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emacs/lisp/mouse-sel.el
1994-10-11 01:49:05 +00:00

455 lines
16 KiB
EmacsLisp

;;; mouse-sel.el --- Multi-click selection support for Emacs 19
;; Copyright (C) 1993, 1994 Free Software Foundation, Inc.
;; Author: Mike Williams <mikew@gopher.dosli.govt.nz>
;; Keywords: mouse
;; Version: 2.1
;; This file is part of GNU Emacs.
;; GNU Emacs is free software; you can redistribute it and/or modify
;; it under the terms of the GNU General Public License as published by
;; the Free Software Foundation; either version 2, or (at your option)
;; any later version.
;; GNU Emacs is distributed in the hope that it will be useful,
;; but WITHOUT ANY WARRANTY; without even the implied warranty of
;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
;; GNU General Public License for more details.
;;; Commentary:
;;
;; This module provides multi-click mouse support for GNU Emacs versions
;; 19.18 and later. I've tried to make it behave more like standard X
;; clients (eg. xterm) than the default Emacs 19 mouse selection handlers.
;; Basically:
;;
;; * Clicking mouse-1 starts (cancels) selection, dragging extends it.
;;
;; * Clicking or dragging mouse-3 extends the selection as well.
;;
;; * Double-clicking on word constituents selects words.
;; Double-clicking on symbol constituents selects symbols.
;; Double-clicking on quotes or parentheses selects sexps.
;; Double-clicking on whitespace selects whitespace.
;; Triple-clicking selects lines.
;;
;; * Selecting sets the region & X primary selection, but does NOT affect
;; the kill-ring. Because the mouse handlers set the primary selection
;; directly, mouse-sel sets the variables interprogram-cut-function
;; and interprogram-paste-function to nil.
;;
;; * Clicking mouse-2 pastes contents of primary selection at the mouse
;; position.
;;
;; * Pressing mouse-2 while selecting or extending copies selection
;; to the kill ring. Pressing mouse-1 or mouse-3 kills it.
;;
;; * Double-clicking mouse-3 also kills selection.
;;
;; This module requires my thingatpt.el module, which it uses to find the
;; bounds of words, lines, sexps, etc.
;;
;; Thanks to KevinB@bartley.demon.co.uk for his useful input.
;;
;;--- Customisation -------------------------------------------------------
;;
;; * You may want to use none or more of following:
;;
;; ;; Enable region highlight
;; (transient-mark-mode 1)
;;
;; ;; But only in the selected window
;; (setq highlight-nonselected-windows nil)
;;
;; ;; Enable pending-delete
;; (delete-selection-mode 1)
;;
;; * You can control the way mouse-sel binds its keys by setting the value
;; of mouse-sel-default-bindings before loading mouse-sel.
;;
;; (a) If mouse-sel-default-bindings = t (the default)
;;
;; Mouse sets and pastes selection
;; mouse-1 mouse-select
;; mouse-2 mouse-insert-selection
;; mouse-3 mouse-extend
;;
;; Selection/kill-ring interaction is disabled
;; interprogram-cut-function = nil
;; interprogram-paste-function = nil
;;
;; (b) If mouse-sel-default-bindings = 'interprogram-cut-paste
;;
;; Mouse sets selection, and pastes from kill-ring
;; mouse-1 mouse-select
;; mouse-2 mouse-yank-at-click
;; mouse-3 mouse-extend
;;
;; Selection/kill-ring interaction is retained
;; interprogram-cut-function = x-select-text
;; interprogram-paste-function = x-cut-buffer-or-selection-value
;;
;; What you lose is the ability to select some text in
;; delete-selection-mode and yank over the top of it.
;;
;; (c) If mouse-sel-default-bindings = nil, no bindings are made.
