Fixing Problem with multiple signatures in tagged PDFs

git-svn-id: https://joinup.ec.europa.eu/svn/pdf-as/trunk@893 7b5415b0-85f9-ee4d-85bd-d5d0c3b42d1c

1 files changed, 108 insertions, 97 deletions

diff --git a/src/main/java/at/knowcenter/wag/egov/egiz/pdf/StructContentHelper.java b/src/main/java/at/knowcenter/wag/egov/egiz/pdf/StructContentHelper.java
index f8cb09e..7ca5a0a 100644
--- a/src/main/java/at/knowcenter/wag/egov/egiz/pdf/StructContentHelper.java
+++ b/src/main/java/at/knowcenter/wag/egov/egiz/pdf/StructContentHelper.java
@@ -53,23 +53,23 @@ import com.lowagie.text.pdfas.UrlInTextFinder;
 /**

  * Helper class for writing the structure hierarchy of the signature elements.

  * Everything is written with the PdfObject low level API because there is no better support.

- * The structured content is only written for structured (==tagged) input documents. The methods have to be called in the 

+ * The structured content is only written for structured (==tagged) input documents. The methods have to be called in the

  * defined order. The object cannot be reused for several signatures.<br>

  * See pdf spec "Logical Structure" for details.<br>

  * The struct writing could be a little more abstracted, but this would include quite some itext extension work. And like this it

  * fits better to PDF-AS / wprinz coding style :-(

  * @author exthex

- * 

+ *

  */

 public class StructContentHelper implements StructContentWriter {

    private static final Logger logger = Logger.getLogger(StructContentHelper.class);

-   

+

    private static final String SIGBLOCK_STRUCT_TYPE = "P";

    private static final PdfName PARENTTREENEXTKEY = new PdfName("ParentTreeNextKey");

-   private static final String ALT_TEXT_DEFAULT = "Signaturbildmarke";     

-   private final static String ALT_TEXT_CONF_KEY = "sigLogoAltText"; 

-   

-      

+   private static final String ALT_TEXT_DEFAULT = "Signaturbildmarke";

+   private final static String ALT_TEXT_CONF_KEY = "sigLogoAltText";

+

+

    private int nextMcid = 0;

    /**

     * MCID value used for the sigblock marked contend identifier

@@ -94,7 +94,7 @@ public class StructContentHelper implements StructContentWriter {
    private PdfDictionary page;

    private PdfNumber parentTreeNextKey = null;

    private PdfNumber annotationParentTreeKey = null;

-   

+

    /**

     * Temporary save a pos

     */

@@ -103,21 +103,21 @@ public class StructContentHelper implements StructContentWriter {
     * Cell position of the signature verify link overlay

     */

    private Rectangle verifyLinkCellPos = null;

-   

+

    /**

     * Kids array (K) of the <code>StructTreeRoot</code>

     */

    private PdfArray structTreeRootKids = null;

 

    /**

-    * Entry in the ParentTree.Nums array used for sigtable structs 

+    * Entry in the ParentTree.Nums array used for sigtable structs

     */

    private PdfArray mainParentTreeNumEntry;

 

    /**

-    * Create new helper for one signature, and bind it to {@link StructContentWriterHolder} 

+    * Create new helper for one signature, and bind it to {@link StructContentWriterHolder}

     * for thread local access from itext.

-    * 

+    *

     * @param stamper

     * @param content

     * @param pageNr

@@ -136,44 +136,55 @@ public class StructContentHelper implements StructContentWriter {
    public void removeCurrent() {

       StructContentWriterHolder.removeThreadLocalWriter();

    }

-   

+

    /**

     * Prepare structured content for signature block. This method initializes the whole StructTreeRoot stuff.

-    * @param sigBlockObj 

+    * @param sigBlockObj

     * @throws PresentableException

     */

    void prepareStructData(PdfTemplate sigBlockObj) throws PresentableException {

 

       try {

-         checkTagging();         

+         checkTagging();

          if (!isTagged) {

             return;

          }

-         

+

          doAnnoTabOrder();

 

          PdfDictionary structTreeRoot = getStructTreeRoot();

          stamperImp.markUsed(structTreeRoot);

 

-         PdfArray parentTreeNums = getParentTreeNums();        

-         

+         PdfArray parentTreeNums = getParentTreeNums();

+

          PdfNumber structParentsNr = page.getAsNumber(PdfName.STRUCTPARENTS);  // read StructParents entry from current page

