Re: address@hidden: mouse-autoselect-window needs a de lay]

[martin rudalics]

Hi Simon.

> Hi Martin, I occasionally get this (taken from *Messages*):
>
> mouse-autoselect-window-start: Wrong type argument: numberp, nil
>
> I just caught it with debug-on-error, though I'm not sure quite how to read
> it as it looks like 2 errors have occurred.  The way I read it, we are in
> the process of switching to the *Backtrace* window when the error
> (presumably) happened again:
>
> Debugger entered--Lisp error: (wrong-type-argument numberp nil)
>   window-at(nil nil #<frame test2/CONTRACT.in 0xd1a200>)
>   mouse-autoselect-window-start()
>   handle-select-window((select-window (#<window 47 on *Backtrace*>)))
>   call-interactively(handle-select-window)
>
> But it is kind-of what I guessed, that the error is thrown by window-at
> because mouse-position returns nil for X and Y.
>
> I can fairly easily reproduce this with emacs -Q if I move from the selected
> first frame to a second frame and then off that second frame quickly when
> (a) the second frame has split windows, (b) the second frame's selected
> window (ie, when the second frame is selected) and its point is covered by
> the first frame.

I can obtain the error too, even when running two distinct Emacs
processes with one frame each.  Obviously, `mouse-position' _should_
return nil whenever it's not able to determine a meaningful position,
hence I can't put the blame on that.

> The amount of time spent in the second frame does not seem to depend on
> mouse-autoselect-window.

I suppose you tell that from using an autoselect timeout in your window
manager that differs from `mouse-autoselect-window'.

> Maybe it has more to do with whether Emacs gets
> the chance to get some info out of X before the mouse has moved off the
> second frame.  I use Solaris CDE on a PC running Exceed, which may
> complicate/slow things.

Honestly, I expected many more problems when switching frames than you
encountered so far.

> Maybe the only fix is to be tolerant of nil for X and Y from mouse-position.

The only thing I can offer is to wrap this in a `condition-case' and
have `handle-select-window' do it's usual stuff when
`mouse-autoselect-window-start' fails.

martin

*** dispextern.h        Sun Jul  2 09:50:00 2006
--- dispextern.h        Wed Jul  5 11:45:28 2006
***************
*** 2690,2696 ****
  extern int help_echo_pos;
  extern struct frame *last_mouse_frame;
  extern int last_tool_bar_item;
! extern int mouse_autoselect_window;
  extern int unibyte_display_via_language_environment;

  extern void reseat_at_previous_visible_line_start P_ ((struct it *));
--- 2690,2696 ----
  extern int help_echo_pos;
  extern struct frame *last_mouse_frame;
  extern int last_tool_bar_item;
! extern Lisp_Object mouse_autoselect_window;
  extern int unibyte_display_via_language_environment;

  extern void reseat_at_previous_visible_line_start P_ ((struct it *));

*** macterm.c   Sun Jul  2 09:50:00 2006
--- macterm.c   Wed Jul  5 12:02:28 2006
***************
*** 10562,10568 ****
                  else
                    {
                      /* Generate SELECT_WINDOW_EVENTs when needed.  */
!                     if (mouse_autoselect_window)
                        {
                          Lisp_Object window;

--- 10562,10568 ----
                  else
                    {
                      /* Generate SELECT_WINDOW_EVENTs when needed.  */
!                     if (!NILP (mouse_autoselect_window))
                        {
                          Lisp_Object window;


*** msdos.c     Sun Jul  2 12:09:26 2006
--- msdos.c     Wed Jul  5 12:02:46 2006
***************
*** 3381,3387 ****
            }

          /* Generate SELECT_WINDOW_EVENTs when needed.  */
!         if (mouse_autoselect_window)
            {
              mouse_window = window_from_coordinates (SELECTED_FRAME(),
                                                      mouse_last_x,
--- 3381,3387 ----
            }

