mirror of
https://git.savannah.gnu.org/git/emacs.git
synced 2024-12-06 08:54:05 +00:00
0111ab41ec
Doc fixes. (ewoc--create-node, ewoc--delete-node-internal): Fix typos in docstring.
615 lines
22 KiB
EmacsLisp
615 lines
22 KiB
EmacsLisp
;;; ewoc.el --- utility to maintain a view of a list of objects in a buffer
|
||
|
||
;; Copyright (C) 1991, 92, 93, 94, 95, 96, 97, 98, 99, 2000, 04
|
||
;; Free Software Foundation
|
||
|
||
;; Author: Per Cederqvist <ceder@lysator.liu.se>
|
||
;; Inge Wallin <inge@lysator.liu.se>
|
||
;; Maintainer: monnier@gnu.org
|
||
;; Created: 3 Aug 1992
|
||
;; Keywords: extensions, lisp
|
||
|
||
;; This file is part of GNU Emacs.
|
||
|
||
;; GNU Emacs 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.
|
||
|
||
;; GNU Emacs 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 GNU Emacs; see the file COPYING. If not, write to the
|
||
;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
|
||
;; Boston, MA 02111-1307, USA.
|
||
|
||
;;; Commentary:
|
||
|
||
;; Ewoc Was Once Cookie
|
||
;; But now it's Emacs' Widget for Object Collections
|
||
|
||
;; As the name implies this derives from the `cookie' package (part
|
||
;; of Elib). The changes are pervasive though mostly superficial:
|
||
|
||
;; - uses CL (and its `defstruct')
|
||
;; - separate from Elib.
|
||
;; - uses its own version of a doubly-linked list which allows us
|
||
;; to merge the elib-wrapper and the elib-node structures into ewoc-node
|
||
;; - dropping functions not used by PCL-CVS (the only client of ewoc at the
|
||
;; time of writing)
|
||
;; - removing unused arguments
|
||
;; - renaming:
|
||
;; elib-node ==> ewoc--node
|
||
;; collection ==> ewoc
|
||
;; tin ==> ewoc--node
|
||
;; cookie ==> data or element or elem
|
||
|
||
;; Introduction
|
||
;; ============
|
||
;;
|
||
;; Ewoc is a package that implements a connection between an
|
||
;; dll (a doubly linked list) and the contents of a buffer.
|
||
;; Possible uses are dired (have all files in a list, and show them),
|
||
;; buffer-list, kom-prioritize (in the LysKOM elisp client) and
|
||
;; others. pcl-cvs.el uses ewoc.el.
|
||
;;
|
||
;; Ewoc can be considered as the `view' part of a model-view-controller.
|
||
;;
|
||
;; A `element' can be any lisp object. When you use the ewoc
|
||
;; package you specify a pretty-printer, a function that inserts
|
||
;; a printable representation of the element in the buffer. (The
|
||
;; pretty-printer should use "insert" and not
|
||
;; "insert-before-markers").
|
||
;;
|
||
;; A `ewoc' consists of a doubly linked list of elements, a
|
||
;; header, a footer and a pretty-printer. It is displayed at a
|
||
;; certain point in a certain buffer. (The buffer and point are
|
||
;; fixed when the ewoc is created). The header and the footer
|
||
;; are constant strings. They appear before and after the elements.
|
||
;;
|
||
;; Ewoc does not affect the mode of the buffer in any way. It
|
||
;; merely makes it easy to connect an underlying data representation
|
||
;; to the buffer contents.
|
||
;;
|
||
;; A `ewoc--node' is an object that contains one element. There are
|
||
;; functions in this package that given an ewoc--node extract the data, or
|
||
;; give the next or previous ewoc--node. (All ewoc--nodes are linked together
|
||
;; in a doubly linked list. The `previous' ewoc--node is the one that appears
|
||
;; before the other in the buffer.) You should not do anything with
|
||
;; an ewoc--node except pass it to the functions in this package.
|
||
;;
|
||
;; An ewoc is a very dynamic thing. You can easily add or delete elements.
|
||
;; You can apply a function to all elements in an ewoc, etc, etc.
|
||
;;
|
||
;; Remember that an element can be anything. Your imagination is the
|
||
;; limit! It is even possible to have another ewoc as an
|
||
;; element. In that way some kind of tree hierarchy can be created.
|
||
;;
|
||
;; Full documentation will, God willing, soon be available in a
|
||
;; Texinfo manual.
