| 1 | ;;; electric.el --- window maker and Command loop for `electric' modes |
| 2 | |
| 3 | ;; Copyright (C) 1985, 1986, 1995, 2001, 2002, 2003, 2004, |
| 4 | ;; 2005, 2006, 2007 Free Software Foundation, Inc. |
| 5 | |
| 6 | ;; Author: K. Shane Hartman |
| 7 | ;; Maintainer: FSF |
| 8 | ;; Keywords: extensions |
| 9 | |
| 10 | ;; This file is part of GNU Emacs. |
| 11 | |
| 12 | ;; GNU Emacs is free software; you can redistribute it and/or modify |
| 13 | ;; it under the terms of the GNU General Public License as published by |
| 14 | ;; the Free Software Foundation; either version 2, or (at your option) |
| 15 | ;; any later version. |
| 16 | |
| 17 | ;; GNU Emacs is distributed in the hope that it will be useful, |
| 18 | ;; but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 19 | ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 20 | ;; GNU General Public License for more details. |
| 21 | |
| 22 | ;; You should have received a copy of the GNU General Public License |
| 23 | ;; along with GNU Emacs; see the file COPYING. If not, write to the |
| 24 | ;; Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, |
| 25 | ;; Boston, MA 02110-1301, USA. |
| 26 | |
| 27 | ;;; Commentary: |
| 28 | |
| 29 | ; zaaaaaaap |
| 30 | |
| 31 | ;;; Code: |
| 32 | |
| 33 | ;; This loop is the guts for non-standard modes which retain control |
| 34 | ;; until some event occurs. It is a `do-forever', the only way out is |
| 35 | ;; to throw. It assumes that you have set up the keymap, window, and |
| 36 | ;; everything else: all it does is read commands and execute them - |
| 37 | ;; providing error messages should one occur (if there is no loop |
| 38 | ;; function - which see). The required argument is a tag which should |
| 39 | ;; expect a value of nil if the user decides to punt. The second |
| 40 | ;; argument is the prompt to be used: if nil, use "->", if 'noprompt, |
| 41 | ;; don't use a prompt, if a string, use that string as prompt, and if |
| 42 | ;; a function of no variable, it will be evaluated in every iteration |
| 43 | ;; of the loop and its return value, which can be nil, 'noprompt or a |
| 44 | ;; string, will be used as prompt. Given third argument non-nil, it |
| 45 | ;; INHIBITS quitting unless the user types C-g at toplevel. This is |
| 46 | ;; so user can do things like C-u C-g and not get thrown out. Fourth |
| 47 | ;; argument, if non-nil, should be a function of two arguments which |
| 48 | ;; is called after every command is executed. The fifth argument, if |
| 49 | ;; provided, is the state variable for the function. If the |
| 50 | ;; loop-function gets an error, the loop will abort WITHOUT throwing |
| 51 | ;; (moral: use unwind-protect around call to this function for any |
| 52 | ;; critical stuff). The second argument for the loop function is the |
| 53 | ;; conditions for any error that occurred or nil if none. |
| 54 | |
| 55 | (defun Electric-command-loop (return-tag |
| 56 | &optional prompt inhibit-quit |
| 57 | loop-function loop-state) |
| 58 | |
| 59 | (let (cmd |
| 60 | (err nil) |
| 61 | (prompt-string prompt)) |
| 62 | (while t |
| 63 | (if (not (or (stringp prompt) (eq prompt nil) (eq prompt 'noprompt))) |
| 64 | (setq prompt-string (funcall prompt))) |
| 65 | (if (not (stringp prompt-string)) |
| 66 | (if (eq prompt-string 'noprompt) |
| 67 | (setq prompt-string nil) |
| 68 | (setq prompt-string "->"))) |
| 69 | (setq cmd (read-key-sequence prompt-string)) |
| 70 | (setq last-command-char (aref cmd (1- (length cmd))) |
