Adobe® Flex® 4 Language Reference
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flash.text.engine 
TextBlock 
Packageflash.text.engine
Classpublic final class TextBlock
InheritanceTextBlock Inheritance Object

Language Version: ActionScript 3.0
Runtime Versions: Flash Player 10, AIR 1.5, Flash Lite 4

The TextBlock class is a factory for the creation of TextLine objects, which you can render by placing them on the display list.

The TextBlock class is intended to contain a single paragraph because the Unicode bidirectional and line-break algorithms operate on one paragraph at a time. For applications that compose multiple paragraphs of text, use a markup language, or text analysis to divide the text into paragraphs and create one TextBlock per paragraph.

The TextBlock object stores its content in the content property, which is an instance of the ContentElement class. Because you can't create an instance of the ContentElement class, set content to an instance of one of its subclasses: TextElement, GraphicElement, or GroupElement. Use TextElement for purely text content, GraphicElement for an image or graphic content, and GroupElement for content that contains a combination of TextElement, GraphicElement, and other GroupElement objects. See the ContentElement class and its subclasses for details on managing formatted runs of text, embedded sub-runs, and graphic elements.

After you create the TextBlock instance and set the content property, call the createTextLine() method to create lines of text, which are instances of the TextLine class.

View the examples

See also



Public Properties
 PropertyDefined By
  applyNonLinearFontScaling : Boolean
Specifies that you want to enhance screen appearance at the expense of what-you-see-is-what-you-get (WYSIWYG) print fidelity.
TextBlock
  baselineFontDescription : FontDescription
The font used to determine the baselines for all the lines created from the block, independent of their content.
TextBlock
  baselineFontSize : Number
The font size used to calculate the baselines for the lines created from the block.
TextBlock
  baselineZero : String
Specifies which baseline is at y=0 for lines created from this block.
TextBlock
  bidiLevel : int
Specifies the default bidirectional embedding level of the text in the text block.
TextBlock
 Inheritedconstructor : Object
A reference to the class object or constructor function for a given object instance.
Object
  content : ContentElement
Holds the contents of the text block.
TextBlock
  firstInvalidLine : flash.text.engine:TextLine
[read-only] Identifies the first line in the text block in which TextLine.validity is not equal to TextLineValidity.VALID.
TextBlock
  firstLine : flash.text.engine:TextLine
[read-only] The first TextLine in the TextBlock, if any.
TextBlock
  lastLine : flash.text.engine:TextLine
[read-only] The last TextLine in the TextBlock, if any.
TextBlock
  lineRotation : String
Rotates the text lines in the text block as a unit.
TextBlock
 Inheritedprototype : Object
[static] A reference to the prototype object of a class or function object.
Object
  tabStops : Vector.<flash.text.engine:TabStop>
Specifies the tab stops for the text in the text block, in the form of a Vector of TabStop objects.
TextBlock
  textJustifier : flash.text.engine:TextJustifier
Specifies the TextJustifier to use during line creation.
TextBlock
  textLineCreationResult : String
[read-only] Indicates the result of a createTextLine() operation.
TextBlock
  userData : *
Provides a way for the application to associate arbitrary data with the text block.
TextBlock
Public Methods
 MethodDefined By
  
TextBlock(content:ContentElement = null, tabStops:Vector.<flash.text.engine:TabStop> = null, textJustifier:flash.text.engine:TextJustifier = null, lineRotation:String = "rotate0", baselineZero:String = "roman", bidiLevel:int = 0, applyNonLinearFontScaling:Boolean = true, baselineFontDescription:FontDescription = null, baselineFontSize:Number = 12.0)
Creates a TextBlock object
TextBlock
  
createTextLine(previousLine:flash.text.engine:TextLine = null, width:Number = 1000000, lineOffset:Number = 0.0, fitSomething:Boolean = false):flash.text.engine:TextLine
Instructs the text block to create a line of text from its content, beginning at the point specified by the previousLine parameter and breaking at the point specified by the width parameter.
TextBlock
  
Dumps the underlying contents of the TextBlock as an XML string.
TextBlock
  
findNextAtomBoundary(afterCharIndex:int):int
Finds the index of the next atom boundary from the specified character index, not including the character at the specified index.
TextBlock
  
findNextWordBoundary(afterCharIndex:int):int
Finds the index of the next word boundary from the specified character index, not including the character at the specified index.
TextBlock
  
Finds the index of the previous atom boundary to the specified character index, not including the character at the specified index.
TextBlock
  
Finds the index of the previous word boundary to the specified character index, not including the character at the specified index.
TextBlock
  
Returns the TextLine containing the character specified by the charIndex parameter.
TextBlock
 Inherited
Indicates whether an object has a specified property defined.
Object
 Inherited
Indicates whether an instance of the Object class is in the prototype chain of the object specified as the parameter.
Object
 Inherited
Indicates whether the specified property exists and is enumerable.
Object
  
recreateTextLine(textLine:flash.text.engine:TextLine, previousLine:flash.text.engine:TextLine = null, width:Number = 1000000, lineOffset:Number = 0.0, fitSomething:Boolean = false):flash.text.engine:TextLine
Instructs the text block to re-use an existing text line to create a line of text from its content, beginning at the point specified by the previousLine parameter and breaking at the point specified by the width parameter.
TextBlock
  
Instructs the text block to release all the temporary data associated with the creation of text lines.
TextBlock
  
Removes a range of text lines from the list of lines maintained by the TextBlock.
TextBlock
 Inherited
Sets the availability of a dynamic property for loop operations.
Object
 Inherited
Returns the string representation of this object, formatted according to locale-specific conventions.
Object
 Inherited
Returns the string representation of the specified object.
Object
 Inherited
Returns the primitive value of the specified object.
Object
Property Detail

applyNonLinearFontScaling

property
applyNonLinearFontScaling:Boolean

Language Version: ActionScript 3.0
Runtime Versions: Flash Player 10, AIR 1.5, Flash Lite 4

Specifies that you want to enhance screen appearance at the expense of what-you-see-is-what-you-get (WYSIWYG) print fidelity. For platforms and fonts that support non-linear scaling, setting this property to true enables the use of those metrics at some cost to WYSIWYG print fidelity, particularly for small point sizes.

