/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.pdfbox.examples.interactive.form;

import java.io.IOException;
import org.apache.pdfbox.cos.COSDictionary;
import org.apache.pdfbox.cos.COSName;
import org.apache.pdfbox.pdmodel.PDDocument;
import org.apache.pdfbox.pdmodel.PDPage;
import org.apache.pdfbox.pdmodel.PDPageContentStream;
import org.apache.pdfbox.pdmodel.PDResources;
import org.apache.pdfbox.pdmodel.common.PDRectangle;
import org.apache.pdfbox.pdmodel.font.PDFont;
import org.apache.pdfbox.pdmodel.font.PDType1Font;
import org.apache.pdfbox.pdmodel.graphics.color.PDColor;
import org.apache.pdfbox.pdmodel.graphics.color.PDDeviceRGB;
import org.apache.pdfbox.pdmodel.interactive.annotation.PDAnnotationWidget;
import org.apache.pdfbox.pdmodel.interactive.annotation.PDAppearanceCharacteristicsDictionary;
import org.apache.pdfbox.pdmodel.interactive.form.PDAcroForm;
import org.apache.pdfbox.pdmodel.interactive.form.PDTextField;
import org.apache.pdfbox.pdmodel.interactive.form.PDVariableText;

/**
 * An example of creating an AcroForm and a form field from scratch.
 * 
 * The form field is created with properties similar to creating
 * a form with default settings in Adobe Acrobat.
 * 
 */
public final class CreateSimpleForm
{
    private CreateSimpleForm()
    {
    }
    
    public static void main(String[] args) throws IOException
    {
        // Create a new document with an empty page.
        PDDocument document = new PDDocument();
        PDPage page = new PDPage(PDRectangle.A4);
        document.addPage(page);
        
        // Adobe Acrobat uses Helvetica as a default font and 
        // stores that under the name '/Helv' in the resources dictionary
        PDFont font = PDType1Font.HELVETICA;
        PDResources resources = new PDResources();
        resources.put(COSName.getPDFName("Helv"), font);
        
        // Add a new AcroForm and add that to the document
        PDAcroForm acroForm = new PDAcroForm(document);
        document.getDocumentCatalog().setAcroForm(acroForm);
        
        // Add and set the resources and default appearance at the form level
        acroForm.setDefaultResources(resources);
        
        // Acrobat sets the font size on the form level to be
        // auto sized as default. This is done by setting the font size to '0'
        String defaultAppearanceString = "/Helv 0 Tf 0 g";
        acroForm.setDefaultAppearance(defaultAppearanceString);
        
        // Add a form field to the form.
        PDTextField textBox = new PDTextField(acroForm);
        textBox.setPartialName("SampleField");
        // Acrobat sets the font size to 12 as default
        // This is done by setting the font size to '12' on the
        // field level. 
        // The text color is set to blue in this example.
        // To use black, replace "0 0 1 rg" with "0 0 0 rg" or "0 g".
        defaultAppearanceString = "/Helv 12 Tf 0 0 1 rg";
        textBox.setDefaultAppearance(defaultAppearanceString);

        // add the field to the acroform
        acroForm.getFields().add(textBox);

        // Specify the widget annotation associated with the field
        PDAnnotationWidget widget = textBox.getWidgets().get(0);
        PDRectangle rect = new PDRectangle(50, 750, 200, 50);
        widget.setRectangle(rect);
        widget.setPage(page);

        // set green border and yellow background
        // if you prefer defaults, delete this code block
        PDAppearanceCharacteristicsDictionary fieldAppearance
                = new PDAppearanceCharacteristicsDictionary(new COSDictionary());
        fieldAppearance.setBorderColour(new PDColor(new float[]{0,1,0}, PDDeviceRGB.INSTANCE));
        fieldAppearance.setBackground(new PDColor(new float[]{1,1,0}, PDDeviceRGB.INSTANCE));
        widget.setAppearanceCharacteristics(fieldAppearance);

        // make sure the widget annotation is visible on screen and paper
        widget.setPrinted(true);
        
        // Add the widget annotation to the page
        page.getAnnotations().add(widget);

        // set the alignment ("quadding")
        textBox.setQ(PDVariableText.QUADDING_CENTERED);

        // set the field value
        textBox.setValue("Sample field content");

        // put some text near the field
        PDPageContentStream cs = new PDPageContentStream(document, page);
        cs.beginText();
        cs.setFont(PDType1Font.HELVETICA, 15);
        cs.newLineAtOffset(50, 810);
        cs.showText("Field:");
        cs.endText();
        cs.close();

        document.save("target/SimpleForm.pdf");
        document.close();
    }
}
