summaryrefslogtreecommitdiff
path: root/libjava/classpath/javax/swing/JEditorPane.java
blob: 8ad1095eedf4c3743f9edfab280e579df97dd15f (plain)
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
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
/* JEditorPane.java --
   Copyright (C) 2002, 2004, 2005, 2006,  Free Software Foundation, Inc.

This file is part of GNU Classpath.

GNU Classpath 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 Classpath 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 Classpath; see the file COPYING.  If not, write to the
Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
02110-1301 USA.

Linking this library statically or dynamically with other modules is
making a combined work based on this library.  Thus, the terms and
conditions of the GNU General Public License cover the whole
combination.

As a special exception, the copyright holders of this library give you
permission to link this library with independent modules to produce an
executable, regardless of the license terms of these independent
modules, and to copy and distribute the resulting executable under
terms of your choice, provided that you also meet, for each linked
independent module, the terms and conditions of the license of that
module.  An independent module is a module which is not derived from
or based on this library.  If you modify this library, you may extend
this exception to your version of the library, but you are not
obligated to do so.  If you do not wish to do so, delete this
exception statement from your version. */


package javax.swing;

import java.awt.Container;
import java.awt.Dimension;
import java.io.BufferedInputStream;
import java.io.FilterInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.Reader;
import java.io.StringReader;
import java.net.MalformedURLException;
import java.net.URL;
import java.net.URLConnection;
import java.util.HashMap;

import javax.accessibility.AccessibleContext;
import javax.accessibility.AccessibleHyperlink;
import javax.accessibility.AccessibleHypertext;
import javax.accessibility.AccessibleStateSet;
import javax.accessibility.AccessibleText;
import javax.swing.event.HyperlinkEvent;
import javax.swing.event.HyperlinkListener;
import javax.swing.plaf.TextUI;
import javax.swing.text.AbstractDocument;
import javax.swing.text.BadLocationException;
import javax.swing.text.DefaultEditorKit;
import javax.swing.text.Document;
import javax.swing.text.EditorKit;
import javax.swing.text.Element;
import javax.swing.text.JTextComponent;
import javax.swing.text.View;
import javax.swing.text.ViewFactory;
import javax.swing.text.WrappedPlainView;
import javax.swing.text.html.HTML;
import javax.swing.text.html.HTMLDocument;
import javax.swing.text.html.HTMLEditorKit;

/**
 * A powerful text editor component that can handle different types of
 * content.
 *
 * The JEditorPane text component is driven by an instance of
 * {@link EditorKit}. The editor kit is responsible for providing
 * a default {@link Document} implementation, a mechanism for loading
 * and saving documents of its supported content type and providing
 * a set of {@link Action}s for manipulating the content.
 *
 * By default the following content types are supported:
 * <ul>
 * <li><code>text/plain</code>: Plain text, handled by
 *   {@link javax.swing.text.DefaultEditorKit}.</li>
 * <li><code>text/html</code>: HTML 4.0 styled text, handled by
 *   {@link javax.swing.text.html.HTMLEditorKit}.</li>
 * <li><code>text/rtf</code>: RTF text, handled by
 *   {@link javax.swing.text.rtf.RTFEditorKit}.</li>
 * </ul>
 *
 * @author original author unknown
 * @author Roman Kennke (roman@kennke.org)
 * @author Anthony Balkissoon abalkiss at redhat dot com
 */
public class JEditorPane extends JTextComponent
{
  /**
   * Provides accessibility support for <code>JEditorPane</code>.
   *
   * @author Roman Kennke (kennke@aicas.com)
   */
  protected class AccessibleJEditorPane extends AccessibleJTextComponent
  {

    /**
     * Creates a new <code>AccessibleJEditorPane</code> object.
     */
    protected AccessibleJEditorPane()
    {
      super();
    }

