PdfDictionary is the Pdf dictionary object.
*
* A dictionary is an associative table containing pairs of objects. The first element
* of each pair is called the key and the second element is called the value.
* Unlike dictionaries in the PostScript language, a key must be a PdfName.
* A value can be any kind of PdfObject, including a dictionary. A dictionary is
* generally used to collect and tie together the attributes of a complex object, with each
* key-value pair specifying the name and value of an attribute.
* A dictionary is represented by two left angle brackets (<<), followed by a sequence of
* key-value pairs, followed by two right angle brackets (>>).
* This object is described in the 'Portable Document Format Reference Manual version 1.3'
* section 4.7 (page 40-41).
*
*
* @see PdfObject
* @see PdfName
* @see BadPdfFormatException
*/
public class PdfDictionary extends PdfObject {
// static membervariables (types of dictionary's)
/** This is a possible type of dictionary */
public static final PdfName FONT = PdfName.FONT;
/** This is a possible type of dictionary */
public static final PdfName OUTLINES = PdfName.OUTLINES;
/** This is a possible type of dictionary */
public static final PdfName PAGE = PdfName.PAGE;
/** This is a possible type of dictionary */
public static final PdfName PAGES = PdfName.PAGES;
/** This is a possible type of dictionary */
public static final PdfName CATALOG = PdfName.CATALOG;
// membervariables
/** This is the type of this dictionary */
private PdfName dictionaryType = null;
/** This is the hashmap that contains all the values and keys of the dictionary */
protected HashMap hashMap;
// constructors
/**
* Constructs an empty PdfDictionary-object.
*/
public PdfDictionary() {
super(DICTIONARY);
hashMap = new HashMap();
}
/**
* Constructs a PdfDictionary-object of a certain type.
*
* @param type a PdfName
*/
public PdfDictionary(PdfName type) {
this();
dictionaryType = type;
put(PdfName.TYPE, dictionaryType);
}
// methods overriding some methods in PdfObject
/**
* Returns the PDF representation of this PdfDictionary.
*
* @return an array of byte
*/
public void toPdf(PdfWriter writer, OutputStream os) throws IOException {
os.write('<');
os.write('<');
// loop over all the object-pairs in the HashMap
PdfName key;
PdfObject value;
int type = 0;
for (Iterator i = hashMap.keySet().iterator(); i.hasNext(); ) {
key = (PdfName) i.next();
value = (PdfObject) hashMap.get(key);
key.toPdf(writer, os);
type = value.type();
if (type != PdfObject.ARRAY && type != PdfObject.DICTIONARY && type != PdfObject.NAME && type != PdfObject.STRING)
os.write(' ');
value.toPdf(writer, os);
}
os.write('>');
os.write('>');
}
// methods concerning the HashMap member value
/**
* Adds a PdfObject and its key to the PdfDictionary.
* If the value is null or PdfNull the key is deleted.
*
* @param key key of the entry (a PdfName)
* @param value value of the entry (a PdfObject)
*/
public void put(PdfName key, PdfObject value) {
if (value == null || value.isNull())
hashMap.remove(key);
else
hashMap.put(key, value);
}
/**
* Adds a PdfObject and its key to the PdfDictionary.
* If the value is null it does nothing.
*
* @param key key of the entry (a PdfName)
* @param value value of the entry (a PdfObject)
*/
public void putEx(PdfName key, PdfObject value) {
if (value == null)
return;
put(key, value);
}
/**
* Removes a PdfObject and its key from the PdfDictionary.
*
* @param key key of the entry (a PdfName)
*/
public void remove(PdfName key) {
hashMap.remove(key);
}
/**
* Gets a PdfObject with a certain key from the PdfDictionary.
*
* @param key key of the entry (a PdfName)
* @return the previous PdfObject corresponding with the key
*/
public PdfObject get(PdfName key) {
return (PdfObject) hashMap.get(key);
}
// methods concerning the type of Dictionary
/**
* Checks if a PdfDictionary is of a certain type.
*
* @param type a type of dictionary
* @return true of false
*
* @deprecated
*/
public boolean isDictionaryType(PdfName type) {
return dictionaryType.compareTo(type) == 0;
}
/**
* Checks if a Dictionary is of the type FONT.
*
* @return true if it is, false if it isn't.
*/
public boolean isFont() {
return dictionaryType.compareTo(FONT) == 0;
}
/**
* Checks if a Dictionary is of the type PAGE.
*
* @return true if it is, false if it isn't.
*/
public boolean isPage() {
return dictionaryType.compareTo(PAGE) == 0;
}
/**
* Checks if a Dictionary is of the type PAGES.
*
* @return true if it is, false if it isn't.
*/
public boolean isPages() {
return dictionaryType.compareTo(PAGES) == 0;
}
/**
* Checks if a Dictionary is of the type CATALOG.
*
* @return true if it is, false if it isn't.
*/
public boolean isCatalog() {
return dictionaryType.compareTo(CATALOG) == 0;
}
/**
* Checks if a Dictionary is of the type OUTLINES.
*
* @return true if it is, false if it isn't.
*/
public boolean isOutlineTree() {
return dictionaryType.compareTo(OUTLINES) == 0;
}
public void merge(PdfDictionary other) {
hashMap.putAll(other.hashMap);
}
public void mergeDifferent(PdfDictionary other) {
for (Iterator i = other.hashMap.keySet().iterator(); i.hasNext();) {
Object key = i.next();
if (!hashMap.containsKey(key)) {
hashMap.put(key, other.hashMap.get(key));
}
}
}
public Set getKeys() {
return hashMap.keySet();
}
public void putAll(PdfDictionary dic) {
hashMap.putAll(dic.hashMap);
}
public int size() {
return hashMap.size();
}
public boolean contains(PdfName key) {
return hashMap.containsKey(key);
}
public String toString() {
return "Dictionary of type: " + get(PdfName.TYPE);
}
}