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!

8 files changed, 95 insertions, 0 deletions

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);