com.itextpdf.layout

Class Canvas

java.lang.Object

com.itextpdf.layout.ElementPropertyContainer<T>

com.itextpdf.layout.RootElement<Canvas>

com.itextpdf.layout.Canvas

All Implemented Interfaces:

IPropertyContainer

public class Canvas
extends RootElement<Canvas>

This class is used for adding content directly onto a specified PdfCanvas. Canvas does not know the concept of a page, so it can't reflow to a 'next' Canvas. This class effectively acts as a bridge between the high-level layout API and the low-level kernel API.

Field Summary

Fields

Modifier and Type	Field and Description
protected PdfPage	page Is initialized and used only when Canvas element autotagging is enabled, see enableAutoTagging(PdfPage).
protected PdfCanvas	pdfCanvas
protected Rectangle	rootArea

Fields inherited from class com.itextpdf.layout.RootElement

childElements, defaultFont, defaultSplitCharacters, immediateFlush, pdfDocument, properties, rootRenderer

Constructor Summary

Constructors

Constructor and Description
Canvas(PdfCanvas pdfCanvas, PdfDocument pdfDocument, Rectangle rootArea) Creates a new Canvas to manipulate a specific document and page.
Canvas(PdfCanvas pdfCanvas, PdfDocument pdfDocument, Rectangle rootArea, boolean immediateFlush) Creates a new Canvas to manipulate a specific document and page.
Canvas(PdfFormXObject formXObject, PdfDocument pdfDocument) Creates a new Canvas to manipulate a specific PdfFormXObject.

Method Summary

Modifier and Type	Method and Description
void	enableAutoTagging(PdfPage page) Enables canvas content autotagging.
protected RootRenderer	ensureRootRendererNotNull()
PdfPage	getPage() Returned value is not null only in case when autotagging is enabled.
PdfCanvas	getPdfCanvas() Gets the PdfCanvas.
PdfDocument	getPdfDocument() Gets the PdfDocument for this canvas.
Rectangle	getRootArea() Gets the root area rectangle.
boolean	isAutoTaggingEnabled()
void	relayout()
void	setRenderer(CanvasRenderer canvasRenderer) Sets the IRenderer for this Canvas.

Methods inherited from class com.itextpdf.layout.RootElement

add, add, deleteOwnProperty, getDefaultProperty, getOwnProperty, getProperty, getRenderer, hasOwnProperty, hasProperty, setProperty, showTextAligned, showTextAligned, showTextAligned, showTextAligned, showTextAligned, showTextAligned, showTextAlignedKerned

Methods inherited from class com.itextpdf.layout.ElementPropertyContainer

getHeight, getSplitCharacters, getStrokeColor, getStrokeWidth, getTextRenderingMode, getWidth, setBackgroundColor, setBackgroundColor, setBaseDirection, setBold, setBorder, setBorderBottom, setBorderLeft, setBorderRight, setBorderTop, setCharacterSpacing, setDestination, setFixedPosition, setFixedPosition, setFixedPosition, setFixedPosition, setFont, setFontColor, setFontKerning, setFontScript, setFontSize, setHeight, setHorizontalAlignment, setHyphenation, setItalic, setLineThrough, setRelativePosition, setSplitCharacters, setStrokeColor, setStrokeWidth, setTextAlignment, setTextRenderingMode, setUnderline, setUnderline, setUnderline, setWidth, setWidth, setWidthPercent, setWordSpacing

Methods inherited from class java.lang.Object

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

Field Detail

pdfCanvas

protected PdfCanvas pdfCanvas

rootArea

protected Rectangle rootArea

page

protected PdfPage page

Is initialized and used only when Canvas element autotagging is enabled, see enableAutoTagging(PdfPage). It is also used to determine if autotagging is enabled.

Constructor Detail

Canvas

public Canvas(PdfCanvas pdfCanvas,
              PdfDocument pdfDocument,
              Rectangle rootArea)

Creates a new Canvas to manipulate a specific document and page.

Parameters:

pdfCanvas - the low-level content stream writer

pdfDocument - the document that the resulting content stream will be written to

rootArea - the maximum area that the Canvas may write upon

Canvas

public Canvas(PdfCanvas pdfCanvas,
              PdfDocument pdfDocument,
              Rectangle rootArea,
              boolean immediateFlush)

Creates a new Canvas to manipulate a specific document and page.

Parameters:

pdfCanvas - the low-level content stream writer

pdfDocument - the document that the resulting content stream will be written to

rootArea - the maximum area that the Canvas may write upon

Canvas

public Canvas(PdfFormXObject formXObject,
              PdfDocument pdfDocument)

Creates a new Canvas to manipulate a specific PdfFormXObject.

Parameters:

formXObject - the form

pdfDocument - the document that the resulting content stream will be written to

Method Detail

getPdfDocument

public PdfDocument getPdfDocument()

Gets the PdfDocument for this canvas.

Returns:

the document that the resulting content stream will be written to

getRootArea

public Rectangle getRootArea()

Gets the root area rectangle.

Returns:

the maximum area that the Canvas may write upon

getPdfCanvas

public PdfCanvas getPdfCanvas()

Gets the PdfCanvas.

Returns:

the low-level content stream writer

setRenderer

public void setRenderer(CanvasRenderer canvasRenderer)

Sets the IRenderer for this Canvas.

Parameters:

canvasRenderer - a renderer specific for canvas operations

getPage

public PdfPage getPage()

Returned value is not null only in case when autotagging is enabled.

Returns:

the page, on which this canvas will be rendered, or null if autotagging is not enabled.

enableAutoTagging

public void enableAutoTagging(PdfPage page)

Enables canvas content autotagging. By default it is disabled.

Parameters:

page - the page, on which this canvas will be rendered.

isAutoTaggingEnabled

public boolean isAutoTaggingEnabled()

Returns:

true if autotagging of canvas content is enabled. Default value - false.

relayout

public void relayout()

ensureRootRendererNotNull

protected RootRenderer ensureRootRendererNotNull()

Specified by:

ensureRootRendererNotNull in class RootElement<Canvas>