    /**
     * Returns a description of this <code>AccessibleJEditorPane</code>. If
     * this property is not set, then this returns the content-type of the
     * editor pane.
     *
     * @return a description of this AccessibleJEditorPane
     */
    public String getAccessibleDescription()
    {
      String descr = super.getAccessibleDescription();
      if (descr == null)
        return getContentType();
      else
        return descr;
    }

    /**
     * Returns the accessible state of this <code>AccessibleJEditorPane</code>.
     *
     * @return  the accessible state of this <code>AccessibleJEditorPane</code>
     */
    public AccessibleStateSet getAccessibleStateSet()
    {
      AccessibleStateSet state = super.getAccessibleStateSet();
      // TODO: Figure out what state must be added here to the super's state.
      return state;
    }
  }

  /**
   * Provides accessibility support for <code>JEditorPane</code>s, when the
   * editor kit is an instance of {@link HTMLEditorKit}.
   *
   * @author Roman Kennke (kennke@aicas.com)
   */
  protected class AccessibleJEditorPaneHTML extends AccessibleJEditorPane
  {
    /**
     * Returns the accessible text of the <code>JEditorPane</code>. This will
     * be an instance of
     * {@link JEditorPaneAccessibleHypertextSupport}.
     *
     * @return the accessible text of the <code>JEditorPane</code>
     */
    public AccessibleText getAccessibleText()
    {
      return new JEditorPaneAccessibleHypertextSupport();
    }
  }

  /**
   * This is the accessible text that is returned by
   * {@link AccessibleJEditorPaneHTML#getAccessibleText()}.
   *
   * @author Roman Kennke (kennke@aicas.com)
   */
  protected class JEditorPaneAccessibleHypertextSupport
    extends AccessibleJEditorPane implements AccessibleHypertext
  {

    /**
     * Creates a new JEditorPaneAccessibleHypertextSupport object.
     */
    public JEditorPaneAccessibleHypertextSupport()
    {
      super();
    }

    /**
     * The accessible representation of a HTML link.
     *
     * @author Roman Kennke (kennke@aicas.com)
     */
    public class HTMLLink extends AccessibleHyperlink
    {

      /**
       * The element in the document that represents the link.
       */
      Element element;

      /**
       * Creates a new <code>HTMLLink</code>.
       *
       * @param el the link element
       */
      public HTMLLink(Element el)
      {
        this.element = el;
      }

      /**
       * Returns <code>true</code> if this <code>HTMLLink</code> is still
       * valid. A <code>HTMLLink</code> can become invalid when the document
       * changes.
       *
       * @return <code>true</code> if this <code>HTMLLink</code> is still
       *         valid
       */
      public boolean isValid()
      {
        // I test here if the element at our element's start offset is the
        // same as the element in the document at this offset. If this is true,
        // I consider the link valid, if not, then this link no longer
        // represented by this HTMLLink and therefor invalid.
        HTMLDocument doc = (HTMLDocument) getDocument();
        return doc.getCharacterElement(element.getStartOffset()) == element;
      }

      /**
       * Returns the number of AccessibleActions in this link object. In
       * general, link have 1 AccessibleAction associated with them. There are
       * special cases where links can have multiple actions associated, like
       * in image maps.
       *
       * @return the number of AccessibleActions in this link object
       */
      public int getAccessibleActionCount()
      {
        // TODO: Implement the special cases.
        return 1;
      }

      /**
       * Performs the specified action on the link object. This ususally means
       * activating the link.
       *
       * @return <code>true</code> if the action has been performed
       *         successfully, <code>false</code> otherwise
       */
      public boolean doAccessibleAction(int i)
      {
        String href = (String) element.getAttributes().getAttribute("href");
        HTMLDocument doc = (HTMLDocument) getDocument();
        try
          {
            URL url = new URL(doc.getBase(), href);
            setPage(url);
            String desc = doc.getText(element.getStartOffset(),
                            element.getEndOffset() - element.getStartOffset());
            HyperlinkEvent ev =
              new HyperlinkEvent(JEditorPane.this,
                                 HyperlinkEvent.EventType.ACTIVATED, url, desc,
                                 element);
            fireHyperlinkUpdate(ev);
            return true;
          }
        catch (Exception ex)
          {
            return false;
          }
      }

