de.intarsys.pdf.pd.PDObject Maven / Gradle / Ivy
/*
* Copyright (c) 2007, intarsys consulting GmbH
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* - Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
*
* - Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
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* - Neither the name of intarsys nor the names of its contributors may be used
* to endorse or promote products derived from this software without specific
* prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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package de.intarsys.pdf.pd;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import de.intarsys.pdf.cos.COSArray;
import de.intarsys.pdf.cos.COSBasedObject;
import de.intarsys.pdf.cos.COSDictionary;
import de.intarsys.pdf.cos.COSDocument;
import de.intarsys.pdf.cos.COSName;
import de.intarsys.pdf.cos.COSNull;
import de.intarsys.pdf.cos.COSObject;
/**
* This is the abstract superclass for all complex PD level objects.
*
*
* PD Level objects provide the PDF semantics on top of the basic datatypes of
* COS Level objects. PDObject provides generic methods used along all subtypes.
*
* PDObjects should be created only using the factory methods of their meta
* classes to ensure the semantics implemented in the PD layer, as for example
* PD object identity, subclass selection or proper initialization.
* Example:
*
* PDPage page = (PDPage)PDPage.META.createNew();
*
*
*/
abstract public class PDObject extends COSBasedObject {
/**
* The meta class implementation
*/
static public class MetaClass extends COSBasedObject.MetaClass {
protected MetaClass(Class instanceClass) {
super(instanceClass);
}
}
/** The meta class instance */
static public final MetaClass META = new MetaClass(MetaClass.class
.getDeclaringClass());
// keys
static public final COSName DK_Type = COSName.constant("Type"); //
public static final COSName DK_Subtype = COSName.constant("Subtype");
/**
* Create the receiver class from an already defined {@link COSDictionary}.
* NEVER use the constructor directly.
*
* @param object
* the PDDocument containing the new object
*/
protected PDObject(COSObject object) {
super(object);
}
protected COSName cosGetExpectedSubtype() {
return null;
}
protected COSName cosGetExpectedType() {
return null;
}
/**
* Convenience method to access fields in {@link COSDictionary} based
* {@link PDObject} instances. This method supports "inheritance" on
* hierarchical structured {@link PDObject} instances. It returns the field
* either from the receiver or one of the known descendants.
*
* @param name
* the field to read
*
* @return the content of the named field in the PD object or one of its
* descendants - COSNull is the field is not found
*/
public COSObject cosGetFieldDescendant(COSName name) {
COSObject cosBase = cosGetField(name);
if (cosBase.isNull()) {
List children = getGenericChildren();
if (children != null) {
for (Iterator i = children.iterator(); i.hasNext();) {
PDObject child = (PDObject) i.next();
cosBase = child.cosGetFieldDescendant(name);
if (!cosBase.isNull()) {
return cosBase;
}
}
}
}
return cosBase;
}
/**
* Convenience method to access fields in {@link COSDictionary} based
* {@link PDObject} instances.
*
* This method supports "inheritance" on hierarchical structured
* {@link PDObject} instances. It returns the field either from the receiver
* or one of its parents.
*
* @param name
* the field to read
*
* @return the content of the named field in the PD object or one of its
* parents - COSNull if the field is not found
*/
public COSObject cosGetFieldInheritable(COSName name) {
COSObject cosBase = cosGetField(name);
if (cosBase.isNull() && (getGenericParent() != null)) {
return getGenericParent().cosGetFieldInheritable(name);
}
return cosBase;
}
/**
* Convenience method to access inherited fields in {@link COSDictionary}
* based {@link PDObject} instances.
*
* This method supports "inheritance" on hierarchical structured
* {@link PDObject} instances. It returns the inherited field value from one
* of the receiver's parents or {@link COSNull}.
*
* @param name
* the field to read
*
* @return the content of the named field in one of the receivers parents -
* COSNull if the field is not found
*/
public COSObject cosGetFieldInherited(COSName name) {
if (getGenericParent() != null) {
return getGenericParent().cosGetFieldInheritable(name);
}
return COSNull.NULL;
}
/**
* The /Subtype field of this {@link PDObject} or null. This method is not
* supported on {@link PDObject} instances that are not based on a
* {@link COSDictionary}
*
* @return The /Subtype field of this.
*/
final public COSName cosGetSubtype() {
return cosGetDict().get(DK_Subtype).asName();
}
/**
* The /Type field of this {@link PDObject} or null. This method is not
* supported on {@link PDObject} instances that are not based on a
* {@link COSDictionary}
*
* @return The /Type field of this.
*/
final public COSName cosGetType() {
return cosGetField(DK_Type).asName();
}
/**
* Convenience method to access fields in {@link COSDictionary} based
* {@link PDObject} instances. This method supports "inheritance" on
* hierarchical structured {@link PDObject} instances. It removes a field in
* the receiver and all its descendants.