|
||
|
||
;; In the mean time `grep '^(.*ewoc-[^-]' emacs-lisp/ewoc.el' can help
|
||
;; you find all the exported functions:
|
||
;;
|
||
;; (defun ewoc-create (pretty-printer &optional header footer)
|
||
;; (defalias 'ewoc-data 'ewoc--node-data)
|
||
;; (defun ewoc-location (node)
|
||
;; (defun ewoc-enter-first (ewoc data)
|
||
;; (defun ewoc-enter-last (ewoc data)
|
||
;; (defun ewoc-enter-after (ewoc node data)
|
||
;; (defun ewoc-enter-before (ewoc node data)
|
||
;; (defun ewoc-next (ewoc node)
|
||
;; (defun ewoc-prev (ewoc node)
|
||
;; (defun ewoc-nth (ewoc n)
|
||
;; (defun ewoc-map (map-function ewoc &rest args)
|
||
;; (defun ewoc-filter (ewoc predicate &rest args)
|
||
;; (defun ewoc-locate (ewoc &optional pos guess)
|
||
;; (defun ewoc-invalidate (ewoc &rest nodes)
|
||
;; (defun ewoc-goto-prev (ewoc arg)
|
||
;; (defun ewoc-goto-next (ewoc arg)
|
||
;; (defun ewoc-goto-node (ewoc node)
|
||
;; (defun ewoc-refresh (ewoc)
|
||
;; (defun ewoc-collect (ewoc predicate &rest args)
|
||
;; (defun ewoc-buffer (ewoc)
|
||
;; (defun ewoc-get-hf (ewoc)
|
||
;; (defun ewoc-set-hf (ewoc header footer)
|
||
|
||
;; Coding conventions
|
||
;; ==================
|
||
;;
|
||
;; All functions of course start with `ewoc'. Functions and macros
|
||
;; starting with the prefix `ewoc--' are meant for internal use,
|
||
;; while those starting with `ewoc-' are exported for public use.
|
||
;; There are currently no global or buffer-local variables used.
|
||
|
||
|
||
;;; Code:
|
||
|
||
(eval-when-compile (require 'cl)) ;because of CL compiler macros
|
||
|
||
;; The doubly linked list is implemented as a circular list
|
||
;; with a dummy node first and last. The dummy node is used as
|
||
;; "the dll" (or rather is the dll handle passed around).
|
||
|
||
(defstruct (ewoc--node
|
||
(:type vector) ;required for ewoc--node-branch hack
|
||
(:constructor ewoc--node-create (start-marker data)))
|
||
left right data start-marker)
|
||
|
||
(defalias 'ewoc--node-branch 'aref
|
||
"Get the left (CHILD=0) or right (CHILD=1) child of the NODE.
|
||
|
||
\(fn NODE CHILD)")
|
||
|
||
(defun ewoc--dll-create ()
|
||
"Create an empty doubly linked list."
|
||
(let ((dummy-node (ewoc--node-create 'DL-LIST 'DL-LIST)))
|
||
(setf (ewoc--node-right dummy-node) dummy-node)
|
||
(setf (ewoc--node-left dummy-node) dummy-node)
|
||
dummy-node))
|
||
|
||
(defun ewoc--node-enter-before (node elemnode)
|
||
"Insert ELEMNODE before NODE in a DLL."
|
||
(assert (and (null (ewoc--node-left elemnode)) (null (ewoc--node-right elemnode))))
|
||
(setf (ewoc--node-left elemnode) (ewoc--node-left node))
|
||
(setf (ewoc--node-right elemnode) node)
|
||
(setf (ewoc--node-right (ewoc--node-left node)) elemnode)
|
||
(setf (ewoc--node-left node) elemnode))
|
||
|
||
(defun ewoc--node-enter-first (dll node)
|
||
"Add a free floating NODE first in DLL."
|
||
(ewoc--node-enter-before (ewoc--node-right dll) node))
|
||
|
||
(defun ewoc--node-enter-last (dll node)
|
||
"Add a free floating NODE last in DLL."
|
||
(ewoc--node-enter-before dll node))
|
||
|
||
(defun ewoc--node-next (dll node)
|
||
"Return the node after NODE, or nil if NODE is the last node."
|
||
(unless (eq (ewoc--node-right node) dll) (ewoc--node-right node)))
|
||
|
||
(defun ewoc--node-prev (dll node)
|
||
"Return the node before NODE, or nil if NODE is the first node."
