com.microblink.blinkinput.entities.parsers.regex

Class RegexParser

java.lang.Object

com.microblink.blinkinput.entities.Entity

com.microblink.blinkinput.entities.parsers.Parser

com.microblink.blinkinput.entities.parsers.regex.RegexParser

All Implemented Interfaces:

android.os.Parcelable

public final class RegexParser
extends Parser

Represents a parser which parses OCR result according to given regular expression. Regular expression parsing is not performed with java's regex engine. Instead, it is performed with custom regular expression engine which can work with multiple char recognition alternatives (if enabled in AbstractOCREngineOptions). Due to differences between parsing normal strings and OCR results, this parser does not support some regex features found in java's regex engine, like back references. See RegexParser.setRegex(String) for more information about what is supported.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	RegexParser.Result

Nested classes/interfaces inherited from interface android.os.Parcelable

android.os.Parcelable.ClassLoaderCreator, android.os.Parcelable.Creator

Field Summary

Fields

Modifier and Type	Field and Description
static android.os.Parcelable.Creator	CREATOR

Fields inherited from class com.microblink.blinkinput.entities.parsers.Parser

CLASS_NAME

Fields inherited from interface android.os.Parcelable

CONTENTS_FILE_DESCRIPTOR, PARCELABLE_WRITE_RETURN_VALUE

Constructor Summary

Constructors

Constructor and Description
RegexParser(java.lang.String regex) Constructor using default OCR engine options and provided regular expression.
RegexParser(java.lang.String regex, AbstractOCREngineOptions ocrEngineOptions) Constructor using provided OCR engine options and provided regular expression.

Method Summary

Modifier and Type	Method and Description
void	clearResult() Clears parser result.
RegexParser	clone() Create a copy of the entity.
void	consumeResult(RegexParser.Result resultToConsume) Consumes given result.
void	consumeResultFrom(Entity other) Consume result from other entity.
protected void	deserializeNativeSettings(byte[] serializedSettings)
AbstractOCREngineOptions	getOcrEngineOptions() Returns the OCR engine options used in Regex OCR parser.
java.lang.String	getRegex() Returns the currently set regular expression.
protected byte[]	serializeNativeSettings()
void	setEndWithWhitespace(boolean mustEndWithWhitespace) If set to true, regex will not be matched if there is no whitespace after matched string.
void	setOcrEngineOptions(AbstractOCREngineOptions ocrEngineOptions) Sets the OCR engine options used in Regex OCR parser.
void	setRegex(java.lang.String regex) Defines regex that will be used to parse OCR data.
void	setStartWithWhitespace(boolean mustStartWithWhitespace) If set to true, regex will not be matched if there is no whitespace before matched string.
void	setUseSieve(boolean useSieve) Enable the usage of algorithm for combining consecutive OCR results between video frames for improving OCR quality.
boolean	shouldEndWithWhitespace() Returns whether matched string must end with whitespace.
boolean	shouldStartWithWhitespace() Returns whether matched string must start with whitespace.
boolean	shouldUseSieve() Returns true if algorithm for combining consecutive OCR results between video frames for improving OCR quality is used.
protected void	terminateNative(long nativeContext)

Methods inherited from class com.microblink.blinkinput.entities.parsers.Parser

getPriority, isRequired, setRequired

Methods inherited from class com.microblink.blinkinput.entities.Entity

describeContents, finalize, getNativeContext, getResult, nativeGetNativeResultContext, readFromParcel, writeToParcel

Methods inherited from class java.lang.Object

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

Field Detail

CREATOR

@NonNull
public static final android.os.Parcelable.Creator CREATOR

Constructor Detail

RegexParser

public RegexParser(@NonNull
                   java.lang.String regex)

Constructor using default OCR engine options and provided regular expression. Since default OCR engine options does not have character whitelist, the regex alphabet is empty - this means that '.' metacharacter which represents any character is not supported. To use regular expressions that contain this metacharacter, use RegexParser.RegexParser(String, AbstractOCREngineOptions) constructor. For more information about regex support, see RegexParser.setRegex(String).

Parameters:

regex - Regular expression.

Throws:

java.lang.IllegalArgumentException - if regular expression cannot be compiled

RegexParser

public RegexParser(@NonNull
                   java.lang.String regex,
                   @NonNull
                   AbstractOCREngineOptions ocrEngineOptions)

Constructor using provided OCR engine options and provided regular expression. Some regex metacharacters, like '.' (represents any character) may not be supported if provided OCR engine options do not have character whitelist. For more information about regex support, see RegexParser.setRegex(String).

Parameters:

regex - Regular expression.

ocrEngineOptions - OCR engine options used for performing OCR.