 

          mainParentTreeNumEntry = obtainParentTreeEntry(structTreeRoot, parentTreeNums, structParentsNr, sigBlockObj);

-         

+

          nextMcid = mainParentTreeNumEntry.size();

          sigBlockMcid = nextMcid;

          nextMcid++;

 

          this.structTreeRootKids = obtainStructTreeRootKids(structTreeRoot);

-         

+

+         if(this.structTreeRootKids == null)

+         {

+        	 this.structTreeRootKids = this.createStructTreeRootKids(structTreeRoot);

+         }

+

       } catch (Exception ex) {

          logger.error("error", ex);

          throw new PresentableException(ErrorCode.CANNOT_WRITE_PDF,

                "error writing structured signature content", ex);

       }

    }

-   

+

+   PdfArray createStructTreeRootKids(PdfDictionary structTreeRoot) {

+	   PdfArray tmp = new PdfArray();

+	   structTreeRoot.put(PdfName.K, tmp);

+	   return tmp;

+   }

+

    /**

     * Create struct data for main signature block

     * @throws PresentableException

@@ -196,7 +207,7 @@ public class StructContentHelper implements StructContentWriter {
                "error writing structured signature content", ex);

       }

    }

-   

+

 

    /**

     * Finish struct data for signblock and it's elements (NOT for the external link and annot!)

@@ -218,8 +229,8 @@ public class StructContentHelper implements StructContentWriter {
    }

 

    /**

-    * Build the structured content for the signature logo (bildmarke). {@link #beginFigureContent(PdfContentByte)} and 

-    * {@link #endFigureContent(PdfContentByte)} have to be called before this method to mark the logo in the stream. This 

+    * Build the structured content for the signature logo (bildmarke). {@link #beginFigureContent(PdfContentByte)} and

+    * {@link #endFigureContent(PdfContentByte)} have to be called before this method to mark the logo in the stream. This

     * is done implicitly in the modified itext source (see {@link StructContentWriterHolder}).

     * @param so

     * @param sigBlockObj

@@ -231,7 +242,7 @@ public class StructContentHelper implements StructContentWriter {
 

             PdfDictionary structTreeRoot = getStructTreeRoot();

             PdfIndirectReference mcrRef = createMcrStructElem(this.figureMcid, sigBlockObj.getIndirectReference());

-            PdfIndirectReference figureRef = createStructElem("Figure", mcrRef, 

+            PdfIndirectReference figureRef = createStructElem("Figure", mcrRef,

                   getAltText(so.getSignatureTypeDefinition().getType()), structTreeRoot.getIndRef());

 

             structTreeRootKids.add(figureRef);

@@ -250,42 +261,42 @@ public class StructContentHelper implements StructContentWriter {
       }

 

    }

-   

+

    /**

     * Build the link annotation for the signature verification link and the structured content accordingly.<br>

     * The tagging does NOT work if the link is placed in a binary signature replace cell (phlengh for this cell)!!

     * @param sigBlockObj

-    * @param atp 

-    * @throws PresentableException 

+    * @param atp

+    * @throws PresentableException

     */

    void buildVerifyLinkStructData(PdfTemplate sigBlockObj, ActualTablePos atp) throws PresentableException {

-      if (!this.isTagged || !this.isLinkMarked() || !isLinkFound()) return; 

+      if (!this.isTagged || !this.isLinkMarked() || !isLinkFound()) return;

 

       try {

          PdfNumber parentTreeKey = getNewParentTreeKey();

-         

-         PdfArray annots = obrainAnnotsFromPage();         

-         

-         PdfIndirectReference linkAnnotRef = createLinkAnnot(parentTreeKey, atp);         

-         annots.add(linkAnnotRef);         

-         

+

+         PdfArray annots = obrainAnnotsFromPage();

+

+         PdfIndirectReference linkAnnotRef = createLinkAnnot(parentTreeKey, atp);

+         annots.add(linkAnnotRef);

+

          PdfIndirectReference objr = createObjrStructElem(linkAnnotRef);

-         PdfIndirectReference mcr = createMcrStructElem(this.linkMcid, sigBlockObj.getIndirectReference());         

-         

+         PdfIndirectReference mcr = createMcrStructElem(this.linkMcid, sigBlockObj.getIndirectReference());

+

          PdfDictionary structTreeRoot = getStructTreeRoot();

