itextpdf-master/itext/src/main/java/com/itextpdf/text/pdf/PdfAcroForm.java
/*
 *
 * This file is part of the iText (R) project.
    Copyright (c) 1998-2022 iText Group NV
 * Authors: Bruno Lowagie, Paulo Soares, et al.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License version 3
 * as published by the Free Software Foundation with the addition of the
 * following permission added to Section 15 as permitted in Section 7(a):
 * FOR ANY PART OF THE COVERED WORK IN WHICH THE COPYRIGHT IS OWNED BY
 * ITEXT GROUP. ITEXT GROUP DISCLAIMS THE WARRANTY OF NON INFRINGEMENT
 * OF THIRD PARTY RIGHTS
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
 * or FITNESS FOR A PARTICULAR PURPOSE.
 * See the GNU Affero General Public License for more details.
 * You should have received a copy of the GNU Affero General Public License
 * along with this program; if not, see http://www.gnu.org/licenses or write to
 * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
 * Boston, MA, 02110-1301 USA, or download the license from the following URL:
 * http://itextpdf.com/terms-of-use/
 *
 * The interactive user interfaces in modified source and object code versions
 * of this program must display Appropriate Legal Notices, as required under
 * Section 5 of the GNU Affero General Public License.
 *
 * In accordance with Section 7(b) of the GNU Affero General Public License,
 * a covered work must retain the producer line in every PDF that is created
 * or manipulated using iText.
 *
 * You can be released from the requirements of the license by purchasing
 * a commercial license. Buying such a license is mandatory as soon as you
 * develop commercial activities involving the iText software without
 * disclosing the source code of your own applications.
 * These activities include: offering paid services to customers as an ASP,
 * serving PDFs on the fly in a web application, shipping iText with a closed
 * source product.
 *
 * For more information, please contact iText Software Corp. at this
 * address: sales@itextpdf.com
 */
package com.itextpdf.text.pdf;

import java.io.IOException;
import java.io.OutputStream;
import java.util.HashSet;

import com.itextpdf.text.BaseColor;
import com.itextpdf.text.ExceptionConverter;
import com.itextpdf.text.Rectangle;
import com.itextpdf.text.pdf.internal.PdfIsoKeys;

/**
 * Each PDF document can contain maximum 1 AcroForm.
 */

public class PdfAcroForm extends PdfDictionary {

    private PdfWriter writer;


    /** This is a map containing FieldTemplates. */
    private HashSet<PdfTemplate> fieldTemplates = new HashSet<PdfTemplate>();

    /** This is an array containing DocumentFields. */
    private PdfArray documentFields = new PdfArray();

    /** This is an array containing the calculationorder of the fields. */
    private PdfArray calculationOrder = new PdfArray();

    /** Contains the signature flags. */
    private int sigFlags = 0;

    /** Creates new PdfAcroForm
     * @param writer
     */
    public PdfAcroForm(PdfWriter writer) {
        super();
        this.writer = writer;
    }

    public void setNeedAppearances(boolean value) {
    	put(PdfName.NEEDAPPEARANCES, new PdfBoolean(value));
    }

    /**
     * Adds fieldTemplates.
     * @param ft
     */

    public void addFieldTemplates(HashSet<PdfTemplate> ft) {
        fieldTemplates.addAll(ft);
    }

    /**
     * Adds documentFields.
     * @param ref
     */

    public void addDocumentField(PdfIndirectReference ref) {
        documentFields.add(ref);
    }

    /**
     * Checks if the Acroform is valid
     * @return true if the Acroform is valid
     */

    public boolean isValid() {
        if (documentFields.size() == 0) return false;
        put(PdfName.FIELDS, documentFields);
        if (sigFlags != 0)
            put(PdfName.SIGFLAGS, new PdfNumber(sigFlags));
        if (calculationOrder.size() > 0)
            put(PdfName.CO, calculationOrder);
        if (fieldTemplates.isEmpty()) return true;
        PdfDictionary dic = new PdfDictionary();
        for (PdfTemplate template: fieldTemplates) {
            PdfFormField.mergeResources(dic, (PdfDictionary)template.getResources());
        }
        put(PdfName.DR, dic);
        put(PdfName.DA, new PdfString("/Helv 0 Tf 0 g "));
        PdfDictionary fonts = (PdfDictionary)dic.get(PdfName.FONT);
        if (fonts != null) {
            writer.eliminateFontSubset(fonts);
        }
        return true;
    }

