Allow arbitrary keys for scrolling, add a third

scrolling speed, fix an unwind-protect.
(mouse-wheel-scroll-amount): Now a three-element list.
(mouse-wheel-scroll-down-slow, mouse-wheel-scroll-up-slow)
(mouse-wheel-scroll-down-normal, mouse-wheel-scroll-up-normal)
(mouse-wheel-scroll-down-fast, mouse-wheel-scroll-up-fast): New functions.

2 files changed, 180 insertions, 93 deletions

diff --git a/lisp/ChangeLog b/lisp/ChangeLog
index 2d46ec19e84..e8b7dfabde1 100644
--- a/lisp/ChangeLog
+++ b/lisp/ChangeLog
@@ -15,6 +15,16 @@
         Discard `help-echo' events.  Handle (menu-bar) events.
         Simplify by converting key sequence to a list and then back to vector.
         
+2002-06-21  Stephen Gildea  <gildea@stop.mail-abuse.org>
+
+        * mwheel.el: Allow arbitrary keys for scrolling, add a third
+        scrolling speed, fix an unwind-protect.
+        (mouse-wheel-scroll-amount): Now a three-element list.
+        (mouse-wheel-scroll-down-slow, mouse-wheel-scroll-up-slow)
+        (mouse-wheel-scroll-down-normal, mouse-wheel-scroll-up-normal)
+        (mouse-wheel-scroll-down-fast, mouse-wheel-scroll-up-fast):
+        New functions.
+
 2002-06-21  Andreas Schwab  <schwab@suse.de>
 
         * files.el (find-file-read-args): Add new argument `mustmatch' and
diff --git a/lisp/mwheel.el b/lisp/mwheel.el
index 3fa83c27773..37862d434ac 100644
--- a/lisp/mwheel.el
+++ b/lisp/mwheel.el
@@ -1,6 +1,6 @@
 ;;; mwheel.el --- Mouse support for MS intelli-mouse type mice
 
-;; Copyright (C) 1998, 2000, 2001 Free Software Foundation, Inc.
+;; Copyright (C) 1998, 2000, 2001, Free Software Foundation, Inc.
 ;; Maintainer: William M. Perry <wmperry@gnu.org>
 ;; Keywords: mouse
 
@@ -63,37 +63,27 @@
   :type 'integer
   :set 'mouse-wheel-change-button)
 
-(defcustom mouse-wheel-scroll-amount '(5 ((shift) . 1) ((control) . nil))
+(defcustom mouse-wheel-scroll-amount '(1 5 nil)
   "Amount to scroll windows by when spinning the mouse wheel.
-This is actually a cons cell, where the first item is the amount to scroll
-on a normal wheel event, and the rest is an alist mapping the modifier key
-to the amount to scroll when the wheel is moved with the modifier key depressed.
+This is actually a list, where the first element is the amount to
+scroll slowly (normally invoked with the Shift key depressed) the
+second is the amount to scroll on a normal wheel event, and the third
+is the amount to scroll fast (normally with the Control key depressed).
 
 Each item should be the number of lines to scroll, or `nil' for near
-full screen.  It can also be a floating point number, specifying
-the fraction of the window to scroll.
+full screen.
 A near full screen is `next-screen-context-lines' less than a full screen."
   :group 'mouse
-  :type '(cons
-          (choice :tag "Normal"
+  :type '(list
+          (choice :tag "Slow (Shift key)"
                   (const :tag "Full screen" :value nil)
-                  (integer :tag "Specific # of lines")
-                  (float :tag "Fraction of window"))
-          (repeat
-           (cons
-            (repeat (choice :tag "modifier" (const alt) (const control) (const hyper)
-                            (const meta) (const shift) (const super)))
-            (choice :tag "scroll amount"
-                    (const :tag "Full screen" :value nil)
-                    (integer :tag "Specific # of lines")
-                    (float :tag "Fraction of window"))))))
-
-(defcustom mouse-wheel-progessive-speed t
-  "If non-nil, the faster the user moves the wheel, the faster the scrolling.
-Note that this has no effect when `mouse-wheel-scroll-amount' specifies
-a \"near full screen\" scroll."
-  :group 'mouse
-  :type 'boolean)
+                  (integer :tag "Specific # of lines"))
+          (choice :tag "Normal (no keys)"
+                  (const :tag "Full screen" :value nil)
+                  (integer :tag "Specific # of lines"))
+          (choice :tag "Fast (Ctrl key)"
+                  (const :tag "Full screen" :value nil)
+                  (integer :tag "Specific # of lines"))))
 