-         

+

          PdfArray linkKids = new PdfArray();

          PdfIndirectReference linkKidsRef = stamper.getWriter().getPdfIndirectReference();

-         

+

          PdfIndirectReference linkRef = createStructElem("Link", linkKidsRef, structTreeRoot.getIndRef());

          linkKids.add(objr);

-         

-         PdfIndirectReference span = createStructElem("Span", mcr, linkRef);        

-         linkKids.add(span);        

-                  

+

+         PdfIndirectReference span = createStructElem("Span", mcr, linkRef);

+         linkKids.add(span);

+

          stamper.getWriter().addToBody(linkKids, linkKidsRef);

          structTreeRootKids.add(linkRef);

-         

+

          // create new entry in ParentTree

          PdfArray parentTreeNums = getParentTreeNums();

          parentTreeNums.add(parentTreeKey);

@@ -295,16 +306,16 @@ public class StructContentHelper implements StructContentWriter {
          stamperImp.markUsed(structTreeRoot.getAsDict(PdfName.PARENTTREE));

          stamperImp.markUsed(structTreeRootKids);

          stamperImp.markUsed(linkKids);

-         

-         stamperImp.markUsed(structTreeRoot);         

-         

+

+         stamperImp.markUsed(structTreeRoot);

+

       } catch (IOException e) {

          logger.error("error", e);

          throw new PresentableException(ErrorCode.CANNOT_WRITE_PDF,

                "error writing structured signature content", e);

       }

    }

-      

+

    private boolean isLinkFound() {

       return this.linkUrlString != null && this.verifyLinkCellPos != null && this.linkPosMap.size() > 0 && this.linkMcid >= 0;

    }

@@ -320,11 +331,11 @@ public class StructContentHelper implements StructContentWriter {
       } else {

          return null;

       }

-   }   

+   }

 

    /**

     * Build and write structured content for adobe signature annotation

-    * 

+    *

     * @param sigFormField

     * @param title

     * @throws PresentableException

@@ -378,7 +389,7 @@ public class StructContentHelper implements StructContentWriter {
          content.endMarkedContentSequence();

       }

    }

-   

+

    /**

     * Writes start tag for signature logo marked content sequence.

     */

@@ -392,18 +403,18 @@ public class StructContentHelper implements StructContentWriter {
          }

       }

    }

-   

+

    /**

     * Writes end tag for signature logo marked content sequence.

     */

    public void endFigureContent(PdfContentByte localContent) {

       if (isTagged && isFigureMarked()) {

-         localContent.endMarkedContentSequence();         

+         localContent.endMarkedContentSequence();

       }

    }

-   

+

    /**

-    * Writes start tag for verify link marked content sequence. 

+    * Writes start tag for verify link marked content sequence.

     */

    public void beginLinkContent(PdfContentByte localContent, String urlString) {

       // it's called from here com.lowagie.text.pdf.PdfContentByte.showText(String)

@@ -416,7 +427,7 @@ public class StructContentHelper implements StructContentWriter {
          } else {

             logger.warn("cannot tag multiple verify links");

          }

-      }      

+      }

    }

 

    /**

@@ -425,8 +436,8 @@ public class StructContentHelper implements StructContentWriter {
    public void endLinkContent(PdfContentByte localContent) {

       if (isTagged && isLinkMarked()) {

          localContent.endMarkedContentSequence();

-      }      

-   }   

+      }

+   }

 

    /**

     * Implements {@link StructContentWriter#markPos(Rectangle)}

@@ -436,22 +447,22 @@ public class StructContentHelper implements StructContentWriter {
    }

 

    /**

-    * Implements {@link StructContentWriter#storeCurrentPosAsLink()} 

+    * Implements {@link StructContentWriter#storeCurrentPosAsLink()}

     */

    public void storeCurrentPosAsLink() {

-      this.verifyLinkCellPos = new Rectangle(this.tempMarkedPos);     

+      this.verifyLinkCellPos = new Rectangle(this.tempMarkedPos);

    }

-      

+

    public void putVal(String key, Object val) {

-      tmpMap.put(key, val);      

+      tmpMap.put(key, val);

    }

 

    public void storeVals() {

       linkPosMap = new HashMap(tmpMap);

