Package com.itextpdf.kernel.pdf.canvas.parser.listener

Class RegexBasedLocationExtractionStrategy

java.lang.Object

com.itextpdf.kernel.pdf.canvas.parser.listener.RegexBasedLocationExtractionStrategy

All Implemented Interfaces:

IEventListener, ILocationExtractionStrategy

public class RegexBasedLocationExtractionStrategy
extends java.lang.Object
implements ILocationExtractionStrategy

This class is designed to search for the occurrences of a regular expression and return the resultant rectangles. Do note that this class holds all text locations and can't be used for processing multiple pages. If you want to extract text from several pages of pdf document you have to create a new instance of RegexBasedLocationExtractionStrategy for each page.

Here is an example of usage with new instance per each page: PdfDocument document = new PdfDocument(new PdfReader("...")); for (int i = 1; i <= document.getNumberOfPages(); ++i) { RegexBasedLocationExtractionStrategy extractionStrategy = new RegexBasedLocationExtractionStrategy(""); PdfCanvasProcessor processor = new PdfCanvasProcessor(extractionStrategy); processor.processPageContent(document.getPage(i)); for (IPdfTextLocation location : extractionStrategy.getResultantLocations()) { //process locations ... } }

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
private static class	RegexBasedLocationExtractionStrategy.PdfTextLocationComparator

Field Summary

Fields

Modifier and Type	Field	Description
private static float	EPS
private java.util.List<CharacterRenderInfo>	parseResult
private java.util.regex.Pattern	pattern

Constructor Summary

Constructors

Constructor	Description
RegexBasedLocationExtractionStrategy(java.lang.String regex)
RegexBasedLocationExtractionStrategy(java.util.regex.Pattern pattern)

Method Summary

Modifier and Type	Method	Description
void	eventOccurred(IEventData data, EventType type)	Called when some event occurs during parsing a content stream.
private static java.lang.Integer	getEndIndex(java.util.Map<java.lang.Integer,java.lang.Integer> indexMap, int index)
java.util.Collection<IPdfTextLocation>	getResultantLocations()	Returns the Rectangles that have been processed so far.
private static java.lang.Integer	getStartIndex(java.util.Map<java.lang.Integer,java.lang.Integer> indexMap, int index, java.lang.String txt)
java.util.Set<EventType>	getSupportedEvents()	Provides the set of event types this listener supports.
private void	removeDuplicates(java.util.List<IPdfTextLocation> sortedList)
protected java.util.List<CharacterRenderInfo>	toCRI(TextRenderInfo tri)	Convert TextRenderInfo to CharacterRenderInfo This method is public and not final so that custom implementations can choose to override it.
protected java.util.List<Rectangle>	toRectangles(java.util.List<CharacterRenderInfo> cris)	Converts CharacterRenderInfo objects to Rectangles This method is protected and not final so that custom implementations can choose to override it.

Methods inherited from class java.lang.Object

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

Field Detail

EPS

private static final float EPS

See Also:

Constant Field Values

pattern

private final java.util.regex.Pattern pattern

parseResult

private final java.util.List<CharacterRenderInfo> parseResult

Constructor Detail

RegexBasedLocationExtractionStrategy

public RegexBasedLocationExtractionStrategy(java.lang.String regex)

RegexBasedLocationExtractionStrategy

public RegexBasedLocationExtractionStrategy(java.util.regex.Pattern pattern)

Method Detail

getResultantLocations

public java.util.Collection<IPdfTextLocation> getResultantLocations()

Returns the Rectangles that have been processed so far.

Specified by:

getResultantLocations in interface ILocationExtractionStrategy

Returns:

Collection<IPdfTextLocation> instance with the current resultant IPdfTextLocations

eventOccurred

public void eventOccurred(IEventData data,
                          EventType type)

Called when some event occurs during parsing a content stream.

Specified by:

eventOccurred in interface IEventListener

Parameters:

data - Combines the data required for processing corresponding event type.

type - Event type.

getSupportedEvents

public java.util.Set<EventType> getSupportedEvents()

Provides the set of event types this listener supports. Returns null if all possible event types are supported.

Specified by:

getSupportedEvents in interface IEventListener

Returns:

Set of event types supported by this listener or null if all possible event types are supported.

toCRI

protected java.util.List<CharacterRenderInfo> toCRI(TextRenderInfo tri)

Convert TextRenderInfo to CharacterRenderInfo This method is public and not final so that custom implementations can choose to override it. Other implementations of CharacterRenderInfo may choose to store different properties than merely the Rectangle describing the bounding box. E.g. a custom implementation might choose to store Color information as well, to better match the content surrounding the redaction Rectangle.

Parameters:

tri - TextRenderInfo object

Returns:

a list of CharacterRenderInfos which represents the passed TextRenderInfo ?

toRectangles

protected java.util.List<Rectangle> toRectangles(java.util.List<CharacterRenderInfo> cris)

Converts CharacterRenderInfo objects to Rectangles This method is protected and not final so that custom implementations can choose to override it. E.g. other implementations may choose to add padding/margin to the Rectangles. This method also offers a convenient access point to the mapping of CharacterRenderInfo to Rectangle. This mapping enables (custom implementations) to match color of text in redacted Rectangles, or match color of background, by the mere virtue of offering access to the CharacterRenderInfo objects that generated the Rectangle.

Parameters:

cris - list of CharacterRenderInfo objects

Returns:

an array containing the elements of this list

removeDuplicates

private void removeDuplicates(java.util.List<IPdfTextLocation> sortedList)

getStartIndex

private static java.lang.Integer getStartIndex(java.util.Map<java.lang.Integer,java.lang.Integer> indexMap,
                                               int index,
                                               java.lang.String txt)

getEndIndex

private static java.lang.Integer getEndIndex(java.util.Map<java.lang.Integer,java.lang.Integer> indexMap,
                                             int index)