The default value is true.



Implementation
    public function get applyNonLinearFontScaling():Boolean
    public function set applyNonLinearFontScaling(value:Boolean):void

baselineFontDescription

property 
baselineFontDescription:FontDescription

Language Version: ActionScript 3.0
Runtime Versions: Flash Player 10, AIR 1.5, Flash Lite 4

The font used to determine the baselines for all the lines created from the block, independent of their content. Baselines depend on font and font size.

The default value is null. When the baseline font is null, the baseline font size is ignored and the baseline for any given line is based on the font and size of the largest text in the line. When you specify both baselineFontDescription and baselineFontSize, they determine the baselines for all the lines in the text block, independent of their content. This combination is most often useful in Asian typography.



Implementation
    public function get baselineFontDescription():FontDescription
    public function set baselineFontDescription(value:FontDescription):void

See also

baselineFontSize

property 
baselineFontSize:Number

Language Version: ActionScript 3.0
Runtime Versions: Flash Player 10, AIR 1.5, Flash Lite 4

The font size used to calculate the baselines for the lines created from the block. Baselines depend on font and font size.

The default value is 12. When the baseline font is null, the baseline font size is ignored and the baseline for any given line is based on the font and size of the largest text in the line.



Implementation
    public function get baselineFontSize():Number
    public function set baselineFontSize(value:Number):void

Throws
ArgumentError — The baselineFontSize specified is less than 0.

See also

baselineZero

property 
baselineZero:String

Language Version: ActionScript 3.0
Runtime Versions: Flash Player 10, AIR 1.5, Flash Lite 4

Specifies which baseline is at y=0 for lines created from this block. Valid values for this property are found in the members of the TextBaseline class.

The default value is TextBaseline.ROMAN.

To set values for this property, use the following string values:

String valueDescription
TextBaseline.ROMANThe roman baseline of the lines is at y=0.
TextBaseline.ASCENTThe ascent baseline of the lines is at y=0.
TextBaseline.DESCENTThe descent baseline of the lines is at y=0.
TextBaseline.IDEOGRAPHIC_TOPThe ideographic top baseline of the lines is at y=0.
TextBaseline.IDEOGRAPHIC_CENTERThe ideographic center baseline of the lines is at y=0.
TextBaseline.IDEOGRAPHIC_BOTTOMThe ideographic bottom baseline of the lines is at y=0.



Implementation
    public function get baselineZero():String
    public function set baselineZero(value:String):void

Throws
ArgumentError — If set to any value which is not a member of TextBaseline.

See also

bidiLevel

property 
bidiLevel:int

Language Version: ActionScript 3.0
Runtime Versions: Flash Player 10, AIR 1.5, Flash Lite 4

Specifies the default bidirectional embedding level of the text in the text block. An even value means left-to-right and an odd value means right-to-left. You can increment bidiLevel to indicate the number of levels by which particular text is embedded with respect to left-to-right and right-to-left.

The default value is 0.

Modifying bidiLevel changes the validity of all previously broken lines to TextLineValidity.INVALID. After changing bidiLevel, the firstInvalidLine property equals the firstLine property, and you must rebreak all the lines in the TextBlock.



Implementation
    public function get bidiLevel():int
    public function set bidiLevel(value:int):void

Throws
ArgumentError — If set to a value which is less than 0.

See also


Example  ( How to use this example )
This example shows the same text string (logical order: a, b, c, alef, bet, gimel) rendered first with bidiLevel even and second with bidiLevel odd.

package {
    
    import flash.display.Sprite;
    import flash.text.engine.TextBlock;
    import flash.text.engine.TextElement;
    import flash.text.engine.TextLine;
    import flash.text.engine.ElementFormat;
    import flash.text.engine.FontDescription;
    
    public class TextBlock_bidiLevelExample extends Sprite {
        
        public function TextBlock_bidiLevelExample():void {             
            var fontSize:Number = 36;

            var format:ElementFormat = new ElementFormat();        
            format.fontDescription = new FontDescription("Adobe Hebrew");
            format.fontSize = fontSize;
            var y:Number = 0;
            var leading:Number = fontSize * 0.2;
            var text:String = "abc" + String.fromCharCode(0x05D0, 0x05D1, 0x05D2);

            var textBlock:TextBlock = new TextBlock();
            textBlock.content = new TextElement(text, format);
                        
            // bidiLevel even
            textBlock.bidiLevel = 0;
            var textLine = textBlock.createTextLine(null, 400);
            y += leading + textLine.ascent;
            textLine.y = y;
            y += textLine.descent;
            addChild(textLine);      
            