-   }   

-   

+   }

+

    /**

-    * set explicit annotation tab order if missing 

+    * set explicit annotation tab order if missing

     */

    private void doAnnoTabOrder() {

       if (page.getAsName(new PdfName("Tabs")) == null) {

@@ -470,31 +481,31 @@ public class StructContentHelper implements StructContentWriter {
       }

       logger.debug("Input is tagged. Writing structure/WAI data.");

    }

-   

+

 

 

    private PdfIndirectReference createLinkAnnot(PdfNumber structParentNr, ActualTablePos atp) throws IOException {

-      PdfDictionary linkAnnot = new PdfDictionary();      

-      

-      PdfDictionary a = new PdfDictionary();            

+      PdfDictionary linkAnnot = new PdfDictionary();

+

+      PdfDictionary a = new PdfDictionary();

       a.put(PdfName.S, new PdfName("URI"));

       a.put(PdfName.TYPE, PdfName.ACTION);

       a.put(PdfName.URI, new PdfString(this.linkUrlString));

       linkAnnot.put(PdfName.A, a);

-      

+

       PdfDictionary bs = new PdfDictionary();

       bs.put(PdfName.W, new PdfNumber(0));

       linkAnnot.put(PdfName.BS, bs);

       linkAnnot.put(PdfName.F, new PdfNumber(4));

-      

+

       // iText "converts" 0.0f to an integer, therefore we cannot use 0, not nice...

       //linkAnnot.put(PdfName.RECT, new PdfArray(new float[] {0.01f, 0.01f, 0.01f, 0.01f}));

       // take cell pos as link pos

       linkAnnot.put(PdfName.RECT, new PdfArray(calcLinkPos(atp)));

-      

+

       linkAnnot.put(PdfName.STRUCTPARENT, structParentNr);

       linkAnnot.put(PdfName.SUBTYPE, PdfName.LINK);

-      

+

       return stamper.getWriter().addToBody(linkAnnot).getIndirectReference();

    }

 

@@ -525,10 +536,10 @@ public class StructContentHelper implements StructContentWriter {
    private float getPosMapVal(String key) {

       return ((Float) this.linkPosMap.get(key)).floatValue();

    }

-   

+

    protected static PdfArray createPdfArrayFromTablePos(ActualTablePos pos) {

       return new PdfArray( new float[] {pos.x, pos.y, pos.x + pos.width, pos.y - pos.height});

-   }   

+   }

 

    private PdfArray obrainAnnotsFromPage() throws IOException {

       PdfArray annots = this.page.getAsArray(PdfName.ANNOTS);

@@ -551,7 +562,7 @@ public class StructContentHelper implements StructContentWriter {
          rk.add(root_k.getIndRef());

          structTreeRoot.put(PdfName.K, structTreeRootKids);

 

-      } else { // has to be array

+      } else if(root_k != null) { // has to be array

          rk = (PdfArray) root_k;

       }

       return rk;

@@ -561,17 +572,17 @@ public class StructContentHelper implements StructContentWriter {
          PdfNumber structParentsNr, PdfTemplate sigBlockObj) {

       int numsIdx = -1;

       PdfArray parentTreeEntry = null;

-      

+

       if (structParentsNr == null) { // no StructParents entry yet, make new one and add new parenttree entry

          PdfNumber parentTreeKey = null;

          parentTreeNextKey = structTreeRoot.getAsNumber(PARENTTREENEXTKEY); // read next proposed key

          if (parentTreeNextKey == null) { // this can be null if a non-perfect pdf creator was at work

             // find the next key by counting

-            int nextI = ((int) parentTreeNums.size() / 2);  // know the "Number Trees" data structure from pdf-ref             

+            int nextI = ((int) parentTreeNums.size() / 2);  // know the "Number Trees" data structure from pdf-ref

             this.parentTreeNextKey = new PdfNumber(nextI);

-            structTreeRoot.put(PARENTTREENEXTKEY, this.parentTreeNextKey); // write ParentTreeNextKey entry         

+            structTreeRoot.put(PARENTTREENEXTKEY, this.parentTreeNextKey); // write ParentTreeNextKey entry

          }

-         

+

          parentTreeKey = new PdfNumber(parentTreeNextKey.intValue());

          parentTreeNextKey.increment();

          page.put(PdfName.STRUCTPARENTS, parentTreeKey); // write /StructParents entry to page

@@ -583,7 +594,7 @@ public class StructContentHelper implements StructContentWriter {
          parentTreeEntry = new PdfArray();

          numsIdx = parentTreeNums.size() - 1;

 