      /**
       * Returns the description of the action at action index <code>i</code>.
       * This method returns the text within the element associated with this
       * link.
       *
       * @param i the action index
       *
       * @return the description of the action at action index <code>i</code>
       */
      public String getAccessibleActionDescription(int i)
      {
        HTMLDocument doc = (HTMLDocument) getDocument();
        try
          {
            return doc.getText(element.getStartOffset(),
                            element.getEndOffset() - element.getStartOffset());
          }
        catch (BadLocationException ex)
          {
            throw (AssertionError)
            new AssertionError("BadLocationException must not be thrown "
                               + "here.")
              .initCause(ex);
          }
      }

      /**
       * Returns an {@link URL} object, that represents the action at action
       * index <code>i</code>.
       *
       * @param i the action index
       *
       * @return an {@link URL} object, that represents the action at action
       *         index <code>i</code>
       */
      public Object getAccessibleActionObject(int i)
      {
        String href = (String) element.getAttributes().getAttribute("href");
        HTMLDocument doc = (HTMLDocument) getDocument();
        try
          {
            URL url = new URL(doc.getBase(), href);
            return url;
          }
        catch (MalformedURLException ex)
          {
            return null;
          }
      }

      /**
       * Returns an object that represents the link anchor. For examples, if
       * the link encloses a string, then a <code>String</code> object is
       * returned, if the link encloses an &lt;img&gt; tag, then an
       * <code>ImageIcon</code> object is returned.
       *
       * @return an object that represents the link anchor
       */
      public Object getAccessibleActionAnchor(int i)
      {
        // TODO: This is only the String case. Implement all cases.
        return getAccessibleActionDescription(i);
      }

      /**
       * Returns the start index of the hyperlink element.
       *
       * @return the start index of the hyperlink element
       */
      public int getStartIndex()
      {
        return element.getStartOffset();
      }

      /**
       * Returns the end index of the hyperlink element.
       *
       * @return the end index of the hyperlink element
       */
      public int getEndIndex()
      {
        return element.getEndOffset();
      }

    }

    /**
     * Returns the number of hyperlinks in the document.
     *
     * @return the number of hyperlinks in the document
     */
    public int getLinkCount()
    {
      HTMLDocument doc = (HTMLDocument) getDocument();
      HTMLDocument.Iterator linkIter = doc.getIterator(HTML.Tag.A);
      int count = 0;
      while (linkIter.isValid())
        {
          count++;
          linkIter.next();
        }
      return count;
    }

    /**
     * Returns the <code>i</code>-th hyperlink in the document or
     * <code>null</code> if there is no hyperlink with the specified index.
     *
     * @param i the index of the hyperlink to return
     *
     * @return the <code>i</code>-th hyperlink in the document or
     *         <code>null</code> if there is no hyperlink with the specified
     *         index
     */
    public AccessibleHyperlink getLink(int i)
    {
      HTMLDocument doc = (HTMLDocument) getDocument();
      HTMLDocument.Iterator linkIter = doc.getIterator(HTML.Tag.A);
      int count = 0;
      while (linkIter.isValid())
        {
          count++;
          if (count == i)
            break;
          linkIter.next();
        }
      if (linkIter.isValid())
        {
          int offset = linkIter.getStartOffset();
          // TODO: I fetch the element for the link via getCharacterElement().
          // I am not sure that this is correct, maybe we must use
          // getParagraphElement()?
          Element el = doc.getCharacterElement(offset);
          HTMLLink link = new HTMLLink(el);
          return link;
        }
      else
        return null;
    }

