[xemacs-hg @ 2001-06-18 07:09:50 by ben] --------------------------------------------------------------- DOCUMENTATION FIXES: --------------------------------------------------------------- eval.c: Correct documentation. elhash.c: Doc correction. --------------------------------------------------------------- LISP OBJECT CLEANUP: --------------------------------------------------------------- bytecode.h, buffer.h, casetab.h, chartab.h, console-msw.h, console.h, database.c, device.h, eldap.h, elhash.h, events.h, extents.h, faces.h, file-coding.h, frame.h, glyphs.h, gui-x.h, gui.h, keymap.h, lisp-disunion.h, lisp-union.h, lisp.h, lrecord.h, lstream.h, mule-charset.h, objects.h, opaque.h, postgresql.h, process.h, rangetab.h, specifier.h, toolbar.h, tooltalk.h, ui-gtk.h: Add wrap_* to all objects (it was already there for a few of them) -- an expression to encapsulate a pointer into a Lisp object, rather than the inconvenient XSET*. "wrap" was chosen because "make" as in make_int(), make_char() is not appropriate. (It implies allocation. The issue does not exist for ints and chars because they are not allocated.) Full error checking has been added to these expressions. When used without error checking, non-union build, use of these expressions will incur no loss of efficiency. (In fact, XSET* is now defined in terms of wrap_* in a non-union build.) In a union build, you will also get no loss of efficiency provided that you have a decent optimizing compiler, and a compiler that either understands inlines or automatically inlines those particular functions. (And since people don't normally do their production builds on union, it doesn't matter.) Update the sample Lisp object definition in lrecord.h accordingly. dumper.c: Fix places in dumper that referenced wrap_object to reference its new name, wrap_pointer_1. buffer.c, bufslots.h, conslots.h, console.c, console.h, devslots.h, device.c, device.h, frame.c, frame.h, frameslots.h, window.c, window.h, winslots.h: -- Extract out the Lisp objects of `struct device' into devslots.h, just like for the other structures. -- Extract out the remaining (not copied into the window config) Lisp objects in `struct window' into winslots.h; use different macros (WINDOW_SLOT vs. WINDOW_SAVED_SLOT) to differentiate them. -- Eliminate the `dead' flag of `struct frame', since it duplicates information already available in `framemeths', and fix FRAME_LIVE_P accordingly. (Devices and consoles already work this way.) -- In *slots.h, switch to system where MARKED_SLOT is automatically undef'd at the end of the file. (Follows what winslots.h already does.) -- Update the comments at the beginning of *slots.h to be accurate. -- When making any of the above objects dead, zero it out entirely and reset all Lisp object slots to Qnil. (We were already doing this somewhat, but not consistently.) This (1) Eliminates the possibility of extra objects hanging around that ought to be GC'd, (2) Causes an immediate crash if anyone tries to access a structure in one of these objects, (3) Ensures consistent behavior wrt dead objects. dialog-msw.c: Use internal_object_printer, since this object should not escape. --------------------------------------------------------------- FIXING A CRASH THAT I HIT ONCE (AND A RELATED BAD BEHAVIOR): --------------------------------------------------------------- eval.c: Fix up some comments about the FSF implementation. Fix two nasty bugs: (1) condition_case_unwind frees the conses sitting in the catch->tag slot too quickly, resulting in a crash that I hit. (2) catches need to be unwound one at a time when calling unwind-protect code, rather than all at once at the end; otherwise, incorrect behavior can result. (A comment shows exactly how.) backtrace.h: Improve comment about FSF differences in the handler stack. --------------------------------------------------------------- FIXING A CRASH THAT I REPEATEDLY HIT WHEN USING THE MOUSE WHEEL UNDER MSWINDOWS: --------------------------------------------------------------- Basic idea: My crash is due either to a dead, non-marked, GC-collected frame inside of a window mirror, or a prematurely freed window mirror. We need to mark the Lisp objects inside of window mirrors. Tracking the lifespan of window mirrors and scrollbar instances is extremely hard, and there may well be lurking bugs where such objects are freed too soon. The only safe way to fix these problems (and it fixes both problems at once) is to make both of these structures Lisp objects. lrecord.h, emacs.c, inline.c, scrollbar-gtk.c, scrollbar-msw.c, scrollbar-x.c, scrollbar.c, scrollbar.h, symsinit.h: Make scrollbar instances actual Lisp objects. Mark the window mirrors in them. inline.c needs to know about scrollbar.h now. Record the new type in lrecord.h. Fix up scrollbar-*.c appropriately. Create a hash table in scrollbar-msw.c so that the scrollbar instances stored in scrollbar HWND's are properly GC-protected. Create complex_vars_of_scrollbar_mswindows() to create the hash table at startup, and call it from emacs.c. Don't store the scrollbar instance as a property of the GTK scrollbar, as it's not used and if we did this, we'd have to separately GC-protect it in a hash table, like in MS Windows. lrecord.h, frame.h, frame.c, frameslots.h, redisplay.c, window.c, window.h: Move mark_window_mirror from redisplay.c to window.c. Make window mirrors actual Lisp objects. Tell lrecord.h about them. Change the window mirror member of struct frame from a pointer to a Lisp object, and add XWINDOW_MIRROR in appropriate places. Mark the scrollbar instances in the window mirror. redisplay.c, redisplay.h, alloc.c: Delete mark_redisplay. Don't call mark_redisplay. We now mark frame-specific structures in mark_frame. NOTE: I also deleted an extremely questionable call to update_frame_window_mirrors(). It was extremely questionable before, and now totally impossible, since it will create Lisp objects during redisplay. frame.c: Mark the scrollbar instances, which are now Lisp objects. Call mark_gutter() here, not in mark_redisplay(). gutter.c: Update comments about correct marking. --------------------------------------------------------------- ISSUES BROUGHT UP BY MARTIN: --------------------------------------------------------------- buffer.h: Put back these macros the way Steve T and I think they ought to be. I already explained in a previous changelog entry why I think these macros should be the way I'd defined them. Once again: We fix these macros so they don't care about the type of their lvalues. The non-C-string equivalents of these already function in the same way, and it's correct because it should be OK to pass in a CBufbyte *, a BufByte *, a Char_Binary *, an UChar_Binary *, etc. The whole reason for these different types is to work around errors caused by signed-vs-unsigned non-matching types. Any possible error that might be caught in a DFC macro would also be caught wherever the argument is used elsewhere. So creating multiple macro versions would add no useful error-checking and just further complicate an already complicated area. As for Martin's "ANSI aliasing" bug, XEmacs is not ANSI-aliasing clean and probably never will be. Unless the board agrees to change XEmacs in this way (and we really don't want to go down that road), this is not a bug. sound.h: Undo Martin's type change. signal.c: Fix problem identified by Martin with Linux and g++ due to non-standard declaration of setitimer(). systime.h: Update the docs for "qxe_" to point out why making the encapsulation explicit is always the right way to go. (setitimer() itself serves as an example.) For 21.4: update-elc-2.el: Correct misplaced parentheses, making lisp/mule not get recompiled.