            // bidiLevel odd
            textBlock.content = new TextElement(text, format);
            textBlock.bidiLevel = 1;
            textLine = textBlock.createTextLine(null, 400);
            y += leading + textLine.ascent;          
            textLine.y = y;
            addChild(textLine);   
        }
    }
}

content

property 
content:ContentElement

Language Version: ActionScript 3.0
Runtime Versions: Flash Player 10, AIR 1.5, Flash Lite 4

Holds the contents of the text block. Because ContentElement is a base class, assign content an instance of a ContentElement subclass: TextElement, GraphicElement, or GroupElement. A TextElement object contains a String, a GraphicElement object contains a DisplayObject, and a GroupElement contains a Vector object that contains one or more TextElement, GraphicElement, or other GroupElement objects. Use a TextElement for a paragraph of homogenous text, a GraphicElement for a graphic, and a GroupElement for a combination of text and graphic elements or multiples instances of these elements, as well as other GroupElement objects.

The default value is null.

Modifying the content property changes the validity of all previously created lines to TextLineValidity.INVALID. After changing content, the firstInvalidLine property equals the firstLine property and you must rebreak all lines in the TextBlock.



Implementation
    public function get content():ContentElement
    public function set content(value:ContentElement):void

Throws
ArgumentError — If set to a value which is not a known subclass of ContentElement.
 
ArgumentError — The value specified is already a member of a group.

See also

firstInvalidLine

property 
firstInvalidLine:flash.text.engine:TextLine  [read-only]

Language Version: ActionScript 3.0
Runtime Versions: Flash Player 10, AIR 1.5, Flash Lite 4

Identifies the first line in the text block in which TextLine.validity is not equal to TextLineValidity.VALID.

The default value is null.



Implementation
    public function get firstInvalidLine():flash.text.engine:TextLine

See also

firstLine

property 
firstLine:flash.text.engine:TextLine  [read-only]

Language Version: ActionScript 3.0
Runtime Versions: Flash Player 10, AIR 1.5, Flash Lite 4

The first TextLine in the TextBlock, if any.

The default value is null.



Implementation
    public function get firstLine():flash.text.engine:TextLine

See also

lastLine

property 
lastLine:flash.text.engine:TextLine  [read-only]

Language Version: ActionScript 3.0
Runtime Versions: Flash Player 10, AIR 1.5, Flash Lite 4

The last TextLine in the TextBlock, if any.

The default value is null.



Implementation
    public function get lastLine():flash.text.engine:TextLine

See also

lineRotation

property 
lineRotation:String

Language Version: ActionScript 3.0
Runtime Versions: Flash Player 10, AIR 1.5, Flash Lite 4

Rotates the text lines in the text block as a unit. Call the createTextLine() method after setting lineRotation for it to take effect. The default value is TextRotation.ROTATE_0.

The final rotation of any glyph depends on the values of ElementFormat.textRotation, ContentElement.textRotation, and TextBlock.lineRotation.

TextBlock.lineRotation is typically used for Asian text. To create a paragraph of vertical Japanese text, do the following:

  1. Set the TextBlock.lineRotation property to TextRotation.ROTATE_90.
  2. Leave the ElementFormat.textRotation property of the content as the default, TextRotation.AUTO.

Use the following constants, which are defined in the TextRotation class, to set the value for this property:

String valueDescription
TextRotation.ROTATE_0Lines are not rotated.
TextRotation.ROTATE_90Lines are rotated 90 degrees clockwise.
TextRotation.ROTATE_180Lines are rotated 180 degrees.
TextRotation.ROTATE_270Lines are rotated 270 degrees clockwise.
TextRotation.AUTONot supported.



Implementation
    public function get lineRotation():String
    public function set lineRotation(value:String):void

Throws
ArgumentError — If set to any value which is not a member of TextRotation.
 
ArgumentError — If set to TextRotation.AUTO.

See also


Example  ( How to use this example )
This example adds Japanese text to a TextBlock and sets the lineRotation property to TextRotation.ROTATE_90 to display the line vertically.

package {
    import flash.display.Sprite;
    import flash.text.engine.FontDescription;
    import flash.text.engine.TextBlock;
    import flash.text.engine.TextElement;
    import flash.text.engine.TextLine;
    import flash.text.engine.TextRotation;
    import flash.text.engine.ElementFormat;
    
    public class TextBlock_lineRotationExample extends Sprite {
        
        public function TextBlock_lineRotationExample():void {
            var Japanese:String = String.fromCharCode(
                0x5185, 0x95A3, 0x5E9C, 0x304C, 0x300C, 0x653F, 0x5E9C, 0x30A4,
                0x30F3, 0x30BF, 0x30FC, 0x30CD, 0x30C3, 0x30C8, 0x30C6, 0x30EC, 
                0x30D3, 0x300D, 0x306E, 0x52D5, 0x753B, 0x914D, 0x4FE1, 0x5411, 
                0x3051, 0x306B, 0x30A2, 0x30C9, 0x30D3, 0x30B7, 0x30B9, 0x30C6, 
                0x30E0, 0x30BA, 0x793E, 0x306E
            ) +
            "FMS 2" +
            String.fromCharCode(0x3092, 0x63A1, 0x7528, 0x3059, 0x308B, 0x3068, 
                0x767a, 0x8868, 0x3057, 0x307e, 0x3057, 0x305F, 0x3002);

            var fontDescription:FontDescription = new FontDescription("MS Mincho");
            var format:ElementFormat = new ElementFormat();
            format.fontSize = 15;
            format.fontDescription = fontDescription;
                        
