fix(sigblock): invalid preview in case of sig-blocks with more than half page height

Issue: #68

## Info:
This is only a work-around, because it looks like a general issue in methods to create visual signature tables.
T

6 files changed, 106 insertions, 38 deletions

diff --git a/pdf-as-cli/src/test/java/at/gv/egiz/pdfas/cli/test/SigblockPreviewMain.java b/pdf-as-cli/src/test/java/at/gv/egiz/pdfas/cli/test/SigblockPreviewMain.java
new file mode 100644
index 00000000..dba52463
--- /dev/null
+++ b/pdf-as-cli/src/test/java/at/gv/egiz/pdfas/cli/test/SigblockPreviewMain.java
@@ -0,0 +1,37 @@
+package at.gv.egiz.pdfas.cli.test;
+
+import java.awt.Image;
+import java.awt.image.BufferedImage;
+import java.io.File;
+import java.io.FileInputStream;
+
+import javax.imageio.ImageIO;
+
+import at.gv.egiz.pdfas.lib.api.PdfAs;
+import at.gv.egiz.pdfas.lib.api.PdfAsFactory;
+import at.gv.egiz.pdfas.lib.api.sign.SignParameter;
+import iaik.x509.X509Certificate;
+import lombok.SneakyThrows;
+
+public class SigblockPreviewMain {
+
+  private static final String PDFAS_CONFIG_DIR = "/home/tlenz/Projekte/pdfas4/config/default_4.2.0/";
+ 
+
+  @SneakyThrows
+  public static void main(String[] args) throws Exception {
+    String cwd = System.getProperty("user.dir");
+    File output = new File(cwd + File.separator + "build/output.png");
+    X509Certificate cert = new X509Certificate(new FileInputStream("/home/tlenz/diverses/cert_debug/binding3.pem"));
+
+    PdfAs pdfas = PdfAsFactory.createPdfAs(new File(PDFAS_CONFIG_DIR));
+    SignParameter param = PdfAsFactory.createSignParameter(pdfas.getConfiguration(), null, null);
+    param.setSignatureProfileId("ERROR_LOGO");    
+    //param.setSignatureProfileId("SIGNATURBLOCK_DE");
+    
+    
+    Image placeholder = pdfas.generateVisibleSignaturePreview(param, cert, 72 * 4);
+    ImageIO.write((BufferedImage)placeholder, "png", output);
+  }
+
+}
diff --git a/pdf-as-lib/src/test/java/at/gv/egiz/pdfas/lib/test/mains/SignatureBlockParameterTest.java b/pdf-as-lib/src/test/java/at/gv/egiz/pdfas/lib/test/stamping/SignatureBlockParameterTest.java
index 23422e8e..378cc19d 100644
--- a/pdf-as-lib/src/test/java/at/gv/egiz/pdfas/lib/test/mains/SignatureBlockParameterTest.java
+++ b/pdf-as-lib/src/test/java/at/gv/egiz/pdfas/lib/test/stamping/SignatureBlockParameterTest.java
@@ -1,4 +1,4 @@
-package at.gv.egiz.pdfas.lib.test.mains;
+package at.gv.egiz.pdfas.lib.test.stamping;
 
 import at.gv.egiz.pdfas.common.settings.DefaultSignatureProfileSettings;
 import at.gv.egiz.pdfas.common.utils.CheckSignatureBlockParameters;
diff --git a/pdf-as-pdfbox-2/src/main/java/at/gv/egiz/pdfas/lib/impl/signing/pdfbox2/PADESPDFBOXSigner.java b/pdf-as-pdfbox-2/src/main/java/at/gv/egiz/pdfas/lib/impl/signing/pdfbox2/PADESPDFBOXSigner.java
index ef1f14b2..42f16598 100644
--- a/pdf-as-pdfbox-2/src/main/java/at/gv/egiz/pdfas/lib/impl/signing/pdfbox2/PADESPDFBOXSigner.java
+++ b/pdf-as-pdfbox-2/src/main/java/at/gv/egiz/pdfas/lib/impl/signing/pdfbox2/PADESPDFBOXSigner.java
@@ -363,7 +363,7 @@ public class PADESPDFBOXSigner implements IPdfSigner, IConfigurationConstants {
         }
 
         properties = new PDFAsVisualSignatureProperties(pdfObject.getStatus().getSettings(), pdfObject,
-            (PdfBoxVisualObject) visualObject, positioningInstruction, signatureProfileSettings);
+            (PdfBoxVisualObject) visualObject, positioningInstruction, signatureProfileSettings, false);
 
         properties.buildSignature();
 