;;; auto-show.el --- perform automatic horizontal scrolling as point moves

;; Copyright (C) 1997 Free Software Foundation, Inc.
;; This file is in the public domain.

;; Author: Pete Ware <ware@cis.ohio-state.edu>
;; Maintainer: XEmacs Development Team
;; Keywords: extensions, internal, dumped

;; This file is part of XEmacs.

;; XEmacs 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.

;; XEmacs 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.

;; You should have received a copy of the GNU General Public License
;; along with XEmacs; see the file COPYING.  If not, write to the Free
;; Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
;; 02111-1307, USA.

;;; Synched up with: Emacs/Mule zeta.

;;; Commentary:

;; This file is dumped with XEmacs.

;; Modified by: Ben Wing <ben@xemacs.org>

;; This file provides functions that
;; automatically scroll the window horizontally when the point moves
;; off the left or right side of the window.

;; Once this library is loaded, automatic horizontal scrolling
;; occurs whenever long lines are being truncated.
;; To request truncation of long lines, set the variable
;; Setting the variable `truncate-lines' to non-nil.
;; You can do this for all buffers as follows:
;;
;; (set-default 'truncate-lines t)

;; Here is how to do it for C mode only:
;;
;; (set-default 'truncate-lines nil)	; this is the original value
;; (defun my-c-mode-hook ()
;;   "Run when C-mode starts up.  Changes ..."
;;   ... set various personal preferences ...
;;   (setq truncate-lines t))
;; (add-hook 'c-mode-hook 'my-c-mode-hook)
;;
;;
;; As a finer level of control, you can still have truncated lines but
;; without the automatic horizontal scrolling by setting the buffer
;; local variable `auto-show-mode' to nil.  The default value is t.
;; The command `auto-show-mode' toggles the value of the variable
;; `auto-show-mode'.