Throws:

java.lang.IllegalArgumentException - if regular expression cannot be compiled

Method Detail

setRegex

public void setRegex(@NonNull
                     java.lang.String regex)

Defines regex that will be used to parse OCR data. Note that not all java regex features are available, such as back references and '^' and '$' meta-character. '.' meta-character that represents any character and '^' inside brackets representing all characters except those in brackets are available only if alphabet is defined.

Parameters:

regex - Regular expression to be used for parsing OCR result.

Throws:

java.lang.IllegalArgumentException - if regular expression cannot be compiled

getRegex

@NonNull
public java.lang.String getRegex()

Returns the currently set regular expression.

Returns:

the currently set regular expression.

setOcrEngineOptions

public void setOcrEngineOptions(@NonNull
                                AbstractOCREngineOptions ocrEngineOptions)

Sets the OCR engine options used in Regex OCR parser. By default, this is set to 'default instance of BlinkOCREngineOptions'.

Parameters:

ocrEngineOptions - OCR engine options used in Regex OCR parser

getOcrEngineOptions

@NonNull
public AbstractOCREngineOptions getOcrEngineOptions()

Returns the OCR engine options used in Regex OCR parser. By default, this is set to 'default instance of BlinkOCREngineOptions'.

Returns:

OCR engine options used in Regex OCR parser

setUseSieve

public void setUseSieve(boolean useSieve)

Enable the usage of algorithm for combining consecutive OCR results between video frames for improving OCR quality. By default this is turned off. Note: This option works together only with if instance of BlinkOCREngineOptions is given to RegexParser.setOcrEngineOptions(AbstractOCREngineOptions). Otherwise, it will not be enabled and IllegalArgumentException will be thrown.

Parameters:

useSieve - whether or not sieve algorithm should be used

shouldUseSieve

public boolean shouldUseSieve()

Returns true if algorithm for combining consecutive OCR results between video frames for improving OCR quality is used.

Returns:

true if sieve algorithm is used

setStartWithWhitespace

public void setStartWithWhitespace(boolean mustStartWithWhitespace)

If set to true, regex will not be matched if there is no whitespace before matched string. Whitespace is not returned in parsed result.

Parameters:

mustStartWithWhitespace - whether or not whitespace is required before matched string

shouldStartWithWhitespace

public boolean shouldStartWithWhitespace()

Returns whether matched string must start with whitespace.

Returns:

whether matched string must start with whitespace.

setEndWithWhitespace

public void setEndWithWhitespace(boolean mustEndWithWhitespace)

If set to true, regex will not be matched if there is no whitespace after matched string. Whitespace is not returned in parsed result.

Parameters:

mustEndWithWhitespace - whether or not whitespace is required after matched string

shouldEndWithWhitespace

public boolean shouldEndWithWhitespace()

Returns whether matched string must end with whitespace.

Returns:

whether matched string must end with whitespace.

terminateNative

protected void terminateNative(long nativeContext)

Specified by:

terminateNative in class Entity

serializeNativeSettings

@Nullable
protected byte[] serializeNativeSettings()

Specified by:

serializeNativeSettings in class Entity

deserializeNativeSettings

protected void deserializeNativeSettings(@NonNull
                                         byte[] serializedSettings)

Specified by:

deserializeNativeSettings in class Entity

clone

@NonNull
public RegexParser clone()

Description copied from class: Entity

Create a copy of the entity. This is required if properties of the entity must be modified while background thread performs processing. In order to avoid race conditions, changing properties is not allowed while entity is used in background processing. However, you are able to make a copy of the entity, change properties of it and then update the RecognizerRunnerView or RecognizerRunner with the updated entity hierarchy.

Specified by:

clone in class Entity

Returns:

a copy of the entity

consumeResultFrom

public void consumeResultFrom(@NonNull
                              Entity other)

Description copied from class: Entity

Consume result from other entity. The result from other will be put instead current result of this entity. This method is used inside com.microblink.blinkinput.entities.recognizers.RecognizerBundle#loadFromIntent(Intent) and similar methods to replace the result content of the saved entities with results that have arrived over Intent

Specified by:

consumeResultFrom in class Entity

Parameters:

other - Entity from which result should be consumed.

consumeResult

public void consumeResult(@NonNull
                          RegexParser.Result resultToConsume)

Description copied from class: Parser

Consumes given result. The given result will be put instead current result of this entity.

Specified by:

consumeResult in class Parser

Parameters:

resultToConsume - Result that should be consumed.

clearResult

public void clearResult()

Description copied from class: Parser

Clears parser result.

Specified by:

clearResult in class Parser