 (defcustom mouse-wheel-follow-mouse nil
   "Whether the mouse wheel should scroll the window that the mouse is over.
@@ -101,52 +91,145 @@ This can be slightly disconcerting, but some people may prefer it."
   :group 'mouse
   :type 'boolean)
 
-(if (not (fboundp 'event-button))
-    (defun mwheel-event-button (event)
-      (let ((x (symbol-name (event-basic-type event))))
-        ;; Map mouse-wheel events to appropriate buttons
-        (if (string-equal "mouse-wheel" x)
-            (let ((amount (car (cdr (cdr (cdr event))))))
-              (if (< amount 0)
-                  mouse-wheel-up-button
-                mouse-wheel-down-button))
-          (if (not (string-match "^mouse-\\([0-9]+\\)" x))
-              (error "Not a button event: %S" event)
-            (string-to-int (substring x (match-beginning 1) (match-end 1)))))))
-  (fset  'mwheel-event-button 'event-button))
-
-(if (not (fboundp 'event-window))
-    (defun mwheel-event-window (event)
-      (posn-window (event-start event)))
-  (fset 'mwheel-event-window 'event-window))
-
-(defun mwheel-scroll (event)
-  "Scroll up or down according to the EVENT.
-This should only be bound to mouse buttons 4 and 5."
-  (interactive "e")
-  (let* ((curwin (if mouse-wheel-follow-mouse
-                     (prog1
-                         (selected-window)
-                       (select-window (mwheel-event-window event)))))
-         (mods
-          (delq 'click (delq 'double (delq 'triple (event-modifiers event)))))
-         (amt
-          (if mods
-              (cdr (assoc mods (cdr mouse-wheel-scroll-amount)))
-            (car mouse-wheel-scroll-amount))))
-    (if (floatp amt) (setq amt (1+ (truncate (* amt (window-height))))))
-    (when (and mouse-wheel-progessive-speed (numberp amt))
-      ;; When the double-mouse-N comes in, a mouse-N has been executed already,
-      ;; So by adding things up we get a squaring up (1, 3, 6, 10, 16, ...).
-      (setq amt (* amt (event-click-count event))))
+(defun mouse-wheel-event-window ()
+  "Return the window associated with this mouse command."
+  ;; If the command was a mouse event, the window is stored in the event.
+  (if (listp last-command-event)
+      (if (fboundp 'event-window)
+          (event-window last-command-event)
+        (posn-window (event-start last-command-event)))
+    ;; If not a mouse event, use the window the mouse is over now.
+    (let* ((coordinates (mouse-position))
+           (x (car (cdr coordinates)))
+           (y (cdr (cdr coordinates))))
+      (and (numberp x)
+           (numberp y)
+           (window-at x y (car coordinates))))))
+
+;; Interpret mouse-wheel-scroll-amount
+;; If the scroll-amount is a cons cell instead of a list,
+;; then the car is the normal speed, the cdr is the slow
+;; speed, and the fast speed is nil.  This is for pre-21.1
+;; backward compatibility.
+(defun mouse-wheel-amount (speed)
+  (cond ((not (consp mouse-wheel-scroll-amount))
+         ;; illegal value
+         mouse-wheel-scroll-amount)
+        ((not (consp (cdr mouse-wheel-scroll-amount)))
+         ;; old-style value: a cons
+         (cond ((eq speed 'normal)
+                (car mouse-wheel-scroll-amount))
+               ((eq speed 'slow)
+                (cdr mouse-wheel-scroll-amount))
+               (t
+                nil)))
+        (t
+         (cond ((eq speed 'slow)
+                (nth 0 mouse-wheel-scroll-amount))
+               ((eq speed 'normal)
+                (nth 1 mouse-wheel-scroll-amount))
+               (t                       ;fast
+                (nth 2 mouse-wheel-scroll-amount))))))
+
+(defun mouse-wheel-scroll-internal (direction speed)
+  "Scroll DIRECTION (up or down) SPEED (slow, normal, or fast).
+`mouse-wheel-scroll-amount' defines the speeds."
+  (let* ((scrollwin (if mouse-wheel-follow-mouse
+                        (mouse-wheel-event-window)))
+         (curwin (if scrollwin
+                     (selected-window)))
+         (amt (mouse-wheel-amount speed)))
     (unwind-protect
-        (let ((button (mwheel-event-button event)))
-          (cond ((= button mouse-wheel-down-button) (scroll-down amt))
-                ((= button mouse-wheel-up-button) (scroll-up amt))
-                (t (error "Bad binding in mwheel-scroll"))))
+        (progn
+          (if scrollwin (select-window scrollwin))
+          (if (eq direction 'down)
+              (scroll-down amt)
+            (scroll-up amt)))
       (if curwin (select-window curwin)))))
 