    /**
     * Returns the index of the link element at the character position
     * <code>c</code> within the document, or <code>-1</code> if there is no
     * link at the specified position.
     *
     * @param c the character index from which to fetch the link index
     *
     * @return the index of the link element at the character position
     *         <code>c</code> within the document, or <code>-1</code> if there
     *         is no link at the specified position
     */
    public int getLinkIndex(int c)
    {
      HTMLDocument doc = (HTMLDocument) getDocument();
      HTMLDocument.Iterator linkIter = doc.getIterator(HTML.Tag.A);
      int count = 0;
      while (linkIter.isValid())
        {
          if (linkIter.getStartOffset() <= c && linkIter.getEndOffset() > c)
            break;
          count++;
          linkIter.next();
        }
      if (linkIter.isValid())
        return count;
      else
        return -1;
    }

    /**
     * Returns the link text of the link at index <code>i</code>, or
     * <code>null</code>, if there is no link at the specified position.
     *
     * @param i the index of the link
     *
     * @return  the link text of the link at index <code>i</code>, or
     *          <code>null</code>, if there is no link at the specified
     *          position
     */
    public String getLinkText(int i)
    {
      HTMLDocument doc = (HTMLDocument) getDocument();
      HTMLDocument.Iterator linkIter = doc.getIterator(HTML.Tag.A);
      int count = 0;
      while (linkIter.isValid())
        {
          count++;
          if (count == i)
            break;
          linkIter.next();
        }
      if (linkIter.isValid())
        {
          int offset = linkIter.getStartOffset();
          // TODO: I fetch the element for the link via getCharacterElement().
          // I am not sure that this is correct, maybe we must use
          // getParagraphElement()?
          Element el = doc.getCharacterElement(offset);
          try
            {
              String text = doc.getText(el.getStartOffset(),
                                      el.getEndOffset() - el.getStartOffset());
              return text;
            }
          catch (BadLocationException ex)
            {
              throw (AssertionError)
                new AssertionError("BadLocationException must not be thrown "
                                   + "here.")
                  .initCause(ex);
            }
        }
      else
        return null;
    }
  }

  /**
   * Used to store a mapping for content-type to editor kit class.
   */
  private static class EditorKitMapping
  {
    /**
     * The classname of the editor kit.
     */
    String className;

    /**
     * The classloader with which the kit is to be loaded.
     */
    ClassLoader classLoader;

    /**
     * Creates a new EditorKitMapping object.
     *
     * @param cn the classname
     * @param cl the classloader
     */
    EditorKitMapping(String cn, ClassLoader cl)
    {
      className = cn;
      classLoader = cl;
    }
  }

  /**
   * An EditorKit used for plain text. This is the default editor kit for
   * JEditorPanes.
   *
   * @author Roman Kennke (kennke@aicas.com)
   */
  private static class PlainEditorKit extends DefaultEditorKit
  {

    /**
     * Returns a ViewFactory that supplies WrappedPlainViews.
     */
    public ViewFactory getViewFactory()
    {
      return new ViewFactory()
      {
        public View create(Element el)
        {
          return new WrappedPlainView(el);
        }
      };
    }
  }

  /**
   * A special stream that can be cancelled.
   */
  private class PageStream
    extends FilterInputStream
  {
    /**
     * True when the stream has been cancelled, false otherwise.
     */
    private boolean cancelled;

    protected PageStream(InputStream in)
    {
      super(in);
      cancelled = false;
    }

    private void checkCancelled()
      throws IOException
    {
      if (cancelled)
        throw new IOException("Stream has been cancelled");
    }

    void cancel()
    {
      cancelled = true;
    }

    public int read()
      throws IOException
    {
      checkCancelled();
      return super.read();
    }

    public int read(byte[] b, int off, int len)
      throws IOException
    {
      checkCancelled();
      return super.read(b, off, len);
    }

    public long skip(long n)
      throws IOException
    {
      checkCancelled();
      return super.skip(n);
    }

    public int available()
      throws IOException
    {
      checkCancelled();
      return super.available();
    }

    public void reset()
      throws IOException
    {
      checkCancelled();
      super.reset();
    }
  }

