修复在 Sublime Text 3 上无法使用中文输入法的问题

Sublime Text 作为自己喜爱的跨平台的跨平台编辑器，一直以来都很受欢迎，尤其是进入 2015 年以后，推翻了在版本 2 上「万年不变」的更新方式，3dev 版本的更新及其频繁。

事实上，在 Ubuntu 以及其他 Linux 发行版下，Sublime text 3 默认是不支持搜狗输入法（基于 fctix）中文输入的，所以对中文开发者来说多多少少会有些不便。好在有位来自中国的开发者 cjacker 编写了一个库文件，通过在启动 Sublime text 时预加载该库的方法，实现搜狗输入法的中文输入。

This is a dirty fix but at least works. cursor position update also
supported.
Use LD_PRELOAD to reimplement gtk_im_context_set_client_window and set
im focus in. use “gdk_region_get_clipbox” to catch the caret position.
(It’s really difficult to find which function can catch the
position….)
Here I made a assumption that the caret width is always 2, since it is 2.
the height is the “font glyph height”.

步入正题：

Environment:

OS:Ubuntu 15.04 (64-bit)
Sublime Text 3 (Build 3083)
Gcc version 4.9.2 (Ubuntu 4.9.2-10ubuntu13)

前期准备:

由于需要编译一个共享库,需要依赖到 build-essential 和 libgtk2.0-dev
所以需提前安装妥当：

1	sudo apt-get install build-essential libgtk2.0-dev

解决方法：

Step 1.保存如下代码为 sublime-imfix.c 文件

 /*sublime-imfix.c
Use LD_PRELOAD to interpose some function to fix sublime input method support for linux.
By Cjacker Huang <jianzhong.huang at i-soft.com.cn>

gcc -shared -o libsublime-imfix.so sublime_imfix.c  `pkg-config --libs --cflags gtk+-2.0` -fPIC
LD_PRELOAD=./libsublime-imfix.so sublime_text
*/
#include <gtk/gtk.h>
#include <gdk/gdkx.h>
typedef GdkSegment GdkRegionBox;

struct _GdkRegion
{
  long size;
  long numRects;
  GdkRegionBox *rects;
  GdkRegionBox extents;
};

GtkIMContext *local_context;

void
gdk_region_get_clipbox (const GdkRegion *region,
            GdkRectangle    *rectangle)
{
  g_return_if_fail (region != NULL);
  g_return_if_fail (rectangle != NULL);

  rectangle->x = region->extents.x1;
  rectangle->y = region->extents.y1;
  rectangle->width = region->extents.x2 - region->extents.x1;
  rectangle->height = region->extents.y2 - region->extents.y1;
  GdkRectangle rect;
  rect.x = rectangle->x;
  rect.y = rectangle->y;
  rect.width = 0;
  rect.height = rectangle->height;
  //The caret width is 2;
  //Maybe sometimes we will make a mistake, but for most of the time, it should be the caret.
  if(rectangle->width == 2 && GTK_IS_IM_CONTEXT(local_context)) {
        gtk_im_context_set_cursor_location(local_context, rectangle);
  }
}

//this is needed, for example, if you input something in file dialog and return back the edit area
//context will lost, so here we set it again.

static GdkFilterReturn event_filter (GdkXEvent *xevent, GdkEvent *event, gpointer im_context)
{
    XEvent *xev = (XEvent *)xevent;
    if(xev->type == KeyRelease && GTK_IS_IM_CONTEXT(im_context)) {
       GdkWindow * win = g_object_get_data(G_OBJECT(im_context),"window");
       if(GDK_IS_WINDOW(win))
         gtk_im_context_set_client_window(im_context, win);
    }
    return GDK_FILTER_CONTINUE;
}

void gtk_im_context_set_client_window (GtkIMContext *context,
          GdkWindow    *window)
{
  GtkIMContextClass *klass;
  g_return_if_fail (GTK_IS_IM_CONTEXT (context));
  klass = GTK_IM_CONTEXT_GET_CLASS (context);
  if (klass->set_client_window)
    klass->set_client_window (context, window);

  if(!GDK_IS_WINDOW (window))
    return;
  g_object_set_data(G_OBJECT(context),"window",window);
  int width = gdk_window_get_width(window);
  int height = gdk_window_get_height(window);
  if(width != 0 && height !=0) {
    gtk_im_context_focus_in(context);
    local_context = context;
  }
  gdk_window_add_filter (window, event_filter, context);
}

Step 2.编译共享库文件：

1	gcc -shared -o libsublime-imfix.so sublime-imfix.c `pkg-config --libs --cflags gtk+-2.0` -fPIC

Step 3.找到该文件并在启动 Sublime text 时将其预加载：

1	LD_PRELOAD=./libsublime-imfix.so subl

（注：Sublime Text 3 使用的启动命令默认为 subl）

预加载的几种方法:

对于不习惯命令行启动应用的人来说，每次启动 Sublime Text 时都要手动的在 Terminal 里将 libsublime-imfix 库进行预加载，未免有些麻烦。

可以通过 2 种方法将其解决：

通过修改图标连接的方式：vi /usr/share/applications/sublime_text.desktop 实现启动时的预加载
编辑 vi /usr/bin/subl 文件实现启时的预加载

第一种方法：

首先将 libsublime-imfix.so 拷贝至系统库中：

1	cp libsublime-imfix.so /usr/lib/

之后打开 .desktop 文件:

1	vi /usr/share/applications/sublime_text.desktop

sublime_text.desktop 文件内容如下:

[Desktop Entry]
Version=1.0
Type=Application
Name=Sublime Text
GenericName=Text Editor
Comment=Sophisticated text editor for code, markup and prose
Exec=/opt/sublime_text/sublime_text %F
Terminal=false
MimeType=text/plain;
Icon=sublime-text
Categories=TextEditor;Development;
StartupNotify=true
Actions=Window;Document;

[Desktop Action Window]
Name=New Window
Exec=/opt/sublime_text/sublime_text -n
OnlyShowIn=Unity;

[Desktop Action Document]
Name=New File
Exec=/opt/sublime_text/sublime_text --command new_file
OnlyShowIn=Unity;

对应的两处 Exec 分别将其修改为:

Old:

1	Exec=/opt/sublime_text/sublime_text %F

New:

1	Exec=bash -c 'LD_PRELOAD=/usr/lib/libsublime-imfix.so /opt/sublime_text/sublime_text' %F

Old:

1	Exec=/opt/sublime_text/sublime_text -n

New:

1	Exec=bash -c 'LD_PRELOAD=/usr/lib/libsublime-imfix.so /opt/sublime_text/sublime_text' -n

第二种方法：

首先把 libsublime-imfix.so 拷贝到相关目录,然后这里拷贝至 /usr/lib/ 目录下。之后编辑 vi /usr/bin/subl 文件。

文件中内容为:

1 2	#!/bin/sh exec /opt/sublime_text/sublime_text "$@"

在 exec 一栏进行相关修改，替换实际的使用文件，这里以 leozhang 的为例：

1 2	#!/bin/sh LD_PRELOAD=/home/leozhang/.config/sublime-text-3/libsublime-imfix.so exec /opt/sublime_text/sublime_text "$@"

保存并退出，之后在终端启动 subl 即可输入中文。

Sublime Text