 
+(defun mouse-wheel-scroll-up-fast ()
+  "Scroll text of current window upward a full screen.
+`mouse-wheel-follow-mouse' controls how the current window is determined.
+`mouse-wheel-scroll-amount' controls the amount of scroll."
+  (interactive)
+  (mouse-wheel-scroll-internal 'up 'fast))
+
+(defun mouse-wheel-scroll-down-fast ()
+  "Scroll text of current window down a full screen.
+`mouse-wheel-follow-mouse' controls how the current window is determined.
+`mouse-wheel-scroll-amount' controls the amount of scroll."
+  (interactive)
+  (mouse-wheel-scroll-internal 'down 'fast))
+
+(defun mouse-wheel-scroll-up-normal ()
+  "Scroll text of current window upward a few lines.
+`mouse-wheel-follow-mouse' controls how the current window is determined.
+`mouse-wheel-scroll-amount' controls the amount of scroll."
+  (interactive)
+  (mouse-wheel-scroll-internal 'up 'normal))
+
+(defun mouse-wheel-scroll-down-normal ()
+  "Scroll text of current window down a few lines.
+`mouse-wheel-follow-mouse' controls how the current window is determined.
+`mouse-wheel-scroll-amount' controls the amount of scroll."
+  (interactive)
+  (mouse-wheel-scroll-internal 'down 'normal))
+
+(defun mouse-wheel-scroll-up-slow ()
+  "Scroll text of current window upward a line.
+`mouse-wheel-follow-mouse' controls how the current window is determined.
+`mouse-wheel-scroll-amount' controls the amount of scroll."
+  (interactive)
+  (mouse-wheel-scroll-internal 'up 'slow))
+
+(defun mouse-wheel-scroll-down-slow ()
+  "Scroll text of current window down a line.
+`mouse-wheel-follow-mouse' controls how the current window is determined.
+`mouse-wheel-scroll-amount' controls the amount of scroll."
+  (interactive)
+  (mouse-wheel-scroll-internal 'down 'slow))
+
+
+;;; helper functions for minor mode mouse-wheel-mode.
+
+(defun mouse-wheel-button-definer (button-pair down-function up-function)
+  (mouse-wheel-key-definer button-pair 'dn down-function)
+  (mouse-wheel-key-definer button-pair 'up up-function))
+
+(defun mouse-wheel-key-definer (button-pair up-or-dn function)
+  (let ((key (if (featurep 'xemacs)
+                 (mouse-wheel-xemacs-key-formatter (car button-pair) up-or-dn)
+               (mouse-wheel-intern-vector (cdr button-pair) up-or-dn))))
+    (cond (mouse-wheel-mode
+           (define-key global-map key function))
+          ((eq (lookup-key global-map key) 'function)
+           (define-key global-map key nil)))))
+
+(defun mouse-wheel-xemacs-key-formatter (key-format-list up-or-dn)
+  (cond ((listp key-format-list)                ;e.g., (shift "button%d")
+         (list (car key-format-list)
+               (mouse-wheel-xemacs-intern  (car (cdr key-format-list)) up-or-dn)))
+        (t
+         (mouse-wheel-xemacs-intern key-format-list up-or-dn))))
+
+(defun mouse-wheel-xemacs-intern (key-format-string up-or-dn)
+  (intern (format key-format-string
+                  (if (eq up-or-dn 'up)
+                      mouse-wheel-up-button
+                    mouse-wheel-down-button))))
+
+(defun mouse-wheel-intern-vector (key-format-string up-or-dn)
+  "Turns \"mouse-%d\" into [mouse-4]."
+  (vector (intern (format key-format-string
+                          (if (eq up-or-dn 'up)