|
||
(unless (eq (ewoc--node-left node) dll) (ewoc--node-left node)))
|
||
|
||
(defun ewoc--node-delete (node)
|
||
"Unbind NODE from its doubly linked list and return it."
|
||
;; This is a no-op when applied to the dummy node. This will return
|
||
;; nil if applied to the dummy node since it always contains nil.
|
||
(setf (ewoc--node-right (ewoc--node-left node)) (ewoc--node-right node))
|
||
(setf (ewoc--node-left (ewoc--node-right node)) (ewoc--node-left node))
|
||
(setf (ewoc--node-left node) nil)
|
||
(setf (ewoc--node-right node) nil)
|
||
node)
|
||
|
||
(defun ewoc--node-nth (dll n)
|
||
"Return the Nth node from the doubly linked list DLL.
|
||
N counts from zero. If DLL is not that long, nil is returned.
|
||
If N is negative, return the -(N+1)th last element.
|
||
Thus, (ewoc--node-nth dll 0) returns the first node,
|
||
and (ewoc--node-nth dll -1) returns the last node."
|
||
;; Branch 0 ("follow left pointer") is used when n is negative.
|
||
;; Branch 1 ("follow right pointer") is used otherwise.
|
||
(let* ((branch (if (< n 0) 0 1))
|
||
(node (ewoc--node-branch dll branch)))
|
||
(if (< n 0) (setq n (- -1 n)))
|
||
(while (and (not (eq dll node)) (> n 0))
|
||
(setq node (ewoc--node-branch node branch))
|
||
(setq n (1- n)))
|
||
(unless (eq dll node) node)))
|
||
|
||
(defun ewoc-location (node)
|
||
"Return the start location of NODE."
|
||
(ewoc--node-start-marker node))
|
||
|
||
|
||
;;; The ewoc data type
|
||
|
||
(defstruct (ewoc
|
||
(:constructor nil)
|
||
(:constructor ewoc--create
|
||
(buffer pretty-printer header footer dll))
|
||
(:conc-name ewoc--))
|
||
buffer pretty-printer header footer dll last-node)
|
||
|
||
(defmacro ewoc--set-buffer-bind-dll-let* (ewoc varlist &rest forms)
|
||
"Execute FORMS with ewoc--buffer selected as current buffer,
|
||
dll bound to ewoc--dll, and VARLIST bound as in a let*.
|
||
dll will be bound when VARLIST is initialized, but the current
|
||
buffer will *not* have been changed.
|
||
Return value of last form in FORMS."
|
||
(let ((old-buffer (make-symbol "old-buffer"))
|
||
(hnd (make-symbol "ewoc")))
|
||
`(let* ((,old-buffer (current-buffer))
|
||
(,hnd ,ewoc)
|
||
(dll (ewoc--dll ,hnd))
|
||
,@varlist)
|
||
(set-buffer (ewoc--buffer ,hnd))
|
||
(unwind-protect
|
||
(progn ,@forms)
|
||
(set-buffer ,old-buffer)))))
|
||
|
||
(defmacro ewoc--set-buffer-bind-dll (ewoc &rest forms)
|
||
`(ewoc--set-buffer-bind-dll-let* ,ewoc nil ,@forms))
|
||
|
||
(defsubst ewoc--filter-hf-nodes (ewoc node)
|
||
"Evaluate NODE once and return it.
|
||
BUT if it is the header or the footer in EWOC return nil instead."
|
||
(unless (or (eq node (ewoc--header ewoc))
|
||
(eq node (ewoc--footer ewoc)))
|
||
node))
|
||
|
||
|
||
(defun ewoc--create-node (data pretty-printer pos)
|
||
"Call PRETTY-PRINTER with point set at POS in current buffer.
|
||
Remember the start position. Create a wrapper containing that
|
||
start position and the element DATA."
|
||
(save-excursion
|
||
;; Remember the position as a number so that it doesn't move
|
||
;; when we insert the string.
|
||
(when (markerp pos) (setq pos (marker-position pos)))
|
||
(goto-char pos)
|
||
(let ((inhibit-read-only t))
|
||
;; Insert the trailing newline using insert-before-markers
|
||
;; so that the start position for the next element is updated.
|
||
(insert-before-markers ?\n)
|
||
;; Move back, and call the pretty-printer.
