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c0274f38 ER |
1 | ;;; electric.el --- window maker and Command loop for `electric' modes. |
2 | ||
f135afd3 | 3 | ;; Copyright (C) 1985, 1986, 1995 Free Software Foundation, Inc. |
9750e079 | 4 | |
e5167999 ER |
5 | ;; Author: K. Shane Hartman |
6 | ;; Maintainer: FSF | |
fd7fa35a | 7 | ;; Keywords: extensions |
e5167999 | 8 | |
0d20f9a0 JB |
9 | ;; This file is part of GNU Emacs. |
10 | ||
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 | |
e5167999 | 13 | ;; the Free Software Foundation; either version 2, or (at your option) |
0d20f9a0 JB |
14 | ;; any later version. |
15 | ||
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. | |
20 | ||
21 | ;; You should have received a copy of the GNU General Public License | |
b578f267 EN |
22 | ;; along with GNU Emacs; see the file COPYING. If not, write to the |
23 | ;; Free Software Foundation, Inc., 59 Temple Place - Suite 330, | |
24 | ;; Boston, MA 02111-1307, USA. | |
0d20f9a0 | 25 | |
c8472948 | 26 | ;;; Commentary: |
0d20f9a0 | 27 | |
49116ac0 | 28 | ; zaaaaaaap |
0d20f9a0 | 29 | |
c8472948 ER |
30 | ;;; Code: |
31 | ||
0d20f9a0 | 32 | ;; This loop is the guts for non-standard modes which retain control |
f135afd3 RS |
33 | ;; until some event occurs. It is a `do-forever', the only way out is |
34 | ;; to throw. It assumes that you have set up the keymap, window, and | |
0d20f9a0 JB |
35 | ;; everything else: all it does is read commands and execute them - |
36 | ;; providing error messages should one occur (if there is no loop | |
37 | ;; function - which see). The required argument is a tag which should | |
f135afd3 RS |
38 | ;; expect a value of nil if the user decides to punt. The second |
39 | ;; argument is the prompt to be used: if nil, use "->", if 'noprompt, | |
40 | ;; don't use a prompt, if a string, use that string as prompt, and if | |
41 | ;; a function of no variable, it will be evaluated in every iteration | |
42 | ;; of the loop and its return value, which can be nil, 'noprompt or a | |
43 | ;; string, will be used as prompt. Given third argument non-nil, it | |
44 | ;; INHIBITS quitting unless the user types C-g at toplevel. This is | |
45 | ;; so user can do things like C-u C-g and not get thrown out. Fourth | |
46 | ;; argument, if non-nil, should be a function of two arguments which | |
47 | ;; is called after every command is executed. The fifth argument, if | |
48 | ;; provided, is the state variable for the function. If the | |
0d20f9a0 JB |
49 | ;; loop-function gets an error, the loop will abort WITHOUT throwing |
50 | ;; (moral: use unwind-protect around call to this function for any | |
51 | ;; critical stuff). The second argument for the loop function is the | |
52 | ;; conditions for any error that occurred or nil if none. | |
53 | ||
54 | (defun Electric-command-loop (return-tag | |
55 | &optional prompt inhibit-quit | |
56 | loop-function loop-state) | |
f135afd3 RS |
57 | |
58 | (let (cmd | |
59 | (err nil) | |
60 | (prompt-string prompt)) | |
0d20f9a0 | 61 | (while t |
f135afd3 RS |
62 | (if (not (or (stringp prompt) (eq prompt nil) (eq prompt 'noprompt))) |
63 | (setq prompt-string (funcall prompt))) | |
64 | (if (not (stringp prompt-string)) | |
65 | (if (eq prompt-string 'noprompt) | |
66 | (setq prompt-string nil) | |
67 | (setq prompt-string "->"))) | |
68 | (setq cmd (read-key-sequence prompt-string)) | |
0d20f9a0 JB |
69 | (setq last-command-char (aref cmd (1- (length cmd))) |
70 | this-command (key-binding cmd) | |
71 | cmd this-command) | |
72 | (if (or (prog1 quit-flag (setq quit-flag nil)) | |
7dc8eff9 | 73 | (eq last-input-char ?\C-g)) |
dbc4e1c1 | 74 | (progn (setq unread-command-events nil |
0d20f9a0 JB |
75 | prefix-arg nil) |
76 | ;; If it wasn't cancelling a prefix character, then quit. | |