;;; Code:

(defgroup auto-show nil
  "Perform automatic horizontal scrolling as point moves."
  :group 'display
  :group 'extensions)

;; This is preloaded, so we don't need special :set, :require, etc.
(defcustom auto-show-mode t
  "*Non-nil enables automatic horizontal scrolling, when lines are truncated.
The default value is t.  To change the default, do this:
	(set-default 'auto-show-mode nil)
See also command `auto-show-mode'.
This variable has no effect when lines are not being truncated.
This variable is automatically local in each buffer where it is set."
  :type 'boolean
  :group 'auto-show)

(make-variable-buffer-local 'auto-show-mode)

(defcustom auto-show-shift-amount 8 
  "*Extra columns to scroll. for automatic horizontal scrolling."
  :type 'integer
  :group 'auto-show)

(defcustom auto-show-show-left-margin-threshold 50
  "*Threshold column for automatic horizontal scrolling to the right.
If point is before this column, we try to scroll to make the left margin
visible.  Setting this to 0 disables this feature."
  :type 'number
  :group 'auto-show)

(defun auto-show-mode (arg)
  "Turn automatic horizontal scroll mode on or off.
With arg, turn auto scrolling on if arg is positive, off otherwise.
This mode is enabled or disabled for each buffer individually.
It takes effect only when `truncate-lines' is non-nil."
  (interactive "P")
  (setq auto-show-mode
	(if (null arg)
	    (not auto-show-mode)
	  (> (prefix-numeric-value arg) 0))))

;; XEmacs addition:
(defvar auto-show-inhibiting-commands
  '(scrollbar-char-left
    scrollbar-char-right
    scrollbar-page-left
    scrollbar-page-right
    scrollbar-to-left
    scrollbar-to-right
    scrollbar-horizontal-drag)
  "Commands that inhibit auto-show behavior.
This normally includes the horizontal scrollbar commands.")

;; XEmacs addition:
(defun auto-show-should-take-action-p ()
  (and auto-show-mode (window-truncated-p)
       (equal (window-buffer) (current-buffer))
       (not (memq this-command auto-show-inhibiting-commands))))

;; XEmacs addition:
(defun auto-show-make-region-visible (start end)
  "Move point in such a way that the region (START, END) is visible.
This only does anything if auto-show-mode is enabled, and it doesn't
actually do any horizontal scrolling; rather, it just sets things up so
that the region will be visible when `auto-show-make-point-visible'
is next called (this happens after every command)."
  (if (auto-show-should-take-action-p)
      (let* ((scroll (window-hscroll))	;how far window is scrolled
	     (w-width (- (window-width) 
			 (if (> scroll 0)
			     2 1)))	;how wide window is on the screen
	     (right-col (+ scroll w-width))
	     (start-col (save-excursion (goto-char start) (current-column)))
	     (end-col (save-excursion (goto-char end) (current-column))))
	(cond ((and (>= start-col scroll)
		    (<= end-col right-col))
	       ;; already completely visible
	       nil)
	      ((< start-col scroll)
	       (scroll-right (- scroll start-col)))
	      (t
	       (scroll-left (- end-col right-col)))))))

(defun auto-show-make-point-visible (&optional ignore-arg)
  "Scroll horizontally to make point visible, if that is enabled.
This function only does something if `auto-show-mode' is non-nil
and longlines are being truncated in the selected window.
See also the command `auto-show-mode'."
  (interactive)
  ;; XEmacs change
  (if (auto-show-should-take-action-p)
      (let* ((col (current-column))	;column on line point is at
	     (scroll (window-hscroll))	;how far window is scrolled
	     (w-width (- (window-width) 
			 (if (> scroll 0)
			     2 1)))	;how wide window is on the screen
	     (right-col (+ scroll w-width)))
	(if (and (< col auto-show-show-left-margin-threshold)
		 (< col (window-width))
		 (> scroll 0))
	    (scroll-right scroll)
	  (if (< col scroll)		;to the left of the screen
	      (scroll-right (+ (- scroll col) auto-show-shift-amount))
	    (if (or (> col right-col)	;to the right of the screen
		    (and (= col right-col)
			 (not (eolp))))
		(scroll-left (+ auto-show-shift-amount 
				(- col (+ scroll w-width))))))))))

;; XEmacs change:
;; #### instead of this, we kludgily call it from the C code, to make sure
;; that it's done after any other things on post-command-hook (which might
;; move point).
;; Do auto-scrolling after commands.
;;(add-hook 'post-command-hook 'auto-show-make-point-visible)

;; If being dumped, turn it on right away.
(when (boundp 'pureload)
  (auto-show-mode 1))

;; Do auto-scrolling in comint buffers after process output also.
; XEmacs -- don't do this now, it messes up comint.
;(add-hook 'comint-output-filter-functions 'auto-show-make-point-visible t)

(provide 'auto-show)

;;; auto-show.el ends here