1 ;;; tv-util.el --- support for Tai Viet -*- coding: utf-8 -*-
3 ;; Copyright (C) 2007, 2008, 2009, 2010, 2011
4 ;; National Institute of Advanced Industrial Science and Technology (AIST)
5 ;; Registration Number H13PRO009
7 ;; Keywords: multilingual, Tai Viet, i18n
9 ;; This file is part of GNU Emacs.
11 ;; GNU Emacs is free software: you can redistribute it and/or modify
12 ;; it under the terms of the GNU General Public License as published by
13 ;; the Free Software Foundation, either version 3 of the License, or
14 ;; (at your option) any later version.
16 ;; GNU Emacs is distributed in the hope that it will be useful,
17 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
18 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
19 ;; GNU General Public License for more details.
21 ;; You should have received a copy of the GNU General Public License
22 ;; along with GNU Emacs. If not, see <http://www.gnu.org/licenses/>.
26 ;; Regexp matching with a sequence of Tai Viet characters.
28 (format "[\xaa80-\xaac2\xaadb-\xaadf-]+"))
30 ;; Char-table of information about glyph type of Tai Viet characters.
31 (defconst tai-viet-glyph-info
32 (let ((table (make-char-table nil
))
33 (specials '((right-overhang .
"ꪊꪋꪌꪍꪏꪓꪖꪜꪞꪡꪤꪨ")
35 (combining-vowel .
"ꪴꪰꪲꪳꪷꪸꪾ")
36 (combining-tone .
"꪿꫁")
38 ;; Set all TaiViet characters to `t'.
39 (set-char-table-range table
(cons #xaa80
#xaac2
) t
)
40 (set-char-table-range table
(cons #xaadb
#xaadf
) t
)
41 ;; Overwrite it for special characters.
42 (dolist (elt specials
)
43 (let ((category (car elt
))
45 (dotimes (i (length chars
))
46 (aset table
(aref chars i
) category
))))
49 (defun tai-viet-compose-string (from to string
)
50 "Compose Tai Viet characters in STRING between indices FROM and TO."
51 (let* ((ch (aref string from
))
52 (info (aref tai-viet-glyph-info ch
))
54 (if (eq info
'non-spacing
)
55 (compose-string string from
(1+ from
) (string ch ?
\t)))
56 (setq from
(1+ from
) prev-info info
)
57 (while (and (< from to
)
58 (>= #xaa80
(setq ch
(aref string from
)))
60 (setq info
(aref tai-viet-glyph-info ch
))
61 (if (and (eq info
'non-spacing
)
62 (eq prev-info
'non-spacing
))
63 (compose-string from
(1+ from
) (string ?
\t ch
)))
64 (setq from
(1+ from
) prev-info info
))
65 (if (eq info
'right-overhang
)
66 (compose-string string
(1- from
) from
(string ch ?
\t)))
69 (defun tai-viet-compose-region (from to
)
70 "Compose Tai Viet characters in the region between FROM and TO."
71 (decompose-region from to
)
72 (let ((normal-rule '(Br . Bl
))
73 (tone-rule '(tr . bl
))
75 ch info pos components overhang
)
78 (setq ch
(char-after from
)
79 info
(aref tai-viet-glyph-info ch
)))
84 (if (memq info
'(combining-vowel combining-tone
))
86 ;; Display this as a spacing glyph.
87 (compose-region (1- from
) from
(string ?
\t ch
))
92 overhang
(if (eq info
'right-overhang
)
94 (if (and (not prev-viet
) (eq info
'left-overhang
))
99 (setq ch
(char-after from
)
100 info
(aref tai-viet-glyph-info ch
)))
101 (if (memq info
'(combining-vowel combining-tone
))
104 (list components normal-rule ch
)
108 (setq ch
(char-after from
)
109 info
(aref tai-viet-glyph-info ch
))
110 (eq info
'combining-tone
))
111 (setq components
(nconc components
114 (if (eq overhang
'left-overhang
)
115 (setq components
(cons ?
\t
116 (cons normal-rule components
)))
117 (if (and (eq overhang
'right-overhang
)
119 (setq components
(nconc components
120 (list normal-rule ?
\t)))))
121 (compose-region pos from components
))
122 (if (eq overhang
'left-overhang
)
123 (compose-region pos from
(string ?
\t components
))))
124 (if (eq overhang
'left-overhang
)
125 (compose-region pos from
(string ?
\t components
))
126 (if (and (eq overhang
'right-overhang
) (>= from to
))
127 (compose-region pos from
(string components ?
\t))))))))
132 (defun tai-viet-composition-function (from to font-object string
)
134 (if (string-match tai-viet-re string from
)
135 (tai-viet-compose-string from
(match-end 0) string
))
137 (if (looking-at tai-viet-re
)
138 (tai-viet-compose-region from
(match-end 0)))))
141 (provide 'tai-viet-util
)
143 ;; arch-tag: a45ac3fc-07d0-44d5-8841-2ebea7e11f5b