PDVariableText.java

package com.tom_roush.pdfbox.pdmodel.interactive.form;

import com.tom_roush.pdfbox.cos.COSBase;
import com.tom_roush.pdfbox.cos.COSDictionary;
import com.tom_roush.pdfbox.cos.COSName;
import com.tom_roush.pdfbox.cos.COSNumber;
import com.tom_roush.pdfbox.cos.COSStream;
import com.tom_roush.pdfbox.cos.COSString;
import com.tom_roush.pdfbox.pdmodel.PDResources;

import java.io.IOException;

/**
 * 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
{
	static final int QUADDING_LEFT = 0;
	static final int QUADDING_CENTERED = 1;
	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()
	{
		COSString defaultAppearance = (COSString) getInheritableAttribute(COSName.DA);
		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
     */
    PDAppearanceString getDefaultAppearanceString() throws IOException
    {
        COSString da = (COSString) getInheritableAttribute(COSName.DA);
        PDResources dr = getAcroForm().getDefaultResources();
        return new PDAppearanceString(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.
	 *
	 * @param daValue a string describing the default appearance
	 */
	public void setDefaultAppearance(String daValue)
	{
		dictionary.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()
	{
		COSString defaultStyleString = (COSString) dictionary.getDictionaryObject(COSName.DS);
		return defaultStyleString.getString();
	}

	/**
	 * 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)
		{
			dictionary.setItem(COSName.DS, new COSString(defaultStyleString));
		}
		else
		{
			dictionary.removeItem(COSName.DS);
		}
	}

	/**
	 * This will get the 'quadding' or justification of the text to be displayed.
	 *
	 * This is an inheritable attribute.
	 *
	 * 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 )
	{
		dictionary.setInt(COSName.Q, q);
	}

	/**
	 * Get the fields rich text value.
	 *
	 * @return the rich text value string
	 */
	public String getRichTextValue() throws IOException
	{
        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)
	{
		// TODO stream instead of string
		if (richTextValue != null)
		{
			dictionary.setItem(COSName.RV, new COSString(richTextValue));
		}
		else
		{
			dictionary.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 String getStringOrStream(COSBase base)
    {
        if (base == null)
		{
            return "";
        }
        else if (base instanceof COSString)
		{
			return ((COSString) base).getString();
		}
		else if (base instanceof COSStream)
		{
			return ((COSStream) base).getString();
		}
		else
		{
            return "";
        }
    }
}