;;
;; * By default, mouse-insert-selection (mouse-2) inserts the selection at
;; the mouse position. You can tell it to insert at point instead with:
;;
;; (setq mouse-yank-at-point t)
;;
;; * I like to leave point at the end of the region nearest to where the
;; mouse was, even though this makes region highlighting mis-leading (the
;; cursor makes it look like one extra character is selected). You can
;; disable this behaviour with:
;;
;; (setq mouse-sel-leave-point-near-mouse nil)
;;
;; * Normally, the selection highlight will be removed when the mouse is
;; lifted. You can tell mouse-sel to retain the selection highlight
;; (useful if you don't use transient-mark-mode) with:
;;
;; (setq mouse-sel-retain-highlight t)
;;
;; * By default, mouse-select cycles the click count after 3 clicks. That
;; is, clicking mouse-1 four times has the same effect as clicking it
;; once, clicking five times has the same effect as clicking twice, etc.
;; Disable this behaviour with:
;;
;; (setq mouse-sel-cycle-clicks nil)
;;
;; * The variables mouse-sel-{set,get,check}-selection-function control how
;; the selection is handled. Under X Windows, these variables default so
;; that the X primary selection is used. Under other windowing systems,
;; alternate functions are used, which simply store the selection value
;; in a variable.
;;
;;--- Hints ---------------------------------------------------------------
;;
;; * You can change the selection highlight face by altering the properties
;; of mouse-drag-overlay, eg.
;;
;; (overlay-put mouse-drag-overlay 'face 'bold)
;;
;; * Pasting from the primary selection under emacs 19.19 is SLOW (there's
;; a two second delay). The following code will cause mouse-sel to use
;; the cut buffer rather than the primary selection. However, be aware
;; that cut buffers are OBSOLETE, and some X applications may not support
;; them.
;;
;; (setq mouse-sel-set-selection-function 'x-select-text
;; mouse-sel-get-selection-function 'x-get-cut-buffer)
;;
;;--- Warnings ------------------------------------------------------------
;;
;; * When selecting sexps, the selection extends by sexps at the same
;; nesting level. This also means the selection cannot be extended out
;; of the enclosing nesting level. This is INTENTIONAL.
;;; Code: =================================================================
(provide 'mouse-sel)
(require 'mouse)
(require 'thingatpt)
;;=== Version =============================================================
(defconst mouse-sel-version "2.1"
"The version number of mouse-sel (as string).")
;;=== User Variables ======================================================
(defvar mouse-sel-leave-point-near-mouse t
"*Leave point near last mouse position.
If non-nil, \\[mouse-select] and \\[mouse-extend] leave point at the end
of the region nearest to where the mouse last was.
If nil, point is always placed at the beginning of the region.")
(defvar mouse-sel-retain-highlight nil
"*Retain highlight after dragging is finished.
If non-nil, regions selected using \\[mouse-select] and \\[mouse-extend] will
remain highlighted.
If nil, highlighting turns off when you release the mouse button.")
(defvar mouse-sel-cycle-clicks t
"*If non-nil, \\[mouse-select] cycles the click-counts after 3 clicks.
Ie. 4 clicks = 1 click, 5 clicks = 2 clicks, etc.")
(defvar mouse-sel-default-bindings t
"Set to nil before loading `mouse-sel' to prevent default mouse bindings.")
;;=== Selection ===========================================================
(defvar mouse-sel-selection-type nil "Type of current selection")
(make-variable-buffer-local 'mouse-sel-selection-type)
(defvar mouse-sel-selection ""
"Store the selection value when using a window systems other than X.")
(defvar mouse-sel-set-selection-function
(if (fboundp 'x-set-selection)
(function (lambda (s) (x-set-selection 'PRIMARY s)))
(function (lambda (s) (setq mouse-sel-selection s))))
"Function to call to set selection.
Called with one argument, the text to select.")
(defvar mouse-sel-get-selection-function
(if (fboundp 'x-get-selection)
'x-get-selection
(function (lambda () mouse-sel-selection)))
"Function to call to get the selection.
Called with no argument.")
(defvar mouse-sel-check-selection-function
(if (fboundp 'x-selection-owner-p)
'x-selection-owner-p
nil)
"Function to check whether Emacs still owns the selection.
Called with no arguments.")
