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!

11 files changed, 224 insertions, 0 deletions

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__