From 90bc642fa8e44272ab76d10c893d397d88012934 Mon Sep 17 00:00:00 2001
From: Alex Baines <alex@abaines.me.uk>
Date: Tue, 19 Aug 2014 23:31:50 +0100
Subject: [PATCH] Add a SDL_IM_INTERNAL_EDITING event to make IMs like iBus
 render editing text in its own UI instead of sending TEXTEDITING events. This
 is useful for applications that handle TEXTINPUT events but not TEXTEDITING
 events.

---
 include/SDL_hints.h       | 12 +++++++++
 src/core/linux/SDL_ibus.c | 57 +++++++++++++++++++++++++++------------
 2 files changed, 52 insertions(+), 17 deletions(-)

diff --git a/include/SDL_hints.h b/include/SDL_hints.h
index e0fce669fdb91..b1feef660c04e 100644
--- a/include/SDL_hints.h
+++ b/include/SDL_hints.h
@@ -477,6 +477,18 @@ extern "C" {
  */
 #define SDL_HINT_ANDROID_APK_EXPANSION_PATCH_FILE_VERSION "SDL_ANDROID_APK_EXPANSION_PATCH_FILE_VERSION"
 
+/**
+ * \brief A variable to control whether certain IMs should handle text editing internally instead of sending TEXTEDITING events.
+ *
+ *
+ * The variable can be set to the following values:
+ *   "0"       - TEXTEDITING events are sent, and it is the application's
+ *               responsibility to render the text from these events and 
+ *               differentiate it somehow from committed text. (default)
+ *   "1"       - If supported by the IM then TEXTEDITING events are not sent, 
+ *               and text that is being composed will be rendered in its own UI.
+ */
+#define SDL_HINT_IM_INTERNAL_EDITING "SDL_IM_INTERNAL_EDITING"
 
 /**
  *  \brief  An enumeration of hint priorities
diff --git a/src/core/linux/SDL_ibus.c b/src/core/linux/SDL_ibus.c
index bad75242fc0c7..203a123683879 100644
--- a/src/core/linux/SDL_ibus.c
+++ b/src/core/linux/SDL_ibus.c
@@ -288,6 +288,41 @@ IBus_GetDBusAddressFilename(void)
     return SDL_strdup(file_path);
 }
 
+static SDL_bool IBus_CheckConnection(SDL_DBusContext *dbus);
+
+static void
+IBus_SetCapabilities(void *data, const char *name, const char *old_val,
+                                                   const char *internal_editing)
+{
+    SDL_DBusContext *dbus = SDL_DBus_GetContext();
+    
+    if(IBus_CheckConnection(dbus)){
+
+        DBusMessage *msg = dbus->message_new_method_call(IBUS_SERVICE,
+                                                         input_ctx_path,
+                                                         IBUS_INPUT_INTERFACE,
+                                                         "SetCapabilities");
+        if(msg){
+            Uint32 caps = IBUS_CAP_FOCUS;
+            if(!(internal_editing && *internal_editing == '1')){
+                caps |= IBUS_CAP_PREEDIT_TEXT;
+            }
+            
+            dbus->message_append_args(msg,
+                                      DBUS_TYPE_UINT32, &caps,
+                                      DBUS_TYPE_INVALID);
+        }
+        
+        if(msg){
+            if(dbus->connection_send(ibus_conn, msg, NULL)){
+                dbus->connection_flush(ibus_conn);
+            }
+            dbus->message_unref(msg);
+        }
+    }
+}
+
+
 static SDL_bool
 IBus_SetupConnection(SDL_DBusContext *dbus, const char* addr)
 {
@@ -340,23 +375,7 @@ IBus_SetupConnection(SDL_DBusContext *dbus, const char* addr)
     }
 
     if(result){
-        msg = dbus->message_new_method_call(IBUS_SERVICE,
-                                            input_ctx_path,
-                                            IBUS_INPUT_INTERFACE,
-                                            "SetCapabilities");
-        if(msg){
-            Uint32 caps = IBUS_CAP_FOCUS | IBUS_CAP_PREEDIT_TEXT;
-            dbus->message_append_args(msg,
-                                      DBUS_TYPE_UINT32, &caps,
-                                      DBUS_TYPE_INVALID);
-        }
-        
-        if(msg){
-            if(dbus->connection_send(ibus_conn, msg, NULL)){
-                dbus->connection_flush(ibus_conn);
-            }
-            dbus->message_unref(msg);
-        }
+        SDL_AddHintCallback(SDL_HINT_IM_INTERNAL_EDITING, &IBus_SetCapabilities, NULL);
         
         dbus->bus_add_match(ibus_conn, "type='signal',interface='org.freedesktop.IBus.InputContext'", NULL);
         dbus->connection_add_filter(ibus_conn, &IBus_MessageFilter, dbus, NULL);
@@ -476,6 +495,8 @@ SDL_IBus_Quit(void)
         inotify_wd = -1;
     }
     
+    SDL_DelHintCallback(SDL_HINT_IM_INTERNAL_EDITING, &IBus_SetCapabilities, NULL);
+    
     SDL_memset(&ibus_cursor_rect, 0, sizeof(ibus_cursor_rect));
 }
 
@@ -548,6 +569,8 @@ SDL_IBus_ProcessKeyEvent(Uint32 keysym, Uint32 keycode)
         
     }
     
+    SDL_IBus_UpdateTextRect(NULL);
+
     return result;
 }