+                              mouse-wheel-up-button
+                            mouse-wheel-down-button)))))
+
+;;; Note this definition must be at the end of the file, because
+;;; `define-minor-mode' actually calls the mode-function if the
+;;; associated variable is non-nil, which requires that all needed
+;;; functions be already defined.
 ;;;###autoload
 (define-minor-mode mouse-wheel-mode
   "Toggle mouse wheel support.
@@ -154,31 +237,24 @@ With prefix argument ARG, turn on if positive, otherwise off.
 Returns non-nil if the new state is enabled."
   :global t
   :group 'mouse
-  ;; In the latest versions of XEmacs, we could just use
-  ;; (S-)*mouse-[45], since those are aliases for the button
-  ;; equivalents in XEmacs, but I want this to work in as many
-  ;; versions of XEmacs as it can.
-  (let* ((prefix (if (featurep 'xemacs) "button%d" "mouse-%d"))
-         (dn (intern (format prefix mouse-wheel-down-button)))
-         (up (intern (format prefix mouse-wheel-up-button)))
-         (keys
-          (nconc (list (vector dn) (vector up))
-                 (mapcar (lambda (amt) `[(,@(car amt) ,up)])
-                         (cdr mouse-wheel-scroll-amount))
-                 (mapcar (lambda (amt) `[(,@(car amt) ,dn)])
-                         (cdr mouse-wheel-scroll-amount)))))
-    ;; This condition-case is here because Emacs 19 will throw an error
-    ;; if you try to define a key that it does not know about.  I for one
-    ;; prefer to just unconditionally do a mwheel-install in my .emacs, so
-    ;; that if the wheeled-mouse is there, it just works, and this way it
-    ;; doesn't yell at me if I'm on my laptop or another machine, etc.
-    (condition-case ()
-        (dolist (key keys)
-          (cond (mouse-wheel-mode
-                 (global-set-key key 'mwheel-scroll))
-                ((eq (lookup-key (current-global-map) key) 'mwheel-scroll)
-                 (global-unset-key key))))
-      (error nil))))
+  ;; This condition-case is here because Emacs 19 will throw an error
+  ;; if you try to define a key that it does not know about.  I for one
+  ;; prefer to just unconditionally do a mwheel-install in my .emacs, so
+  ;; that if the wheeled-mouse is there, it just works, and this way it
+  ;; doesn't yell at me if I'm on my laptop or another machine, etc.
+  (condition-case ()
+      (progn
+        ;; In the latest versions of XEmacs, we could just use
+        ;; (S-)*mouse-[45], since those are aliases for the button
+        ;; equivalents in XEmacs, but I want this to work in as many
+        ;; versions of XEmacs as it can.
+        (mouse-wheel-button-definer '("button%d" .  "mouse-%d")
+         'mouse-wheel-scroll-down-normal 'mouse-wheel-scroll-up-normal)
+        (mouse-wheel-button-definer '((shift "button%d") . "S-mouse-%d")
+         'mouse-wheel-scroll-down-slow 'mouse-wheel-scroll-up-slow)
+        (mouse-wheel-button-definer '((control  "button%d") . "C-mouse-%d")
+         'mouse-wheel-scroll-down-fast 'mouse-wheel-scroll-up-fast))
+    (error nil)))
 
 ;;; Compatibility entry point
 ;;;###autoload
@@ -186,6 +262,7 @@ Returns non-nil if the new state is enabled."
   "Enable mouse wheel support."
   (mouse-wheel-mode t))
 
+
 (provide 'mwheel)
 
 ;;; mwheel.el ends here