input Method Editor data - complex character input (esp. for asian character input)
+	 * Currently WIN32, runtime-only data */
+	struct wmIMEData *ime_data;
+
 	int drawmethod, drawfail;     /* internal for wm_draw.c only */
 	void *drawdata;               /* internal for wm_draw.c only */
 
@@ -208,6 +219,10 @@ typedef struct wmWindow {
 	ListBase gesture;             /* gesture stuff */
 } wmWindow;
 
+#ifdef ime_data
+#  undef ime_data
+#endif
+
 /* These two Lines with # tell makesdna this struct can be excluded. */
 /* should be something like DNA_EXCLUDE 
  * but the preprocessor first removes all comments, spaces etc */
diff --git a/source/blender/windowmanager/CMakeLists.txt b/source/blender/windowmanager/CMakeLists.txt
index 4cbadda1732..78b5d499644 100644
--- a/source/blender/windowmanager/CMakeLists.txt
+++ b/source/blender/windowmanager/CMakeLists.txt
@@ -130,6 +130,12 @@ if(WITH_BUILDINFO)
 	add_definitions(-DWITH_BUILDINFO)
 endif()
 
+if(WIN32)
+	if(WITH_INPUT_IME)
+		add_definitions(-DWITH_INPUT_IME)
+	endif()
+endif()
+
 if(WITH_COMPOSITOR)
 	add_definitions(-DWITH_COMPOSITOR)
 endif()
diff --git a/source/blender/windowmanager/SConscript b/source/blender/windowmanager/SConscript
index 3c44ff6107c..a6f64f7cdae 100644
--- a/source/blender/windowmanager/SConscript
+++ b/source/blender/windowmanager/SConscript
@@ -69,6 +69,10 @@ if env['OURPLATFORM'] in ('win32-vc', 'win32-mingw', 'linuxcross', 'win64-vc', '
 if env['BF_BUILDINFO']:
     defs.append('WITH_BUILDINFO')
 
+if env['OURPLATFORM'] in ('win32-vc', 'win32-mingw', 'win64-vc', 'win64-mingw'):
+    if env['WITH_BF_IME']:
+        defs.append('WITH_INPUT_IME')
+
 if env['WITH_BF_INTERNATIONAL']:
     defs.append('WITH_INTERNATIONAL')
 
diff --git a/source/blender/windowmanager/WM_api.h b/source/blender/windowmanager/WM_api.h
index ced7222b046..d2abfd419d1 100644
--- a/source/blender/windowmanager/WM_api.h
+++ b/source/blender/windowmanager/WM_api.h
@@ -462,6 +462,10 @@ void        WM_event_ndof_to_quat(const struct wmNDOFMotionData *ndof, float q[4
 float       WM_event_tablet_data(const struct wmEvent *event, int *pen_flip, float tilt[2]);
 bool        WM_event_is_tablet(const struct wmEvent *event);
 
+#ifdef WITH_INPUT_IME
+bool        WM_event_is_ime_switch(const struct wmEvent *event);
+#endif
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/source/blender/windowmanager/WM_types.h b/source/blender/windowmanager/WM_types.h
index 4b6b5e95366..d9924cfb053 100644
--- a/source/blender/windowmanager/WM_types.h
+++ b/source/blender/windowmanager/WM_types.h
@@ -570,6 +570,24 @@ typedef struct wmOperatorType {
 
 } wmOperatorType;
 
+#ifdef WITH_INPUT_IME
+/* *********** Input Method Editor (IME) *********** */
+
+/* similar to GHOST_TEventImeData */
+typedef struct wmIMEData {
+	size_t result_len, composite_len;
+
+	char *str_result;           /* utf8 encoding */
+	char *str_composite;        /* utf8 encoding */
+
+	int cursor_pos;             /* cursor position in the IME composition. */
+	int sel_start;              /* beginning of the selection */
+	int sel_end;                /* end of the selection */
+
+	bool is_ime_composing;
+} wmIMEData;
+#endif
+
 /* **************** Paint Cursor ******************* */
 
 typedef void (*wmPaintCursorDraw)(struct bContext *C, int, int, void *customdata);
diff --git a/source/blender/windowmanager/intern/wm_event_system.c b/source/blender/windowmanager/intern/wm_event_system.c
index cca267a9fbb..3de34e7ca3f 100644
--- a/source/blender/windowmanager/intern/wm_event_system.c
+++ b/source/blender/windowmanager/intern/wm_event_system.c
@@ -3373,6 +3373,33 @@ void wm_event_add_ghostevent(wmWindowManager *wm, wmWindow *win, int type, int U
 			break;
 		}
 