    /**
     * Adds an object to the calculationOrder.
     * @param formField
     */

    public void addCalculationOrder(PdfFormField formField) {
        calculationOrder.add(formField.getIndirectReference());
    }

    /**
     * Sets the signature flags.
     * @param f
     */

    public void setSigFlags(int f) {
        sigFlags |= f;
    }

    /**
     * Adds a formfield to the AcroForm.
     * @param formField
     */

    public void addFormField(PdfFormField formField) {
        writer.addAnnotation(formField);
    }

    /**
     * @param name
     * @param caption
     * @param value
     * @param url
     * @param font
     * @param fontSize
     * @param llx
     * @param lly
     * @param urx
     * @param ury
     * @return a PdfFormField
     */
    public PdfFormField addHtmlPostButton(String name, String caption, String value, String url, BaseFont font, float fontSize, float llx, float lly, float urx, float ury) {
        PdfAction action = PdfAction.createSubmitForm(url, null, PdfAction.SUBMIT_HTML_FORMAT);
        PdfFormField button = new PdfFormField(writer, llx, lly, urx, ury, action);
        setButtonParams(button, PdfFormField.FF_PUSHBUTTON, name, value);
        drawButton(button, caption, font, fontSize, llx, lly, urx, ury);
        addFormField(button);
	return button;
    }

    /**
     * @param name
     * @param caption
     * @param value
     * @param font
     * @param fontSize
     * @param llx
     * @param lly
     * @param urx
     * @param ury
     * @return a PdfFormField
     */
    public PdfFormField addResetButton(String name, String caption, String value, BaseFont font, float fontSize, float llx, float lly, float urx, float ury) {
        PdfAction action = PdfAction.createResetForm(null, 0);
        PdfFormField button = new PdfFormField(writer, llx, lly, urx, ury, action);
        setButtonParams(button, PdfFormField.FF_PUSHBUTTON, name, value);
        drawButton(button, caption, font, fontSize, llx, lly, urx, ury);
        addFormField(button);
        return button;
    }

    /**
     * @param name
     * @param value
     * @param url
     * @param appearance
     * @param llx
     * @param lly
     * @param urx
     * @param ury
     * @return a PdfFormField
     */
    public PdfFormField addMap(String name, String value, String url, PdfContentByte appearance, float llx, float lly, float urx, float ury) {
        PdfAction action = PdfAction.createSubmitForm(url, null, PdfAction.SUBMIT_HTML_FORMAT | PdfAction.SUBMIT_COORDINATES);
        PdfFormField button = new PdfFormField(writer, llx, lly, urx, ury, action);
        setButtonParams(button, PdfFormField.FF_PUSHBUTTON, name, null);
        PdfAppearance pa = PdfAppearance.createAppearance(writer, urx - llx, ury - lly);
        pa.add(appearance);
        button.setAppearance(PdfAnnotation.APPEARANCE_NORMAL, pa);
        addFormField(button);
        return button;
    }

    /**
     * @param button
     * @param characteristics
     * @param name
     * @param value
     */
    public void setButtonParams(PdfFormField button, int characteristics, String name, String value) {
        button.setButton(characteristics);
        button.setFlags(PdfAnnotation.FLAGS_PRINT);
        button.setPage();
        button.setFieldName(name);
        if (value != null) button.setValueAsString(value);
    }

    /**
     * @param button
     * @param caption
     * @param font
     * @param fontSize
     * @param llx
     * @param lly
     * @param urx
     * @param ury
     */
    public void drawButton(PdfFormField button, String caption, BaseFont font, float fontSize, float llx, float lly, float urx, float ury) {
        PdfAppearance pa = PdfAppearance.createAppearance(writer, urx - llx, ury - lly);
        pa.drawButton(0f, 0f, urx - llx, ury - lly, caption, font, fontSize);
        button.setAppearance(PdfAnnotation.APPEARANCE_NORMAL, pa);
    }

    /**
     * @param name
     * @param value
     * @return a PdfFormField
     */
    public PdfFormField addHiddenField(String name, String value) {
        PdfFormField hidden = PdfFormField.createEmpty(writer);
        hidden.setFieldName(name);
        hidden.setValueAsName(value);
        addFormField(hidden);
        return hidden;
    }