  /**
   * The thread that loads documents asynchronously.
   */
  private class PageLoader
    implements Runnable
  {
    private Document doc;
    private PageStream in;
    private URL old;
    URL page;
    PageLoader(Document doc, InputStream in, URL old, URL page)
    {
      this.doc = doc;
      this.in = new PageStream(in);
      this.old = old;
      this.page = page;
    }

    public void run()
    {
      try
        {
          read(in, doc);
        }
      catch (IOException ex)
        {
          UIManager.getLookAndFeel().provideErrorFeedback(JEditorPane.this);
        }
      finally
        {
          if (SwingUtilities.isEventDispatchThread())
            firePropertyChange("page", old, page);
          else
            {
              SwingUtilities.invokeLater(new Runnable()
              {
                public void run()
                {
                  firePropertyChange("page", old, page);
                }
              });
            }
         }
     }

     void cancel()
     {
       in.cancel();
     }
  }

  private static final long serialVersionUID = 3140472492599046285L;

  private EditorKit editorKit;

  boolean focus_root;

  /**
   * Maps content-types to editor kit instances.
   */
  static HashMap editorKits;

  // A mapping between content types and registered EditorKit types
  static HashMap registerMap;

  static
  {
    registerMap = new HashMap();
    editorKits = new HashMap();
    registerEditorKitForContentType("application/rtf",
                                    "javax.swing.text.rtf.RTFEditorKit");
    registerEditorKitForContentType("text/plain",
                                    "javax.swing.JEditorPane$PlainEditorKit");
    registerEditorKitForContentType("text/html",
                                    "javax.swing.text.html.HTMLEditorKit");
    registerEditorKitForContentType("text/rtf",
                                    "javax.swing.text.rtf.RTFEditorKit");

  }

  // A mapping between content types and used EditorKits
  HashMap editorMap;

  /**
   * The currently loading stream, if any.
   */
  private PageLoader loader;

  public JEditorPane()
  {
    init();
    setEditorKit(createDefaultEditorKit());
  }

  public JEditorPane(String url) throws IOException
  {
    this(new URL(url));
  }

  public JEditorPane(String type, String text)
  {
    init();
    setEditorKit(createEditorKitForContentType(type));
    setText(text);
  }

  public JEditorPane(URL url) throws IOException
  {
    init();
    setEditorKit(createEditorKitForContentType("text/html"));
    setPage(url);
  }

  /**
   * Called by the constructors to set up the default bindings for content
   * types and EditorKits.
   */
  void init()
  {
    editorMap = new HashMap();
  }

  protected EditorKit createDefaultEditorKit()
  {
    return new PlainEditorKit();
  }

  /**
   * Creates and returns an EditorKit that is appropriate for the given
   * content type.  This is created using the default recognized types
   * plus any EditorKit types that have been registered.
   *
   * @see #registerEditorKitForContentType(String, String)
   * @see #registerEditorKitForContentType(String, String, ClassLoader)
   * @param type the content type
   * @return an EditorKit for use with the given content type
   */
  public static EditorKit createEditorKitForContentType(String type)
  {
    // Try cached instance.
    EditorKit e = (EditorKit) editorKits.get(type);
    if (e == null)
      {
        EditorKitMapping m = (EditorKitMapping) registerMap.get(type);
        if (m != null)
          {
            String className = m.className;
            ClassLoader loader = m.classLoader;
            try
              {
                e = (EditorKit) loader.loadClass(className).newInstance();
              }
            catch (Exception e2)
              {
                // The reference implementation returns null when class is not
                // loadable or instantiatable.
              }
          }
        // Cache this for later retrieval.
        if (e != null)
          editorKits.put(type, e);
      }
    return e;
  }

  /**
   * Sends a given <code>HyperlinkEvent</code> to all registered listeners.
   *
   * @param event the event to send
   */
  public void fireHyperlinkUpdate(HyperlinkEvent event)
  {
    HyperlinkListener[] listeners = getHyperlinkListeners();

    for (int index = 0; index < listeners.length; ++index)
       listeners[index].hyperlinkUpdate(event);
  }