          /* Generate SELECT_WINDOW_EVENTs when needed.  */
!         if (!NILP (mouse_autoselect_window))
            {
              mouse_window = window_from_coordinates (SELECTED_FRAME(),
                                                      mouse_last_x,

*** w32term.c   Sun Jul  2 09:50:02 2006
--- w32term.c   Wed Jul  5 12:02:08 2006
***************
*** 4286,4292 ****
          if (f)
            {
              /* Generate SELECT_WINDOW_EVENTs when needed.  */
!             if (mouse_autoselect_window)
                {
                  Lisp_Object window;
                  int x = LOWORD (msg.msg.lParam);
--- 4286,4292 ----
          if (f)
            {
              /* Generate SELECT_WINDOW_EVENTs when needed.  */
!             if (!NILP (mouse_autoselect_window))
                {
                  Lisp_Object window;
                  int x = LOWORD (msg.msg.lParam);

*** xdisp.c     Sun Jul  2 09:50:02 2006
--- xdisp.c     Wed Jul 19 11:06:30 2006
***************
*** 258,264 ****

  /* Non-zero means automatically select any window when the mouse
     cursor moves into it.  */
! int mouse_autoselect_window;

  /* Non-zero means draw tool bar buttons raised when the mouse moves
     over them.  */
--- 258,264 ----

  /* Non-zero means automatically select any window when the mouse
     cursor moves into it.  */
! Lisp_Object mouse_autoselect_window;

  /* Non-zero means draw tool bar buttons raised when the mouse moves
     over them.  */
***************
*** 23933,23941 ****
  See `set-window-redisplay-end-trigger'.  */);
    Vredisplay_end_trigger_functions = Qnil;

!   DEFVAR_BOOL ("mouse-autoselect-window", &mouse_autoselect_window,
!     doc: /* *Non-nil means autoselect window with mouse pointer.  */);
!   mouse_autoselect_window = 0;

    DEFVAR_BOOL ("auto-resize-tool-bars", &auto_resize_tool_bars_p,
      doc: /* *Non-nil means automatically resize tool-bars.
--- 23933,23949 ----
  See `set-window-redisplay-end-trigger'.  */);
    Vredisplay_end_trigger_functions = Qnil;

!   DEFVAR_LISP ("mouse-autoselect-window", &mouse_autoselect_window,
!      doc: /* *Non-nil means autoselect window with mouse pointer.
! If nil, do not autoselect windows.  A positive number means delay
! autoselection by that many seconds: A window is selected iff Emacs
! can establish that the mouse has remained within that window for
! the time indicated by the delay \(see `mouse-autoselect-quiescent').
! Any other value means autoselection occurs instantaneously.
! 
! Autoselection does not unselect the minibuffer and selects the
! minibuffer iff it is active.  */);
!   mouse_autoselect_window = Qnil;

    DEFVAR_BOOL ("auto-resize-tool-bars", &auto_resize_tool_bars_p,
      doc: /* *Non-nil means automatically resize tool-bars.

*** xterm.c     Sun Jul  2 12:10:00 2006
--- xterm.c     Wed Jul  5 12:03:04 2006
***************
*** 6575,6581 ****
            {

              /* Generate SELECT_WINDOW_EVENTs when needed.  */
!             if (mouse_autoselect_window)
                {
                  Lisp_Object window;

--- 6575,6581 ----
            {

              /* Generate SELECT_WINDOW_EVENTs when needed.  */
!             if (!NILP (mouse_autoselect_window))
                {
                  Lisp_Object window;

