IDocumentPartitioner


1   /*******************************************************************************
2    * Copyright (c) 2000, 2005 IBM Corporation and others.
3    * All rights reserved. This program and the accompanying materials
4    * are made available under the terms of the Eclipse Public License v1.0
5    * which accompanies this distribution, and is available at
6    * http://www.eclipse.org/legal/epl-v10.html
7    *
8    * Contributors:
9    *     IBM Corporation - initial API and implementation
10   *******************************************************************************/
11  package org.eclipse.jface.text;
12  
13  
14  
15  /**
16   * A document partitioner divides a document into a set
17   * of disjoint text partitions. Each partition has a content type, an
18   * offset, and a length. The document partitioner is connected to one document
19   * and informed about all changes of this document before any of the
20   * document's document listeners. A document partitioner can thus
21   * incrementally update on the receipt of a document change event.<p>
22   *
23   * In order to provided backward compatibility for clients of <code>IDocumentPartitioner</code>, extension
24   * interfaces are used to provide a means of evolution. The following extension interfaces
25   * exist:
26   * <ul>
27   * <li> {@link org.eclipse.jface.text.IDocumentPartitionerExtension} since version 2.0 replacing
28   *      the <code>documentChanged</code> method with a new one returning the minimal document region
29   *      comprising all partition changes.</li>
30   * <li> {@link org.eclipse.jface.text.IDocumentPartitionerExtension2} since version 3.0
31   *      introducing zero-length partitions in conjunction with the distinction between
32   *      open and closed partitions. Also provides inside in the implementation of the partitioner
33   *      by exposing the position category used for managing the partitioning information.</li>
34   * <li> {@link org.eclipse.jface.text.IDocumentPartitionerExtension3} since version 3.1 introducing
35   *      rewrite session. It also replaces the existing {@link #connect(IDocument)} method with
36   *      a new one: {@link org.eclipse.jface.text.IDocumentPartitionerExtension3#connect(IDocument, boolean)}.
37   * </ul>
38   * <p>
39   * Clients may implement this interface and its extension interfaces or use the standard
40   * implementation <code>DefaultPartitioner</code>.
41   * </p>
42   *
43   * @see org.eclipse.jface.text.IDocumentPartitionerExtension
44   * @see org.eclipse.jface.text.IDocumentPartitionerExtension2
45   * @see org.eclipse.jface.text.IDocument
46   */
47  public interface IDocumentPartitioner {
48  
49      /**
50       * Connects the partitioner to a document.
51       * Connect indicates the begin of the usage of the receiver
52       * as partitioner of the given document. Thus, resources the partitioner
53       * needs to be operational for this document should be allocated.<p>
54       *
55       * The caller of this method must ensure that this partitioner is
56       * also set as the document's document partitioner.<p>
57       *
58       * This method has been replaced with {@link IDocumentPartitionerExtension3#connect(IDocument, boolean)}.
59       * Implementers should default a call <code>connect(document)</code> to
60       * <code>connect(document, false)</code> in order to sustain the same semantics.
61       *
62       * @param document the document to be connected to
63       */
64      void connect(IDocument document);
65  
66      /**
67       * Disconnects the partitioner from the document it is connected to.
68       * Disconnect indicates the end of the usage of the receiver as
69       * partitioner of the connected document. Thus, resources the partitioner
70       * needed to be operation for its connected document should be deallocated.<p>
71       * The caller of this method should also must ensure that this partitioner is
72       * no longer the document's partitioner.
73       */
74      void disconnect();
75  
76      /**
77       * Informs about a forthcoming document change. Will be called by the
78       * connected document and is not intended to be used by clients
79       * other than the connected document.
80       *
81       * @param event the event describing the forthcoming change
82       */
83      void documentAboutToBeChanged(DocumentEvent event);
84  
85      /**
86       * The document has been changed. The partitioner updates
87       * the document's partitioning and returns whether the structure of the
88       * document partitioning has been changed, i.e. whether partitions
89       * have been added or removed. Will be called by the connected document and
90       * is not intended to be used by clients other than the connected document.<p>
91       *
92       * This method has been replaced by {@link IDocumentPartitionerExtension#documentChanged2(DocumentEvent)}.
93       *
94       * @param event the event describing the document change
95       * @return <code>true</code> if partitioning changed
96       */
97      boolean documentChanged(DocumentEvent event);
98  
99      /**
100      * Returns the set of all legal content types of this partitioner.
101      * I.e. any result delivered by this partitioner may not contain a content type
102      * which would not be included in this method's result.
103      *
104      * @return the set of legal content types
105      */
106     String  [] getLegalContentTypes();
107 
108     /**
109      * Returns the content type of the partition containing the
110      * given offset in the connected document. There must be a
111      * document connected to this partitioner.<p>
112      *
113      * Use {@link IDocumentPartitionerExtension2#getContentType(int, boolean)} when
114      * zero-length partitions are supported. In that case this method is
115      * equivalent:
116      * <pre>
117      *    IDocumentPartitionerExtension2 extension= (IDocumentPartitionerExtension2) partitioner;
118      *    return extension.getContentType(offset, false);
119      * </pre>
120      *
121      * @param offset the offset in the connected document
122      * @return the content type of the offset's partition
123      */
124     String   getContentType(int offset);
125 
126     /**
127      * Returns the partitioning of the given range of the connected
128      * document. There must be a document connected to this partitioner.<p>
129      *
130      * Use {@link IDocumentPartitionerExtension2#computePartitioning(int, int, boolean)} when
131      * zero-length partitions are supported. In that case this method is
132      * equivalent:
133      * <pre>
134      *    IDocumentPartitionerExtension2 extension= (IDocumentPartitionerExtension2) partitioner;
135      *    return extension.computePartitioning(offset, length, false);
136      * </pre>
137      *
138      * @param offset the offset of the range of interest
139      * @param length the length of the range of interest
140      * @return the partitioning of the range
141      */
142     ITypedRegion[] computePartitioning(int offset, int length);
143 
144     /**
145      * Returns the partition containing the given offset of
146      * the connected document. There must be a document connected to this
147      * partitioner.<p>
148      *
149      * Use {@link IDocumentPartitionerExtension2#getPartition(int, boolean)} when
150      * zero-length partitions are supported. In that case this method is
151      * equivalent:
152      * <pre>
153      *    IDocumentPartitionerExtension2 extension= (IDocumentPartitionerExtension2) partitioner;
154      *    return extension.getPartition(offset, false);
155      * </pre>
156      *
157      * @param offset the offset for which to determine the partition
158      * @return the partition containing the offset
159      */
160     ITypedRegion getPartition(int offset);
161 }
162
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