(defun mouse-sel-determine-selection-type (NCLICKS)
"Determine what \"thing\" `mouse-sel' should operate on.
The first argument, NCLICKS, is the number of consecutive
mouse clicks at the same position."
(let* ((next-char (char-after (point)))
(char-syntax (if next-char (char-syntax next-char)))
(nclicks (if mouse-sel-cycle-clicks (1+ (% (1- NCLICKS) 3)) NCLICKS)))
(cond
((= nclicks 1) nil)
((>= nclicks 3) 'line)
((memq char-syntax '(?\( ?\) ?\" ?')) 'sexp)
((memq next-char '(? ?\t ?\n)) 'whitespace)
((eq char-syntax ?_) 'symbol)
((eq char-syntax ?w) 'word))))
(defun mouse-select (EVENT)
"Set region/selection using the mouse.
Clicking sets point to click position, and deactivates the mark
if you are in Transient Mark mode.
Dragging extends region/selection.
Double-clicking on word constituents selects words.
Double-clicking on symbol constituents selects symbols.
Double-clicking on quotes or parentheses selects sexps.
Double-clicking on whitespace selects whitespace.
Triple-clicking selects lines.
Clicking mouse-2 while selecting copies the region to the kill-ring.
Clicking mouse-1 or mouse-3 kills the region.
This should be bound to a down-mouse event."
(interactive "e")
(mouse-set-point EVENT)
(setq mouse-sel-selection-type
(mouse-sel-determine-selection-type (event-click-count EVENT)))
(let ((object-bounds (bounds-of-thing-at-point mouse-sel-selection-type)))
(if object-bounds
(progn
(setq mark-active t)
(goto-char (car object-bounds))
(set-mark (cdr object-bounds)))
(deactivate-mark)))
(mouse-extend (if mouse-sel-selection-type EVENT)))
(defun mouse-extend (&optional EVENT)
"Extend region/selection using the mouse.
See documentation for mouse-select for more details.
This should be bound to a down-mouse event."
(interactive "e")
(if EVENT (select-window (posn-window (event-end EVENT))))
(let* ((use-region (and (or EVENT transient-mark-mode) mark-active))
(min (if use-region (region-beginning) (point)))
(max (if use-region (region-end) (point)))
(orig-window (selected-window))
(orig-window-frame (window-frame orig-window))
(top (nth 1 (window-edges orig-window)))
(bottom (nth 3 (window-edges orig-window)))
(orig-cursor-type
(cdr (assoc 'cursor-type (frame-parameters (selected-frame)))))
direction
event)
;; Inhibit normal region highlight
(setq mark-active nil)
;; Highlight region (forcing re-highlight)
(move-overlay mouse-drag-overlay min max (current-buffer))
(overlay-put mouse-drag-overlay 'face
(overlay-get mouse-drag-overlay 'face))
;; Bar cursor
(if (fboundp 'modify-frame-parameters)
(modify-frame-parameters (selected-frame) '((cursor-type . bar))))
;; Handle dragging
(unwind-protect
(progn
(track-mouse
(while (if EVENT ; Use initial event
(prog1
(setq event EVENT)
(setq EVENT nil))
(setq event (read-event))
(and (consp event)
(memq (car event) '(mouse-movement switch-frame))))
(let ((end (event-end event)))
(cond
;; Ignore any movement outside the frame
((eq (car-safe event) 'switch-frame) nil)
((and (posn-window end)
(not (eq (let ((posn-w (posn-window end)))
(if (windowp posn-w)
(window-frame posn-w)
posn-w))
(window-frame orig-window)))) nil)
;; Different window, same frame
((not (eq (posn-window end) orig-window))
(let ((end-row (cdr (cdr (mouse-position)))))
(cond
((and end-row (not (bobp)) (< end-row top))
(mouse-scroll-subr orig-window (- end-row top)
mouse-drag-overlay max))
((and end-row (not (eobp)) (>= end-row bottom))
(mouse-scroll-subr orig-window (1+ (- end-row bottom))