            var textElement:TextElement = new TextElement(Japanese, format); 
            var textBlock:TextBlock = new TextBlock();
            textBlock.content = textElement;
            textBlock.lineRotation = TextRotation.ROTATE_90;

            var linePosition:Number = this.stage.stageWidth - 120;
            var previousLine:TextLine = null;
        
            while (true) {
                var textLine:TextLine = textBlock.createTextLine(
                    previousLine, 
                    300);
                if (textLine == null) 
                    break;
                textLine.y = 30;    
                textLine.x = linePosition;
                linePosition -= 24;
                addChild(textLine);                
                previousLine = textLine;
            }        
        }
    }
}

tabStops

property 
tabStops:Vector.<flash.text.engine:TabStop>

Language Version: ActionScript 3.0
Runtime Versions: Flash Player 10, AIR 1.5, Flash Lite 4

Specifies the tab stops for the text in the text block, in the form of a Vector of TabStop objects.

The default value is null, which means no tab stops are specified. When no tab stops are specified (or the insertion point is beyond the last specified tab stop) the runtime creates half-inch tabs by default.

When the tabStops property is set, the TextBlock makes a copy of the Vector for internal use. Modifying the original Vector or its contents does not affect the TextBlock. When the tabStops property is queried, a copy of the internal Vector is returned. Again, modifying this returned vector or its contents does not affect the TextBlock.



Implementation
    public function get tabStops():Vector.<flash.text.engine:TabStop>
    public function set tabStops(value:Vector.<flash.text.engine:TabStop>):void

Throws
ArgumentError — The tabStops specified contain null elements.
 
ArgumentError — The tabStops specified are not sorted by increasing position.

See also

textJustifier

property 
textJustifier:flash.text.engine:TextJustifier

Language Version: ActionScript 3.0
Runtime Versions: Flash Player 10, AIR 1.5, Flash Lite 4

Specifies the TextJustifier to use during line creation.

The default value is a constructed default TextJustifier object.

When the textJustifier property is set, the TextBlock makes a copy of the object for internal use. Modifying the original object does not affect the TextBlock. When the textJustifier property is queried, a copy of the internal object is returned. Again, modifying this returned object does not affect the TextBlock.



Implementation
    public function get textJustifier():flash.text.engine:TextJustifier
    public function set textJustifier(value:flash.text.engine:TextJustifier):void

Throws
ArgumentError — If set to a value which is not a known subclass of TextJustifier.

See also

textLineCreationResult

property 
textLineCreationResult:String  [read-only]

Language Version: ActionScript 3.0
Runtime Versions: Flash Player 10, AIR 1.5, Flash Lite 4

Indicates the result of a createTextLine() operation. Changing the content of the block invalidates previously broken lines and resets this property to null.

The default value is null.

Values for this property are found in TextLineCreationResult

String valueDescription
TextLineCreationResult.SUCCESSThe line was successfully broken.
TextLineCreationResult.COMPLETEEither the new line created aligned perfectly with following lines which have transitioned from POSSIBLY_INVALID to VALID, or no line was created because all text in the block had already been broken.
TextLineCreationResult.INSUFFICIENT_WIDTHNo line was created because no text could fit in the specified width.



Implementation
    public function get textLineCreationResult():String

See also

userData

property 
public var userData:*

Language Version: ActionScript 3.0
Runtime Versions: Flash Player 10, AIR 1.5, Flash Lite 4

Provides a way for the application to associate arbitrary data with the text block. The data could be information that refers to the content, such as a revision date or the name of the author, or it could be cached data that you use during processing.

Constructor Detail

TextBlock

()Constructor
public function TextBlock(content:ContentElement = null, tabStops:Vector.<flash.text.engine:TabStop> = null, textJustifier:flash.text.engine:TextJustifier = null, lineRotation:String = "rotate0", baselineZero:String = "roman", bidiLevel:int = 0, applyNonLinearFontScaling:Boolean = true, baselineFontDescription:FontDescription = null, baselineFontSize:Number = 12.0)

Language Version: ActionScript 3.0
Runtime Versions: Flash Player 10, AIR 1.5, Flash Lite 4

Creates a TextBlock object

Parameters
content:ContentElement (default = null) — The contents of the text block.
 
tabStops:Vector.<flash.text.engine:TabStop> (default = null) — The tab stops for the text in the text block.
 
textJustifier:flash.text.engine:TextJustifier (default = null) — The TextJustifier object to use during line creation for this block. If no justifier is provided, a default justifier is constructed based on an English locale.
 
lineRotation:String (default = "rotate0") — The rotation applied to the text lines generated from the text block as units.
 
baselineZero:String (default = "roman") — Specifies which baseline is at y=0 for all lines in the block.
 
bidiLevel:int (default = 0) — The default bidirectional embedding level of the text in the text block.
 
applyNonLinearFontScaling:Boolean (default = true) — Specifies that you want to enhance screen appearance at the expense of WYSIWYG print fidelity.
 
baselineFontDescription:FontDescription (default = null) — Specifies a font description from which to derive line baselines for all lines in the block.
 
baselineFontSize:Number (default = 12.0) — Specifies the size to use with the baselineFontDescription. This parameter is ignored if baselineFontDescription is null.

Throws
ArgumentError — The content specified is not a known subclass of ContentElement.
 
ArgumentError — The content specified is already a member of a group.
 
