Source

hyperbole / kotl / kview.el

   1
   2
   3
   4
   5
   6
   7
   8
   9
  10
  11
  12
  13
  14
  15
  16
  17
  18
  19
  20
  21
  22
  23
  24
  25
  26
  27
  28
  29
  30
  31
  32
  33
  34
  35
  36
  37
  38
  39
  40
  41
  42
  43
  44
  45
  46
  47
  48
  49
  50
  51
  52
  53
  54
  55
  56
  57
  58
  59
  60
  61
  62
  63
  64
  65
  66
  67
  68
  69
  70
  71
  72
  73
  74
  75
  76
  77
  78
  79
  80
  81
  82
  83
  84
  85
  86
  87
  88
  89
  90
  91
  92
  93
  94
  95
  96
  97
  98
  99
 100
 101
 102
 103
 104
 105
 106
 107
 108
 109
 110
 111
 112
 113
 114
 115
 116
 117
 118
 119
 120
 121
 122
 123
 124
 125
 126
 127
 128
 129
 130
 131
 132
 133
 134
 135
 136
 137
 138
 139
 140
 141
 142
 143
 144
 145
 146
 147
 148
 149
 150
 151
 152
 153
 154
 155
 156
 157
 158
 159
 160
 161
 162
 163
 164
 165
 166
 167
 168
 169
 170
 171
 172
 173
 174
 175
 176
 177
 178
 179
 180
 181
 182
 183
 184
 185
 186
 187
 188
 189
 190
 191
 192
 193
 194
 195
 196
 197
 198
 199
 200
 201
 202
 203
 204
 205
 206
 207
 208
 209
 210
 211
 212
 213
 214
 215
 216
 217
 218
 219
 220
 221
 222
 223
 224
 225
 226
 227
 228
 229
 230
 231
 232
 233
 234
 235
 236
 237
 238
 239
 240
 241
 242
 243
 244
 245
 246
 247
 248
 249
 250
 251
 252
 253
 254
 255
 256
 257
 258
 259
 260
 261
 262
 263
 264
 265
 266
 267
 268
 269
 270
 271
 272
 273
 274
 275
 276
 277
 278
 279
 280
 281
 282
 283
 284
 285
 286
 287
 288
 289
 290
 291
 292
 293
 294
 295
 296
 297
 298
 299
 300
 301
 302
 303
 304
 305
 306
 307
 308
 309
 310
 311
 312
 313
 314
 315
 316
 317
 318
 319
 320
 321
 322
 323
 324
 325
 326
 327
 328
 329
 330
 331
 332
 333
 334
 335
 336
 337
 338
 339
 340
 341
 342
 343
 344
 345
 346
 347
 348
 349
 350
 351
 352
 353
 354
 355
 356
 357
 358
 359
 360
 361
 362
 363
 364
 365
 366
 367
 368
 369
 370
 371
 372
 373
 374
 375
 376
 377
 378
 379
 380
 381
 382
 383
 384
 385
 386
 387
 388
 389
 390
 391
 392
 393
 394
 395
 396
 397
 398
 399
 400
 401
 402
 403
 404
 405
 406
 407
 408
 409
 410
 411
 412
 413
 414
 415
 416
 417
 418
 419
 420
 421
 422
 423
 424
 425
 426
 427
 428
 429
 430
 431
 432
 433
 434
 435
 436
 437
 438
 439
 440
 441
 442
 443
 444
 445
 446
 447
 448
 449
 450
 451
 452
 453
 454
 455
 456
 457
 458
 459
 460
 461
 462
 463
 464
 465
 466
 467
 468
 469
 470
 471
 472
 473
 474
 475
 476
 477
 478
 479
 480
 481
 482
 483
 484
 485
 486
 487
 488
 489
 490
 491
 492
 493
 494
 495
 496
 497
 498
 499
 500
 501
 502
 503
 504
 505
 506
 507
 508
 509
 510
 511
 512
 513
 514
 515
 516
 517
 518
 519
 520
 521
 522
 523
 524
 525
 526
 527
 528
 529
 530
 531
 532
 533
 534
 535
 536
 537
 538
 539
 540
 541
 542
 543
 544
 545
 546
 547
 548
 549
 550
 551
 552
 553
 554
 555
 556
 557
 558
 559
 560
 561
 562
 563
 564
 565
 566
 567
 568
 569
 570
 571
 572
 573
 574
 575
 576
 577
 578
 579
 580
 581
 582
 583
 584
 585
 586
 587
 588
 589
 590
 591
 592
 593
 594
 595
 596
 597
 598
 599
 600
 601
 602
 603
 604
 605
 606
 607
 608
 609
 610
 611
 612
 613
 614
 615
 616
 617
 618
 619
 620
 621
 622
 623
 624
 625
 626
 627
 628
 629
 630
 631
 632
 633
 634
 635
 636
 637
 638
 639
 640
 641
 642
 643
 644
 645
 646
 647
 648
 649
 650
 651
 652
 653
 654
 655
 656
 657
 658
 659
 660
 661
 662
 663
 664
 665
 666
 667
 668
 669
 670
 671
 672
 673
 674
 675
 676
 677
 678
 679
 680
 681
 682
 683
 684
 685
 686
 687
 688
 689
 690
 691
 692
 693
 694
 695
 696
 697
 698
 699
 700
 701
 702
 703
 704
 705
 706
 707
 708
 709
 710
 711
 712
 713
 714
 715
 716
 717
 718
 719
 720
 721
 722
 723
 724
 725
 726
 727
 728
 729
 730
 731
 732
 733
 734
 735
 736
 737
 738
 739
 740
 741
 742
 743
 744
 745
 746
 747
 748
 749
 750
 751
 752
 753
 754
 755
 756
 757
 758
 759
 760
 761
 762
 763
 764
 765
 766
 767
 768
 769
 770
 771
 772
 773
 774
 775
 776
 777
 778
 779
 780
 781
 782
 783
 784
 785
 786
 787
 788
 789
 790
 791
 792
 793
 794
 795
 796
 797
 798
 799
 800
 801
 802
 803
 804
 805
 806
 807
 808
 809
 810
 811
 812
 813
 814
 815
 816
 817
 818
 819
 820
 821
 822
 823
 824
 825
 826
 827
 828
 829
 830
 831
 832
 833
 834
 835
 836
 837
 838
 839
 840
 841
 842
 843
 844
 845
 846
 847
 848
 849
 850
 851
 852
 853
 854
 855
 856
 857
 858
 859
 860
 861
 862
 863
 864
 865
 866
 867
 868
 869
 870
 871
 872
 873
 874
 875
 876
 877
 878
 879
 880
 881
 882
 883
 884
 885
 886
 887
 888
 889
 890
 891
 892
 893
 894
 895
 896
 897
 898
 899
 900
 901
 902
 903
 904
 905
 906
 907
 908
 909
 910
 911
 912
 913
 914
 915
 916
 917
 918
 919
 920
 921
 922
 923
 924
 925
 926
 927
 928
 929
 930
 931
 932
 933
 934
 935
 936
 937
 938
 939
 940
 941
 942
 943
 944
 945
 946
 947
 948
 949
 950
 951
 952
 953
 954
 955
 956
 957
 958
 959
 960
 961
 962
 963
 964
 965
 966
 967
 968
 969
 970
 971
 972
 973
 974
 975
 976
 977
 978
 979
 980
 981
 982
 983
 984
 985
 986
 987
 988
 989
 990
 991
 992
 993
 994
 995
 996
 997
 998
 999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
;;!emacs
;;
;; FILE:         kview.el
;; SUMMARY:      Display handling of koutlines.
;; USAGE:        GNU Emacs Lisp Library
;; KEYWORDS:     outlines, wp
;;
;; AUTHOR:       Bob Weiner
;; ORG:          BeOpen.com
;;
;; ORIG-DATE:    6/30/93
;; LAST-MOD:     13-Jun-99 at 02:18:15 by Bob Weiner
;;
;; Copyright (C) 1993-1999  BeOpen.com
;; See the "../HY-COPY" file for license information.
;;
;; This file is part of Hyperbole.