|
||
(backward-char 1)
|
||
(funcall pretty-printer data)
|
||
(ewoc--node-create (copy-marker pos) data))))
|
||
|
||
|
||
(defun ewoc--delete-node-internal (ewoc node)
|
||
"Delete a data string from EWOC.
|
||
Can not be used on the footer. Returns the wrapper that is deleted.
|
||
The start-marker in the wrapper is set to nil, so that it doesn't
|
||
consume any more resources."
|
||
(let ((dll (ewoc--dll ewoc))
|
||
(inhibit-read-only t))
|
||
;; If we are about to delete the node pointed at by last-node,
|
||
;; set last-node to nil.
|
||
(if (eq (ewoc--last-node ewoc) node)
|
||
(setf (ewoc--last-node ewoc) nil))
|
||
|
||
(delete-region (ewoc--node-start-marker node)
|
||
(ewoc--node-start-marker (ewoc--node-next dll node)))
|
||
(set-marker (ewoc--node-start-marker node) nil)
|
||
;; Delete the node, and return the wrapper.
|
||
(ewoc--node-delete node)))
|
||
|
||
|
||
(defun ewoc--refresh-node (pp node)
|
||
"Redisplay the element represented by NODE using the pretty-printer PP."
|
||
(let ((inhibit-read-only t))
|
||
(save-excursion
|
||
;; First, remove the string from the buffer:
|
||
(delete-region (ewoc--node-start-marker node)
|
||
(1- (marker-position
|
||
(ewoc--node-start-marker (ewoc--node-right node)))))
|
||
;; Calculate and insert the string.
|
||
(goto-char (ewoc--node-start-marker node))
|
||
(funcall pp (ewoc--node-data node)))))
|
||
|
||
;;; ===========================================================================
|
||
;;; Public members of the Ewoc package
|
||
|
||
|
||
(defun ewoc-create (pretty-printer &optional header footer)
|
||
"Create an empty ewoc.
|
||
|
||
The ewoc will be inserted in the current buffer at the current position.
|
||
|
||
PRETTY-PRINTER should be a function that takes one argument, an
|
||
element, and inserts a string representing it in the buffer (at
|
||
point). The string PRETTY-PRINTER inserts may be empty or span
|
||
several lines. A trailing newline will always be inserted
|
||
automatically. The PRETTY-PRINTER should use `insert', and not
|
||
`insert-before-markers'.
|
||
|
||
Optional second argument HEADER is a string that will always be
|
||
present at the top of the ewoc. HEADER should end with a
|
||
newline. Optional third argument FOOTER is similar, and will
|
||
be inserted at the bottom of the ewoc."
|
||
(let ((new-ewoc
|
||
(ewoc--create (current-buffer)
|
||
pretty-printer nil nil (ewoc--dll-create)))
|
||
(pos (point)))
|
||
(ewoc--set-buffer-bind-dll new-ewoc
|
||
;; Set default values
|
||
(unless header (setq header ""))
|
||
(unless footer (setq footer ""))
|
||
(setf (ewoc--node-start-marker dll) (copy-marker pos))
|
||
(let ((foot (ewoc--create-node footer (lambda (x) (insert footer)) pos))
|
||
(head (ewoc--create-node header (lambda (x) (insert header)) pos)))
|
||
(ewoc--node-enter-first dll head)
|
||
(ewoc--node-enter-last dll foot)
|
||
(setf (ewoc--header new-ewoc) head)
|
||
(setf (ewoc--footer new-ewoc) foot)))
|
||
;; Return the ewoc
|
||
new-ewoc))
|
||
|
||
(defalias 'ewoc-data 'ewoc--node-data)
|
||
|
||
(defun ewoc-enter-first (ewoc data)
|
||
"Enter DATA first in EWOC."
|
||
(ewoc--set-buffer-bind-dll ewoc
|
||
(ewoc-enter-after ewoc (ewoc--node-nth dll 0) data)))
|
||
|
||
(defun ewoc-enter-last (ewoc data)
|
||
"Enter DATA last in EWOC."
|
||
(ewoc--set-buffer-bind-dll ewoc
|
||
(ewoc-enter-before ewoc (ewoc--node-nth dll -1) data)))
|
||
|
||
|
||
(defun ewoc-enter-after (ewoc node data)
|
||
"Enter a new element DATA after NODE in EWOC.
|
||
Returns the new NODE."