  /**
   * Returns the accessible context associated with this editor pane.
   *
   * @return the accessible context associated with this editor pane
   */
  public AccessibleContext getAccessibleContext()
  {
    if (accessibleContext == null)
      {
        if (getEditorKit() instanceof HTMLEditorKit)
          accessibleContext = new AccessibleJEditorPaneHTML();
        else
          accessibleContext = new AccessibleJEditorPane();
      }
    return accessibleContext;
  }

  public final String getContentType()
  {
    return getEditorKit().getContentType();
  }

  /**
   * Returns the EditorKit. If there is no EditorKit set this method
   * calls createDefaultEditorKit() and setEditorKit() first.
   */
  public EditorKit getEditorKit()
  {
    if (editorKit == null)
      setEditorKit(createDefaultEditorKit());
    return editorKit;
  }

  /**
   * Returns the class name of the EditorKit associated with the given
   * content type.
   *
   * @since 1.3
   * @param type the content type
   * @return the class name of the EditorKit associated with this content type
   */
  public static String getEditorKitClassNameForContentType(String type)
  {
    EditorKitMapping m = (EditorKitMapping) registerMap.get(type);
    String kitName = m != null ? m.className : null;
    return kitName;
  }

  /**
   * Returns the EditorKit to use for the given content type.  If an
   * EditorKit has been explicitly set via
   * <code>setEditorKitForContentType</code>
   * then it will be returned.  Otherwise an attempt will be made to create
   * an EditorKit from the default recognzied content types or any
   * EditorKits that have been registered.  If none can be created, a
   * PlainEditorKit is created.
   *
   * @see #registerEditorKitForContentType(String, String)
   * @see #registerEditorKitForContentType(String, String, ClassLoader)
   * @param type the content type
   * @return an appropriate EditorKit for the given content type
   */
  public EditorKit getEditorKitForContentType(String type)
  {
    // First check if an EditorKit has been explicitly set.
    EditorKit e = (EditorKit) editorMap.get(type);
    // Then check to see if we can create one.
    if (e == null)
      {
        e = createEditorKitForContentType(type);
        if (e != null)
          setEditorKitForContentType(type, e);
      }
    // Otherwise default to PlainEditorKit.
    if (e == null)
      e = createDefaultEditorKit();
    return e;
  }

  /**
   * Returns the preferred size for the JEditorPane. This is implemented to
   * return the super's preferred size, unless one of
   * {@link #getScrollableTracksViewportHeight()} or
   * {@link #getScrollableTracksViewportWidth()} returns <code>true</code>,
   * in which case the preferred width and/or height is replaced by the UI's
   * minimum size.
   *
   * @return the preferred size for the JEditorPane
   */
  public Dimension getPreferredSize()
  {
    Dimension pref = super.getPreferredSize();
    Container parent = getParent();
    if (parent instanceof JViewport)
      {
        JViewport vp = (JViewport) getParent();
        TextUI ui = getUI();
        Dimension min = null;
        if (! getScrollableTracksViewportWidth())
          {
            min = ui.getMinimumSize(this);
            int vpWidth = vp.getWidth();
            if (vpWidth != 0 && vpWidth < min.width)
              pref.width = min.width;
          }
        if (! getScrollableTracksViewportHeight())
          {
            if (min == null)
              min = ui.getMinimumSize(this);
            int vpHeight = vp.getHeight();
            if (vpHeight != 0 && vpHeight < min.height)
              pref.height = min.height;
          }
      }
    return pref;
  }