ArgumentError — The lineRotation specified is not a member of TextRotation.
 
ArgumentError — The baselineZero specified is not a member of TextBaseline.
 
ArgumentError — The bidiLevel specified is less than 0.
 
ArgumentError — The tabStops specified contain null elements.
 
ArgumentError — The tabStops specified are not sorted by increasing position.
 
ArgumentError — The baselineFontSize specified is less than 0.

See also

Method Detail

createTextLine

()method
public function createTextLine(previousLine:flash.text.engine:TextLine = null, width:Number = 1000000, lineOffset:Number = 0.0, fitSomething:Boolean = false):flash.text.engine:TextLine

Language Version: ActionScript 3.0
Runtime Versions: Flash Player 10, AIR 1.5, Flash Lite 4

Instructs the text block to create a line of text from its content, beginning at the point specified by the previousLine parameter and breaking at the point specified by the width parameter. The text line is a TextLine object, which you can add to the display list.

Breaking lines over a range of a text block that has already been broken can change the validity of lines in and beyond the area where breaking takes place. The status of lines can change from VALID to INVALID or POSSIBLY_INVALID. If a newly broken line aligns perfectly with a previously broken line which has a status of POSSIBLY_INVALID, that previously broken line and all following POSSIBLY_INVALID lines change back to a status of VALID. The validity of lines that have been set to values that are not members of TextLineValidity do not change to VALID, but could change to INVALID. Check the firstInvalidLine property after any change to the text block to see where to begin or continue rebreaking text lines.

You can create artificial word breaks by including the Unicode Zero Width Space (ZWSP) character in the text. This can be useful for languages such as Thai, which require a dictionary for correct line breaking. The Flash runtime does not include such a dictionary.

In order to reduce memory overhead, when all the desired lines have been created, unless it is expected that the lines will need to be repeatedly rebroken due to, for example, the resizing of the container, the user should call the releaseLineCreationData() method allowing the text block to dispose of the temporary data associated with line breaking.

Parameters

previousLine:flash.text.engine:TextLine (default = null) — Specifies the previously broken line after which breaking is to commence. Can be null when breaking the first line.
 
width:Number (default = 1000000) — Specifies the desired width of the line in pixels. The actual width may be less.
 
lineOffset:Number (default = 0.0) — An optional parameter which specifies the difference in pixels between the origin of the line and the origin of the tab stops. This can be used when lines are not aligned, but it is desirable for their tabs to be so. The default value for this parameter is 0.0.
 
fitSomething:Boolean (default = false) — An optional parameter which instructs Flash Player to fit at least one character into the text line, no matter what width has been specified (even if width is zero or negative, which would otherwise result in an exception being thrown).

Returns
flash.text.engine:TextLine — A text line, or null if the text block is empty or the width specified is less than the width of the next element. To distinguish between these cases, check the textLineCreationResult property of the text block.

Throws
ArgumentError — If the TextLine specified by previousLine is not valid.
 
ArgumentError — If the TextLine specified by previousLine is owned by a different TextBlock.
 
ArgumentError — If width is less than zero, unless fitSomething is true.
 
ArgumentError — If width is greater than TextLine.MAX_LINE_WIDTH.
 
IllegalOperationError — If one or more elements in the content of the text block has a null ElementFormat.

See also


Example  ( How to use this example )

This example calls the createTextLine() method to create lines of text in a text block. It accomplishes this by performing the following tasks:
  • Creating a TextElement from a String and giving it a font size of 20
  • Creating a TextBlock and assigning the TextElement to it
  • Calling createTextLine() to create lines 300 pixels wide from the text block
  • Placing each line on Stage (addChild()) and setting its position (x and y)

package {
    import flash.display.Sprite;
    import flash.text.engine.TextBlock;
    import flash.text.engine.TextElement;
    import flash.text.engine.TextLine;
    import flash.text.engine.ElementFormat;
    import flash.text.engine.FontDescription;
    
    public class TextBlock_createTextLineExample extends Sprite {
        
        public function TextBlock_createTextLineExample():void {
            
            var str:String = "I am a TextElement, created from a String and assigned " +
            "to the content property of a TextBlock. The createTextLine() method " +
            "then created these lines, 300 pixels wide, for display." ;
            
            var fontDescription:FontDescription = new FontDescription("Arial");
            var format:ElementFormat = new ElementFormat(fontDescription);
            format.fontSize = 16;
            var textElement:TextElement = new TextElement(str, format); 
            var textBlock:TextBlock = new TextBlock();
            textBlock.content = textElement; 
            createLines(textBlock); 
        }
        
        private function createLines(textBlock:TextBlock):void 
        {            
            var lineWidth:Number = 300;
            var xPos:Number = 15.0;
            var yPos:Number = 20.0;
            
            var textLine:TextLine = textBlock.createTextLine (null, lineWidth);
            while (textLine)
            {
                textLine.x = xPos;
                textLine.y = yPos;
                yPos += textLine.height + 2;
                addChild (textLine);
                textLine = textBlock.createTextLine (textLine, lineWidth);
            }
        }
    }
}

dump

()method 
public function dump():String

Language Version: ActionScript 3.0
Runtime Versions: Flash Player 10, AIR 1.5

Dumps the underlying contents of the TextBlock as an XML string. This can be useful in automated testing, and includes text, formatting, and layout information.

The following describes the output:

	 >block<
	 	[0-N LINE]
	 >/block<
	 

For a description of the output for each line, see the TextLine.dump() method.