+#ifdef WITH_INPUT_IME
+		case GHOST_kEventImeCompositionStart:
+		{
+			event.val = KM_PRESS;
+			win->ime_data = customdata;
+			win->ime_data->is_ime_composing = true;
+			event.type = WM_IME_COMPOSITE_START;
+			wm_event_add(win, &event);
+			break;
+		}
+		case GHOST_kEventImeComposition:
+		{
+			event.val = KM_PRESS;
+			event.type = WM_IME_COMPOSITE_EVENT;
+			wm_event_add(win, &event);
+			break;
+		}
+		case GHOST_kEventImeCompositionEnd:
+		{
+			event.val = KM_PRESS;
+			win->ime_data->is_ime_composing = false;
+			event.type = WM_IME_COMPOSITE_END;
+			wm_event_add(win, &event);
+			break;
+		}
+#endif /* WITH_INPUT_IME */
+
 	}
 
 #if 0
@@ -3479,5 +3506,12 @@ bool WM_event_is_tablet(const struct wmEvent *event)
 	return (event->tablet_data) ? true : false;
 }
 
+#ifdef WITH_INPUT_IME
+/* most os using ctrl/oskey + space to switch ime, avoid added space */
+bool WM_event_is_ime_switch(const struct wmEvent *event) {
+	return event->val == KM_PRESS && event->type == SPACEKEY &&
+	       (event->ctrl || event->oskey || event->shift || event->alt);
+}
+#endif
 
 /** \} */
diff --git a/source/blender/windowmanager/intern/wm_window.c b/source/blender/windowmanager/intern/wm_window.c
index 46a20d3bf88..0b33dbb2c32 100644
--- a/source/blender/windowmanager/intern/wm_window.c
+++ b/source/blender/windowmanager/intern/wm_window.c
@@ -1524,3 +1524,20 @@ bool WM_window_is_fullscreen(wmWindow *win)
 	return win->windowstate == GHOST_kWindowStateFullScreen;
 }
 
+
+#ifdef WITH_INPUT_IME
+void wm_window_IME_begin(wmWindow *win, int x, int y, int w, int h, bool complete)
+{
+	BLI_assert(win && (win->ime_data == NULL));
+
+	GHOST_BeginIME(win->ghostwin, x, win->sizey - y, w, h, complete);
+}
+
+void wm_window_IME_end(wmWindow *win)
+{
+	BLI_assert(win && win->ime_data);
+
+	GHOST_EndIME(win->ghostwin);
+	win->ime_data = NULL;
+}
+#endif  /* WITH_INPUT_IME */
diff --git a/source/blender/windowmanager/wm_event_types.h b/source/blender/windowmanager/wm_event_types.h
index fe6d3431183..2301405a8ea 100644
--- a/source/blender/windowmanager/wm_event_types.h
+++ b/source/blender/windowmanager/wm_event_types.h
@@ -86,6 +86,13 @@ enum {
 	 * paint and drawing tools however will want to handle these. */
 	INBETWEEN_MOUSEMOVE = 0x0011,
 
+/* IME event, GHOST_kEventImeCompositionStart in ghost */
+	WM_IME_COMPOSITE_START = 0x0014,
+/* IME event, GHOST_kEventImeComposition in ghost */
+	WM_IME_COMPOSITE_EVENT      = 0x0015,
+/* IME event, GHOST_kEventImeCompositionEnd in ghost */
+	WM_IME_COMPOSITE_END   = 0x0016,
+
 	/* *** Start of keyboard codes. *** */
 
 	/* standard keyboard.
diff --git a/source/blender/windowmanager/wm_window.h b/source/blender/windowmanager/wm_window.h
index 9c9c79d2f54..833234b0f13 100644
--- a/source/blender/windowmanager/wm_window.h
+++ b/source/blender/windowmanager/wm_window.h
@@ -69,6 +69,11 @@ wmWindow	*wm_window_copy			(bContext *C, wmWindow *winorig);
 
 void		wm_window_testbreak		(void);
 
+#ifdef WITH_INPUT_IME
+void		wm_window_IME_begin	(wmWindow *win, int x, int y, int w, int h, bool complete);
+void		wm_window_IME_end	(wmWindow *win);
+#endif
+
 /* *************** window operators ************** */
 int			wm_window_duplicate_exec(bContext *C, struct wmOperator *op);
 int			wm_window_fullscreen_toggle_exec(bContext *C, struct wmOperator *op);