@@ -825,7 +825,7 @@ public class PADESPDFBOXSigner implements IPdfSigner, IConfigurationConstants {
         positioningInstruction = Positioning.determineTablePositioning(new TablePos(), "", origDoc,
             visualObject, pdfObject.getStatus().getSettings());
       }
-
+          
       origDoc.close();
 
       final SignaturePositionImpl position = new SignaturePositionImpl();
@@ -839,15 +839,16 @@ public class PADESPDFBOXSigner implements IPdfSigner, IConfigurationConstants {
 
       final PDFAsVisualSignatureProperties properties = new PDFAsVisualSignatureProperties(
           pdfObject.getStatus().getSettings(), pdfObject, (PdfBoxVisualObject) visualObject,
-          positioningInstruction, signatureProfileSettings);
-
+          positioningInstruction, signatureProfileSettings, true);
+      
+      // build visual-signature form
       properties.buildSignature();
-      PDDocument visualDoc;
+            
+      PDDocument visualDoc;     
       synchronized (PDDocument.class) {
         visualDoc = PDDocument.load(properties.getVisibleSignature());
       }
 
-
       final float stdRes = 72;
       final float targetRes = resolution;
       final float factor = targetRes / stdRes;
@@ -859,7 +860,7 @@ public class PADESPDFBOXSigner implements IPdfSigner, IConfigurationConstants {
 
       visualDoc.close();
       pdfRenderer = null;
-      
+            
       final BufferedImage cutOut = new BufferedImage(
           (int) (position.getWidth() * factor),
           (int) (position.getHeight() * factor), 
diff --git a/pdf-as-pdfbox-2/src/main/java/at/gv/egiz/pdfas/lib/impl/stamping/pdfbox2/PDFAsTemplateCreator.java b/pdf-as-pdfbox-2/src/main/java/at/gv/egiz/pdfas/lib/impl/stamping/pdfbox2/PDFAsTemplateCreator.java
index b07e6ed5..62ad4dbf 100644
--- a/pdf-as-pdfbox-2/src/main/java/at/gv/egiz/pdfas/lib/impl/stamping/pdfbox2/PDFAsTemplateCreator.java
+++ b/pdf-as-pdfbox-2/src/main/java/at/gv/egiz/pdfas/lib/impl/stamping/pdfbox2/PDFAsTemplateCreator.java
@@ -23,11 +23,11 @@
  ******************************************************************************/
 package at.gv.egiz.pdfas.lib.impl.stamping.pdfbox2;
 
-import java.io.*;
+import java.io.ByteArrayInputStream;
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
+import java.io.InputStream;
 
-import at.gv.egiz.pdfas.common.settings.SignatureProfileSettings;
-import at.gv.egiz.pdfas.lib.impl.stamping.TableFactory;
-import org.apache.pdfbox.cos.COSName;
 import org.apache.pdfbox.pdmodel.PDDocument;
 import org.apache.pdfbox.pdmodel.PDPage;
 import org.apache.pdfbox.pdmodel.PDResources;
@@ -42,6 +42,7 @@ import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 import at.gv.egiz.pdfas.common.exceptions.PdfAsException;
+import at.gv.egiz.pdfas.common.settings.SignatureProfileSettings;
 
 public class PDFAsTemplateCreator extends PDFTemplateCreator {
 
@@ -54,7 +55,7 @@ public class PDFAsTemplateCreator extends PDFTemplateCreator {
 	}
 
 	
-	public InputStream buildPDF(PDFAsVisualSignatureDesigner properties, PDDocument originalDocument)
+	public InputStream buildPDF(PDFAsVisualSignatureDesigner properties, PDDocument originalDocument, boolean buildPreviewOnly)
 			throws IOException, PdfAsException {
 		logger.debug("pdf building has been started");
         PDFTemplateStructure pdfStructure = pdfBuilder.getStructure();
@@ -80,7 +81,7 @@ public class PDFAsTemplateCreator extends PDFTemplateCreator {
         
         // create signature
         this.pdfBuilder.createSignature(pdSignatureField, page, properties.getSignatureFieldName());
-       
+               
         // that is /AcroForm/DR entry
         this.pdfBuilder.createAcroFormDictionary(acroForm, pdSignatureField);
         
@@ -92,6 +93,8 @@ public class PDFAsTemplateCreator extends PDFTemplateCreator {
         this.pdfBuilder.createSignatureRectangle(pdSignatureField, properties, properties.getRotation() + properties.getPageRotation());
         this.pdfBuilder.createFormaterRectangle(properties.getFormaterRectangleParams());
         PDRectangle formater = pdfStructure.getFormatterRectangle();
+       
+        
         
