# PDComboBox.java

    /*
     * 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.pdmodel.interactive.form;

    import java.io.IOException;
    import java.util.List;

    import org.apache.pdfbox.cos.COSDictionary;
    import org.apache.pdfbox.cos.COSName;

    /**
     * A combo box consisting of a drop-down list.
     * May be accompanied by an editable text box in which non-predefined values may be entered.
     *
     * @author John Hewson
     */
    public final class PDComboBox extends PDChoice
    {
        private static final int FLAG_EDIT = 1 << 18;

        /**
         * @see PDField#PDField(PDAcroForm)
         *
         * @param acroForm The acroform.
         */
        public PDComboBox(PDAcroForm acroForm)
        {
            super(acroForm);
            setCombo(true);
        }

        /**
         * Constructor.
         *
         * @param acroForm The form that this field is part of.
         * @param field the PDF object to represent as a field.
         * @param parent the parent node of the node
         */
        PDComboBox(PDAcroForm acroForm, COSDictionary field, PDNonTerminalField parent)
        {
            super(acroForm, field, parent);
        }

        /**
         * Determines if Edit is set.
         *
         * @return true if the combo box shall include an editable text box as well as a drop-down list.
         */
        public boolean isEdit()
        {
            return getCOSObject().getFlag(COSName.FF, FLAG_EDIT);
        }

        /**
         * Set the Edit bit.
         *
         * @param edit The value for Edit.
         */
        public void setEdit(boolean edit)
        {
            getCOSObject().setFlag(COSName.FF, FLAG_EDIT, edit);
        }

        @Override
        void constructAppearances() throws IOException
        {
            AppearanceGeneratorHelper apHelper;
            apHelper = new AppearanceGeneratorHelper(this);
            List<String> values = getValue();

            if (!values.isEmpty())
            {
                apHelper.setAppearanceValue(values.get(0));
            }
            else
            {
                apHelper.setAppearanceValue("");
            }
        }
    }