org.eclipse.swt.custom

Class BidiSegmentEvent

java.lang.Object

java.util.EventObject

org.eclipse.swt.internal.SWTEventObject

org.eclipse.swt.events.TypedEvent

org.eclipse.swt.events.SegmentEvent

org.eclipse.swt.custom.BidiSegmentEvent

All Implemented Interfaces:

java.io.Serializable

public class BidiSegmentEvent
extends SegmentEvent

This event is sent to BidiSegmentListeners when a line is to be measured or rendered in a bidi locale. 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 in the line that should be treated as separate segments for bidi reordering. Each segment will be reordered and rendered separately.

The elements in the segments field specify the start offset of a segment relative to the start of the line. They must follow the following rules:

• elements must be in ascending order and must not have duplicates
• elements must not exceed the line 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 line should be reordered as is.

A BidiSegmentListener 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 line = "R1R2R3" + "R4R5R6"
                R1 to R6 are right-to-left characters. The quotation marks
                are part of the line text. The line is 13 characters long.
 
        segments = null: 
                entire line will be reordered and thus the two R2L segments 
                swapped (as per the bidi algorithm). 
                visual line (rendered on screen) = "R6R5R4" + "R3R2R1"
 
        segments = [0, 5, 8]    
                "R1R2R3" will be reordered, followed by [blank]+[blank] and 
                "R4R5R6". 
                visual line = "R3R2R1" + "R6R5R4"
 

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 line, 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 line length

See Also:

Sample code and further information, Serialized Form

Structure Diagram

Field Summary

Fields

Modifier and Type	Field and Description
(package private) static long	serialVersionUID

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

lineOffset, lineText, segments, segmentsChars

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
BidiSegmentEvent(StyledTextEvent e)

Method Summary

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

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

serialVersionUID

static final long serialVersionUID

See Also:

Constant Field Values

Constructor Detail

BidiSegmentEvent

BidiSegmentEvent(StyledTextEvent e)