1 /*******************************************************************************
2 * Copyright (c) 2000, 2012 IBM Corporation and others.
4 * This program and the accompanying materials
5 * are made available under the terms of the Eclipse Public License 2.0
6 * which accompanies this distribution, and is available at
7 * https://www.eclipse.org/legal/epl-2.0/
9 * SPDX-License-Identifier: EPL-2.0
12 * IBM Corporation - initial API and implementation
13 *******************************************************************************/
14 package org.eclipse.swt.events;
16 import org.eclipse.swt.widgets.*;
19 * This event is sent to SegmentListeners when a text content is to be modified.
20 * The segments field can be used in conjunction with the segmentsChars field or
21 * by itself. Setting only the segmentsChars field has no effect. When used by
22 * itself, the segments field specify text ranges that should be treated as
25 * The elements in the segments field specify the start offset of a segment
26 * relative to the start of the text. They must follow the following rules:</p>
28 * <li>elements must be in ascending order and must not have duplicates
29 * <li>elements must not exceed the text length
31 * In addition, the first element may be set to zero and the last element may
32 * be set to the end of the line but this is not required.
34 * The segments field may be left null if the entire text content doesn't
35 * require segmentation.
37 * A SegmentListener may be used when adjacent segments of right-to-left text
38 * should not be reordered relative to each other. For example, within a Java
39 * editor, you may wish multiple right-to-left string literals to be reordered
40 * differently than the bidi algorithm specifies.
44 * stored text = "R1R2R3" + "R4R5R6"
45 * R1 to R6 are right-to-left characters. The quotation marks
46 * are part of the text. The text is 13 characters long.
49 * entire text content will be reordered and thus the two R2L segments
50 * swapped (as per the bidi algorithm).
51 * visual display (rendered on screen) = "R6R5R4" + "R3R2R1"
53 * segments = [0, 5, 8]
54 * "R1R2R3" will be reordered, followed by [blank]+[blank] and
56 * visual display = "R3R2R1" + "R6R5R4"
60 * The segments and segmentsChars fields can be used together to obtain different
61 * types of bidi reordering and text display. The application can use these two fields
62 * to insert Unicode Control Characters in specific offsets in the text, the character
63 * at segmentsChars[i] is inserted at the offset specified by segments[i]. When both fields
64 * are set, the rules for the segments field are less restrictive:
67 * <li>elements must be in ascending order, duplicates are allowed
68 * <li>elements must not exceed the text length
74 public class SegmentEvent extends TypedEvent {
77 * The start offset of the <code>lineText</code> relative to text (always zero for single line widget)
79 public int lineOffset;
82 * Text used to calculate the segments
84 public String lineText;
87 * Text ranges that should be treated as separate segments (e.g. for bidi reordering)
89 public int[] segments;
92 * Characters to be used in the segment boundaries (optional)
94 public char[] segmentsChars;
96 static final long serialVersionUID = -2414889726745247762L;
98 public SegmentEvent(Event e) {
101 lineOffset = e.detail;