Note: The content and format of the output may change in the future. Adobe does not guarantee backward compatibility of this method.

Returns
String

See also

findNextAtomBoundary

()method 
public function findNextAtomBoundary(afterCharIndex:int):int

Language Version: ActionScript 3.0
Runtime Versions: Flash Player 10, AIR 1.5, Flash Lite 4

Finds the index of the next atom boundary from the specified character index, not including the character at the specified index. The characters between atom boundaries combine to form one atom in a TextLine, such as an 'e' and a combining acute accent.

Parameters

afterCharIndex:int — Specifies the index of the character from which to search for the next atom boundary.

Returns
int — The index of the next atom boundary from the specified character index.

Throws
RangeError — The index specified is out of range.
 
IllegalOperationError — The TextLine to which the indexed character belongs is not valid.

See also

findNextWordBoundary

()method 
public function findNextWordBoundary(afterCharIndex:int):int

Language Version: ActionScript 3.0
Runtime Versions: Flash Player 10, AIR 1.5, Flash Lite 4

Finds the index of the next word boundary from the specified character index, not including the character at the specified index. Word boundaries are determined based on the Unicode properties of the characters.

Parameters

afterCharIndex:int — Specifies the index of the character from which to search for the next word boundary.

Returns
int — The index of the next word boundary from the specified character index.

Throws
RangeError — The index specified is out of range.
 
IllegalOperationError — The TextLine to which the indexed character belongs is not valid.

findPreviousAtomBoundary

()method 
public function findPreviousAtomBoundary(beforeCharIndex:int):int

Language Version: ActionScript 3.0
Runtime Versions: Flash Player 10, AIR 1.5, Flash Lite 4

Finds the index of the previous atom boundary to the specified character index, not including the character at the specified index. The characters between atom boundaries combine to form one atom in a TextLine, such as an 'e' and a combining acute accent.

Parameters

beforeCharIndex:int — Specifies the index of the character from which to search for the previous atom boundary.

Returns
int — The index of the previous atom boundary to the specified character index.

Throws
RangeError — The index specified is out of range.
 
IllegalOperationError — The TextLine to which the indexed character belongs is not valid.

See also

findPreviousWordBoundary

()method 
public function findPreviousWordBoundary(beforeCharIndex:int):int

Language Version: ActionScript 3.0
Runtime Versions: Flash Player 10, AIR 1.5, Flash Lite 4

Finds the index of the previous word boundary to the specified character index, not including the character at the specified index. Word boundaries are determined based on the Unicode properties of the characters.

Parameters

beforeCharIndex:int — Specifies the index of the character from which to search for the previous word boundary.

Returns
int — The index of the previous word boundary to the specified character index.

Throws
RangeError — The index specified is out of range.
 
IllegalOperationError — The TextLine to which the indexed character belongs is not valid.

getTextLineAtCharIndex

()method 
public function getTextLineAtCharIndex(charIndex:int):flash.text.engine:TextLine

Language Version: ActionScript 3.0
Runtime Versions: Flash Player 10, AIR 1.5, Flash Lite 4

Returns the TextLine containing the character specified by the charIndex parameter.

Parameters

charIndex:int — The zero-based index value of the character (for example, the first character is 0, the second character is 1, and so on).

Returns
flash.text.engine:TextLine — The TextLine containing the character at charIndex.

Throws
RangeError — The character index specified is out of range.

recreateTextLine

()method 
public function recreateTextLine(textLine:flash.text.engine:TextLine, previousLine:flash.text.engine:TextLine = null, width:Number = 1000000, lineOffset:Number = 0.0, fitSomething:Boolean = false):flash.text.engine:TextLine

Language Version: ActionScript 3.0
Runtime Versions: Flash Player 10.1, AIR 2, Flash Lite 4

Instructs the text block to re-use an existing text line to create a line of text from its content, beginning at the point specified by the previousLine parameter and breaking at the point specified by the width parameter. The text line is a TextLine object, which you can add to the display list. By re-using an existing text line, performance is enhanced due to reduced object creation.

The textLine being recreated is released from whatever text block it is in, if any. In addition, all properties, including inherited properties from DisplayObjectContainer, InteractiveObject, and DisplayObject are reset to their default values. Finally, all children of the line are removed including graphic elements and other decorations, and all event listeners on the line are removed. To improve performance, the only exception to this complete reset is that the line itself is not removed from its parent.

Breaking lines over a range of a text block that has already been broken can change the validity of lines in and beyond the area where breaking takes place. The status of lines can change from VALID to INVALID or POSSIBLY_INVALID. If a newly broken line aligns perfectly with a previously broken line which has a status of POSSIBLY_INVALID, that previously broken line and all following POSSIBLY_INVALID lines change back to a status of VALID. The validity of lines that have been set to values that are not members of TextLineValidity do not change to VALID, but could change to INVALID. Check the firstInvalidLine property after any change to the text block to see where to begin or continue rebreaking text lines.

You can create artificial word breaks by including the Unicode Zero Width Space (ZWSP) character in the text. This can be useful for languages such as Thai, which require a dictionary for correct line breaking. The Flash runtime does not include such a dictionary.

In order to reduce memory overhead, when all the desired lines have been created, unless it is expected that the lines will need to be repeatedly rebroken due to, for example, the resizing of the container, the user should call the releaseLineCreationData() method allowing the text block to dispose of the temporary data associated with line breaking.

