129 lines
5.2 KiB
EmacsLisp
129 lines
5.2 KiB
EmacsLisp
;; Mode-specific mouse-highlighting of text.
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;; Copyright (C) 1992, 1993 Free Software Foundation, Inc.
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;; This file is part of XEmacs.
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;; XEmacs is free software; you can redistribute it and/or modify it
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;; 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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;; XEmacs is distributed in the hope that it will be useful, but
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;; WITHOUT ANY WARRANTY; without even the implied warranty of
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;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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;; 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 XEmacs; see the file COPYING. If not, write to the
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;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
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;; Boston, MA 02111-1307, USA.
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;;; Synched up with: Not in FSF.
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(defvar mode-motion-hook nil
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"Function or functions which are called whenever the mouse moves.
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You should normally use this rather than `mouse-motion-handler', which
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does some additional window-system-dependent things. This hook is local
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to every buffer, and should normally be set up by major-modes which want
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to use special highlighting. Every time the mouse moves over a window,
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the mode-motion-hook of the buffer of that window is run.")
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(make-variable-buffer-local 'mode-motion-hook)
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(defvar mode-motion-extent nil)
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(make-variable-buffer-local 'mode-motion-extent)
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(defvar mode-motion-help-echo-string nil
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"String to be added as the 'help-echo property of the mode-motion extent.
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In order for this to work, you need to add the hook function
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`mode-motion-add-help-echo' to the mode-motion hook. If this is a function,
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it will be called with one argument (the event) and should return a string
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to be added. This variable is local to every buffer.")
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(make-variable-buffer-local 'mode-motion-help-echo-string)
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(defun mode-motion-ensure-extent-ok (event)
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(let ((buffer (event-buffer event)))
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(if (and (extent-live-p mode-motion-extent)
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(eq buffer (extent-object mode-motion-extent)))
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nil
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(setq mode-motion-extent (make-extent nil nil buffer))
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(set-extent-property mode-motion-extent 'mouse-face 'highlight))))
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(defun mode-motion-highlight-internal (event backward forward)
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(let* ((buffer (event-buffer event))
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(point (and buffer (event-point event))))
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(if (and buffer
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(not (eq buffer mouse-grabbed-buffer)))
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;; #### ack!! Too many calls to save-window-excursion /
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;; save-excursion (x-track-pointer calls, so does
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;; minibuf-mouse-tracker ...) This needs to be looked
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;; into. It's complicated by the fact that sometimes
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;; a mode-motion-hook might really want to change
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;; the point.
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;;
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;; #### The save-excursion must come before the
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;; save-window-excursion in order to function properly. I
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;; haven't given this much thought. Is it a bug that this
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;; ordering is necessary or is it correct behavior?
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(save-excursion
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(save-window-excursion
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(set-buffer buffer)
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(mode-motion-ensure-extent-ok event)
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(if point
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(progn
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(goto-char point)
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(condition-case nil (funcall backward) (error nil))
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(setq point (point))
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(condition-case nil (funcall forward) (error nil))
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(if (eq point (point))
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(detach-extent mode-motion-extent)
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(set-extent-endpoints mode-motion-extent point (point))))
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;; not over text; zero the extent.
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(detach-extent mode-motion-extent)))))))
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(defun mode-motion-highlight-line (event)
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"For use as the value of `mode-motion-hook' -- highlight line under mouse."
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(mode-motion-highlight-internal event 'beginning-of-line 'end-of-line))
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(defun mode-motion-highlight-word (event)
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"For use as the value of `mode-motion-hook' -- highlight word under mouse."
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(mode-motion-highlight-internal
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event
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#'(lambda () (default-mouse-track-beginning-of-word nil))
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#'(lambda () (default-mouse-track-end-of-word nil))))
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(defun mode-motion-highlight-symbol (event)
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"For use as the value of `mode-motion-hook' -- highlight symbol under mouse."
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(mode-motion-highlight-internal
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event
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#'(lambda () (default-mouse-track-beginning-of-word t))
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#'(lambda () (default-mouse-track-end-of-word t))))
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(defun mode-motion-highlight-sexp (event)
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"For use as the value of `mode-motion-hook' -- highlight form under mouse."
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(mode-motion-highlight-internal
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event
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#'(lambda ()
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(if (= (char-syntax (following-char)) ?\()
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nil
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(goto-char (scan-sexps (point) -1))))
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#'(lambda ()
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(if (= (char-syntax (following-char)) ?\))
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(forward-char 1))
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(goto-char (scan-sexps (point) 1)))))
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(defun mode-motion-add-help-echo (event)
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"For use as the value of `mode-motion-hook' -- add a 'help-echo property.
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This causes the string in the 'help-echo property to be displayed when the
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mouse moves over the extent. See `mode-motion-help-echo-string' for
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documentation on how to control the string that is added."
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(mode-motion-ensure-extent-ok event)
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(let ((string (cond ((null mode-motion-help-echo-string) nil)
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((stringp mode-motion-help-echo-string)
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mode-motion-help-echo-string)
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(t (funcall mode-motion-help-echo-string event)))))
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(if (stringp string)
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(set-extent-property mode-motion-extent 'help-echo string))))
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(provide 'mode-motion)
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