(put 'display-table 'char-table-extra-slots 6)
(defun make-display-table ()
"Return a new, empty display table."
(make-char-table 'display-table nil))
(or standard-display-table
(setq standard-display-table (make-display-table)))
(put 'truncation 'display-table-slot 0)
(put 'wrap 'display-table-slot 1)
(put 'escape 'display-table-slot 2)
(put 'control 'display-table-slot 3)
(put 'selective-display 'display-table-slot 4)
(put 'vertical-border 'display-table-slot 5)
(defun display-table-slot (display-table slot)
"Return the value of the extra slot in DISPLAY-TABLE named SLOT.
SLOT may be a number from 0 to 5 inclusive, or a slot name (symbol).
Valid symbols are `truncation', `wrap', `escape', `control',
`selective-display', and `vertical-border'."
(let ((slot-number
(if (numberp slot) slot
(or (get slot 'display-table-slot)
(error "Invalid display-table slot name: %s" slot)))))
(char-table-extra-slot display-table slot-number)))
(defun set-display-table-slot (display-table slot value)
"Set the value of the extra slot in DISPLAY-TABLE named SLOT to VALUE.
SLOT may be a number from 0 to 5 inclusive, or a name (symbol).
Valid symbols are `truncation', `wrap', `escape', `control',
`selective-display', and `vertical-border'."
(let ((slot-number
(if (numberp slot) slot
(or (get slot 'display-table-slot)
(error "Invalid display-table slot name: %s" slot)))))
(set-char-table-extra-slot display-table slot-number value)))
(defun describe-display-table (dt)
"Describe the display table DT in a help buffer."
(with-output-to-temp-buffer "*Help*"
(princ "\nTruncation glyph: ")
(prin1 (display-table-slot dt 'truncation))
(princ "\nWrap glyph: ")
(prin1 (display-table-slot dt 'wrap))
(princ "\nEscape glyph: ")
(prin1 (display-table-slot dt 'escape))
(princ "\nCtrl glyph: ")
(prin1 (display-table-slot dt 'control))
(princ "\nSelective display glyph sequence: ")
(prin1 (display-table-slot dt 'selective-display))
(princ "\nVertical window border glyph: ")
(prin1 (display-table-slot dt 'vertical-border))
(princ "\nCharacter display glyph sequences:\n")
(save-excursion
(set-buffer standard-output)
(let ((vector (make-vector 256 nil))
(i 0))
(while (< i 256)
(aset vector i (aref dt i))
(setq i (1+ i)))
(describe-vector vector))
(help-mode))
(print-help-return-message)))
(defun describe-current-display-table ()
"Describe the display table in use in the selected window and buffer."
(interactive)
(let ((disptab (or (window-display-table (selected-window))
buffer-display-table
standard-display-table)))
(if disptab
(describe-display-table disptab)
(message "No display table"))))
(defun standard-display-8bit (l h)
"Display characters in the range L to H literally."
(while (<= l h)
(if (and (>= l ?\ ) (< l 127))
(aset standard-display-table l nil)
(aset standard-display-table l (vector l)))
(setq l (1+ l))))
(defun standard-display-default (l h)
"Display characters in the range L to H using the default notation."
(while (<= l h)
(if (and (>= l ?\ ) (char-valid-p l))
(aset standard-display-table l nil))
(setq l (1+ l))))
(defun standard-display-ascii (c s)
"Display character C using printable string S."
(aset standard-display-table c (vconcat s)))
(defun standard-display-g1 (c sc)
"Display character C as character SC in the g1 character set.
This function assumes that your terminal uses the SO/SI characters;
it is meaningless for an X frame."
(if (memq window-system '(x w32))
(error "Cannot use string glyphs in a windowing system"))
(aset standard-display-table c
(vector (create-glyph (concat "\016" (char-to-string sc) "\017")))))
(defun standard-display-graphic (c gc)
"Display character C as character GC in graphics character set.
This function assumes VT100-compatible escapes; it is meaningless for an
X frame."
(if (memq window-system '(x w32))
(error "Cannot use string glyphs in a windowing system"))
(aset standard-display-table c
(vector (create-glyph (concat "\e(0" (char-to-string gc) "\e(B")))))
(defun standard-display-underline (c uc)
"Display character C as character UC plus underlining."
(aset standard-display-table c
(vector
(if window-system
(logior uc (lsh (face-id 'underline) 19))
(create-glyph (concat "\e[4m" (char-to-string uc) "\e[m"))))))
(defun create-glyph (string)
"Allocate a glyph code to display by sending STRING to the terminal."
(if (= (length glyph-table) 65536)
(error "No free glyph codes remain"))
(if (= (length glyph-table) 32)
(setq glyph-table (vconcat glyph-table (make-vector 224 nil))))
(setq glyph-table (vconcat glyph-table (list string)))
(1- (length glyph-table)))
(defun standard-display-european (arg)
"Semi-obsolete way to toggle display of ISO 8859 European characters.
This function is semi-obsolete; if you want to do your editing with
unibyte characters, it is better to `set-language-environment' coupled
with either the `--unibyte' option or the EMACS_UNIBYTE environment
variable, or else customize `enable-multibyte-characters'.
With prefix argument, this command enables European character display
if arg is positive, disables it otherwise. Otherwise, it toggles
European character display.
When this mode is enabled, characters in the range of 160 to 255
display not as octal escapes, but as accented characters. Codes 146
and 160 display as apostrophe and space, even though they are not the
ASCII codes for apostrophe and space.
Enabling European character display with this command noninteractively
from Lisp code also selects Latin-1 as the language environment, and
selects unibyte mode for all Emacs buffers \(both existing buffers and
those created subsequently). This provides increased compatibility
for users who call this function in `.emacs'."
(if (or (<= (prefix-numeric-value arg) 0)
(and (null arg)
(char-table-p standard-display-table)
(equal (aref standard-display-table 161) [161])))
(progn
(standard-display-default 160 255)
(unless (or (memq window-system '(x w32))
(interactive-p))
(and (terminal-coding-system)
(set-terminal-coding-system nil))))
(unless (interactive-p)
(setq-default enable-multibyte-characters nil)
(mapcar (lambda (buffer)
(with-current-buffer buffer
(if enable-multibyte-characters
(set-buffer-multibyte nil))))
(buffer-list)))
(unless (interactive-p)
(if (equal current-language-environment "English")
(set-language-environment "latin-1")))
(unless (or noninteractive (memq window-system '(x w32))
(interactive-p))
(set-terminal-coding-system
(let ((c (intern (downcase current-language-environment))))
(if (coding-system-p c) c 'latin-1))))
(standard-display-european-internal)))
(provide 'disp-table)