    /**
     * @param name
     * @param text
     * @param font
     * @param fontSize
     * @param llx
     * @param lly
     * @param urx
     * @param ury
     * @return a PdfFormField
     */
    public PdfFormField addSingleLineTextField(String name, String text, BaseFont font, float fontSize, float llx, float lly, float urx, float ury) {
        PdfFormField field = PdfFormField.createTextField(writer, PdfFormField.SINGLELINE, PdfFormField.PLAINTEXT, 0);
        setTextFieldParams(field, text, name, llx, lly, urx, ury);
        drawSingleLineOfText(field, text, font, fontSize, llx, lly, urx, ury);
        addFormField(field);
        return field;
    }

    /**
     * @param name
     * @param text
     * @param font
     * @param fontSize
     * @param llx
     * @param lly
     * @param urx
     * @param ury
     * @return a PdfFormField
     */
    public PdfFormField addMultiLineTextField(String name, String text, BaseFont font, float fontSize, float llx, float lly, float urx, float ury) {
        PdfFormField field = PdfFormField.createTextField(writer, PdfFormField.MULTILINE, PdfFormField.PLAINTEXT, 0);
        setTextFieldParams(field, text, name, llx, lly, urx, ury);
        drawMultiLineOfText(field, text, font, fontSize, llx, lly, urx, ury);
        addFormField(field);
        return field;
    }

    /**
     * @param name
     * @param text
     * @param font
     * @param fontSize
     * @param llx
     * @param lly
     * @param urx
     * @param ury
     * @return PdfFormField
     */
    public PdfFormField addSingleLinePasswordField(String name, String text, BaseFont font, float fontSize, float llx, float lly, float urx, float ury) {
        PdfFormField field = PdfFormField.createTextField(writer, PdfFormField.SINGLELINE, PdfFormField.PASSWORD, 0);
        setTextFieldParams(field, text, name, llx, lly, urx, ury);
        drawSingleLineOfText(field, text, font, fontSize, llx, lly, urx, ury);
        addFormField(field);
        return field;
    }

    /**
     * @param field
     * @param text
     * @param name
     * @param llx
     * @param lly
     * @param urx
     * @param ury
     */
    public void setTextFieldParams(PdfFormField field, String text, String name, float llx, float lly, float urx, float ury) {
        field.setWidget(new Rectangle(llx, lly, urx, ury), PdfAnnotation.HIGHLIGHT_INVERT);
        field.setValueAsString(text);
        field.setDefaultValueAsString(text);
        field.setFieldName(name);
        field.setFlags(PdfAnnotation.FLAGS_PRINT);
        field.setPage();
    }

    /**
     * @param field
     * @param text
     * @param font
     * @param fontSize
     * @param llx
     * @param lly
     * @param urx
     * @param ury
     */
    public void drawSingleLineOfText(PdfFormField field, String text, BaseFont font, float fontSize, float llx, float lly, float urx, float ury) {
        PdfAppearance tp = PdfAppearance.createAppearance(writer, urx - llx, ury - lly);
        PdfAppearance tp2 = (PdfAppearance)tp.getDuplicate();
        tp2.setFontAndSize(font, fontSize);
        tp2.resetRGBColorFill();
        field.setDefaultAppearanceString(tp2);
        tp.drawTextField(0f, 0f, urx - llx, ury - lly);
        tp.beginVariableText();
        tp.saveState();
        tp.rectangle(3f, 3f, urx - llx - 6f, ury - lly - 6f);
        tp.clip();
        tp.newPath();
        tp.beginText();
        tp.setFontAndSize(font, fontSize);
        tp.resetRGBColorFill();
        tp.setTextMatrix(4, (ury - lly) / 2 - fontSize * 0.3f);
        tp.showText(text);
        tp.endText();
        tp.restoreState();
        tp.endVariableText();
        field.setAppearance(PdfAnnotation.APPEARANCE_NORMAL, tp);
    }