-      } else { // structparents entry already available, find parenttree entry 

+      } else { // structparents entry already available, find parenttree entry

          //parentTreeKey = structParentsNr;

          parentTreeNextKey = structTreeRoot.getAsNumber(PARENTTREENEXTKEY); // read next proposed key

          if (parentTreeNextKey == null) { // this can be null if a non-perfact pdf creator was at work

@@ -593,10 +604,10 @@ public class StructContentHelper implements StructContentWriter {
                nextI = ((int) parentTreeNums.size() / 2);

             }

             this.parentTreeNextKey = new PdfNumber(nextI);

-            structTreeRoot.put(PARENTTREENEXTKEY, this.parentTreeNextKey);               

-         }            

+            structTreeRoot.put(PARENTTREENEXTKEY, this.parentTreeNextKey);

+         }

       }

-      

+

       // add Structparents entry to xobject content stream

       sigBlockObj.addAttribute(PdfName.STRUCTPARENTS, structParentsNr);

 

@@ -620,7 +631,7 @@ public class StructContentHelper implements StructContentWriter {
       }

       return parentTreeEntry;

    }

-   

+

 //   private PdfIndirectReference createStructElem(String structType, PdfObject kid) throws IOException {

 //      return createStructElem(structType, kid, null);

 //   }

@@ -628,10 +639,10 @@ public class StructContentHelper implements StructContentWriter {
    private PdfIndirectReference createStructElem(String structType, PdfObject kid, PdfIndirectReference parentRef) throws IOException {

       return createStructElem(structType, kid, null, parentRef);

    }

-   

+

    private PdfIndirectReference createStructElem(String structType, PdfObject kid, String altText,

          PdfIndirectReference parentRef) throws IOException {

-      

+

       PdfDictionary newStruct = new PdfDictionary();

       newStruct.put(PdfName.S, new PdfName(structType));

       //newStruct.put(PdfName.T, new PdfString("PDF-AS Signaturblock"));// eher nicht

@@ -649,21 +660,21 @@ public class StructContentHelper implements StructContentWriter {
       newStruct.put(PdfName.K, kid);

 

       return stamper.getWriter().addToBody(newStruct).getIndirectReference();

-   }   

+   }

 

    private boolean isFigureMarked() {

       return this.figureMcid > -1;

    }

-   

+

    private boolean isLinkMarked() {

       return this.linkMcid > -1;

    }

-   

+

 

    private PdfNumber getNewParentTreeKey() {

       // new parent tree entry

       if (parentTreeNextKey == null) {

-         parentTreeNextKey = getStructTreeRoot().getAsNumber(PARENTTREENEXTKEY); // read next proposed key              

+         parentTreeNextKey = getStructTreeRoot().getAsNumber(PARENTTREENEXTKEY); // read next proposed key

       }

       PdfNumber res = new PdfNumber(parentTreeNextKey.intValue());

       parentTreeNextKey.increment();

@@ -676,28 +687,28 @@ public class StructContentHelper implements StructContentWriter {
       objr.put(PdfName.TYPE, new PdfName("OBJR"));

       objr.put(PdfName.PG, page.getIndRef());

       objr.put(new PdfName("Obj"), objRef);

-      

+

       return stamper.getWriter().addToBody(objr).getIndirectReference();

    }

-   

+

    private PdfIndirectReference createMcrStructElem(int mcid, PdfIndirectReference streamRef) throws IOException {

       PdfDictionary objr = new PdfDictionary();

       objr.put(PdfName.TYPE, new PdfName("MCR"));

       objr.put(PdfName.PG, page.getIndRef());

       objr.put(PdfName.MCID, new PdfNumber(mcid));

       objr.put(new PdfName("Stm"), streamRef);

-      

+

       return stamper.getWriter().addToBody(objr).getIndirectReference();

    }

-   

+

    private PdfArray getParentTreeNums() {

       return getStructTreeRoot().getAsDict(PdfName.PARENTTREE).getAsArray(PdfName.NUMS);

    }

 

    private PdfDictionary getStructTreeRoot() {

       return stamper.getReader().getCatalog().getAsDict(PdfName.STRUCTTREEROOT);

-   }   

-   

+   }

+

    private static String getAltText(String sigProfile) {

       return AdobeSignatureHelper.getDefaultableConfigProperty(sigProfile, ALT_TEXT_CONF_KEY, ALT_TEXT_DEFAULT);

    }