# PDVariableText.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 org.apache.pdfbox.cos.COSBase;
    import org.apache.pdfbox.cos.COSDictionary;
    import org.apache.pdfbox.cos.COSName;
    import org.apache.pdfbox.cos.COSNumber;
    import org.apache.pdfbox.cos.COSStream;
    import org.apache.pdfbox.cos.COSString;
    import org.apache.pdfbox.pdmodel.PDResources;

    /**
     * Base class for fields which use "Variable Text".
     * These fields construct an appearance stream dynamically at viewing time.
     *
     * @author Ben Litchfield
     */
    public abstract class PDVariableText extends PDTerminalField
    {
        public static final int QUADDING_LEFT = 0;
        public static final int QUADDING_CENTERED = 1;
        public static final int QUADDING_RIGHT = 2;

        /**
         * @see PDTerminalField#PDTerminalField(PDAcroForm)
         *
         * @param acroForm The acroform.
         */
        PDVariableText(PDAcroForm acroForm)
        {
            super(acroForm);
        }

        /**
         * 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
         */
        PDVariableText(PDAcroForm acroForm, COSDictionary field, PDNonTerminalField parent)
        {
            super(acroForm, field, parent);
        }

        /**
         * Get the default appearance.
         *
         * This is an inheritable attribute.
         *
         * The default appearance contains a set of default graphics and text operators
         * to define the field’s text size and color.
         *
         * @return the DA element of the dictionary object
         */
        public String getDefaultAppearance()
        {
            COSBase base = getInheritableAttribute(COSName.DA);
            COSString defaultAppearance;
            if (!(base instanceof COSString))
            {
                return null;
            }
            defaultAppearance = (COSString) base;
            return defaultAppearance.getString();
        }

        /**
         * Get the default appearance.
         *
         * This is an inheritable attribute.
         *
         * The default appearance contains a set of default graphics and text operators
         * to define the field’s text size and color.
         *
         * @return the DA element of the dictionary object
         */
        PDDefaultAppearanceString getDefaultAppearanceString() throws IOException
        {
            COSBase base = getInheritableAttribute(COSName.DA);
            COSString da = null;
            if (base instanceof COSString)
            {
                da = (COSString) base;
            }
            PDResources dr = getAcroForm().getDefaultResources();
            return new PDDefaultAppearanceString(da, dr);
        }

        /**
         * Set the default appearance.
         *
         * This will set the local default appearance for the variable text field only, not
         * affecting a default appearance in the parent hierarchy.
         *
         * Providing null as the value will remove the local default appearance.
         * <p>
         * This method can also be used to change the font of a field, by replacing the font name from
         * this string with another font name found in the AcroForm default resources <u>before</u>
         * calling {@link #setValue(java.lang.String) setValue(String)}, see also
         * <a href="https://stackoverflow.com/questions/47995062/pdfbox-api-how-to-handle-cyrillic-values">this
         * stackoverflow answer</a>. For example, "/Helv 10 Tf 0 g" can be replaced with "/F1 10 Tf 0
         * g". Performance may go down (see
         * <a href="https://issues.apache.org/jira/browse/PDFBOX-4508">PDFBOX-4508)</a> if this is done
         * for many fields and with a very large font (e.g. ArialUni); to avoid this, save and reload
         * the file after changing all fields.
         *
         * @param daValue a string describing the default appearance
         */
        public void setDefaultAppearance(String daValue)
        {
            getCOSObject().setString(COSName.DA, daValue);
        }

        /**
         * Get the default style string.
         *
         * The default style string defines the default style for
         * rich text fields.
         *
         * @return the DS element of the dictionary object
         */
        public String getDefaultStyleString()
        {
            return getCOSObject().getString(COSName.DS);
        }

        /**
         * Set the default style string.
         *
         * Providing null as the value will remove the default style string.
         *
         * @param defaultStyleString a string describing the default style.
         */
        public void setDefaultStyleString(String defaultStyleString)
        {
            if (defaultStyleString != null)
            {
                getCOSObject().setItem(COSName.DS, new COSString(defaultStyleString));
            }
            else
            {
                getCOSObject().removeItem(COSName.DS);
            }
        }

        /**
         * This will get the 'quadding' or justification of the text to be displayed.
         *
         * This is an inheritable attribute.
         * <br>
         * 0 - Left (default)<br>
         * 1 - Centered<br>
         * 2 - Right<br>
         * Please see the QUADDING_CONSTANTS.
         *
         * @return The justification of the text strings.
         */
        public int getQ()
        {
            int retval = 0;

            COSNumber number = (COSNumber)getInheritableAttribute(COSName.Q);

            if (number != null)
            {
                retval = number.intValue();
            }
            return retval;
        }

        /**
         * This will set the quadding/justification of the text.  See QUADDING constants.
         *
         * @param q The new text justification.
         */
        public void setQ(int q)
        {
            getCOSObject().setInt(COSName.Q, q);
        }

        /**
         * Get the fields rich text value.
         *
         * @return the rich text value string
         */
        public String getRichTextValue()
        {
            return getStringOrStream(getInheritableAttribute(COSName.RV));
        }

        /**
         * Set the fields rich text value.
         *
         * <p>
         * Setting the rich text value will not generate the appearance
         * for the field.
         * <br>
         * You can set {@link PDAcroForm#setNeedAppearances(Boolean)} to
         * signal a conforming reader to generate the appearance stream.
         * </p>
         *
         * Providing null as the value will remove the default style string.
         *
         * @param richTextValue a rich text string
         */
        public void setRichTextValue(String richTextValue)
        {
            if (richTextValue != null)
            {
                getCOSObject().setItem(COSName.RV, new COSString(richTextValue));
            }
            else
            {
                getCOSObject().removeItem(COSName.RV);
            }
        }

        /**
         * Get a text as text stream.
         *
         * Some dictionary entries allow either a text or a text stream.
         *
         * @param base the potential text or text stream
         * @return the text stream
         */
        protected final String getStringOrStream(COSBase base)
        {
            if (base instanceof COSString)
            {
                return ((COSString)base).getString();
            }
            else if (base instanceof COSStream)
            {
                return ((COSStream)base).toTextString();
            }
            return "";
        }
    }