|
||
(ewoc--set-buffer-bind-dll ewoc
|
||
(ewoc-enter-before ewoc (ewoc--node-next dll node) data)))
|
||
|
||
(defun ewoc-enter-before (ewoc node data)
|
||
"Enter a new element DATA before NODE in EWOC.
|
||
Returns the new NODE."
|
||
(ewoc--set-buffer-bind-dll ewoc
|
||
(ewoc--node-enter-before
|
||
node
|
||
(ewoc--create-node
|
||
data
|
||
(ewoc--pretty-printer ewoc)
|
||
(ewoc--node-start-marker node)))))
|
||
|
||
(defun ewoc-next (ewoc node)
|
||
"Get the next node.
|
||
Returns nil if NODE is nil or the last element."
|
||
(when node
|
||
(ewoc--filter-hf-nodes
|
||
ewoc (ewoc--node-next (ewoc--dll ewoc) node))))
|
||
|
||
(defun ewoc-prev (ewoc node)
|
||
"Get the previous node.
|
||
Returns nil if NODE is nil or the first element."
|
||
(when node
|
||
(ewoc--filter-hf-nodes
|
||
ewoc
|
||
(ewoc--node-prev (ewoc--dll ewoc) node))))
|
||
|
||
|
||
(defun ewoc-nth (ewoc n)
|
||
"Return the Nth node.
|
||
N counts from zero. Return nil if there is less than N elements.
|
||
If N is negative, return the -(N+1)th last element.
|
||
Thus, (ewoc-nth dll 0) returns the first node,
|
||
and (ewoc-nth dll -1) returns the last node.
|
||
Use `ewoc--node-data' to extract the data from the node."
|
||
;; Skip the header (or footer, if n is negative).
|
||
(setq n (if (< n 0) (1- n) (1+ n)))
|
||
(ewoc--filter-hf-nodes ewoc
|
||
(ewoc--node-nth (ewoc--dll ewoc) n)))
|
||
|
||
(defun ewoc-map (map-function ewoc &rest args)
|
||
"Apply MAP-FUNCTION to all elements in EWOC.
|
||
MAP-FUNCTION is applied to the first element first.
|
||
If MAP-FUNCTION returns non-nil the element will be refreshed (its
|
||
pretty-printer will be called once again).
|
||
|
||
Note that the buffer for EWOC will be the current buffer when
|
||
MAP-FUNCTION is called. MAP-FUNCTION must restore the current
|
||
buffer before it returns, if it changes it.
|
||
|
||
If more than two arguments are given, the remaining
|
||
arguments will be passed to MAP-FUNCTION."
|
||
(ewoc--set-buffer-bind-dll-let* ewoc
|
||
((footer (ewoc--footer ewoc))
|
||
(node (ewoc--node-nth dll 1)))
|
||
(while (not (eq node footer))
|
||
(if (apply map-function (ewoc--node-data node) args)
|
||
(ewoc--refresh-node (ewoc--pretty-printer ewoc) node))
|
||
(setq node (ewoc--node-next dll node)))))
|
||
|
||
(defun ewoc-filter (ewoc predicate &rest args)
|
||
"Remove all elements in EWOC for which PREDICATE returns nil.
|
||
Note that the buffer for EWOC will be current-buffer when PREDICATE
|
||
is called. PREDICATE must restore the current buffer before it returns
|
||
if it changes it.
|
||
The PREDICATE is called with the element as its first argument. If any
|
||
ARGS are given they will be passed to the PREDICATE."
|
||
(ewoc--set-buffer-bind-dll-let* ewoc
|
||
((node (ewoc--node-nth dll 1))
|
||
(footer (ewoc--footer ewoc))
|
||
(next nil))
|
||
(while (not (eq node footer))
|
||
(setq next (ewoc--node-next dll node))
|
||
(unless (apply predicate (ewoc--node-data node) args)
|
||
(ewoc--delete-node-internal ewoc node))
|
||
(setq node next))))
|
||
|
||
(defun ewoc-locate (ewoc &optional pos guess)
|
||
"Return the node that POS (a buffer position) is within.
|
||
POS may be a marker or an integer. It defaults to point.
|
||
GUESS should be a node that it is likely to be near POS.
|
||
|
||
If POS points before the first element, the first node is returned.
|
||
If POS points after the last element, the last node is returned.
|
||
If the EWOC is empty, nil is returned."
|
||
(unless pos (setq pos (point)))
|
||
(ewoc--set-buffer-bind-dll-let* ewoc
|
||
((footer (ewoc--footer ewoc)))
|
||
|
||
(cond
|
||
;; Nothing present?
