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197 lines
6.9 KiB
EmacsLisp
197 lines
6.9 KiB
EmacsLisp
;;; electric.el --- window maker and Command loop for `electric' modes.
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;; Copyright (C) 1985, 1986 Free Software Foundation, Inc.
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;; Author: K. Shane Hartman
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;; Maintainer: FSF
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;; Keywords: extensions
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;; This file is part of GNU Emacs.
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;; GNU Emacs is free software; you can redistribute it and/or modify
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;; it under the terms of the GNU General Public License as published by
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;; the Free Software Foundation; either version 2, or (at your option)
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;; any later version.
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;; GNU Emacs is distributed in the hope that it will be useful,
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;; but WITHOUT ANY WARRANTY; without even the implied warranty of
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;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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;; GNU General Public License for more details.
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;; You should have received a copy of the GNU General Public License
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;; along with GNU Emacs; see the file COPYING. If not, write to
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;; the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
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;;; Commentary:
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; zaaaaaaap
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;;; Code:
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;; perhaps this should be in subr.el...
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(defun shrink-window-if-larger-than-buffer (&optional window)
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"Shrink the WINDOW to be as small as possible to display its contents. Do
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nothing if only one window is displayed or if the buffer contains more lines
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than the present window height."
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(save-excursion
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(set-buffer (window-buffer window))
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(let ((w (selected-window)) ;save-window-excursion can't win
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(buffer-file-name buffer-file-name)
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(p (point))
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(n 0)
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(window-min-height 0)
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(buffer-read-only nil)
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(modified (buffer-modified-p))
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(buffer (current-buffer)))
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(unwind-protect
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(progn
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(select-window window)
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(goto-char (point-min))
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(while (pos-visible-in-window-p (point-max))
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;; defeat file locking... don't try this at home, kids!
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(setq buffer-file-name nil)
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(insert ?\n) (setq n (1+ n)))
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(if (> n 0) (shrink-window (1- n))))
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(delete-region (point-min) (point))
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(set-buffer-modified-p modified)
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(goto-char p)
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(select-window w)
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;; Make sure we unbind buffer-read-only
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;; with the proper current buffer.
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(set-buffer buffer)))))
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;; This loop is the guts for non-standard modes which retain control
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;; until some event occurs. It is a `do-forever', the only way out is to
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;; throw. It assumes that you have set up the keymap, window, and
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;; everything else: all it does is read commands and execute them -
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;; providing error messages should one occur (if there is no loop
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;; function - which see). The required argument is a tag which should
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;; expect a value of nil if the user decides to punt. The
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;; second argument is a prompt string (defaults to "->"). Given third
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;; argument non-nil, it INHIBITS quitting unless the user types C-g at
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;; toplevel. This is so user can do things like C-u C-g and not get
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;; thrown out. Fourth argument, if non-nil, should be a function of two
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;; arguments which is called after every command is executed. The fifth
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;; argument, if provided, is the state variable for the function. If the
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;; loop-function gets an error, the loop will abort WITHOUT throwing
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;; (moral: use unwind-protect around call to this function for any
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;; critical stuff). The second argument for the loop function is the
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;; conditions for any error that occurred or nil if none.
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(defun Electric-command-loop (return-tag
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&optional prompt inhibit-quit
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loop-function loop-state)
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(if (not prompt) (setq prompt "->"))
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(let (cmd (err nil))
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(while t
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(setq cmd (read-key-sequence (if (stringp prompt)
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prompt (funcall prompt))))
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(setq last-command-char (aref cmd (1- (length cmd)))
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this-command (key-binding cmd)
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cmd this-command)
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(if (or (prog1 quit-flag (setq quit-flag nil))
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(= last-input-char ?\C-g))
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(progn (setq unread-command-events nil
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prefix-arg nil)
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;; If it wasn't cancelling a prefix character, then quit.
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(if (or (= (length (this-command-keys)) 1)
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(not inhibit-quit)) ; safety
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(progn (ding)
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(message "Quit")
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(throw return-tag nil))
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(setq cmd nil))))
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(setq current-prefix-arg prefix-arg)
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(if cmd
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(condition-case conditions
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(progn (command-execute cmd)
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(setq last-command this-command)
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(if (or (prog1 quit-flag (setq quit-flag nil))
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(= last-input-char ?\C-g))
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(progn (setq unread-command-events nil)
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(if (not inhibit-quit)
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(progn (ding)
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(message "Quit")
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(throw return-tag nil))
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(ding)))))
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(buffer-read-only (if loop-function
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(setq err conditions)
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(ding)
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(message "Buffer is read-only")
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(sit-for 2)))
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(beginning-of-buffer (if loop-function
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(setq err conditions)
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(ding)
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(message "Beginning of Buffer")
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(sit-for 2)))
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(end-of-buffer (if loop-function
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(setq err conditions)
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(ding)
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(message "End of Buffer")
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(sit-for 2)))
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(error (if loop-function
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(setq err conditions)
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(ding)
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(message "Error: %s"
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(if (eq (car conditions) 'error)
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(car (cdr conditions))
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(prin1-to-string conditions)))
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(sit-for 2))))
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(ding))
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(if loop-function (funcall loop-function loop-state err))))
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(ding)
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(throw return-tag nil))
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;; This function is like pop-to-buffer, sort of.
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;; The algorithm is
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;; If there is a window displaying buffer
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;; Select it
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;; Else if there is only one window
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;; Split it, selecting the window on the bottom with height being
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;; the lesser of max-height (if non-nil) and the number of lines in
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;; the buffer to be displayed subject to window-min-height constraint.
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;; Else
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;; Switch to buffer in the current window.
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;;
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;; Then if max-height is nil, and not all of the lines in the buffer
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;; are displayed, grab the whole frame.
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;;
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;; Returns selected window on buffer positioned at point-min.
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(defun Electric-pop-up-window (buffer &optional max-height)
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(let* ((win (or (get-buffer-window buffer) (selected-window)))
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(buf (get-buffer buffer))
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(one-window (one-window-p t))
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(pop-up-windows t)
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(target-height)
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(lines))
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(if (not buf)
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(error "Buffer %s does not exist" buffer)
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(save-excursion
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(set-buffer buf)
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(setq lines (count-lines (point-min) (point-max)))
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(setq target-height
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(min (max (if max-height (min max-height (1+ lines)) (1+ lines))
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window-min-height)
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(save-window-excursion
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(delete-other-windows)
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(1- (window-height (selected-window)))))))
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(cond ((and (eq (window-buffer win) buf))
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(select-window win))
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(one-window
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(goto-char (window-start win))
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(pop-to-buffer buffer)
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(setq win (selected-window))
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(enlarge-window (- target-height (window-height win))))
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(t
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(switch-to-buffer buf)))
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(if (and (not max-height)
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(> target-height (window-height (selected-window))))
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(progn (goto-char (window-start win))
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(enlarge-window (- target-height (window-height win)))))
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(goto-char (point-min))
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win)))
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(provide 'electric)
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;;; electric.el ends here
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