  /**
   * Returns <code>true</code> when a Viewport should force the height of
   * this component to match the viewport height. This is implemented to return
   * <code>true</code> when  the parent is an instance of JViewport and
   * the viewport height > the UI's minimum height.
   *
   * @return <code>true</code> when a Viewport should force the height of
   *         this component to match the viewport height
   */
  public boolean getScrollableTracksViewportHeight()
  {
    // Tests show that this returns true when the parent is a JViewport
    // and has a height > minimum UI height.
    Container parent = getParent();
    int height = parent.getHeight();
    TextUI ui = getUI();
    return parent instanceof JViewport
           && height >= ui.getMinimumSize(this).height
           && height <= ui.getMaximumSize(this).height;
  }

  /**
   * Returns <code>true</code> when a Viewport should force the width of
   * this component to match the viewport width. This is implemented to return
   * <code>true</code> when  the parent is an instance of JViewport and
   * the viewport width > the UI's minimum width.
   *
   * @return <code>true</code> when a Viewport should force the width of
   *         this component to match the viewport width
   */
  public boolean getScrollableTracksViewportWidth()
  {
    // Tests show that this returns true when the parent is a JViewport
    // and has a width > minimum UI width.
    Container parent = getParent();
    return parent != null && parent instanceof JViewport
           && parent.getWidth() > getUI().getMinimumSize(this).width;
  }

  public URL getPage()
  {
    return loader != null ? loader.page : null;
  }

  protected InputStream getStream(URL page)
    throws IOException
  {
    URLConnection conn = page.openConnection();
    // Try to detect the content type of the stream data.
    String type = conn.getContentType();
    if (type != null)
      setContentType(type);
    InputStream stream = conn.getInputStream();
    return new BufferedInputStream(stream);
  }

  public String getText()
  {
    return super.getText();
  }

  public String getUIClassID()
  {
    return "EditorPaneUI";
  }

  public boolean isFocusCycleRoot()
  {
    return focus_root;
  }

  protected String paramString()
  {
    return "JEditorPane";
  }

  /**
   * This method initializes from a stream.
   */
  public void read(InputStream in, Object desc) throws IOException
  {
    EditorKit kit = getEditorKit();
    if (kit instanceof HTMLEditorKit && desc instanceof HTMLDocument)
      {
        HTMLDocument doc = (HTMLDocument) desc;
        setDocument(doc);
        try
          {
            InputStreamReader reader = new InputStreamReader(in);
            kit.read(reader, doc, 0);
          }
        catch (BadLocationException ex)
          {
            assert false : "BadLocationException must not be thrown here.";
          }
      }
    else
      {
        Reader inRead = new InputStreamReader(in);
        super.read(inRead, desc);
      }
  }

  /**
   * Establishes a binding between type and classname.  This enables
   * us to create an EditorKit later for the given content type.
   *
   * @param type the content type
   * @param classname the name of the class that is associated with this
   * content type
   */
  public static void registerEditorKitForContentType(String type,
                                                     String classname)
  {
    registerEditorKitForContentType(type, classname,
                               Thread.currentThread().getContextClassLoader());
  }

  /**
   * Establishes the default bindings of type to classname.
   */
  public static void registerEditorKitForContentType(String type,
                                                     String classname,
                                                     ClassLoader loader)
  {
    registerMap.put(type, new EditorKitMapping(classname, loader));
  }

  /**
   * Replaces the currently selected content with new content represented
   * by the given string.
   */
  public void replaceSelection(String content)
  {
    // TODO: Implement this properly.
    super.replaceSelection(content);
  }

  /**
   * Scrolls the view to the given reference location (that is, the value
   * returned by the UL.getRef method for the URL being displayed).
   */
  public void scrollToReference(String reference)
  {
    // TODO: Implement this properly.
  }

  public final void setContentType(String type)
  {
    // Strip off content type parameters.
    int paramIndex = type.indexOf(';');
    if (paramIndex > -1)
      {
        // TODO: Handle character encoding.
        type = type.substring(0, paramIndex).trim();
      }
    if (editorKit != null
        && editorKit.getContentType().equals(type))
      return;