|
||
((eq (ewoc--node-nth dll 1) (ewoc--node-nth dll -1))
|
||
nil)
|
||
|
||
;; Before second elem?
|
||
((< pos (ewoc--node-start-marker (ewoc--node-nth dll 2)))
|
||
(ewoc--node-nth dll 1))
|
||
|
||
;; After one-before-last elem?
|
||
((>= pos (ewoc--node-start-marker (ewoc--node-nth dll -2)))
|
||
(ewoc--node-nth dll -2))
|
||
|
||
;; We now know that pos is within a elem.
|
||
(t
|
||
;; Make an educated guess about which of the three known
|
||
;; node'es (the first, the last, or GUESS) is nearest.
|
||
(let* ((best-guess (ewoc--node-nth dll 1))
|
||
(distance (abs (- pos (ewoc--node-start-marker best-guess)))))
|
||
(when guess
|
||
(let ((d (abs (- pos (ewoc--node-start-marker guess)))))
|
||
(when (< d distance)
|
||
(setq distance d)
|
||
(setq best-guess guess))))
|
||
|
||
(let* ((g (ewoc--node-nth dll -1)) ;Check the last elem
|
||
(d (abs (- pos (ewoc--node-start-marker g)))))
|
||
(when (< d distance)
|
||
(setq distance d)
|
||
(setq best-guess g)))
|
||
|
||
(when (ewoc--last-node ewoc) ;Check "previous".
|
||
(let* ((g (ewoc--last-node ewoc))
|
||
(d (abs (- pos (ewoc--node-start-marker g)))))
|
||
(when (< d distance)
|
||
(setq distance d)
|
||
(setq best-guess g))))
|
||
|
||
;; best-guess is now a "best guess".
|
||
;; Find the correct node. First determine in which direction
|
||
;; it lies, and then move in that direction until it is found.
|
||
|
||
(cond
|
||
;; Is pos after the guess?
|
||
((>= pos
|
||
(ewoc--node-start-marker best-guess))
|
||
;; Loop until we are exactly one node too far down...
|
||
(while (>= pos (ewoc--node-start-marker best-guess))
|
||
(setq best-guess (ewoc--node-next dll best-guess)))
|
||
;; ...and return the previous node.
|
||
(ewoc--node-prev dll best-guess))
|
||
|
||
;; Pos is before best-guess
|
||
(t
|
||
(while (< pos (ewoc--node-start-marker best-guess))
|
||
(setq best-guess (ewoc--node-prev dll best-guess)))
|
||
best-guess)))))))
|
||
|
||
(defun ewoc-invalidate (ewoc &rest nodes)
|
||
"Refresh some elements.
|
||
The pretty-printer set for EWOC will be called for all NODES."
|
||
(ewoc--set-buffer-bind-dll ewoc
|
||
(dolist (node nodes)
|
||
(ewoc--refresh-node (ewoc--pretty-printer ewoc) node))))
|
||
|
||
(defun ewoc-goto-prev (ewoc arg)
|
||
"Move point to the ARGth previous element.
|
||
Don't move if we are at the first element, or if EWOC is empty.
|
||
Returns the node we moved to."
|
||
(ewoc--set-buffer-bind-dll-let* ewoc
|
||
((node (ewoc-locate ewoc (point))))
|
||
(when node
|
||
;; If we were past the last element, first jump to it.
|
||
(when (>= (point) (ewoc--node-start-marker (ewoc--node-right node)))
|
||
(setq arg (1- arg)))
|
||
(while (and node (> arg 0))
|
||
(setq arg (1- arg))
|
||
(setq node (ewoc--node-prev dll node)))
|
||
;; Never step above the first element.
|
||
(unless (ewoc--filter-hf-nodes ewoc node)
|
||
(setq node (ewoc--node-nth dll 1)))
|
||
(ewoc-goto-node ewoc node))))
|
||
|
||
(defun ewoc-goto-next (ewoc arg)
|
||
"Move point to the ARGth next element.
|
||
Returns the node (or nil if we just passed the last node)."
|
||
(ewoc--set-buffer-bind-dll-let* ewoc
|
||
((node (ewoc-locate ewoc (point))))
|
||
(while (and node (> arg 0))
|
||
(setq arg (1- arg))
|
||
(setq node (ewoc--node-next dll node)))
|
||
;; Never step below the first element.