*** cus-start.el        Sun Jul  2 09:49:56 2006
--- cus-start.el        Wed Jul 19 11:07:46 2006
***************
*** 360,365 ****
--- 360,374 ----
                                            (other :tag "Unlimited" t)))
             (unibyte-display-via-language-environment mule boolean)
             (blink-cursor-alist cursor alist "22.1")
+              (mouse-autoselect-window display
+                                     (choice
+                                      (const :tag "Off" :value nil)
+                                      (const :tag "Immediate" :value t)
+                                      (restricted-sexp :tag "Delay by secs"
+                                                       :value 0.5
+                                                       :match-alternatives
+                                                       ((lambda (val) (and 
(numberp val) (> val 0))))))
+                                     "21.3")
             ;; xfaces.c
             (scalable-fonts-allowed display boolean)
             ;; xfns.c
***************
*** 369,375 ****
             (x-gtk-show-hidden-files menu boolean "22.1")
             (x-gtk-whole-detached-tool-bar x boolean "22.1")
             ;; xterm.c
-              (mouse-autoselect-window display boolean "21.3")
             (x-use-underline-position-properties display boolean "21.3")
             (x-stretch-cursor display boolean "21.1")))
        this symbol group type standard version native-p
--- 378,383 ----

*** mouse.el    Wed Jul  5 11:33:32 2006
--- mouse.el    Wed Jul 19 11:11:44 2006
***************
*** 1729,1734 ****
--- 1729,1835 ----
                            (overlay-start mouse-secondary-overlay)
                            (overlay-end mouse-secondary-overlay)))))))

+ (defvar mouse-autoselect-window-timer nil
+   "Timer used by delayed window autoselection.")
+ 
+ (defvar mouse-autoselect-window-position nil
+   "Last mouse position calculated during delayed window autoselection.")
+ 
+ (defvar mouse-autoselect-window-at nil
+   "Window at `mouse-autoselect-window-position'.")
+ 
+ (defcustom mouse-autoselect-quiescent nil
+   "Specify mouse quiescence in delayed window autoselection.
+ A value of nil means that Emacs may autoselect a window if the mouse has
+ remained within that window for `mouse-autoselect-window' seconds.  An
+ integer has Emacs select the window iff the mouse has not moved by that
+ many characters within `mouse-autoselect-window' seconds.  Any other
+ value means Emacs selects the window iff the mouse position has not
+ changed for at least `mouse-autoselect-window' seconds.
+ 
+ Settings for this variable are honored iff `mouse-autoselect-window' has
+ a numeric value."
+   :type '(choice (const :tag "Off" nil)
+                (const :tag "On" t)
+                (integer :tag "Chars" 1))
+   :group 'display)
+ 
+ (defun mouse-autoselect-window-cancel ()
+   "Terminate delayed window autoselection."
+   (when (timerp mouse-autoselect-window-timer)
+     (cancel-timer mouse-autoselect-window-timer))
+   (remove-hook 'pre-command-hook 'mouse-autoselect-window-cancel))
+ 
+ (defun mouse-autoselect-window-start ()
+   "Start delayed window autoselection.
+ This function should be called when the mouse has crossed a window
+ border and the variable `mouse-autoselect-window' has a numeric value.
+ The return value is non-nil iff delayed autoselection could be
+ successfully started."
+   (condition-case nil
+       (progn
+       (mouse-autoselect-window-cancel)
+       (when (and (numberp mouse-autoselect-window)
+                  (> mouse-autoselect-window 0))
+         (setq mouse-autoselect-window-position (mouse-position))
+         (when (setq mouse-autoselect-window-at
+                     (window-at (cadr mouse-autoselect-window-position)
+                                (cddr mouse-autoselect-window-position)
+                                (car mouse-autoselect-window-position)))
+           (setq mouse-autoselect-window-timer
+                 (run-at-time
+                  mouse-autoselect-window mouse-autoselect-window
+                  'mouse-autoselect-window-select))
+           (add-hook 'pre-command-hook 'mouse-autoselect-window-cancel))))
+     (error nil)))
+ 
+ (defun mouse-autoselect-window-select ()
+   "Select window with delayed window autoselection.
+ If `mouse-position' has stabilized in a non-selected window, select that
+ window.  The minibuffer window is selected iff the minibuffer is active.
+ `mouse-autoselect-quiescent' specifies how mouse-position stabilizes.
+ This function is run by `mouse-autoselect-window-timer'."
+   (condition-case nil
+       (let* ((mouse-position (mouse-position))
+            (mouse-x-pos (cadr mouse-position))
+            (mouse-y-pos (cddr mouse-position))
+            (frame (car mouse-position))
+            (window (window-at mouse-x-pos mouse-y-pos frame)))
+       (cond
+        ((and window (not (eq window (selected-window)))
+              (or (and (not mouse-autoselect-quiescent)
+                       (eq window mouse-autoselect-window-at))
+                  (and (integerp mouse-autoselect-quiescent)
+                       (and (eq frame (car mouse-autoselect-window-position))
+                            (<= (abs (- mouse-x-pos
+                                        (cadr 
mouse-autoselect-window-position)))
+                                mouse-autoselect-quiescent)
+                            (<= (abs (- mouse-y-pos
+                                        (cddr 
mouse-autoselect-window-position)))
+                                mouse-autoselect-quiescent)))
+                  (equal mouse-position mouse-autoselect-window-position))
+              (or (not (window-minibuffer-p window))
+                  (eq window (active-minibuffer-window)))
+              (let ((edges (window-inside-edges window)))
+                (and (<= (nth 0 edges) mouse-x-pos)
+                     (<= mouse-x-pos (nth 2 edges))
+                     (<= (nth 1 edges) mouse-y-pos)
+                     (<= mouse-y-pos (nth 3 edges)))))
+         ;; mouse-position has stabilized in another window.
+         (mouse-autoselect-window-cancel)
+         (unless (window-minibuffer-p (selected-window))
+           (run-hooks 'mouse-leave-buffer-hook)
+           (select-window window)))
+        ((and window (eq window (selected-window)))
+         ;; mouse-position has stabilized in same window.
+         (mouse-autoselect-window-cancel))
+        (t
+         ;; mouse-position has not stabilized yet, record new position and
+         ;; window.
+         (setq mouse-autoselect-window-position mouse-position)
+         (setq mouse-autoselect-window-at window))))
+     (error nil)))
+ 
  