| 71 | this-command (key-binding cmd t) |
| 72 | cmd this-command) |
| 73 | ;; This makes universal-argument-other-key work. |
| 74 | (setq universal-argument-num-events 0) |
| 75 | (if (or (prog1 quit-flag (setq quit-flag nil)) |
| 76 | (eq last-input-char ?\C-g)) |
| 77 | (progn (setq unread-command-events nil |
| 78 | prefix-arg nil) |
| 79 | ;; If it wasn't cancelling a prefix character, then quit. |
| 80 | (if (or (= (length (this-command-keys)) 1) |
| 81 | (not inhibit-quit)) ; safety |
| 82 | (progn (ding) |
| 83 | (message "Quit") |
| 84 | (throw return-tag nil)) |
| 85 | (setq cmd nil)))) |
| 86 | (setq current-prefix-arg prefix-arg) |
| 87 | (if cmd |
| 88 | (condition-case conditions |
| 89 | (progn (command-execute cmd) |
| 90 | (setq last-command this-command) |
| 91 | (if (or (prog1 quit-flag (setq quit-flag nil)) |
| 92 | (eq last-input-char ?\C-g)) |
| 93 | (progn (setq unread-command-events nil) |
| 94 | (if (not inhibit-quit) |
| 95 | (progn (ding) |
| 96 | (message "Quit") |
| 97 | (throw return-tag nil)) |
| 98 | (ding))))) |
| 99 | (buffer-read-only (if loop-function |
| 100 | (setq err conditions) |
| 101 | (ding) |
| 102 | (message "Buffer is read-only") |
| 103 | (sit-for 2))) |
| 104 | (beginning-of-buffer (if loop-function |
| 105 | (setq err conditions) |
| 106 | (ding) |
| 107 | (message "Beginning of Buffer") |
| 108 | (sit-for 2))) |
| 109 | (end-of-buffer (if loop-function |
| 110 | (setq err conditions) |
| 111 | (ding) |
| 112 | (message "End of Buffer") |
| 113 | (sit-for 2))) |
| 114 | (error (if loop-function |
| 115 | (setq err conditions) |
| 116 | (ding) |
| 117 | (message "Error: %s" |
| 118 | (if (eq (car conditions) 'error) |
| 119 | (car (cdr conditions)) |
| 120 | (prin1-to-string conditions))) |
| 121 | (sit-for 2)))) |
| 122 | (ding)) |
| 123 | (if loop-function (funcall loop-function loop-state err)))) |
| 124 | (ding) |
| 125 | (throw return-tag nil)) |
| 126 | |
| 127 | ;; This function is like pop-to-buffer, sort of. |
| 128 | ;; The algorithm is |
| 129 | ;; If there is a window displaying buffer |
| 130 | ;; Select it |
| 131 | ;; Else if there is only one window |
| 132 | ;; Split it, selecting the window on the bottom with height being |
| 133 | ;; the lesser of max-height (if non-nil) and the number of lines in |
| 134 | ;; the buffer to be displayed subject to window-min-height constraint. |
| 135 | ;; Else |
| 136 | ;; Switch to buffer in the current window. |
| 137 | ;; |
| 138 | ;; Then if max-height is nil, and not all of the lines in the buffer |
| 139 | ;; are displayed, grab the whole frame. |
| 140 | ;; |
| 141 | ;; Returns selected window on buffer positioned at point-min. |
| 142 | |
| 143 | (defun Electric-pop-up-window (buffer &optional max-height) |
| 144 | (let* ((win (or (get-buffer-window buffer) (selected-window))) |
| 145 | (buf (get-buffer buffer)) |
| 146 | (one-window (one-window-p t)) |
| 147 | (pop-up-windows t) |
| 148 | (pop-up-frames nil)) |
| 149 | (if (not buf) |
| 150 | (error "Buffer %s does not exist" buffer) |
| 151 | (cond ((and (eq (window-buffer win) buf)) |
| 152 | (select-window win)) |
| 153 | (one-window |
| 154 | (pop-to-buffer buffer) |
| 155 | (setq win (selected-window))) |
| 156 | (t |
| 157 | (switch-to-buffer buf))) |
| 158 | (fit-window-to-buffer win max-height) |
| 159 | (goto-char (point-min)) |
| 160 | win))) |
| 161 | |
| 162 | (provide 'electric) |
| 163 | |
| 164 | ;;; arch-tag: dae045eb-dc2d-4fb7-9f27-9cc2ce277be8 |
| 165 | ;;; electric.el ends here |