|
||
;; (unless (ewoc--filter-hf-nodes ewoc node)
|
||
;; (setq node (ewoc--node-nth dll -2)))
|
||
(ewoc-goto-node ewoc node)))
|
||
|
||
(defun ewoc-goto-node (ewoc node)
|
||
"Move point to NODE."
|
||
(ewoc--set-buffer-bind-dll ewoc
|
||
(goto-char (ewoc--node-start-marker node))
|
||
(if goal-column (move-to-column goal-column))
|
||
(setf (ewoc--last-node ewoc) node)))
|
||
|
||
(defun ewoc-refresh (ewoc)
|
||
"Refresh all data in EWOC.
|
||
The pretty-printer that was specified when the EWOC was created
|
||
will be called for all elements in EWOC.
|
||
Note that `ewoc-invalidate' is more efficient if only a small
|
||
number of elements needs to be refreshed."
|
||
(ewoc--set-buffer-bind-dll-let* ewoc
|
||
((footer (ewoc--footer ewoc)))
|
||
(let ((inhibit-read-only t))
|
||
(delete-region (ewoc--node-start-marker (ewoc--node-nth dll 1))
|
||
(ewoc--node-start-marker footer))
|
||
(goto-char (ewoc--node-start-marker footer))
|
||
(let ((node (ewoc--node-nth dll 1)))
|
||
(while (not (eq node footer))
|
||
(set-marker (ewoc--node-start-marker node) (point))
|
||
(funcall (ewoc--pretty-printer ewoc)
|
||
(ewoc--node-data node))
|
||
(insert "\n")
|
||
(setq node (ewoc--node-next dll node)))))
|
||
(set-marker (ewoc--node-start-marker footer) (point))))
|
||
|
||
(defun ewoc-collect (ewoc predicate &rest args)
|
||
"Select elements from EWOC using PREDICATE.
|
||
Return a list of all selected data elements.
|
||
PREDICATE is a function that takes a data element as its first
|
||
argument. The elements on the returned list will appear in the
|
||
same order as in the buffer. You should not rely on the order of
|
||
calls to PREDICATE.
|
||
Note that the buffer the EWOC is displayed in is the current
|
||
buffer when PREDICATE is called. PREDICATE must restore it if it
|
||
changes it.
|
||
If more than two arguments are given the
|
||
remaining arguments will be passed to PREDICATE."
|
||
(ewoc--set-buffer-bind-dll-let* ewoc
|
||
((header (ewoc--header ewoc))
|
||
(node (ewoc--node-nth dll -2))
|
||
result)
|
||
(while (not (eq node header))
|
||
(if (apply predicate (ewoc--node-data node) args)
|
||
(push (ewoc--node-data node) result))
|
||
(setq node (ewoc--node-prev dll node)))
|
||
(nreverse result)))
|
||
|
||
(defun ewoc-buffer (ewoc)
|
||
"Return the buffer that is associated with EWOC.
|
||
Returns nil if the buffer has been deleted."
|
||
(let ((buf (ewoc--buffer ewoc)))
|
||
(when (buffer-name buf) buf)))
|
||
|
||
(defun ewoc-get-hf (ewoc)
|
||
"Return a cons cell containing the (HEADER . FOOTER) of EWOC."
|
||
(cons (ewoc--node-data (ewoc--header ewoc))
|
||
(ewoc--node-data (ewoc--footer ewoc))))
|
||
|
||
(defun ewoc-set-hf (ewoc header footer)
|
||
"Set the HEADER and FOOTER of EWOC."
|
||
(setf (ewoc--node-data (ewoc--header ewoc)) header)
|
||
(setf (ewoc--node-data (ewoc--footer ewoc)) footer)
|
||
(ewoc--refresh-node (lambda (x) (insert header)) (ewoc--header ewoc))
|
||
(ewoc--refresh-node (lambda (x) (insert footer)) (ewoc--footer ewoc)))
|
||
|
||
|
||
(provide 'ewoc)
|
||
|
||
;;; Local Variables:
|
||
;;; eval: (put 'ewoc--set-buffer-bind-dll 'lisp-indent-hook 1)
|
||
;;; eval: (put 'ewoc--set-buffer-bind-dll-let* 'lisp-indent-hook 2)
|
||
;;; End:
|
||
|
||
;;; arch-tag: d78915b9-9a07-44bf-aac6-04a1fc1bd6d4
|
||
;;; ewoc.el ends here
|