/*
 * 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.font.Standard14Fonts.FontName;
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
{
    static final String DEFAULT_FILENAME = "target/SimpleForm.pdf";

    private CreateSimpleForm()
    {
    }
    
    public static void main(String[] args) throws IOException
    {
        // Create a new document with an empty page.
        try (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 = new PDType1Font(FontName.HELVETICA);
            PDResources resources = new PDResources();
            resources.put(COSName.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
            try (PDPageContentStream cs = new PDPageContentStream(document, page))
            {
                cs.beginText();
                cs.setFont(new PDType1Font(FontName.HELVETICA), 15);
                cs.newLineAtOffset(50, 810);
                cs.showText("Field:");
                cs.endText();
            }

            if (args == null || args.length == 0)
            {
                document.save(DEFAULT_FILENAME);
            }
            else
            {
                document.save(args[0]); // used for concurrent build tests
            }
        }
    }
}
