Streamlined. Add code for encryption of string and text values. All PDF objects may...

git-svn-id: https://svn.apache.org/repos/asf/xmlgraphics/fop/trunk@196156 13f79535-47bb-0310-9956-ffa450edef68

diff --git a/src/java/org/apache/fop/pdf/PDFObject.java b/src/java/org/apache/fop/pdf/PDFObject.java
index 2390a57ca1e64bad45c65ba3308e7c40381bd89f..0a10c510f2e26fc138bc250d282678b89d6080c1 100644 (file)
--- a/src/java/org/apache/fop/pdf/PDFObject.java
+++ b/src/java/org/apache/fop/pdf/PDFObject.java
@@ -66,21 +66,17 @@ public abstract class PDFObject {
     /**
      * the object's number
      */
-    protected int number;
+    private int objnum;
 
     /**
      * the object's generation (0 in new documents)
      */
-    protected int generation = 0;
+    private int generation = 0;
 
     /**
-     * create an empty object
-     *
-     * @param number the object's number
+     * the parent PDFDocument
      */
-    public PDFObject(int number) {
-        this.number = number;
-    }
+    private PDFDocument document;
 
     /**
      * Create a PDFObject
@@ -90,14 +86,93 @@ public abstract class PDFObject {
     }
 
     /**
+     * Returns the object's number.
      * @return the PDF Object number
      */
-    public int getNumber() {
-        return this.number;
+    public int getObjectNumber() {
+        if (this.objnum == 0) {
+            throw new IllegalStateException("Object has no number assigned: " + this.toString());
+            //System.out.println("Object has no number assigned: " + this.toString());
+        }
+        return this.objnum;
+    }
+    
+    /**
+     * Indicates whether this PDFObject has already been assigned an 
+     * object number.
+     * @return True if it has an object number
+     */
+    public boolean hasObjectNumber() {
+        return this.objnum > 0;
+    }
+
+    /**
+     * Sets the object number
+     * @param objnum the object number
+     */
+    public void setObjectNumber(int objnum) {
+        this.objnum = objnum;
+        //System.out.println("Assigning "+this+" object number "+objnum);
+    }
+
+    /**
+     * Returns the object's generation.
+     * @return the PDF Object generation
+     */
+    public int getGeneration() {
+        return this.generation;
+    }
+
+    /**
+     * Returns the parent PDFDocument if assigned.
+     * @return the parent PDFDocument (May be null if the parent PDFDocument
+     * has not been assigned)
+     */
+    public final PDFDocument getDocument() {
+        return this.document;
+    }
+
+    /**
+     * Returns the parent PDFDocument, but unlike <code>getDocument()</code>
+     * it throws an informative Exception if the parent document is unavailable
+     * instead of having a NullPointerException somewhere without a message.
+     * @return the parent PDFDocument
+     */
+    public final PDFDocument getDocumentSafely() {
+        final PDFDocument doc = getDocument();
+        if (doc == null) {
+            throw new IllegalStateException("Parent PDFDocument is unavailable");
+        }
+        return doc;
+    }
+
+    /**
+     * Sets the parent PDFDocument.
+     * @param doc the PDFDocument.
+     */
+    public void setDocument(PDFDocument doc) {
+        this.document = doc;
+    }
+
+    /**
+     * Returns the PDF representation of the Object ID.
+     * @return the Object ID
+     */
+    public String getObjectID() {
+        return getObjectNumber() + " " + getGeneration() + " obj\n";
     }
 
     /**
-     * write the PDF represention of this object
+     * Returns the PDF representation of a reference to this object.
+     * @return the reference string
+     */
+    public String referencePDF() {
+        String ref = getObjectNumber() + " " + getGeneration() + " R";
+        return ref;
+    }
+
+    /**
+     * Write the PDF represention of this object
      *
      * @param stream the stream to write the PDF to
      * @throws IOException if there is an error writing to the stream
@@ -110,19 +185,68 @@ public abstract class PDFObject {
     }
 
     /**
-     * the PDF representation of a reference to this object
+     * Encodes the object as a byte array for output to a PDF file.
      *
-     * @return the reference string
+     * @return PDF string
      */
-    public String referencePDF() {
-        String p = this.number + " " + this.generation + " R";
-        return p;
+    protected byte[] toPDF() {
+        return encode(toPDFString());
     }
-
+    
+    
     /**
-     * represent object as PDF
-     *
-     * @return PDF string
+     * This method returns a String representation of the PDF object. The result
+     * is normally converted/encoded to a byte array by toPDF(). Only use 
+     * this method to implement the serialization if the object can be fully 
+     * represented as text. If the PDF representation of the object contains
+     * binary content use toPDF() or output(OutputStream) instead.
+     * @return String the String representation
      */
-    abstract byte[] toPDF();
+    protected String toPDFString() {
+        throw new UnsupportedOperationException("Not implemented. "
+                    + "Use output(OutputStream) instead.");
+    }
+    
+    
+    /**
+     * Converts text to a byte array for writing to a PDF file.
+     * @param text text to convert/encode
+     * @return byte[] the resulting byte array
+     */
+    public static final byte[] encode(String text) {
+        return PDFDocument.encode(text);
+    }
+    
+    /**
+     * Encodes a Text String (3.8.1 in PDF 1.4 specs)
+     * @param text the text to encode
+     * @return byte[] the encoded text
+     */
+    protected byte[] encodeText(String text) {
+        if (getDocumentSafely().isEncryptionActive()) {
+            final byte[] buf = PDFText.toUTF16(text);
+            return PDFText.escapeByteArray(
+                getDocument().getEncryption().encrypt(buf, this));
+        } else {
+            return encode(PDFText.escapeText(text, true));
+        }
+    }
+    
+    /**
+     * Encodes a String (3.2.3 in PDF 1.4 specs)
+     * @param string the string to encode
+     * @return byte[] the encoded string
+     */
+    protected byte[] encodeString(String string) {
+        return encodeText(string);
+        /*
+        final byte[] buf = encode(PDFText.escapeString(string));
+        if (getDocumentSafely().isEncryptionActive()) {
+            return PDFText.escapeByteArray(
+                getDocument().getEncryption().encrypt(buf, this));
+        } else {
+            return buf;
+        }*/
+    }
+
 }