com.snowtide.pdf.forms
Class AcroSignatureField

java.lang.Object
  com.snowtide.pdf.forms.AcroSignatureField

All Implemented Interfaces:

AcroFormField, FormField

public class AcroSignatureField
extends java.lang.Object

Represents a digital signature field in an interactive AcroForm.

PDFTextStream does not provide higher-level support for this type of field, and its value cannot be updated (calling setValue(String) on an AcroSignatureField will result in an UnsupportedOperationException exception being thrown).

However, all of a signature field's raw data may be accessed via getValue(), which will return a java.util.Map object containing dictionary values as specified by Section 8.6.3 ('Signature Fields') and Table 8.9.3 in the PDF document specification.

Version:

©2004-2009 Snowtide Informatics Systems, Inc.

Field Summary

protected com.snowtide.pdf.PDFTextStreamCallback

callback

Fields inherited from interface com.snowtide.pdf.forms.AcroFormField

FIELD_TYPE_BUTTON, FIELD_TYPE_CHOICE, FIELD_TYPE_OTHER, FIELD_TYPE_SIGNATURE, FIELD_TYPE_TEXT

Method Summary

boolean	canChangeValue() This function returns true only if this form field is of a subtype that supports setting its value.
java.lang.Object	getDefaultValue() Returns the default value to which the field reverts when a reset-form action is executed, as specified in the /DV entry in this field's PDF dictionary.
java.lang.String	getFullName() Returns the fully-qualified name of this field, which should be unique within a PDF document form.
java.lang.String	getLocalName() Returns the local name of the field, as specified in the /T entry in this field's PDF dictionary.
java.lang.String	getMappingName() Returns the 'mapping name' of this field, as specified in the /TM entry in this field's PDF dictionary.
java.lang.String	getName() Returns the canonical name of this field.
java.lang.Object	getType() Returns the type of field, as specified in the /FT entry in this field's PDF dictionary.
java.lang.String	getUIName() Returns the user-friendly name of this field, as specified in the /TU entry in this field's PDF dictionary.
java.lang.Object	getValue() Returns the value of this field, as specified in the /V entry in this field's PDF dictionary.
boolean	hasValueChanged() Returns true only if this field's value has been changed since being loaded from the PDF document.
boolean	isReadOnly() Returns true only if this field is designated as read-only.
boolean	setValue(java.lang.String arg0) Sets the value of this form field.

Methods inherited from class java.lang.Object

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

Field Detail

callback

protected final com.snowtide.pdf.PDFTextStreamCallback callback

Method Detail

isReadOnly

public boolean isReadOnly()

Description copied from interface: AcroFormField

Returns true only if this field is designated as read-only. Note that this is just a hint, provided for the benefit of end-user tools. PDFTextStream does not enforce the read-only state of a form field; i.e. it will allow a field's value to be set even if it is designated as read-only.

Specified by:

isReadOnly in interface AcroFormField

getDefaultValue

public java.lang.Object getDefaultValue()

Description copied from interface: AcroFormField

Returns the default value to which the field reverts when a reset-form action is executed, as specified in the /DV entry in this field's PDF dictionary. The type of the returned object will be the same as the type of object returned by the AcroFormField.getValue() function, and depends upon the type of this field.

Specified by:

getDefaultValue in interface AcroFormField

getFullName

public java.lang.String getFullName()

Description copied from interface: AcroFormField

Returns the fully-qualified name of this field, which should be unique within a PDF document form. Details of how full names are constructed are specified in Section 8.6.2 (Field Names) of the PDF Document Specification.

It suffices to say here that form fields in an interactive AcroForm are defined in a hierarchical manner, and that their local names are used to derive a period-delimited full name that guarantees each name's uniqueness within the parent AcroForm.

Specified by:

getFullName in interface AcroFormField

getLocalName

public java.lang.String getLocalName()

Description copied from interface: AcroFormField

Returns the local name of the field, as specified in the /T entry in this field's PDF dictionary. This name is also used as the value returned by the FormField.getName() implementation.

Specified by:

getLocalName in interface AcroFormField

getMappingName

public java.lang.String getMappingName()

Description copied from interface: AcroFormField

Returns the 'mapping name' of this field, as specified in the /TM entry in this field's PDF dictionary. The mapping name is used to identify the field in exported form data formats. This function can return null if no mapping name is defined.

Specified by:

getMappingName in interface AcroFormField

getName

public java.lang.String getName()

Description copied from interface: FormField

Returns the canonical name of this field. Only one FormField instance with a particular name should be available from a Form instance.

Specified by:

getName in interface FormField

getType

public java.lang.Object getType()

Description copied from interface: AcroFormField

Returns the type of field, as specified in the /FT entry in this field's PDF dictionary. This is an indication of the subtype of this AcroFormField instance:

• If the return value is FIELD_TYPE_BUTTON, then this AcroFormField is an instance of AcroButtonField
• If the return value is FIELD_TYPE_TEXT, then this AcroFormField is an instance of AcroTextField
• If the return value is FIELD_TYPE_CHOICE, then this AcroFormField is an instance of AcroChoiceField
• If the return value is FIELD_TYPE_SIGNATURE, then this AcroFormField is an instance of AcroSignatureField
• If the return value is FIELD_TYPE_OTHER, then this AcroFormField has no specific concrete implementation. This case is reserved for form fields with new type indicators that may be introduced by Adobe in the future.

Specified by:

getType in interface AcroFormField

setValue

public boolean setValue(java.lang.String arg0)
                 throws java.lang.UnsupportedOperationException

Description copied from interface: AcroFormField

Sets the value of this form field. Each AcroFormField implementation may specify additional varieties of setValue() to support unique functionality (such as holding multiple values). For any form field instance, this function will throw an UnsupportedOperationException if it does not support updates; such instances will return false from AcroFormField.canChangeValue(). This function will return true if the form field's value changes as a result of calling this function (i.e. the given value is different from the current value of the form field).

Either AcroForm.writeUpdatedDocument(java.io.File) or AcroForm.writeUpdatedDocument(java.io.OutputStream) must be called after setting any form field values in order to persist such changes to a PDF document.

Specified by:

setValue in interface AcroFormField

Throws:

java.lang.UnsupportedOperationException - - if an AcroFormField implementation does not support updates.

hasValueChanged

public boolean hasValueChanged()

Description copied from interface: AcroFormField

Returns true only if this field's value has been changed since being loaded from the PDF document.

Specified by:

hasValueChanged in interface AcroFormField

canChangeValue

public boolean canChangeValue()

Description copied from interface: AcroFormField

This function returns true only if this form field is of a subtype that supports setting its value. This includes checkboxes, radio button groups, text fields, and choice fields (lists and dropdown controls).

Specified by:

canChangeValue in interface AcroFormField

getUIName

public java.lang.String getUIName()

Description copied from interface: AcroFormField

Returns the user-friendly name of this field, as specified in the /TU entry in this field's PDF dictionary. This function can return null if no user-friendly field name is defined.

Specified by:

getUIName in interface AcroFormField

Specified by:

getUIName in interface FormField

getValue

public java.lang.Object getValue()

Description copied from interface: AcroFormField

Returns the value of this field, as specified in the /V entry in this field's PDF dictionary. The type of the returned object depends upon the type of this field.

Specified by:

getValue in interface AcroFormField

Specified by:

getValue in interface FormField