    /**
     * @param field
     * @param text
     * @param font
     * @param fontSize
     * @param llx
     * @param lly
     * @param urx
     * @param ury
     */
    public void drawMultiLineOfText(PdfFormField field, String text, BaseFont font, float fontSize, float llx, float lly, float urx, float ury) {
        PdfAppearance tp = PdfAppearance.createAppearance(writer, urx - llx, ury - lly);
        PdfAppearance tp2 = (PdfAppearance)tp.getDuplicate();
        tp2.setFontAndSize(font, fontSize);
        tp2.resetRGBColorFill();
        field.setDefaultAppearanceString(tp2);
        tp.drawTextField(0f, 0f, urx - llx, ury - lly);
        tp.beginVariableText();
        tp.saveState();
        tp.rectangle(3f, 3f, urx - llx - 6f, ury - lly - 6f);
        tp.clip();
        tp.newPath();
        tp.beginText();
        tp.setFontAndSize(font, fontSize);
        tp.resetRGBColorFill();
        tp.setTextMatrix(4, 5);
        java.util.StringTokenizer tokenizer = new java.util.StringTokenizer(text, "\n");
        float yPos = ury - lly;
        while (tokenizer.hasMoreTokens()) {
            yPos -= fontSize * 1.2f;
            tp.showTextAligned(PdfContentByte.ALIGN_LEFT, tokenizer.nextToken(), 3, yPos, 0);
        }
        tp.endText();
        tp.restoreState();
        tp.endVariableText();
        field.setAppearance(PdfAnnotation.APPEARANCE_NORMAL, tp);
    }

    /**
     * @param name
     * @param value
     * @param status
     * @param llx
     * @param lly
     * @param urx
     * @param ury
     * @return a PdfFormField
     */
    public PdfFormField addCheckBox(String name, String value, boolean status, float llx, float lly, float urx, float ury) {
        PdfFormField field = PdfFormField.createCheckBox(writer);
        setCheckBoxParams(field, name, value, status, llx, lly, urx, ury);
        drawCheckBoxAppearences(field, value, llx, lly, urx, ury);
        addFormField(field);
        return field;
    }

    /**
     * @param field
     * @param name
     * @param value
     * @param status
     * @param llx
     * @param lly
     * @param urx
     * @param ury
     */
    public void setCheckBoxParams(PdfFormField field, String name, String value, boolean status, float llx, float lly, float urx, float ury) {
        field.setWidget(new Rectangle(llx, lly, urx, ury), PdfAnnotation.HIGHLIGHT_TOGGLE);
        field.setFieldName(name);
        if (status) {
            field.setValueAsName(value);
            field.setAppearanceState(value);
        }
        else {
            field.setValueAsName("Off");
            field.setAppearanceState("Off");
        }
        field.setFlags(PdfAnnotation.FLAGS_PRINT);
        field.setPage();
        field.setBorderStyle(new PdfBorderDictionary(1, PdfBorderDictionary.STYLE_SOLID));
    }

    /**
     * @param field
     * @param value
     * @param llx
     * @param lly
     * @param urx
     * @param ury
     */
    public void drawCheckBoxAppearences(PdfFormField field, String value, float llx, float lly, float urx, float ury) {
        BaseFont font = null;
        try {
            font = BaseFont.createFont(BaseFont.ZAPFDINGBATS, BaseFont.WINANSI, BaseFont.NOT_EMBEDDED);
        }
        catch(Exception e) {
            throw new ExceptionConverter(e);
        }
        float size = ury - lly;
        PdfAppearance tpOn = PdfAppearance.createAppearance(writer, urx - llx, ury - lly);
        PdfAppearance tp2 = (PdfAppearance)tpOn.getDuplicate();
        tp2.setFontAndSize(font, size);
        tp2.resetRGBColorFill();
        field.setDefaultAppearanceString(tp2);
        tpOn.drawTextField(0f, 0f, urx - llx, ury - lly);
        tpOn.saveState();
        tpOn.resetRGBColorFill();
        tpOn.beginText();
        tpOn.setFontAndSize(font, size);
        tpOn.showTextAligned(PdfContentByte.ALIGN_CENTER, "4", (urx - llx) / 2, (ury - lly) / 2 - size * 0.3f, 0);
        tpOn.endText();
        tpOn.restoreState();
        field.setAppearance(PdfAnnotation.APPEARANCE_NORMAL, value, tpOn);
        PdfAppearance tpOff = PdfAppearance.createAppearance(writer, urx - llx, ury - lly);
        tpOff.drawTextField(0f, 0f, urx - llx, ury - lly);
        field.setAppearance(PdfAnnotation.APPEARANCE_NORMAL, "Off", tpOff);
    }