;;; ************************************************************************
;;; Other required Lisp Libraries
;;; ************************************************************************
(mapcar 'require '(klabel kfill hypb))
(eval-when-compile (mapc #'require '(klabel kfill hypb)))

;;; ************************************************************************
;;; Public variables
;;; ************************************************************************

(set-default 'kview nil)

(defvar kview:default-blank-lines t
  "*Default setting of whether to show blank lines between koutline cells.
T means show them, nil means don't show them.")

(defvar kview:default-levels-to-show 0
  "*Default number of cell levels to show.  0 means all levels.")

(defvar kview:default-lines-to-show 0
  "*Default number of lines per cell to show.  0 means all lines.")


(defvar kview:default-label-min-width 4
  "*Minimum width to which to pad labels in a kotl view.
Labels are padded with spaces on the left.")

(defvar kview:default-label-separator ". "
  "*Default string of characters to insert between label and contents of a koutline cell.")

(defvar kview:default-label-type 'alpha
  "*Default label-type to use for new koutlines.
It must be one of the following symbols:
  no              for no labels
  id              for permanent idstamp labels, e.g. 001, 002, etc.
  alpha           for `1a2' full alphanumeric labels
  legal           for `1.1.2' labels
  partial-alpha   for partial alphanumeric labels, e.g. `2' for node `1a2'
  star            for multi-star labeling, e.g. `***'.")

(defvar kview:default-level-indent 3
  "*Default number of spaces to indent each succeeding level in koutlines.")

;;; ************************************************************************
;;; Public functions
;;; ************************************************************************

;;;
;;; kcell-view
;;;

(defun kcell-view:backward (&optional visible-p label-sep-len)
  "Move to start of the prior cell at the same level as the current cell.
With optional VISIBLE-P, consider only visible cells.
Return t unless no such cell."
  (or label-sep-len (setq label-sep-len
			  (kview:label-separator-length kview)))
  (let ((opoint (point))
	(found) (done)
	(curr-indent 0)
	(start-indent (kcell-view:indent nil label-sep-len)))
    (while (and (not (or found done))
		(kcell-view:previous visible-p label-sep-len))
      (if (bobp)
	  (progn (setq done t)
		 (goto-char opoint))
	(setq curr-indent (kcell-view:indent nil label-sep-len))
	(cond ((= curr-indent start-indent)
	       (goto-char (kcell-view:start nil label-sep-len))
	       (setq found t))
	      ((< curr-indent start-indent)
	       ;; Went past start of this tree without a match.
	       (setq done t)
	       (goto-char opoint))
	      ;; else go to prior node
	      )))
    found))

(defun kview:beginning-of-actual-line ()
  "Go to the beginning of the current line whether collapsed or not."
  (if (re-search-backward "[\n\r]" nil 'move)
      (forward-char 1)))

(defun kcell-view:cell (&optional pos)
  "Return kcell at optional POS or point."
  (kproperty:get (kcell-view:plist-point pos) 'kcell))

(defun kcell-view:child (&optional visible-p label-sep-len)
  "Move to start of current cell's child.
With optional VISIBLE-P, consider only visible children.
Return t unless cell has no matching child.
Optional LABEL-SEP-LEN is the length of the separation between
a cell's label and the start of its contents."
  (let* ((opoint (point))
	 (prev-indent (kcell-view:indent nil label-sep-len))
	 (next (kcell-view:next visible-p label-sep-len)))
    (or label-sep-len (setq label-sep-len
			    (kview:label-separator-length kview)))
    ;; Since kcell-view:next leaves point at the start of a cell, the cell's
    ;; indent is just the current-column of point.
    (if (and next (> (current-column) prev-indent))
	t
      ;; Move back to previous point and return nil.
      (goto-char opoint)
      nil)))

(defun kcell-view:child-p (&optional pos visible-p label-sep-len)
  "Return t if cell at optional POS or point has a child.
With optional VISIBLE-P, consider only visible children.
Optional LABEL-SEP-LEN is the length of the separation between
a cell's label and the start of its contents."
  (save-excursion
    (if pos (goto-char pos))
    (kcell-view:child visible-p label-sep-len)))

(defun kcell-view:collapse (&optional pos label-sep-len)
  "Collapse cell at optional POS or point within the current view."
  (save-excursion
    (goto-char (kcell-view:start pos label-sep-len))
    (subst-char-in-region (point) (kcell-view:end-contents) ?\n ?\r t)))

