Function: mouse-set-region
mouse-set-region is an interactive and byte-compiled function defined
in mouse.el.gz.
Signature
(mouse-set-region CLICK)
Documentation
Set the region to the text dragged over, and copy to kill ring.
This should be bound to a mouse drag event.
See the mouse-drag-copy-region variable to control whether this
command alters the kill ring or not.
Key Bindings
Source Code
;; Defined in /usr/src/emacs/lisp/mouse.el.gz
(defun mouse-set-region (click)
"Set the region to the text dragged over, and copy to kill ring.
This should be bound to a mouse drag event.
See the `mouse-drag-copy-region' variable to control whether this
command alters the kill ring or not."
(interactive "e")
(mouse-minibuffer-check click)
(select-window (posn-window (event-start click)))
(let ((beg (or mouse-shift-adjust-point (posn-point (event-start click))))
(end
(if (eq (posn-window (event-end click)) (selected-window))
(posn-point (event-end click))
;; If the mouse ends up in any other window or on the menu
;; bar, use `window-point' of selected window (Bug#23707).
(window-point)))
(click-count (event-click-count click)))
(let ((drag-start (terminal-parameter nil 'mouse-drag-start)))
(when (and drag-start (not mouse-shift-adjust-point))
;; Drag events don't come with a click count, sadly, so we hack
;; our way around this problem by remembering the start-event in
;; `mouse-drag-start' and fetching the click-count from there.
(when (and (<= click-count 1)
(equal beg (posn-point (event-start drag-start))))
(setq click-count (event-click-count drag-start)))
;; Occasionally we get spurious drag events where the user hasn't
;; dragged his mouse, but instead Emacs has dragged the text under the
;; user's mouse. Try to recover those cases (bug#17562).
(when (and (equal (posn-x-y (event-start click))
(posn-x-y (event-end click)))
(not (eq (car drag-start) 'mouse-movement)))
(setq end beg))
(setf (terminal-parameter nil 'mouse-drag-start) nil)))
(when mouse-shift-adjust-point
(setq click-count (1+ mouse-selection-click-count)))
(setq mouse-shift-adjust-point nil)
(when (and (integerp beg) (integerp end))
(let ((range (mouse-start-end beg end (1- click-count))))
(if (< end beg)
(setq end (nth 0 range) beg (nth 1 range))
(setq beg (nth 0 range) end (nth 1 range)))))
(when (and mouse-drag-copy-region
(integerp beg)
(integerp end)
(or (not (eq mouse-drag-copy-region 'non-empty))
(/= beg end)))
;; Don't set this-command to `kill-region', so a following
;; C-w won't double the text in the kill ring. Ignore
;; `last-command' so we don't append to a preceding kill.
(let ((last-command last-command)
this-command deactivate-mark)
(copy-region-as-kill beg end)))
(if (numberp beg) (goto-char beg))
;; On a text terminal, bounce the cursor.
(or transient-mark-mode
(window-system)
(sit-for 1))
(push-mark)
(set-mark (point))
(if (numberp end) (goto-char end))
(mouse-set-region-1)))