equals implementation violated spec -> replaced with new contentEquals function

git-svn-id: https://svn.apache.org/repos/asf/xmlgraphics/fop/trunk@815358 13f79535-47bb-0310-9956-ffa450edef68

src/java/org/apache/fop/pdf/PDFColor.java

@@ -541,13 +541,8 @@ public class PDFColor extends PDFPathPaint {
         return (new byte[0]);
     }
 
-    /**
-     * Check for equality of color with another object.
-     *
-     * @param obj the object to compare
-     * @return true if colors are equal
-     */
-    public boolean equals(Object obj) {
+    /** {@inheritDoc} */
+    protected boolean contentEquals(PDFObject obj) {
         if (!(obj instanceof PDFColor)) {
             return false;
         }

src/java/org/apache/fop/pdf/PDFDocument.java

@@ -526,8 +526,8 @@ public class PDFDocument {
 
     private Object findPDFObject(List list, PDFObject compare) {
         for (Iterator iter = list.iterator(); iter.hasNext();) {
-            Object obj = iter.next();
-            if (compare.equals(obj)) {
+            PDFObject obj = (PDFObject) iter.next();
+            if (compare.contentEquals(obj)) {
                 return obj;
             }
         }

src/java/org/apache/fop/pdf/PDFFileSpec.java

@@ -63,13 +63,8 @@ public class PDFFileSpec extends PDFObject {
      * endobj
      */
 
-    /**
-     * Check if this equals another object.
-     *
-     * @param obj the object to compare
-     * @return true if this equals other object
-     */
-    public boolean equals(Object obj) {
+    /** {@inheritDoc} */
+    protected boolean contentEquals(PDFObject obj) {
         if (this == obj) {
             return true;
         }

src/java/org/apache/fop/pdf/PDFFunction.java

@@ -696,15 +696,8 @@ public class PDFFunction extends PDFObject {
 
     }
 
-    /**
-     * Check if this function is equal to another object.
-     * This is used to find if a particular function already exists
-     * in a document.
-     *
-     * @param obj the obj to compare
-     * @return true if the functions are equal
-     */
-    public boolean equals(Object obj) {
+    /** {@inheritDoc} */
+    protected boolean contentEquals(PDFObject obj) {
         if (obj == null) {
             return false;
         }

src/java/org/apache/fop/pdf/PDFGState.java

@@ -175,10 +175,8 @@ public class PDFGState extends PDFObject {
      * endobj
      */
 
-    /**
-     * {@inheritDoc}
-     */
-    public boolean equals(Object obj) {
+    /** {@inheritDoc} */
+    protected boolean contentEquals(PDFObject obj) {
         if (obj == this) {
             return true;
         }

src/java/org/apache/fop/pdf/PDFGoTo.java

@@ -143,13 +143,8 @@ public class PDFGoTo extends PDFAction {
      * endobj
      */
 
-    /**
-     * Check if this equals another object.
-     *
-     * @param obj the object to compare
-     * @return true if this equals other object
-     */
-    public boolean equals(Object obj) {
+    /** {@inheritDoc} */
+    protected boolean contentEquals(PDFObject obj) {
         if (this == obj) {
             return true;
         }

src/java/org/apache/fop/pdf/PDFGoToRemote.java

@@ -127,13 +127,8 @@ public class PDFGoToRemote extends PDFAction {
      * endobj
      */
 
-    /**
-     * Check if this equals another object.
-     *
-     * @param obj the object to compare
-     * @return true if this equals other object
-     */
-    public boolean equals(Object obj) {
+    /** {@inheritDoc} */
+    protected boolean contentEquals(PDFObject obj) {
         if (this == obj) {
             return true;
         }

src/java/org/apache/fop/pdf/PDFLaunch.java

@@ -42,13 +42,8 @@ public class PDFLaunch extends PDFAction {
         return sb.toString();
     }
 
-    /**
-     * Check if this equals another object.
-     *
-     * @param obj the object to compare
-     * @return true if this equals other object
-     */
-    public boolean equals(Object obj) {
+    /** {@inheritDoc} */
+    protected boolean contentEquals(PDFObject obj) {
         if (this == obj) {
             return true;
         }

src/java/org/apache/fop/pdf/PDFLink.java

@@ -106,13 +106,8 @@ public class PDFLink extends PDFObject {
      * endobj
      */
 
-    /**
-     * Check if this equals another object.
-     *
-     * @param obj the object to compare
-     * @return true if this equals other object
-     */
-    public boolean equals(Object obj) {
+    /** {@inheritDoc} */
+    protected boolean contentEquals(PDFObject obj) {
         if (this == obj) {
             return true;
         }

src/java/org/apache/fop/pdf/PDFObject.java

@@ -393,4 +393,20 @@ public abstract class PDFObject implements PDFWritable {
         return formatDateTime(time, TimeZone.getDefault());
     }
 
+    /**
+     * Check if the other PDFObject has the same content as the current object.
+     * <p>
+     * Note: This function has a contract which is less binding than
+     * {@link #equals(Object)}. Whereas equals would require all values to be
+     * identical, this method is not required to check everything. In the case
+     * of PDFObjects, this means that the overriding function does not have to
+     * check for {@link #getObjectID()}.
+     * 
+     * @param o
+     *            object to compare to.
+     * @return true if the other object has the same content.
+     */
+    protected boolean contentEquals(PDFObject o) {
+        return this.equals(o);
+    }
 }

src/java/org/apache/fop/pdf/PDFPattern.java

@@ -336,13 +336,8 @@ public class PDFPattern extends PDFPathPaint {
      */
     public byte[] toPDF() { return null; }
 
-    /**
-     * Check if this pattern is equal to another.
-     *
-     * @param obj the object to compare against
-     * @return true if the patterns are equal
-     */
-    public boolean equals(Object obj) {
+    /** {@inheritDoc} */
+    protected boolean contentEquals(PDFObject obj) {
         if (obj == null) {
             return false;
         }

src/java/org/apache/fop/pdf/PDFShading.java

@@ -529,14 +529,8 @@ public class PDFShading extends PDFObject {
         return (p.toString());
     }
 
-    /**
-     * Check if this shading is equal to another shading.
-     * This is used to check if a shading already exists.
-     *
-     * @param obj the object to compare against
-     * @return true if the shadings are equal
-     */
-    public boolean equals(Object obj) {
+    /** {@inheritDoc} */
+    protected boolean contentEquals(PDFObject obj) {
         if (obj == null) {
             return false;
         }