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comparison dwtx/jface/internal/text/NonDeletingPositionUpdater.d @ 129:eb30df5ca28b

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Added JFace Text sources
author Frank Benoit <benoit@tionex.de>
date Sat, 23 Aug 2008 19:10:48 +0200
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children c4fb132a086c
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128:8df1d4193877 129:eb30df5ca28b
1 /*******************************************************************************
2 * Copyright (c) 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 * Port to the D programming language:
11 * Frank Benoit <benoit@tionex.de>
12 *******************************************************************************/
13 module dwtx.jface.internal.text.NonDeletingPositionUpdater;
14
15 import dwt.dwthelper.utils;
16
17 import dwtx.jface.text.BadPositionCategoryException;
18 import dwtx.jface.text.DocumentEvent;
19 import dwtx.jface.text.IPositionUpdater;
20 import dwtx.jface.text.Position;
21
22
23 /**
24 * A position updater that never deletes a position. If the region containing
25 * the position is deleted, the position is moved to the beginning/end (falling
26 * together) of the change. If the region containing the position is replaced,
27 * the position is placed at the same location inside the replacement text, but
28 * always inside the replacement text.
29 *
30 * @since 3.1
31 */
32 public final class NonDeletingPositionUpdater : IPositionUpdater {
33 /** The position category. */
34 private final String fCategory;
35
36 /**
37 * Creates a new updater for the given <code>category</code>.
38 *
39 * @param category the new category.
40 */
41 public NonDeletingPositionUpdater(String category) {
42 fCategory= category;
43 }
44
45 /*
46 * @see dwtx.jface.text.IPositionUpdater#update(dwtx.jface.text.DocumentEvent)
47 */
48 public void update(DocumentEvent event) {
49
50 int eventOffset= event.getOffset();
51 int eventOldEndOffset= eventOffset + event.getLength();
52 int eventNewLength= event.getText() is null ? 0 : event.getText().length();
53 int eventNewEndOffset= eventOffset + eventNewLength;
54 int deltaLength= eventNewLength - event.getLength();
55
56 try {
57 Position[] positions= event.getDocument().getPositions(fCategory);
58
59 for (int i= 0; i !is positions.length; i++) {
60
61 Position position= positions[i];
62
63 if (position.isDeleted())
64 continue;
65
66 int offset= position.getOffset();
67 int length= position.getLength();
68 int end= offset + length;
69
70 if (offset > eventOldEndOffset) {
71 // position comes way after change - shift
72 position.setOffset(offset + deltaLength);
73 } else if (end < eventOffset) {
74 // position comes way before change - leave alone
75 } else if (offset <= eventOffset && end >= eventOldEndOffset) {
76 // event completely internal to the position - adjust length
77 position.setLength(length + deltaLength);
78 } else if (offset < eventOffset) {
79 // event extends over end of position - include the
80 // replacement text into the position
81 position.setLength(eventNewEndOffset - offset);
82 } else if (end > eventOldEndOffset) {
83 // event extends from before position into it - adjust
84 // offset and length, including the replacement text into
85 // the position
86 position.setOffset(eventOffset);
87 int deleted= eventOldEndOffset - offset;
88 position.setLength(length - deleted + eventNewLength);
89 } else {
90 // event comprises the position - keep it at the same
91 // position, but always inside the replacement text
92 int newOffset= Math.min(offset, eventNewEndOffset);
93 int newEndOffset= Math.min(end, eventNewEndOffset);
94 position.setOffset(newOffset);
95 position.setLength(newEndOffset - newOffset);
96 }
97 }
98 } catch (BadPositionCategoryException e) {
99 // ignore and return
100 }
101 }
102
103 /**
104 * Returns the position category.
105 *
106 * @return the position category
107 */
108 public String getCategory() {
109 return fCategory;
110 }
111 }