/*******************************************************************************
* Copyright (c) 2000, 2012 IBM Corporation and others.
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Public License v1.0
* which accompanies this distribution, and is available at
* http://www.eclipse.org/legal/epl-v10.html
*
* Contributors:
* IBM Corporation - initial API and implementation
*******************************************************************************/
package org.eclipse.swt.events;
import org.eclipse.swt.widgets.*;
/**
* This event is sent to SegmentListeners when a text content is to be modified.
* The segments field can be used in conjunction with the segmentsChars field or
* by itself. Setting only the segmentsChars field has no effect. When used by
* itself, the segments field specify text ranges that should be treated as
* separate segments.
* <p>
* The elements in the segments field specify the start offset of a segment
* relative to the start of the text. They must follow the following rules:
* <ul>
* <li>elements must be in ascending order and must not have duplicates
* <li>elements must not exceed the text length
* </ul>
* In addition, the first element may be set to zero and the last element may
* be set to the end of the line but this is not required.
*
* The segments field may be left null if the entire text content doesn't
* require segmentation.
* </p>
* A SegmentListener may be used when adjacent segments of right-to-left text
* should not be reordered relative to each other. For example, within a Java
* editor, you may wish multiple right-to-left string literals to be reordered
* differently than the bidi algorithm specifies.
*
* Example:
* <pre>
* stored text = "R1R2R3" + "R4R5R6"
* R1 to R6 are right-to-left characters. The quotation marks
* are part of the text. The text is 13 characters long.
*
* segments = null:
* entire text content will be reordered and thus the two R2L segments
* swapped (as per the bidi algorithm).
* visual display (rendered on screen) = "R6R5R4" + "R3R2R1"
*
* segments = [0, 5, 8]
* "R1R2R3" will be reordered, followed by [blank]+[blank] and
* "R4R5R6".
* visual display = "R3R2R1" + "R6R5R4"
* </pre>
*
* <p>
* The segments and segmentsChars fields can be used together to obtain different
* types of bidi reordering and text display. The application can use these two fields
* to insert Unicode Control Characters in specific offsets in the text, the character
* at segmentsChars[i] is inserted at the offset specified by segments[i]. When both fields
* are set, the rules for the segments field are less restrictive:
* <ul>
* <li>elements must be in ascending order, duplicates are allowed
* <li>elements must not exceed the text length
* </ul>
* </p>
*
* @since 3.8
*/
public class SegmentEvent extends TypedEvent {
/**
* The start offset of the <code>lineText</code> relative to text (always zero for single line widget)
*/
public int lineOffset;
/**
* Text used to calculate the segments
*/
public String lineText;
/**
* Text ranges that should be treated as separate segments (e.g. for bidi reordering)
*/
public int[] segments;
/**
* Characters to be used in the segment boundaries (optional)
*/
public char[] segmentsChars;
static final long serialVersionUID = -2414889726745247762L;
public SegmentEvent(Event e) {
super(e);
lineText = e.text;
lineOffset = e.detail;
}
}