(defun kcell-view:collapsed-p (&optional pos label-sep-len)
  "Return t if cell at optional POS or point is collapsed within the current view."
  (save-excursion
    (goto-char (kcell-view:start pos label-sep-len))
    (if (search-forward "\r" (kcell-view:end-contents) t)
	t)))

(defun kcell-view:contents (&optional pos)
  "Return contents of cell at optional POS or point."
  (save-excursion
    (if pos (goto-char pos))
    (let ((indent (kcell-view:indent))
	  (start (kcell-view:start))
	  (end (kcell-view:end-contents)))
      ;; Remove indentation from all but first line.
      (hypb:replace-match-string
       (concat "\\([\n\r]\\)" (make-string indent ?\ ))
       (buffer-substring start end) "\\1"))))

(defun kcell-view:create (kview cell level klabel &optional no-fill)
  "Insert into KVIEW at point, CELL at LEVEL (1 = first level) with KLABEL.
Optional NO-FILL non-nil suppresses filling of cell's contents upon insertion
or movement."
  (if (= (kcell:idstamp cell) 0)
      nil
    (or no-fill (setq no-fill (kcell:get-attr cell 'no-fill)))
    (let* ((label-min-width (kview:label-min-width kview))
	   (label-fmt (format "%%%ds" label-min-width))
	   (label (if (string= klabel "") "" (format label-fmt klabel)))
	   (label-separator (if (string= klabel "") " "
			      (kview:label-separator kview)))
	   (mult-line-indent (* (1- level) (kview:level-indent kview)))
	   (thru-label (+ mult-line-indent label-min-width
			  (length label-separator)))
	   (old-point (point))
	   (fill-prefix (make-string thru-label ?\ ))
	   contents
	   new-point)
      (if no-fill (kcell:set-attr cell 'no-fill t))
      (insert fill-prefix)
      (setq contents (kview:insert-contents cell nil no-fill fill-prefix))
      ;; Insert lines to separate cell from next.
      (insert (if (or no-fill (equal contents ""))
		  "\n\n" "\n"))
      (if (kview:get-attr kview 'blank-lines)
	  nil
	;; Make blank lines invisible.
	(kproperty:put (1- (point)) (min (point) (point-max))
		       '(invisible t)))
      (kfile:narrow-to-kcells)
      (setq new-point (point))
      (goto-char old-point)
      ;; Delete leading spaces used to get fill right in first cell
      ;; line.  Replace it with label.
      (delete-char thru-label)
      (insert (format
	       (format "%%%ds" (- thru-label (length label-separator)))
	       label))
      (setq old-point (point))
      (insert label-separator)
      (goto-char old-point)
      ;; Add cell's attributes to the text property list at point.
      (kproperty:set 'kcell cell)
      (goto-char new-point))))

(defun kcell-view:end (&optional pos)
  "Return end position of cell from optional POS or point.
Includes blank lines following cell contents."
  (or pos (setq pos (point)))
  (save-excursion
    (or (re-search-forward "[\n\r][\n\r]" nil t)
	(point-max))))

(defun kcell-view:end-contents (&optional pos)
  "Return end position of cell contents from optional POS or point.
Excludes blank lines following cell contents."
  (save-excursion
    (if pos (goto-char pos))
    (goto-char (kcell-view:end))
    (skip-chars-backward "\n\r")
    (point)))

(defun kcell-view:expand (&optional pos label-sep-len)
  "Expand cell at optional POS or point within the current view."
  (save-excursion
    (goto-char (kcell-view:start pos label-sep-len))
    (subst-char-in-region (point) (kcell-view:end-contents) ?\r ?\n t)))

(defun kcell-view:forward (&optional visible-p label-sep-len)
  "Move to start of the following cell at the same level as the current cell.
With optional VISIBLE-P, consider only visible cells.
Return t unless no such cell."
  (or label-sep-len (setq label-sep-len
			  (kview:label-separator-length kview)))
  (let ((opoint (point))
	(found) (done)
	(curr-indent 0)
	(start-indent (kcell-view:indent nil label-sep-len)))
    (while (and (not (or found done))
		(kcell-view:next visible-p label-sep-len))
      (setq curr-indent (kcell-view:indent nil label-sep-len))
      (cond ((= curr-indent start-indent)
	     (goto-char (kcell-view:start nil label-sep-len))
	     (setq found t))
	    ((< curr-indent start-indent)
	     ;; Went past end of this tree without a match.
	     (setq done t)
	     (goto-char opoint))
	    ;; else go to following node
	    ))
    ;; If didn't find a match, return to original point.
    (or found (goto-char opoint))
    found))

(defun kcell-view:get-attr (attribute &optional pos)
  "Return ATTRIBUTE's value for current cell or cell at optional POS."
  (save-excursion
    (if pos (goto-char pos))
    (kcell:get-attr (kcell-view:cell) attribute)))

(defun kcell-view:idstamp (&optional pos)
  "Return idstamp string of cell at optional POS or point."
  (save-excursion
    (if pos (goto-char pos))
    (format "0%s" (or (kcell:idstamp (kcell-view:cell)) ""))))

(defun kcell-view:indent (&optional pos label-sep-len)
  "Return indentation of cell at optional POS or point.
Optional LABEL-SEP-LEN is the view-specific length of the separator between a
cell's label and the start of its contents."
  (+ (save-excursion
       (kcell-view:to-label-end pos)
       (current-column))
     (or label-sep-len (kview:label-separator-length kview))))

(defun kcell-view:label (&optional pos)
  "Return displayed label string of cell at optional POS or point.
If labels are off, return cell's idstamp as a string."
  (save-excursion
    (if pos (goto-char pos))
    (let ((label-type (kview:label-type kview)))
      (if (eq label-type 'no)
	  (kcell-view:idstamp)
	(kcell-view:to-label-end)
	(buffer-substring (point) (progn (skip-chars-backward "^ \t\n\r")
					 (point)))))))