mouse-drag-overlay min))
)))
;; On the mode line
((eq (posn-point end) 'mode-line)
(mouse-scroll-subr orig-window 1 mouse-drag-overlay min))
;; In original window
(t (goto-char (posn-point end)))
)
;; Determine direction of drag
(cond
((and (not direction) (not (eq min max)))
(setq direction (if (< (point) (/ (+ min max) 2)) -1 1)))
((and (not (eq direction -1)) (<= (point) min))
(setq direction -1))
((and (not (eq direction 1)) (>= (point) max))
(setq direction 1)))
(if (not mouse-sel-selection-type) nil
;; If dragging forward, goal is next character
(if (and (eq direction 1) (not (eobp))) (forward-char 1))
;; Move to start/end of selected thing
(let ((goal (point))
last)
(goto-char (if (eq 1 direction) min max))
(condition-case nil
(progn
(while (> (* direction (- goal (point))) 0)
(setq last (point))
(forward-thing mouse-sel-selection-type
direction))
(let ((end (point)))
(forward-thing mouse-sel-selection-type
(- direction))
(goto-char
(if (> (* direction (- goal (point))) 0)
end last))))
(error))))
;; Move overlay
(move-overlay mouse-drag-overlay
(if (eq 1 direction) min (point))
(if (eq -1 direction) max (point))
(current-buffer))
))) ; end track-mouse
(let ((overlay-start (overlay-start mouse-drag-overlay))
(overlay-end (overlay-end mouse-drag-overlay)))
;; Set region
(if (eq overlay-start overlay-end)
(deactivate-mark)
(if (and mouse-sel-leave-point-near-mouse (eq direction 1))
(progn
(set-mark overlay-start)
(goto-char overlay-end))
(set-mark overlay-end)
(goto-char overlay-start)))
;; Set selection
(if (and mark-active mouse-sel-set-selection-function)
(funcall mouse-sel-set-selection-function
(buffer-substring overlay-start overlay-end)))
;; Handle copy/kill
(cond
((eq (car-safe last-input-event) 'down-mouse-2)
(copy-region-as-kill overlay-start overlay-end)
(read-event) (read-event))
((memq (car-safe last-input-event) '(down-mouse-1 down-mouse-3))
(kill-region overlay-start overlay-end)
(deactivate-mark)
(read-event) (read-event))
((eq (car-safe last-input-event) 'double-mouse-3)
(kill-region overlay-start overlay-end)
(deactivate-mark)))))
;; Restore cursor
(if (fboundp 'modify-frame-parameters)
(modify-frame-parameters
(selected-frame) (list (cons 'cursor-type orig-cursor-type))))
;; Remove overlay
(or mouse-sel-retain-highlight
(delete-overlay mouse-drag-overlay)))))
(defun mouse-insert-selection (click)
"Insert the contents of the selection at mouse click.
If `mouse-yank-at-point' is non-nil, insert at point instead."
(interactive "e")
(or mouse-yank-at-point
(mouse-set-point click))
(deactivate-mark)
(if mouse-sel-get-selection-function
(insert (or (funcall mouse-sel-get-selection-function) ""))))
(defun mouse-sel-validate-selection ()
"Remove selection highlight if emacs no longer owns the primary selection."
(or (not mouse-sel-check-selection-function)
(funcall mouse-sel-check-selection-function)
(delete-overlay mouse-drag-overlay)))
(add-hook 'pre-command-hook 'mouse-sel-validate-selection)
;;=== Key bindings ========================================================
(if (not mouse-sel-default-bindings) nil
(global-unset-key [mouse-1])
(global-unset-key [drag-mouse-1])
(global-unset-key [mouse-3])
(global-set-key [down-mouse-1] 'mouse-select)
(global-set-key [down-mouse-3] 'mouse-extend)
(if (eq mouse-sel-default-bindings 'interprogram-cut-paste) nil
(global-set-key [mouse-2] 'mouse-insert-selection)
(setq interprogram-cut-function nil
interprogram-paste-function nil))
)
;; mouse-sel.el ends here.