Parameters

textLine:flash.text.engine:TextLine — Specifies a previously created TextLine to be re-used.
 
previousLine:flash.text.engine:TextLine (default = null) — Specifies the previously broken line after which breaking is to commence. Can be null when breaking the first line.
 
width:Number (default = 1000000) — Specifies the desired width of the line in pixels. The actual width may be less.
 
lineOffset:Number (default = 0.0) — An optional parameter which specifies the difference in pixels between the origin of the line and the origin of the tab stops. This can be used when lines are not aligned, but it is desirable for their tabs to be so. The default value for this parameter is 0.0.
 
fitSomething:Boolean (default = false) — An optional parameter which instructs Flash Player to fit at least one character into the text line, no matter what width has been specified (even if width is zero or negative, which would otherwise result in an exception being thrown).

Returns
flash.text.engine:TextLine — A text line, or null if the text block is empty or the width specified is less than the width of the next element. To distinguish between these cases, check the textLineCreationResult property of the text block.

Throws
ArgumentError — If textLine is null.
 
ArgumentError — If the TextLine specified by previousLine is not valid.
 
ArgumentError — If the TextLine specified by previousLine is owned by a different TextBlock.
 
ArgumentError — If the TextLine specified by previousLine is also specified by textLine.
 
ArgumentError — If width is less than zero, unless fitSomething is true.
 
ArgumentError — If width is greater than TextLine.MAX_LINE_WIDTH.
 
IllegalOperationError — If one or more elements in the content of the text block has a null ElementFormat.

See also


Example  ( How to use this example )

This example re-uses the TextLine object textLine:
var elementFormat:ElementFormat = new ElementFormat();
elementFormat.fontDescription = new FontDescription("Arial");
elementFormat.fontSize = 48;

var textElement:TextElement = new TextElement("Text you'll never see", elementFormat)
var textBlock:TextBlock = new TextBlock(textElement);
var textLine:TextLine = textBlock.createTextLine();
textLine.x = 50;
textLine.y = 50;
addChild(textLine);

// Reuse the element format to preserve the text formatting
var elementTwo:TextElement = new TextElement("Text you see", elementFormat);  
textBlock.content = elementTwo;
textBlock.recreateTextLine(textLine);

// Set the position (and any other display object properties like alpha, children, etc.)
// otherwise, they're all set to default properties.
textLine.x = 50;  
textLine.y = 50;

releaseLineCreationData

()method 
public function releaseLineCreationData():void

Language Version: ActionScript 3.0
Runtime Versions: Flash Player 10.1, AIR 2, Flash Lite 4

Instructs the text block to release all the temporary data associated with the creation of text lines. To minimize an application's memory foot print, you should call the releaseLineCreationData() method when you are done creating text lines from a text block. However, to maximize performance for rebreaking the lines (for example when the container is resized) the releaseLineCreationData() method should not be called. It is up to the application to balance memory vs. performance.

The recommended process for text that is not expected to change is: initialize a text block, call the createTextLine() method as often as necessary to create the desired output, and then call the releaseLineCreationData() method.

See also

releaseLines

()method 
public function releaseLines(firstLine:flash.text.engine:TextLine, lastLine:flash.text.engine:TextLine):void

Language Version: ActionScript 3.0
Runtime Versions: Flash Player 10, AIR 1.5, Flash Lite 4

Removes a range of text lines from the list of lines maintained by the TextBlock. This allows the lines to be garbage-collected if no other references exist.

Sets the textBlock, nextLine, and previousLine members of the removed lines to null. Sets the validity of the removed lines and of all lines which follow the removed lines in the TextBlock to TextLineValidity.INVALID.

Parameters

firstLine:flash.text.engine:TextLine — Specifies the first line to release.
 
lastLine:flash.text.engine:TextLine — Specifies the last line to release.


Throws
ArgumentError — If the TextLine specified by firstLine or lastLine is not in the list of text lines maintained by the text block.

See also

TextBlockExample.as

This example displays three TextBlock paragraphs of Japanese and English text. The Japanese text is converted to Strings from Unicode character codes. When you click on the button, the example rotates the text from horizontal to vertical or from veritcal to horizontal.
package { 
    import fl.controls.Button;
     import flash.text.engine.TextBlock;
    import flash.text.engine.TextLine;
    import flash.text.engine.TextElement;
    import flash.text.engine.ElementFormat;
    import flash.text.engine.TextRotation;
    import flash.text.engine.TextBaseline;
    import flash.text.engine.LineJustification;
    import flash.text.engine.FontDescription;
    import flash.text.engine.EastAsianJustifier; 
    import flash.display.Loader;
    import flash.display.Sprite;
    import flash.display.Stage;
    import flash.events.MouseEvent;
    import flash.system.Capabilities;
    
    public class TextBlockExample extends Sprite {
        
        var vertical:Boolean;    
        var container:Sprite;
        var textBlocks:Vector.<TextBlock>;
        var loader:Loader = new Loader();
        var directionButton:Button = new Button();
        
        public function TextBlockExample():void {
            addChild(directionButton);
            directionButton.width = 30;
            directionButton.move(50, 350);
            directionButton.addEventListener(MouseEvent.CLICK, clickHandler);
            createContent();
            createLines();
        }