(defun kcell-view:level (&optional pos label-sep-len indent)
  "Return cell level relative to top cell of the outline for current cell or one at optional POS.
0 = top cell level, 1 = 1st level in outline.
Optional LABEL-SEP-LEN is length of spaces between a cell label and its the
start of its body in the current view.  Optional INDENT is the indentation in
characters of the cell whose level is desired."
  (or label-sep-len (setq label-sep-len (kview:label-separator-length kview)))
  (save-excursion
    (if pos (goto-char pos))
    (/ (- (or indent (kcell-view:indent nil label-sep-len)) label-sep-len)
       (kview:level-indent kview))))

(defun kcell-view:line (&optional pos)
  "Return contents of cell line at point or optional POS as a string."
  (save-excursion
    (if pos (goto-char pos))
    (if (kview:valid-position-p)
	(buffer-substring
	 (kotl-mode:start-of-line)
	 (kotl-mode:end-of-line))
      (error "(kcell-view:line): Invalid position, `%d'" (point)))))

(defun kcell-view:next (&optional visible-p label-sep-len)
  "Move to start of next cell within current view.
With optional VISIBLE-P, consider only visible cells.
Return t unless no next cell."
  (let ((opoint (point))
	pos)
    ;;
    ;; If a subtree is collapsed, be sure we end up at the start of a visible
    ;; cell rather than within an invisible one.
    (if visible-p
	(progn (goto-char (kcell-view:end-contents)) (end-of-line)))
    (setq pos (kproperty:next-single-change (point) 'kcell))
    (if (or (null pos)
	    (if (goto-char pos) (kotl-mode:eobp)))
	(progn (goto-char opoint)
	       nil)
      (goto-char (kcell-view:start nil label-sep-len))
      (not (eq opoint (point))))))

(defun kcell-view:operate (function &optional start end)
  "Invoke FUNCTION with view restricted to current cell contents.
Optional START and END are start and endpoints of cell to use."
  (save-restriction
    (narrow-to-region (or start (kcell-view:start))
		      (or end (kcell-view:end-contents)))
    (funcall function)))

(defun kcell-view:parent (&optional visible-p label-sep-len)
  "Move to start of current cell's parent within current view.
If parent is top cell, move to first cell within view and return 0.
Otherwise, return t unless optional VISIBLE-P is non-nil and the parent cell
is not part of the current view."
  (or label-sep-len (setq label-sep-len (kview:label-separator-length kview)))
  (let ((opoint (point))
	(parent-level (1- (kcell-view:level nil label-sep-len))))
    (if (= parent-level 0) ;; top cell
	(progn (goto-char (point-min))
	       (goto-char (kcell-view:start nil label-sep-len))
	       0)
      ;; Skip from point back past any siblings
      (while (kcell-view:backward visible-p label-sep-len))
      ;; Move back to parent.
      (if (kcell-view:previous visible-p label-sep-len)
	  t
	;; Move back to previous point and return nil.
	(goto-char opoint)
	nil))))

(defun kcell-view:previous (&optional visible-p label-sep-len)
  "Move to start of previous cell within current view.
With optional VISIBLE-P, consider only visible cells.
Return t unless no previous cell."
  (let ((opoint (point))
	(pos (point)))
    (goto-char (kcell-view:start nil label-sep-len))
    ;;
    ;; If a subtree is collapsed, be sure we end up at the start of a visible
    ;; cell rather than within an invisible one.
    (if visible-p
	(beginning-of-line)
      (if (setq pos (kproperty:previous-single-change (point) 'kcell))
	  (goto-char pos)))
    (if (and pos (not (kotl-mode:bobp))
	     (setq pos (kproperty:previous-single-change (point) 'kcell)))
	(progn (goto-char pos)
	       (skip-chars-backward "\n\r")
	       (if visible-p (beginning-of-line))
	       (goto-char (kcell-view:start nil label-sep-len))
	       (not (eq opoint (point))))
      ;; No previous cell exists
      (goto-char opoint)
      nil)))

(defun kcell-view:plist (&optional pos)
  "Return attributes associated with cell at optional POS or point."
  (kcell:plist (kcell-view:cell pos)))

(defun kcell-view:plist-point (&optional pos)
  "Return buffer position of attributes associated with cell at optional POS or point."
  (save-excursion (1+ (kcell-view:to-label-end pos))))

(defun kcell-view:to-label-end (&optional pos)
  "Move point after end of current cell's label and return point."
  (if pos (goto-char pos))
  (kview:end-of-actual-line)
  (cond ((null kview)
	 (error "(kcell-view:to-label-end): Invalid kview; try {M-x kotl-mode RET} to fix it."))
	(klabel-type:changing-flag
	 ;; When changing from one label type to another, e.g. alpha to
	 ;; legal, we can't depend on the label being of the type given by
	 ;; the kview, so use kcell properties to find label end.
	 (if (kproperty:get (1- (point)) 'kcell)
	     nil
	   ;; If not at beginning of cell contents, move there.
	   (goto-char (kproperty:previous-single-change (point) 'kcell)))
	 ;; Then move to end of label via embedded kcell property.
	 (goto-char (kproperty:previous-single-change (point) 'kcell)))
	((funcall (kview:get-attr kview 'to-label-end))
	 (point))
	(t (error "(kcell-view:to-label-end): Can't find end of current cell's label"))))

(defun kcell-view:reference (&optional pos relative-dir)
  "Return a reference to the kcell at optional POS or point for use in a link.
The reference is a string of the form, \"<kcell-file, cell-ref>\" where
cell-ref is as described in the documentation for `kcell:ref-to-id'.
Kcell-file is made relative to optional RELATIVE-DIR before it is returned."
  (format "<%s, %s=%s>" (hpath:relative-to buffer-file-name relative-dir)
	  (kcell-view:label pos) (kcell-view:idstamp pos)))

(defun kcell-view:remove-attr (attribute &optional pos)
  "Remove ATTRIBUTE, if any, for current cell or cell at optional POS."
  (interactive "*SAttribute to remove: ")
  (save-excursion
    (if pos (goto-char pos))
    (let ((kcell (kcell:remove-attr (kcell-view:cell) attribute)))
      (if (interactive-p)
	  (message "Cell <%s> now has no %s attribute."
		   (kcell-view:label) attribute))
      kcell)))

(defun kcell-view:set-attr (attribute value &optional pos)
  "Set ATTRIBUTE's VALUE for current cell or cell at optional POS and return the cell."
  (save-excursion
    (if pos (goto-char pos))
    ;; Returns kcell.
    (kcell:set-attr (kcell-view:cell) attribute value)))