77 | (if (or (= (length (this-command-keys)) 1) | |
78 | (not inhibit-quit)) ; safety | |
79 | (progn (ding) | |
80 | (message "Quit") | |
81 | (throw return-tag nil)) | |
82 | (setq cmd nil)))) | |
83 | (setq current-prefix-arg prefix-arg) | |
84 | (if cmd | |
85 | (condition-case conditions | |
86 | (progn (command-execute cmd) | |
17c17ec9 | 87 | (setq last-command this-command) |
0d20f9a0 | 88 | (if (or (prog1 quit-flag (setq quit-flag nil)) |
7dc8eff9 | 89 | (eq last-input-char ?\C-g)) |
dbc4e1c1 | 90 | (progn (setq unread-command-events nil) |
0d20f9a0 JB |
91 | (if (not inhibit-quit) |
92 | (progn (ding) | |
93 | (message "Quit") | |
94 | (throw return-tag nil)) | |
95 | (ding))))) | |
96 | (buffer-read-only (if loop-function | |
97 | (setq err conditions) | |
98 | (ding) | |
99 | (message "Buffer is read-only") | |
100 | (sit-for 2))) | |
101 | (beginning-of-buffer (if loop-function | |
102 | (setq err conditions) | |
103 | (ding) | |
104 | (message "Beginning of Buffer") | |
105 | (sit-for 2))) | |
106 | (end-of-buffer (if loop-function | |
107 | (setq err conditions) | |
108 | (ding) | |
109 | (message "End of Buffer") | |
110 | (sit-for 2))) | |
111 | (error (if loop-function | |
112 | (setq err conditions) | |
113 | (ding) | |
114 | (message "Error: %s" | |
115 | (if (eq (car conditions) 'error) | |
116 | (car (cdr conditions)) | |
117 | (prin1-to-string conditions))) | |
118 | (sit-for 2)))) | |
119 | (ding)) | |
120 | (if loop-function (funcall loop-function loop-state err)))) | |
121 | (ding) | |
122 | (throw return-tag nil)) | |
123 | ||
124 | ;; This function is like pop-to-buffer, sort of. | |
125 | ;; The algorithm is | |
126 | ;; If there is a window displaying buffer | |
127 | ;; Select it | |
128 | ;; Else if there is only one window | |
129 | ;; Split it, selecting the window on the bottom with height being | |
130 | ;; the lesser of max-height (if non-nil) and the number of lines in | |
131 | ;; the buffer to be displayed subject to window-min-height constraint. | |
132 | ;; Else | |
133 | ;; Switch to buffer in the current window. | |
134 | ;; | |
135 | ;; Then if max-height is nil, and not all of the lines in the buffer | |
f98955ea | 136 | ;; are displayed, grab the whole frame. |
0d20f9a0 JB |
137 | ;; |
138 | ;; Returns selected window on buffer positioned at point-min. | |
139 | ||
140 | (defun Electric-pop-up-window (buffer &optional max-height) | |
141 | (let* ((win (or (get-buffer-window buffer) (selected-window))) | |
142 | (buf (get-buffer buffer)) | |
143 | (one-window (one-window-p t)) | |
144 | (pop-up-windows t) | |
145 | (target-height) | |
146 | (lines)) | |
147 | (if (not buf) | |
148 | (error "Buffer %s does not exist" buffer) | |
149 | (save-excursion | |
150 | (set-buffer buf) | |
151 | (setq lines (count-lines (point-min) (point-max))) | |
152 | (setq target-height | |
153 | (min (max (if max-height (min max-height (1+ lines)) (1+ lines)) | |
154 | window-min-height) | |
155 | (save-window-excursion | |
156 | (delete-other-windows) | |
157 | (1- (window-height (selected-window))))))) | |
158 | (cond ((and (eq (window-buffer win) buf)) | |
159 | (select-window win)) | |
160 | (one-window | |
161 | (goto-char (window-start win)) | |
162 | (pop-to-buffer buffer) | |
163 | (setq win (selected-window)) | |
164 | (enlarge-window (- target-height (window-height win)))) | |
165 | (t | |
166 | (switch-to-buffer buf))) | |
167 | (if (and (not max-height) | |
168 | (> target-height (window-height (selected-window)))) | |
169 | (progn (goto-char (window-start win)) | |
170 | (enlarge-window (- target-height (window-height win))))) | |
171 | (goto-char (point-min)) | |
172 | win))) | |
49116ac0 | 173 | |
c0274f38 ER |
174 | (provide 'electric) |
175 | ||
c8472948 | 176 | ;;; electric.el ends here |