    /**
     * @param name
     * @param defaultValue
     * @param noToggleToOff
     * @return a PdfFormField
     */
    public PdfFormField getRadioGroup(String name, String defaultValue, boolean noToggleToOff) {
        PdfFormField radio = PdfFormField.createRadioButton(writer, noToggleToOff);
        radio.setFieldName(name);
        radio.setValueAsName(defaultValue);
        return radio;
    }

    /**
     * @param radiogroup
     */
    public void addRadioGroup(PdfFormField radiogroup) {
        addFormField(radiogroup);
    }

    /**
     * @param radiogroup
     * @param value
     * @param llx
     * @param lly
     * @param urx
     * @param ury
     * @return a PdfFormField
     */
    public PdfFormField addRadioButton(PdfFormField radiogroup, String value, float llx, float lly, float urx, float ury) {
        PdfFormField radio = PdfFormField.createEmpty(writer);
        radio.setWidget(new Rectangle(llx, lly, urx, ury), PdfAnnotation.HIGHLIGHT_TOGGLE);
        String name = ((PdfName)radiogroup.get(PdfName.V)).toString().substring(1);
        if (name.equals(value)) {
            radio.setAppearanceState(value);
        }
        else {
            radio.setAppearanceState("Off");
        }
        drawRadioAppearences(radio, value, llx, lly, urx, ury);
        radiogroup.addKid(radio);
        return radio;
    }

    /**
     * @param field
     * @param value
     * @param llx
     * @param lly
     * @param urx
     * @param ury
     */
    public void drawRadioAppearences(PdfFormField field, String value, float llx, float lly, float urx, float ury) {
        PdfAppearance tpOn = PdfAppearance.createAppearance(writer, urx - llx, ury - lly);
        tpOn.drawRadioField(0f, 0f, urx - llx, ury - lly, true);
        field.setAppearance(PdfAnnotation.APPEARANCE_NORMAL, value, tpOn);
        PdfAppearance tpOff = PdfAppearance.createAppearance(writer, urx - llx, ury - lly);
        tpOff.drawRadioField(0f, 0f, urx - llx, ury - lly, false);
        field.setAppearance(PdfAnnotation.APPEARANCE_NORMAL, "Off", tpOff);
    }

    /**
     * @param name
     * @param options
     * @param defaultValue
     * @param font
     * @param fontSize
     * @param llx
     * @param lly
     * @param urx
     * @param ury
     * @return a PdfFormField
     */
    public PdfFormField addSelectList(String name, String[] options, String defaultValue, BaseFont font, float fontSize, float llx, float lly, float urx, float ury) {
        PdfFormField choice = PdfFormField.createList(writer, options, 0);
        setChoiceParams(choice, name, defaultValue, llx, lly, urx, ury);
        StringBuffer text = new StringBuffer();
        for (String option : options) {
            text.append(option).append('\n');
        }
        drawMultiLineOfText(choice, text.toString(), font, fontSize, llx, lly, urx, ury);
        addFormField(choice);
        return choice;
    }

    /**
     * @param name
     * @param options
     * @param defaultValue
     * @param font
     * @param fontSize
     * @param llx
     * @param lly
     * @param urx
     * @param ury
     * @return a PdfFormField
     */
    public PdfFormField addSelectList(String name, String[][] options, String defaultValue, BaseFont font, float fontSize, float llx, float lly, float urx, float ury) {
        PdfFormField choice = PdfFormField.createList(writer, options, 0);
        setChoiceParams(choice, name, defaultValue, llx, lly, urx, ury);
        StringBuffer text = new StringBuffer();
        for (String[] option : options) {
            text.append(option[1]).append('\n');
        }
        drawMultiLineOfText(choice, text.toString(), font, fontSize, llx, lly, urx, ury);
        addFormField(choice);
        return choice;
    }

    /**
     * @param name
     * @param options
     * @param defaultValue
     * @param editable
     * @param font
     * @param fontSize
     * @param llx
     * @param lly
     * @param urx
     * @param ury
     * @return a PdfFormField
     */
    public PdfFormField addComboBox(String name, String[] options, String defaultValue, boolean editable, BaseFont font, float fontSize, float llx, float lly, float urx, float ury) {
        PdfFormField choice = PdfFormField.createCombo(writer, editable, options, 0);
        setChoiceParams(choice, name, defaultValue, llx, lly, urx, ury);
        if (defaultValue == null) {
            defaultValue = options[0];
        }
        drawSingleLineOfText(choice, defaultValue, font, fontSize, llx, lly, urx, ury);
        addFormField(choice);
        return choice;
    }