(defun kcell-view:set-cell (kcell)
  "Attach KCELL property to cell at point."
  (save-excursion
    (kcell-view:to-label-end)
    (kproperty:set 'kcell kcell)))

(defun kcell-view:sibling-p (&optional pos visible-p label-sep-len)
  "Return t if cell at optional POS or point has a successor.
With optional VISIBLE-P, consider only visible siblings."
  (save-excursion
    (if pos (goto-char pos))
    (kcell-view:forward visible-p label-sep-len)))

(defun kcell-view:start (&optional pos label-sep-len)
  "Return start position of cell contents from optional POS or point."
  (save-excursion
    (+ (kcell-view:to-label-end pos)
       (or label-sep-len (kview:label-separator-length kview)))))

;;;
;;; kview - one view per buffer, multiple views per kotl
;;;

(defun kview:add-cell (klabel level &optional contents prop-list no-fill)
  "Create a new cell with full KLABEL and add it at point at LEVEL within outline.
1 = first level.  Optional cell CONTENTS and PROP-LIST may also be given, as
well as NO-FILL which skips filling of any CONTENTS.
Return new cell.  This function does not renumber any other cells."
  (let ((new-cell (kcell:create contents (kview:id-increment kview)
				prop-list)))
    (kcell-view:create kview new-cell level klabel no-fill)
    new-cell))

(defun kview:buffer (kview)
  "Return kview's buffer or nil if argument is not a kview."
  (if (kview:is-p kview)
      (get-buffer (kview:get-attr kview 'view-buffer-name))))

(defun kview:create (buffer-name
			 &optional id-counter label-type level-indent
			 label-separator label-min-width blank-lines
			 levels-to-show lines-to-show)
  "Return a new kview for BUFFER-NAME.
Optional ID-COUNTER is the maximum permanent id previously given out in this
outline.  Optional LABEL-TYPE, LEVEL-INDENT, LABEL-SEPARATOR, LABEL-MIN-WIDTH,
BLANK-LINES, LEVELS-TO-SHOW, and LINES-TO-SHOW may also be given, otherwise default values are used.

  See documentation of:
 `kview:default-label-type' for LABEL-TYPE,
 `kview:default-level-indent' for LEVEL-INDENT,
 `kview:default-label-separator' for LABEL-SEPARATOR,
 `kview:default-label-min-width' for LABEL-MIN-WIDTH,
 `kview:default-blank-lines' for BLANK-LINES,
 `kview:default-levels-to-show' for LEVELS-TO-SHOW,
 `kview:default-lines-to-show' for LINES-TO-SHOW."

  (let ((buf (get-buffer buffer-name)))
    (cond ((null buf)
	   (error "(kview:create): No such buffer, `%s'." buffer-name))
	  ((or (null id-counter) (= id-counter 0))
	   (setq id-counter 0))
	  ((not (integerp id-counter))
	   (error "(kview:create): 2nd arg, `%s', must be an integer." id-counter)))
    (set-buffer buf)
    (if (and (boundp 'kview) (eq (kview:buffer kview) buf))
	;; Don't recreate view if it exists.
	nil
      (make-local-variable 'kview)
      (setq kview
	    (list 'kview 'plist
		  (list 'view-buffer-name buffer-name
			'top-cell
			(kcell:create-top buffer-file-name id-counter)
			'label-type (or label-type kview:default-label-type)
			'label-min-width (or label-min-width
					     kview:default-label-min-width)
			'label-separator (or label-separator
					     kview:default-label-separator)
			'label-separator-length
			(length (or label-separator
				    kview:default-label-separator))
			'level-indent (or level-indent
					  kview:default-level-indent)
			'blank-lines
			(or blank-lines kview:default-blank-lines)
			'levels-to-show
			(or levels-to-show kview:default-levels-to-show)
			'lines-to-show
			(or lines-to-show kview:default-lines-to-show)
)))
      (kview:set-functions (or label-type kview:default-label-type)))
    kview))

;;; Using this stimulates an GNU Emacs V19.19 bug in text-property handling,
;;  visible when one deletes a sibling cell and then deletes the prior cell,
;;  the following cell is left with a different idstamp and its label
;;  displays as "0".  Using delete-char here would solve the problem but we
;;  suggest you upgrade to a newer version of GNU Emacs in which the bug is
;;  fixed.
(defun kview:delete-region (start end)
  "Delete cells between START and END points from current view."
  (delete-region start end))

(defun kview:end-of-actual-line ()
  "Go to the end of the current line whether collapsed or not."
  (if (re-search-forward "[\n\r]" nil 'move)
      (backward-char 1)))

(defun kview:fill-region (start end &optional kcell justify)
  "Fill region between START and END within current view.
With optional KCELL, assume START and END delimit that cell's contents.
With optional JUSTIFY, justify region as well.
Fill-prefix must be a string of spaces the length of this cell's indent, when
this function is called."
  (let ((opoint (set-marker (make-marker) (point)))
	(label-sep-len (kview:label-separator-length kview))
	(continue t)
	prev-point)
    (goto-char start)
    (while continue
      (if (kcell:get-attr (or kcell (kcell-view:cell)) 'no-fill)
	  (setq continue (kcell-view:next nil label-sep-len))
	(fill-paragraph justify t)
	(setq prev-point (point))
	(forward-paragraph)
	(re-search-forward "[^ \t\n\r]" nil t))
      (setq continue (and continue
			  (/= (point) prev-point)
			  (< (point) (min end (point-max))))))
    ;; Return to original point.
    (goto-char opoint)
    (set-marker opoint nil)))

