org.eclipse.swt.events

Class SegmentEvent

java.lang.Object

java.util.EventObject

org.eclipse.swt.internal.SWTEventObject

org.eclipse.swt.events.TypedEvent

org.eclipse.swt.events.SegmentEvent

All Implemented Interfaces:

java.io.Serializable

Direct Known Subclasses:

BidiSegmentEvent

public class SegmentEvent
extends TypedEvent

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.

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:

• elements must be in ascending order and must not have duplicates
• elements must not exceed the text length

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.

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:

        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"
 

The segments and segementsChars 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:

• elements must be in ascending order, duplicates are allowed
• elements must not exceed the text length

Since:

3.8

See Also:

Serialized Form

Structure Diagram

Field Summary

Fields

Modifier and Type	Field and Description
int	lineOffset The start offset of the lineText relative to text (always zero for single line widget)
java.lang.String	lineText Text used to calculate the segments
int[]	segments Text ranges that should be treated as separate segments (e.g. for bidi reordering)
char[]	segmentsChars Characters to be used in the segment boundaries (optional)
(package private) static long	serialVersionUID

Fields inherited from class org.eclipse.swt.events.TypedEvent

data, display, time, widget

Fields inherited from class java.util.EventObject

source

Constructor Summary

Constructors

Constructor and Description
SegmentEvent(Event e)

Method Summary

Methods inherited from class org.eclipse.swt.events.TypedEvent

getName, toString

Methods inherited from class java.util.EventObject

getSource

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

lineOffset

public int lineOffset

The start offset of the lineText relative to text (always zero for single line widget)

lineText

public java.lang.String lineText

Text used to calculate the segments

segments

public int[] segments

Text ranges that should be treated as separate segments (e.g. for bidi reordering)

segmentsChars

public char[] segmentsChars

Characters to be used in the segment boundaries (optional)

serialVersionUID

static final long serialVersionUID

See Also:

Constant Field Values

Constructor Detail

SegmentEvent

public SegmentEvent(Event e)