    EditorKit kit = getEditorKitForContentType(type);

    if (kit != null)
      setEditorKit(kit);
  }

  public void setEditorKit(EditorKit newValue)
  {
    if (editorKit == newValue)
      return;

    if (editorKit != null)
      editorKit.deinstall(this);

    EditorKit oldValue = editorKit;
    editorKit = newValue;

    if (editorKit != null)
      {
        editorKit.install(this);
        setDocument(editorKit.createDefaultDocument());
      }

    firePropertyChange("editorKit", oldValue, newValue);
    invalidate();
    repaint();
    // Reset the accessibleContext since this depends on the editorKit.
    accessibleContext = null;
  }

  /**
   * Explicitly sets an EditorKit to be used for the given content type.
   * @param type the content type
   * @param k the EditorKit to use for the given content type
   */
  public void setEditorKitForContentType(String type, EditorKit k)
  {
    editorMap.put(type, k);
  }

  /**
   * Sets the current URL being displayed.
   */
  public void setPage(String url) throws IOException
  {
    setPage(new URL(url));
  }

  /**
   * Sets the current URL being displayed.
   */
  public void setPage(URL page) throws IOException
  {
    if (page == null)
      throw new IOException("invalid url");

    URL old = getPage();
    // Only reload if the URL doesn't point to the same file.
    // This is not the same as equals because there might be different
    // URLs on the same file with different anchors.
    if (old == null || ! old.sameFile(page))
      {
        InputStream in = getStream(page);
        if (editorKit != null)
          {
            Document doc = editorKit.createDefaultDocument();
            doc.putProperty(Document.StreamDescriptionProperty, page);

            if (loader != null)
              loader.cancel();
            loader = new PageLoader(doc, in, old, page);

            int prio = -1;
            if (doc instanceof AbstractDocument)
              {
                AbstractDocument aDoc = (AbstractDocument) doc;
                prio = aDoc.getAsynchronousLoadPriority();
              }
            if (prio >= 0)
              {
                // Load asynchronously.
                setDocument(doc);
                Thread loadThread = new Thread(loader,
                                               "JEditorPane.PageLoader");
                loadThread.setDaemon(true);
                loadThread.setPriority(prio);
                loadThread.start();
              }
            else
              {
                // Load synchronously.
                loader.run();
                setDocument(doc);
              }
          }
      }
  }

  /**
   * Sets the text of the JEditorPane.  The argument <code>t</code>
   * is expected to be in the format of the current EditorKit.  This removes
   * the content of the current document and uses the EditorKit to read in the
   * new text.  This allows the EditorKit to handle the String rather than just
   * inserting in plain text.
   *
   * @param t the text to display in this JEditorPane
   */
  public void setText(String t)
  {
    try
    {
      // Remove the current content.
      Document doc = getDocument();
      doc.remove(0, doc.getLength());
      if (t == null || t.equals(""))
        return;

      // Let the EditorKit read the text into the Document.
      getEditorKit().read(new StringReader(t), doc, 0);
    }
    catch (BadLocationException ble)
    {
      // TODO: Don't know what to do here.
    }
    catch (IOException ioe)
    {
      // TODO: Don't know what to do here.
    }
  }

  /**
   * Add a <code>HyperlinkListener</code> object to this editor pane.
   *
   * @param listener the listener to add
   */
  public void addHyperlinkListener(HyperlinkListener listener)
  {
    listenerList.add(HyperlinkListener.class, listener);
  }

  /**
   * Removes a <code>HyperlinkListener</code> object to this editor pane.
   *
   * @param listener the listener to remove
   */
  public void removeHyperlinkListener(HyperlinkListener listener)
  {
    listenerList.remove(HyperlinkListener.class, listener);
  }

  /**
   * Returns all added <code>HyperlinkListener</code> objects.
   *
   * @return array of listeners
   *
   * @since 1.4
   */
  public HyperlinkListener[] getHyperlinkListeners()
  {
    return (HyperlinkListener[]) getListeners(HyperlinkListener.class);
  }
}