(cond ((and hyperb:xemacs-p (or (>= emacs-minor-version 12)
				(> emacs-major-version 19)))
       (defun kview:goto-cell-id (id-string)
	 "Move point to start of cell with idstamp ID-STRING and return t, else nil."
	 (let ((cell-id (string-to-int id-string))
	       label-end kcell)
	   (setq label-end
		 (map-extents
		  (function (lambda (extent unused)
			      (setq kcell (extent-property extent 'kcell))
			      (if (= (kcell:idstamp kcell) cell-id)
				  (extent-end-position extent))))
		  nil nil nil nil nil 'kcell))
	   (if (null label-end)
	       nil
	     (goto-char label-end)
	     t))))
      (hyperb:xemacs-p
       (defun kview:goto-cell-id (id-string)
	 "Move point to start of cell with idstamp ID-STRING and return t, else nil."
	 (let ((cell-id (string-to-int id-string))
	       label-end kcell)
	   (setq label-end
		 (map-extents
		  (function (lambda (extent unused)
			      (setq kcell (extent-property extent 'kcell))
			      (and kcell (= (kcell:idstamp kcell) cell-id)
				   (extent-end-position extent))))))
	   (if (null label-end)
	       nil
	     (goto-char label-end)
	     t))))
      ;; Emacs 19
      (t (defun kview:goto-cell-id (id-string)
	   "Move point to start of cell with idstamp ID-STRING and return t, else nil."
	   (let ((cell-id (string-to-int id-string))
		 (opoint (point))
		 pos kcell)
	     (goto-char (point-min))
	     (while (and (setq pos
			       (kproperty:next-single-change (point) 'kcell))
			 (goto-char pos)
			 (or (null (setq kcell (kproperty:get pos 'kcell)))
			     (/= (kcell:idstamp kcell) cell-id))))
	     (if pos
		 (progn
		   (forward-char (kview:label-separator-length kview))
		   t)
	       (goto-char opoint)
	       nil))))
)

(defun kview:id-increment (kview)
  "Return next idstamp (an integer) for KVIEW."
  (let* ((top-cell (kview:get-attr kview 'top-cell))
	 (counter (1+ (kcell:get-attr top-cell 'id-counter))))
    (kcell:set-attr top-cell 'id-counter counter)
    counter))

(defun kview:idstamp-to-label (permanent-id)
  "Return relative label for cell with PERMANENT-ID within current kview."
  (save-excursion
    (if (kotl-mode:goto-cell permanent-id)
	(kcell-view:label))))

(defun kview:insert-contents (kcell contents no-fill fill-prefix)
  "Insert KCELL's CONTENTS into view at point and fill resulting paragraphs, unless NO-FILL is non-nil.
FILL-PREFIX is the indentation string for the current cell.
If CONTENTS is nil, get contents from KCELL.  Return contents inserted (this
value may differ from the value passed in.)"
  (let ((start (point))
	end)
    (setq contents (or contents (kcell:contents kcell) ""))
    (insert contents)
    ;;
    ;; Delete any extra newlines at end of cell contents.
    (setq end (point))
    (skip-chars-backward "\n\r")
    (delete-region (point) end)
    (setq end (point))
    ;;
    (save-restriction
      (if no-fill
	  ;; Insert proper indent in all but the first line which has
	  ;; already been indented.
	  (progn
	    (narrow-to-region start end)
	    (goto-char (point-min))
	    (while (re-search-forward "[\n\r]" nil t)
	      (insert fill-prefix))
	    (goto-char (point-max)))
	;;
	;; Filling cell will insert proper indent on all lines.
	(if (equal contents "")
	    nil
	  (goto-char start)
	  (beginning-of-line)
	  (narrow-to-region (point) end)
	  ;; Add fill-prefix to all but paragraph separator lines, so
	  ;; filling is done properly.
	  (while (re-search-forward "[\n\r][^\n\r]" nil t)
	    (forward-char -1) (insert fill-prefix))
	  (kview:fill-region start end kcell)
	  (goto-char (point-min))
	  ;; Now add fill-prefix to paragraph separator lines.
	  (while (re-search-forward "[\n\r][\n\r]" nil t)
	    (forward-char -1) (insert fill-prefix))
	  ;;
	  (goto-char (point-max))))))
  contents)

(defun kview:is-p (object)
  "Is OBJECT a kview?"
  (if (listp object) (eq (car object) 'kview)))

(defun kview:kotl (kview)
  "Return kview's kotl object or nil if argument is not a kview."
  (if (kview:is-p kview)
      (kview:get-attr kview 'kotl)))

(defun kview:label (klabel-function prev-label child-p)
  "Return label string to display for current cell computed from KLABEL-FUNCTION, PREV-LABEL and CHILD-P."
  (funcall klabel-function prev-label child-p))

(defun kview:label-function (kview)
  "Return function which will return display label for current cell in KVIEW.
Function signature is: (func prev-label &optional child-p), where prev-label
is the display label of the cell preceding the current one and child-p is
non-nil if cell is to be the child of the preceding cell."
  (kview:get-attr kview 'label-function))

(defun kview:label-min-width (kview)
  "Return kview's label-min-width setting or nil if argument is not a kview.
See documentation for kview:default-label-min-width."
  (if (kview:is-p kview)
      (kview:get-attr kview 'label-min-width)))

(defun kview:label-separator (kview)
  "Return kview's label-separator setting or nil if argument is not a kview.
See documentation for kview:default-label-separator."
  (if (kview:is-p kview)
      (kview:get-attr kview 'label-separator)))

(defun kview:label-separator-length (kview)
  "Return kview's label-separator length or nil if argument is not a kview.
See documentation for kview:default-label-separator."
  (kview:get-attr kview 'label-separator-length))

(defun kview:label-type (kview)
  "Return kview's label-type setting or nil if argument is not a kview.
See documentation for kview:default-label-type."
  (if (kview:is-p kview)
      (kview:get-attr kview 'label-type)))

(defun kview:level-indent (kview)
  "Return kview's level-indent setting or nil if argument is not a kview.
See documentation for kview:default-level-indent."
  (if (kview:is-p kview)
      (kview:get-attr kview 'level-indent)))

(defun kview:map-branch (func kview &optional first-p visible-p)
  "Applies FUNC to the sibling trees from point forward within KVIEW and returns results as a list.
With optional FIRST-P non-nil, begins with first sibling in current branch.
With optional VISIBLE-P, considers only those sibling cells that are visible
in the view.

FUNC should take one argument, the kview local variable of the current
buffer or some other kview, and should operate upon the cell at point.

`Cell-indent' contains the indentation value of the first cell mapped when
FUNC is called so that it may test against this value.  `Label-sep-len'
contains the label separator length.