*
* @param name
* the field to remove from the receiver
* @return The object previously associated with name in this
*/
public COSObject cosRemoveFieldInheritable(COSName name) {
COSObject result = cosRemoveField(name);
List children = getGenericChildren();
if (children != null) {
for (Iterator i = children.iterator(); i.hasNext();) {
PDObject child = (PDObject) i.next();
child.cosRemoveFieldInheritable(name);
}
}
return result;
}
/**
* Convenience method to access fields in {@link COSDictionary} based
* {@link PDObject} instances. This method supports "inheritance" on
* hierarchical structured {@link PDObject} instances. It sets a field value
* in the receiver when the field is inheritable. This method removes the
* field from every child to make sure it uses the inherited value.
*
* @param name
* the field to set
* @param cosObj
* the object to set in the field
* @return The object previously associated with name in this
*/
public COSObject cosSetFieldInheritable(COSName name, COSObject cosObj) {
COSObject result = cosSetField(name, cosObj);
List children = getGenericChildren();
if (children != null) {
for (Iterator i = children.iterator(); i.hasNext();) {
PDObject child = (PDObject) i.next();
child.cosRemoveFieldInheritable(name);
}
}
return result;
}
/**
* Set the /Subtype field of this {@link PDObject}. This method is not
* supported on {@link PDObject} instances that are not based on a
* {@link COSDictionary}
*
* @return The /Subtype previously associated with this.
*/
final public COSName cosSetSubtype(COSName newType) {
return cosSetField(DK_Subtype, newType).asName();
}
/**
* Set the /Type field of this {@link PDObject}. This method is not
* supported on {@link PDObject} instances that are not based on a
* {@link COSDictionary}
*
* @return The /Type previously associated with this.
*/
final public COSName cosSetType(COSName newType) {
return cosSetField(DK_Type, newType).asName();
}
/**
* Try the best in finding the PDDocument for this PDObject.
*
* @return Try the best in finding the PDDocument for this PDObject.
*/
public PDDocument getDoc() {
COSDocument cosDoc = cosGetObject().getDoc();
if (cosDoc == null) {
return null;
}
return PDDocument.createFromCos(cosDoc);
}
/**
* Get a collection of {@link PDObject} children if the receiver is a node
* in a hierarchical structure (like page nodes or form fields).
*
*
* This enables the generic implementation of inherited field values and so
* on.
*
*
*
* A concrete PDObject implementation supporting inheritance should
* implement this method.
*
*
* @return A collection of {@link PDObject} children if the receiver is a
* node in a hierarchical structure .
*/
public List getGenericChildren() {
return null;
}
/**
* The parent of the receiver if it is a node in a hierarchical structure
* (like page nodes or form fields).
*
*
* A concrete PDObject implementation supporting inheritance should
* implement this method.
*
*
* @return The parent of the receiver if it is a node in a hierarchical
* structure (like page nodes or form fields).
*/
public PDObject getGenericParent() {
return null;
}
protected List getPDObjects(COSName key,
COSBasedObject.MetaClass metaclass, boolean addListener) {
COSArray array = cosGetField(key).asArray();
if (array != null) {
List result = new ArrayList();
Iterator i = array.iterator();
while (i.hasNext()) {
COSBasedObject pdObject = metaclass.createFromCos((COSObject) i
.next());
if (pdObject != null) {
result.add(pdObject);
}
}
if (addListener) {
array.addObjectListener(this);
}
return result;
}
return null;
}
@Override
protected void initializeFromScratch() {
super.initializeFromScratch();
COSName type = cosGetExpectedType();
if (type != null) {
cosSetField(DK_Type, type.copyShallow());
}
COSName subtype = cosGetExpectedSubtype();
if (subtype != null) {
cosSetField(DK_Subtype, subtype.copyShallow());
}
}
/**
* Set the parent of the receiver if it is a node in a hierarchical
* structure (like page nodes or form fields).
*
*
* A concrete PDObject implementation supporting inheritance should
* implement this method.
*
*
* @param parent
* The new parent object.
*/
public void setGenericParent(PDObject parent) {
// do nothing by default
}
protected void setPDObjects(COSName key, List list) {
if (list == null) {
cosRemoveField(key);
return;
}
COSArray array = cosGetField(key).asArray();
if (array == null) {
array = COSArray.create();
} else {
array.clear();
}
for (Iterator i = list.iterator(); i.hasNext();) {
array.add(((PDObject) i.next()).cosGetDict());
}
cosSetField(key, array);
}
/*
* (non-Javadoc)
*
* @see java.lang.Object#toString()
*/
@Override
public String toString() {
if (cosGetObject() == null) {
return "a " + getClass().getName();
}
if (cosGetObject().isIndirect()) {
return "[" + cosGetObject().getIndirectObject().toString() + "] "
+ getClass().getName();
}
return "a " + getClass().getName();
}
}