        private function createEmptyBlock():TextBlock {
        
            var textBlock:TextBlock = new TextBlock();
            textBlock.baselineZero = TextBaseline.IDEOGRAPHIC_CENTER;
            textBlock.textJustifier = new EastAsianJustifier("ja", LineJustification.ALL_BUT_LAST);
            textBlock.lineRotation = vertical? TextRotation.ROTATE_90: TextRotation.ROTATE_0;
            return textBlock;    
        }
        
        private function paragraph1(format:ElementFormat):TextBlock {
        
            var textBlock:TextBlock = createEmptyBlock();
            textBlock.content = new TextElement(
            String.fromCharCode(
                0x5185, 0x95A3, 0x5E9C, 0x304C, 0x300C, 0x653F, 0x5E9C, 0x30A4,
                0x30F3, 0x30BF, 0x30FC, 0x30CD, 0x30C3, 0x30C8, 0x30C6, 0x30EC, 
                0x30D3, 0x300D, 0x306E, 0x52D5, 0x753B, 0x914D, 0x4FE1, 0x5411, 
                0x3051, 0x306B, 0x30A2, 0x30C9, 0x30D3, 0x30B7, 0x30B9, 0x30C6, 
                0x30E0, 0x30BA, 0x793E, 0x306E
            ) +
            "FMS 2" +
            String.fromCharCode(0x3092, 0x63A1, 0x7528, 0x3059, 0x308B, 0x3068, 
                0x767a, 0x8868, 0x3057, 0x307e, 0x3057, 0x305F, 0x3002), format);
            return textBlock;
        }

        private function paragraph2(format:ElementFormat):TextBlock {
            
            var textBlock:TextBlock = createEmptyBlock();
            textBlock.content = new TextElement(
            String.fromCharCode(
                0x30AF, 0x30ED, 0x30B9, 0x30D7, 0x30E9, 0x30C3, 0x30C8, 0x30D5, 
                0x30A9, 0x30FC, 0x30E0, 0x4E0A, 0x3067, 0x518D, 0x751F, 0x53EF, 
                0x80FD, 0x306A
            ) + 
            "Flash Video" +
            String.fromCharCode(
                0x3092, 0x914D, 0x4FE1, 0x3001, 0x653F, 0x5E9C, 0x6700, 0x65B0, 
                0x60C5, 0x5831, 0x3092, 0x3088, 0x308A, 0x591A, 0x304F, 0x306E, 
                0x56FD, 0x6C11, 0x306B, 0x9AD8, 0x54C1, 0x8CEA, 0x306A, 0x753B, 
                0x50CF, 0x3067, 0x7C21, 0x5358, 0x304B, 0x3064, 0x30EA, 0x30A2, 
                0x30EB, 0x30BF, 0x30A4, 0x30E0, 0x306B, 0x63D0, 0x4F9B, 0x3059, 
                0x308B, 0x3053, 0x3068, 0x304C, 0x53EF, 0x80FD, 0x306B, 0x306A, 
                0x308A, 0x307e, 0x3057, 0x305F, 0x3002), format);
            return textBlock;    
        }

        private function paragraph3(format:ElementFormat):TextBlock {
            
            var textBlock:TextBlock = createEmptyBlock();
            textBlock.content = new TextElement(
            String.fromCharCode(0x3010) +
            "2007" +
            String.fromCharCode(0x5E74) + "2" + String.fromCharCode(0x6708) +
            "21" +
            String.fromCharCode(0x65E5, 0x3011),
            format);
            return textBlock;    
        }

        private function createContent():void {
            
            var font:FontDescription = new FontDescription();
            if (Capabilities.os.search("Mac OS") > -1) 
                font.fontName = String.fromCharCode(0x5C0F, 0x585A, 0x660E, 0x671D) + " Pro R"; // "Kozuka Mincho Pro R"                    koFont.fontName = "Adobe " + String.fromCharCode(0xBA85, 0xC870) + " Std M"; // "Adobe Myungjo Std M"
            else 
                font.fontName = "Kozuka Mincho Pro R";        
            var format:ElementFormat = new ElementFormat();
            format.fontDescription = font;
            format.fontSize = 12;
            format.locale = "ja";
            format.color = 0x000000;
            if (!vertical) 
                format.textRotation = TextRotation.ROTATE_0; 
            textBlocks = new Vector.<TextBlock>();
            textBlocks.push(
                paragraph1(format),
                paragraph2(format),
                paragraph3(format)//,
            );
        }

        private function createLines():void {    
        
            if (container != null) {
                removeChild(container);
            }            
            container = new Sprite();
            container.y = 45;
            container.x = 40;
            addChild(container);
            var linePosition:Number = vertical? this.stage.stageWidth - 120: 12;
        
            for (var i:uint = 0; i < textBlocks.length; i++) {
                var textBlock:TextBlock = textBlocks[i];
                var previousLine:TextLine = null;
        
                while (true) {
                    var textLine:TextLine = textBlock.createTextLine(
                        previousLine, 
                        300);
                    if (textLine == null) 
                        break;
                    if (vertical) 
                    {
                        textLine.x = linePosition;
                        linePosition -= 24;
                        directionButton.label = " -- ";
                    }
                    else 
                    {
                        textLine.y = linePosition+50;
                        linePosition += 24;
                        directionButton.label = " | ";
                    }
                    container.addChild(textLine);                
                    previousLine = textLine;
                }
                if (vertical) 
                    linePosition -= 16;
                else 
                    linePosition += 16; 
            }
        }

        private function clickHandler(event:MouseEvent):void {
            
            vertical = !vertical;
            createContent();
            createLines();
        }
    }
}