See also `kview:map-siblings' and `kview:map-tree'."
    (save-excursion
      (set-buffer (kview:buffer kview))
      (let ((results)
	    (label-sep-len (kview:label-separator-length kview)))
	(if first-p
	    ;; Move back to first predecessor at same level.
	    (while (kcell-view:backward t label-sep-len)))
	(let ((cell-indent (kcell-view:indent nil label-sep-len)))
	  ;; Terminate when no further cells or when reach a cell at an equal
	  ;; or higher level in the kotl than the first cell that we processed.
	  (while (and (progn (setq results (cons (funcall func kview) results))
			     (kcell-view:next visible-p label-sep-len))
		      (> (kcell-view:indent nil label-sep-len) cell-indent))))
	(nreverse results))))

(defun kview:map-siblings (func kview &optional first-p visible-p)
  "Applies FUNC to the sibling cells from point forward within KVIEW and returns results as a list.
With optional FIRST-P non-nil, begins with first sibling in current branch.
With optional VISIBLE-P, considers only those sibling cells that are visible
in the view.

FUNC should take one argument, the kview local variable of the current
buffer or some other kview, and should operate upon the cell at point.

`Cell-indent' contains the indentation value of the first cell mapped when
FUNC is called so that it may test against this value.  `Label-sep-len'
contains the label separator length.

See also `kview:map-branch' and `kview:map-tree'."
    (save-excursion
      (set-buffer (kview:buffer kview))
      (let ((results)
	    (label-sep-len (kview:label-separator-length kview)))
	(if first-p
	    ;; Move back to first predecessor at same level.
	    (while (kcell-view:backward t label-sep-len)))
	(let ((cell-indent (kcell-view:indent nil label-sep-len)))
	  ;; Terminate when no further cells at same level.
	  (while (progn (setq results (cons (funcall func kview) results))
			(kcell-view:forward visible-p label-sep-len))))
	(nreverse results))))

(defun kview:map-tree (func kview &optional top-p visible-p)
  "Applies FUNC to the tree starting at point within KVIEW and returns results as a list.
With optional TOP-P non-nil, maps over all of kview's cells.
With optional VISIBLE-P, considers only those cells that are visible in the
view.

FUNC should take one argument, the kview local variable of the current
buffer or some other kview, and should operate upon the cell at point.

`Cell-indent' contains the indentation value of the first cell mapped when
FUNC is called so that it may test against this value.  `Label-sep-len'
contains the label separator length.

See also `kview:map-branch' and `kview:map-siblings'."
  (let ((results)
	(label-sep-len (kview:label-separator-length kview)))
    (save-excursion
      (set-buffer (kview:buffer kview))
      (if top-p
	  (progn (goto-char (point-min))
		 (kview:end-of-actual-line)
		 ;; Terminate when no further cells to process.
		 (while (progn 
			  (setq results (cons (funcall func kview) results))
			  (kcell-view:next visible-p label-sep-len))))
	(let ((cell-indent (kcell-view:indent nil label-sep-len)))
	  ;; Terminate when no further cells or when reach a cell at an equal
	  ;; or higher level in the kotl than the first cell that we processed.
	  (while (and (progn (setq results (cons (funcall func kview) results))
			     (kcell-view:next visible-p label-sep-len))
		      (> (kcell-view:indent nil label-sep-len)
			 cell-indent))))))
    (nreverse results)))

(defun kview:move (from-start from-end to-start from-indent to-indent
                   &optional copy-p fill-p)
  "Move tree between FROM-START and FROM-END to TO-START, changing FROM-INDENT to TO-INDENT.
Copy tree if optional COPY-P is non-nil.  Refill cells if optional
FILL-P is non-nil.  Leave point at TO-START."
  (let ((region (buffer-substring from-start from-end))
	(new-start (set-marker (make-marker) to-start))
	collapsed-cells	expr new-end space)
    ;;
    ;; Move or copy tree region to new location.
    (or copy-p (delete-region from-start from-end))
    (goto-char new-start)
    (insert region)
    (setq new-end (point))
    ;;
    ;; Change indentation of tree cells.
    (if (/= from-indent to-indent)
	(save-restriction
	  (narrow-to-region new-start new-end)
	  ;; Store list of which cells are presently collapsed.
	  (setq collapsed-cells
		(kview:map-tree
		 (function (lambda (view)
			     ;; Use free variable label-sep-len bound in
			     ;; kview:map-tree for speed.
			     (kcell-view:collapsed-p nil label-sep-len)))
		 kview t))
	  ;; Expand all cells.
	  (subst-char-in-region new-start new-end ?\r ?\n t)
	  ;;
	  (goto-char (point-min))
	  (if (< from-indent to-indent)
	      ;; Add indent
	      (progn
		(setq expr (make-string (1+ (- to-indent from-indent)) ?\ ))
		(while (re-search-forward "^ " nil t)
		  (replace-match expr t t)
		  (forward-line 1)))
	    ;; Reduce indent in all but first cell lines.
	    (setq expr (concat "^" (make-string
				    (- from-indent to-indent) ?\ )))
	    (while (re-search-forward expr nil t)
	      (replace-match "" t t)
	      (forward-line 1))
	    ;; Reduce indent in first cell lines which may have an
	    ;; autonumber or other cell delimiter.
	    (setq space (- from-indent to-indent
			   (kview:label-separator-length kview)
			   1))
	    (if (zerop space)
		nil
	      (setq expr (concat "^" (make-string
				      (- from-indent to-indent
					 (kview:label-separator-length kview)
					 1)
				      ?\ )))
	      (kview:map-tree
	       (function (lambda (view)
			   (save-excursion
			     (beginning-of-line)
			     (if (looking-at expr)
				 (replace-match "" t t)))))
	       kview t)))
	  ;;
	  (if fill-p
	      ;; Refill cells without no-fill attribute.
	      (kview:map-tree (function (lambda (view)
					  (kotl-mode:fill-cell nil t)))
			      kview t))
	  ;;
	  ;; Collapse temporarily expanded cells.
	  (if (delq nil collapsed-cells)
	      (kview:map-tree
	       (function
		(lambda (view)
		  (if (car collapsed-cells)
		      ;; Use free variable label-sep-len bound in
		      ;; kview:map-tree for speed.
		      (kcell-view:collapse nil label-sep-len))
		  (setq collapsed-cells (cdr collapsed-cells))))
	       kview t))))
    ;;
    (goto-char new-start)
    ;;
    ;; Delete temporary markers.
    (set-marker new-start nil)))

