Chapter 13. Examples of I18N

108

13.4 A Quasi Wrapper to Internationalize Text Output of X Clients

The author of this section is Tomohiro KUBOTA (

).

13.4.1 Introduction

X11 supplies

XFontSet

 related internationalized functions for text output. However, many X

clients use conventional

XFontStruct

 related non internationalized functions and cannot out 

put languages which need multiple fonts (Chinese, Japanese, and Korean).

Now I introduce a wrapper which easily modify non internationalized X clients to use interna 

tionalized X11 functions.

13.4.2 Strategy

Almost

XFontStruct

 related functions can be replaced easily by

XFontSet

 related functions.

  XFontStruct  > XFontSet

  XLoadQueryFont()  > XCreateFontSet()

  XFreeFont()  > XFreeFontSet()

  XDrawString()  > XmbDrawString()

  XDrawImageString()  > XmbImageString()

  XTextExtents()  > XmbTextExtents()

  XTextWidth()  > XmbTextEscapement()

However, there were several problems.

1. The font for

XDrawString

is specified by

GC

parameter, while

XFontSet

parameter is used

for

XmbDrawString

.

2.

XFontSet

does not have structure members of

ascent

and

descent

, while

XFontStruct

has them and these members are often referred.

3. Many software specify font name with iso8859 1 specific way. This avoids 'fontset' related

functions work fully and disables non iso8859 1 languages be displayed.