  (defcustom mouse-buffer-menu-maxlen 20
    "*Number of buffers in one pane (submenu) of the buffer menu.

*** window.el   Mon Jul  3 17:35:12 2006
--- window.el   Wed Jul 19 10:40:24 2006
***************
*** 777,792 ****
    "Handle select-window events."
    (interactive "e")
    (let ((window (posn-window (event-start event))))
!     (if (and (window-live-p window)
!            ;; Don't switch if we're currently in the minibuffer.
!            ;; This tries to work around problems where the minibuffer gets
!            ;; unselected unexpectedly, and where you then have to move
!            ;; your mouse all the way down to the minibuffer to select it.
!            (not (window-minibuffer-p (selected-window)))
!            ;; Don't switch to a minibuffer window unless it's active.
!            (or (not (window-minibuffer-p window))
!                (minibuffer-window-active-p window)))
!       (select-window window))))

  (define-key ctl-x-map "2" 'split-window-vertically)
  (define-key ctl-x-map "3" 'split-window-horizontally)
--- 777,797 ----
    "Handle select-window events."
    (interactive "e")
    (let ((window (posn-window (event-start event))))
!     (when (and (window-live-p window)
!              ;; Don't switch if we're currently in the minibuffer.
!              ;; This tries to work around problems where the minibuffer gets
!              ;; unselected unexpectedly, and where you then have to move
!              ;; your mouse all the way down to the minibuffer to select it.
!              (not (window-minibuffer-p (selected-window)))
!              ;; Don't switch to a minibuffer window unless it's active.
!              (or (not (window-minibuffer-p window))
!                  (minibuffer-window-active-p window)))
!       (unless (and (numberp mouse-autoselect-window)
!                  (> mouse-autoselect-window 0)
!                  (mouse-autoselect-window-start))
!       (when mouse-autoselect-window
!         (run-hooks 'mouse-leave-buffer-hook))
!       (select-window window)))))

  (define-key ctl-x-map "2" 'split-window-vertically)
  (define-key ctl-x-map "3" 'split-window-horizontally)