(defun kview:set-buffer-name (kview new-name)
  "Set kview's buffer name to NEW-NAME."
  (if (kview:is-p kview)
      (save-excursion
	(let ((buf (kview:buffer kview)))
	  (if buf (set-buffer buf)))
	(kview:set-attr kview 'view-buffer-name new-name))
    (error "(kview:set-buffer-name): Invalid kview argument")))

(defun kview:set-label-type (kview new-type)
  "Change kview's label display type to NEW-TYPE, updating all displayed labels.
See documentation for variable, kview:default-label-type, for
valid values of NEW-TYPE."
  (interactive (list kview
		     (let ((completion-ignore-case)
			   (label-type (kview:label-type kview))
			   new-type-str)
		       (if (string=
			    ""
			    (setq new-type-str
				  (completing-read
				   (format "View label type (current = %s): "
					   label-type)
				   '(("alpha") ("legal") ("id") ("no")
				     ("partial-alpha") ("star"))
				   nil t)))
			   label-type
			 (intern new-type-str)))))
  (if (not (memq new-type '(alpha legal id no partial-alpha star)))
      (error "(kview:set-label-type): Invalid label type, `%s'." new-type))
  ;; Disable use of partial-alpha for now since it is broken.
  (if (eq new-type 'partial-alpha)
      (error "(kview:set-label-type): Partial-alpha labels don't work, choose another type"))
  (let ((old-label-type (kview:label-type kview)))
    (if (eq old-label-type new-type)
	nil
      (klabel-type:set-labels new-type)
      (kview:set-attr kview 'label-type new-type)
      (kview:set-functions new-type)
      (kvspec:update t))))

(defun kview:top-cell (kview)
  "Return kview's invisible top cell with idstamp 0 or nil if argument is not a kview."
  (if (kview:is-p kview)
      (kview:get-attr kview 'top-cell)))

(defun kview:valid-position-p (&optional pos)
  "Return non-nil iff point or optional POS is at a position where editing may occur.
The read-only positions between cells and within cell indentations are invalid."
  (cond ((null pos)
	 (>= (current-column) (kcell-view:indent)))
	((not (integer-or-marker-p pos))
	 (error "(kview:valid-position-p): Argument POS not an integer
or marker, `%s'" pos))
	((or (< pos (point-min)) (> pos (point-max)))
	 (error "(kview:valid-position-p): Invalid POS argument, `%d'"
		pos))
	(t (save-excursion
	     (goto-char pos)
	     (>= (current-column) (kcell-view:indent))))))

;;; ************************************************************************
;;; Private functions
;;; ************************************************************************

(defun kview:get-attr (obj attribute)
  "Return the value of OBJECT's ATTRIBUTE."
  (car (cdr (memq attribute (car (cdr (memq 'plist obj)))))))

(defun kview:set-attr (obj attribute value)
  "Set OBJECT's ATTRIBUTE to VALUE and return VALUE."
  (let* ((plist-ptr (cdr (memq 'plist obj)))
	 (plist (car plist-ptr))
	 (attr (memq attribute plist)))
    (if attr
	(setcar (cdr attr) value)
      (setcar plist-ptr
	      (nconc (list attribute value) plist)))
    value))

(defun kview:set-functions (label-type)
  "Setup functions which handle labels of LABEL-TYPE for current view."
  (kview:set-attr kview 'label-function (klabel-type:function label-type))
  (kview:set-attr kview 'label-child (klabel-type:child label-type))
  (kview:set-attr kview 'label-increment (klabel-type:increment label-type))
  (kview:set-attr kview 'label-parent (klabel-type:parent label-type))
  (kview:set-attr kview 'to-label-end (klabel-type:to-label-end label-type)))

(defun kview:set-label-separator (label-separator &optional set-default-p)
  "Set the LABEL-SEPARATOR (a string) between labels and cell contents for the current kview.
With optional prefix arg SET-DEFAULT-P, the default separator value used for
new outlines is also set to this new value."
  (interactive
   (progn (barf-if-buffer-read-only)
	  (list (if (kview:is-p kview)
		    (read-string
		     (format
		      "Change current%s label separator from \"%s\" to: "
		      (if current-prefix-arg " and default" "")
		      (kview:label-separator kview))))
		current-prefix-arg)))

  (barf-if-buffer-read-only)
  (cond ((not (kview:is-p kview))
	 (error "(kview:set-label-separator): This is not a koutline"))
	((not (stringp label-separator))
	 (error "(kview:set-label-separator): Invalid separator, \"%s\""
		label-separator))
	((< (length label-separator) 2)
	 (error "(kview:set-label-separator): Separator must be two or more characters, \"%s\""
		label-separator)))

  (let* ((old-sep-len (kview:label-separator-length kview))
	 (sep-len (length label-separator))
	 (sep-len-increase (- sep-len old-sep-len))
	 (indent)
	 (reindent-function
	  (cond ((zerop sep-len-increase)
		 (function (lambda ())))
		((> sep-len-increase 0)
		 ;; Increase indent in each cell line.
		 (function (lambda ()
			     (goto-char (point-min))
			     (setq indent (make-string
					   sep-len-increase ?\ ))
			     (while (re-search-forward "[^\n\r][\n\r] " nil t)
			       (insert indent)))))
		(t
		 ;; Decrease indent in each cell line.
		 (function (lambda ()
			     (goto-char (point-min))
			     (setq indent
				   (concat "[^\n\r][\n\r]"
					   (make-string
					    (- sep-len-increase) ?\ )))
			     (while (re-search-forward indent nil t)
			       (delete-region
				(+ (match-beginning 0) 2) (match-end 0))))))))
	 pos)
    (save-excursion
      (goto-char (point-min))
      (kproperty:replace-separator pos label-separator old-sep-len)
      ;; Reindent all lines in cells except the first line which has already
      ;; been done.
      (funcall reindent-function))
    (kview:set-attr kview 'label-separator label-separator)
    (kview:set-attr kview 'label-separator-length sep-len)
    (if set-default-p
	(setq kview:default-label-separator label-separator))))

(provide 'kview)