-;; Normal terminal mouse click reporting: expect three bytes, of the
-;; form <BUTTON+32> <X+32> <Y+32>. Return a list (EVENT-TYPE X Y).
-(defun xterm-mouse--read-event-sequence-1000 ()
- (let* ((code (- (read-event) 32))
- (type
- ;; For buttons > 3, the release-event looks differently
- ;; (see xc/programs/xterm/button.c, function EditorButton),
- ;; and come in a release-event only, no down-event.
- (cond ((>= code 64)
- (format "mouse-%d" (- code 60)))
- ((memq code '(8 9 10))
- (format "M-down-mouse-%d" (- code 7)))
- ((memq code '(3 11))
- (let ((down (car (terminal-parameter
- nil 'xterm-mouse-last-down))))
- (when (and down (string-match "[0-9]" (symbol-name down)))
- (format (if (eq code 3) "mouse-%s" "M-mouse-%s")
- (match-string 0 (symbol-name down))))))
- ((memq code '(0 1 2))
- (format "down-mouse-%d" (+ 1 code)))))
- (x (- (read-event) 33))
- (y (- (read-event) 33)))
- (and type (wholenump x) (wholenump y)
- (list (intern type) x y))))
-
-;; XTerm's 1006-mode terminal mouse click reporting has the form
-;; <BUTTON> ; <X> ; <Y> <M or m>, where the button and ordinates are
-;; in encoded (decimal) form. Return a list (EVENT-TYPE X Y).
-(defun xterm-mouse--read-event-sequence-1006 ()
- (let (button-bytes x-bytes y-bytes c)
- (while (not (eq (setq c (read-event)) ?\;))
- (push c button-bytes))
- (while (not (eq (setq c (read-event)) ?\;))
- (push c x-bytes))
- (while (not (memq (setq c (read-event)) '(?m ?M)))
- (push c y-bytes))
- (list (let* ((code (string-to-number
- (apply 'string (nreverse button-bytes))))
- (wheel (>= code 64))
- (down (and (not wheel)
- (eq c ?M))))
- (intern (format "%s%smouse-%d"
- (cond (wheel "")
- ((< code 4) "")
- ((< code 8) "S-")
- ((< code 12) "M-")
- ((< code 16) "M-S-")
- ((< code 20) "C-")
- ((< code 24) "C-S-")
- ((< code 28) "C-M-")
- ((< code 32) "C-M-S-")
- (t
- (error "Unexpected escape sequence from XTerm")))
- (if down "down-" "")
- (if wheel
- (- code 60)
- (1+ (mod code 4))))))
- (1- (string-to-number (apply 'string (nreverse x-bytes))))
- (1- (string-to-number (apply 'string (nreverse y-bytes)))))))
+(defcustom xterm-mouse-utf-8 nil
+ "Non-nil if UTF-8 coordinates should be used to read mouse coordinates.
+Set this to non-nil if you are sure that your terminal
+understands UTF-8 coordinates, but not SGR coordinates."
+ :version "25.1"
+ :type 'boolean
+ :risky t
+ :group 'xterm)
+
+(defun xterm-mouse--read-coordinate ()
+ "Read a mouse coordinate from the current terminal.
+If `xterm-mouse-utf-8' was non-nil when
+`turn-on-xterm-mouse-tracking-on-terminal' was called, reads the
+coordinate as an UTF-8 code unit sequence; otherwise, reads a
+single byte."
+ (let ((previous-keyboard-coding-system (keyboard-coding-system)))
+ (unwind-protect
+ (progn
+ (set-keyboard-coding-system
+ (if (terminal-parameter nil 'xterm-mouse-utf-8)
+ 'utf-8-unix
+ 'no-conversion))
+ ;; Wait only a little; we assume that the entire escape sequence
+ ;; has already been sent when this function is called.
+ (read-char nil nil 0.1))
+ (set-keyboard-coding-system previous-keyboard-coding-system))))
+
+;; In default mode, each numeric parameter of XTerm's mouse report is
+;; a single char, possibly encoded as utf-8. The actual numeric
+;; parameter then is obtained by subtracting 32 from the character
+;; code. In extended mode the parameters are returned as decimal
+;; string delimited either by semicolons or for the last parameter by
+;; one of the characters "m" or "M". If the last character is a "m",
+;; then the mouse event was a button release, else it was a button
+;; press or a mouse motion. Return value is a cons cell with
+;; (NEXT-NUMERIC-PARAMETER . LAST-CHAR)
+(defun xterm-mouse--read-number-from-terminal (extension)
+ (let (c)
+ (if extension
+ (let ((n 0))
+ (while (progn
+ (setq c (read-char))
+ (<= ?0 c ?9))
+ (setq n (+ (* 10 n) c (- ?0))))
+ (cons n c))
+ (cons (- (setq c (xterm-mouse--read-coordinate)) 32) c))))
+
+;; XTerm reports mouse events as
+;; <EVENT-CODE> <X> <Y> in default mode, and
+;; <EVENT-CODE> ";" <X> ";" <Y> <"M" or "m"> in extended mode.
+;; The macro read-number-from-terminal takes care of reading
+;; the response parameters appropriately. The EVENT-CODE differs
+;; slightly between default and extended mode.
+;; Return a list (EVENT-TYPE-SYMBOL X Y).
+(defun xterm-mouse--read-event-sequence (&optional extension)
+ (pcase-let*
+ ((`(,code . ,_) (xterm-mouse--read-number-from-terminal extension))
+ (`(,x . ,_) (xterm-mouse--read-number-from-terminal extension))
+ (`(,y . ,c) (xterm-mouse--read-number-from-terminal extension))
+ (wheel (/= (logand code 64) 0))
+ (move (/= (logand code 32) 0))
+ (ctrl (/= (logand code 16) 0))
+ (meta (/= (logand code 8) 0))
+ (shift (/= (logand code 4) 0))
+ (down (and (not wheel)
+ (not move)
+ (if extension
+ (eq c ?M)
+ (/= (logand code 3) 3))))
+ (btn (cond
+ ((or extension down wheel)
+ (+ (logand code 3) (if wheel 4 1)))
+ ;; The default mouse protocol does not report the button
+ ;; number in release events: extract the button number
+ ;; from last button-down event.
+ ((terminal-parameter nil 'xterm-mouse-last-down)
+ (string-to-number
+ (substring
+ (symbol-name
+ (car (terminal-parameter nil 'xterm-mouse-last-down)))
+ -1)))
+ ;; Spurious release event without previous button-down
+ ;; event: assume, that the last button was button 1.
+ (t 1)))
+ (sym (if move 'mouse-movement
+ (intern (concat (if ctrl "C-" "")
+ (if meta "M-" "")
+ (if shift "S-" "")
+ (if down "down-" "")
+ "mouse-"
+ (number-to-string btn))))))
+ (list sym (1- x) (1- y))))