    /**
     * @param name
     * @param options
     * @param defaultValue
     * @param editable
     * @param font
     * @param fontSize
     * @param llx
     * @param lly
     * @param urx
     * @param ury
     * @return a PdfFormField
     */
    public PdfFormField addComboBox(String name, String[][] options, String defaultValue, boolean editable, BaseFont font, float fontSize, float llx, float lly, float urx, float ury) {
        PdfFormField choice = PdfFormField.createCombo(writer, editable, options, 0);
        setChoiceParams(choice, name, defaultValue, llx, lly, urx, ury);
        String value = null;
        for (String[] option : options) {
            if (option[0].equals(defaultValue)) {
                value = option[1];
                break;
            }
        }
        if (value == null) {
            value = options[0][1];
        }
        drawSingleLineOfText(choice, value, font, fontSize, llx, lly, urx, ury);
        addFormField(choice);
        return choice;
    }

    /**
     * @param field
     * @param name
     * @param defaultValue
     * @param llx
     * @param lly
     * @param urx
     * @param ury
     */
    public void setChoiceParams(PdfFormField field, String name, String defaultValue, float llx, float lly, float urx, float ury) {
        field.setWidget(new Rectangle(llx, lly, urx, ury), PdfAnnotation.HIGHLIGHT_INVERT);
        if (defaultValue != null) {
            field.setValueAsString(defaultValue);
            field.setDefaultValueAsString(defaultValue);
        }
        field.setFieldName(name);
        field.setFlags(PdfAnnotation.FLAGS_PRINT);
        field.setPage();
        field.setBorderStyle(new PdfBorderDictionary(2, PdfBorderDictionary.STYLE_SOLID));
    }

    /**
     * @param name
     * @param llx
     * @param lly
     * @param urx
     * @param ury
     * @return a PdfFormField
     */
    public PdfFormField addSignature(String name,
                    float llx, float lly, float urx, float ury) {
        PdfFormField signature = PdfFormField.createSignature(writer);
        setSignatureParams(signature, name, llx, lly, urx, ury);
        drawSignatureAppearences(signature, llx, lly, urx, ury);
        addFormField(signature);
        return signature;
    }

    /**
     * @param field
     * @param name
     * @param llx
     * @param lly
     * @param urx
     * @param ury
     */
    public void setSignatureParams(PdfFormField field, String name,
                    float llx, float lly, float urx, float ury) {
        field.setWidget(new Rectangle(llx, lly, urx, ury), PdfAnnotation.HIGHLIGHT_INVERT);
        field.setFieldName(name);
        field.setFlags(PdfAnnotation.FLAGS_PRINT);
        field.setPage();
        field.setMKBorderColor(BaseColor.BLACK);
        field.setMKBackgroundColor(BaseColor.WHITE);
    }

    /**
     * @param field
     * @param llx
     * @param lly
     * @param urx
     * @param ury
     */
    public void drawSignatureAppearences(PdfFormField field,
                    float llx, float lly, float urx, float ury) {
        PdfAppearance tp = PdfAppearance.createAppearance(writer, urx - llx, ury - lly);
        tp.setGrayFill(1.0f);
        tp.rectangle(0, 0, urx - llx, ury - lly);
        tp.fill();
        tp.setGrayStroke(0);
        tp.setLineWidth(1);
        tp.rectangle(0.5f, 0.5f, urx - llx - 0.5f, ury - lly - 0.5f);
        tp.closePathStroke();
        tp.saveState();
        tp.rectangle(1, 1, urx - llx - 2, ury - lly - 2);
        tp.clip();
        tp.newPath();
        tp.restoreState();
        field.setAppearance(PdfAnnotation.APPEARANCE_NORMAL, tp);
    }

    @Override
    public void toPdf(final PdfWriter writer, final OutputStream os) throws IOException {
        PdfWriter.checkPdfIsoConformance(writer, PdfIsoKeys.PDFISOKEY_FORM, this);
        super.toPdf(writer, os);
    }

}