         //this.pdfBuilder.createSignatureImage(template, properties.getImageStream());
 
@@ -108,11 +111,13 @@ public class PDFAsTemplateCreator extends PDFTemplateCreator {
         
         // inner formstream, form and resource (hlder form containts inner form)
         this.pdfBuilder.createInnerFormStreamPdfAs(template, originalDocument);
+        
         this.pdfBuilder.createInnerFormResource();
         PDResources innerFormResource = pdfStructure.getInnerFormResources();
+        
         this.pdfBuilder.createInnerForm(innerFormResource, pdfStructure.getInnerFormStream(), formater);
         PDFormXObject innerForm = pdfStructure.getInnerForm();
-       
+        
         // inner form must be in the holder form as we wrote
         this.pdfBuilder.insertInnerFormToHolerResources(innerForm, holderFormResources);
         
@@ -127,10 +132,10 @@ public class PDFAsTemplateCreator extends PDFTemplateCreator {
         // now inject procSetArray
         /*this.pdfBuilder.injectProcSetArray(innerForm, page, innerFormResource, imageFormResources, holderFormResources,
                 pdfStructure.getProcSet());*/
+        
         this.pdfBuilder.injectProcSetArray(innerForm, page, innerFormResource, null, holderFormResources,
                 pdfStructure.getProcSet());
         
-
         /*String imgFormName = pdfStructure.getImageFormName();
         String imgName = pdfStructure.getImageName();*/
         String innerFormName = pdfStructure.getInnerFormName().getName();
@@ -138,13 +143,16 @@ public class PDFAsTemplateCreator extends PDFTemplateCreator {
         // now create Streams of AP
         /*this.pdfBuilder.injectAppearanceStreams(holderFormStream, imageFormStream, imageFormStream, imgFormName,
                 imgName, innerFormName, properties);*/
-        this.pdfBuilder.injectAppearanceStreams(holderFormStream, null, null, null,
-        		null, innerFormName, properties);
+        
+        if (!buildPreviewOnly) {        
+          this.pdfBuilder.injectAppearanceStreams(holderFormStream, null, null, null,
+              null, innerFormName, properties);
+          
+        }
+        
         this.pdfBuilder.createVisualSignature(template);
         this.pdfBuilder.createWidgetDictionary(pdSignatureField, holderFormResources);
 
-
-
         ByteArrayInputStream in = null;
     
         	//COSDocument doc = pdfStructure.getVisualSignature();
@@ -152,8 +160,8 @@ public class PDFAsTemplateCreator extends PDFTemplateCreator {
             //in = pdfStructure.getTemplateAppearanceStream();
         	ByteArrayOutputStream baos = new ByteArrayOutputStream();
         	template.save(baos);
-        	baos.close();
-
+        	baos.close();                    
+        	
         SignatureProfileSettings signatureProfileSettings =
                 this.pdfBuilder.signatureProfileSettings;
 
@@ -188,4 +196,17 @@ public class PDFAsTemplateCreator extends PDFTemplateCreator {
         // return result of the stream 
         return in;
 	}
+	
+//	@SneakyThrows
+//	private void saveDebuggingSnapshot(PDDocument template, String fileName) {
+//	  ByteArrayOutputStream baos = new ByteArrayOutputStream();
+//    template.save(baos);
+//    baos.close();
+//
+//    FileOutputStream fos = new FileOutputStream("/home/tlenz/Projekte/pdfas4/source/pdf-as-cli/build/" + fileName + ".pdf");
+//    fos.write(baos.toByteArray());
+//    fos.close();  
+//	  
+//	}
+	
 }
diff --git a/pdf-as-pdfbox-2/src/main/java/at/gv/egiz/pdfas/lib/impl/stamping/pdfbox2/PDFAsVisualSignatureProperties.java b/pdf-as-pdfbox-2/src/main/java/at/gv/egiz/pdfas/lib/impl/stamping/pdfbox2/PDFAsVisualSignatureProperties.java
index f482f49f..34093a9d 100644
--- a/pdf-as-pdfbox-2/src/main/java/at/gv/egiz/pdfas/lib/impl/stamping/pdfbox2/PDFAsVisualSignatureProperties.java
+++ b/pdf-as-pdfbox-2/src/main/java/at/gv/egiz/pdfas/lib/impl/stamping/pdfbox2/PDFAsVisualSignatureProperties.java
@@ -23,12 +23,8 @@
  ******************************************************************************/
 package at.gv.egiz.pdfas.lib.impl.stamping.pdfbox2;
 
-import at.gv.egiz.pdfas.common.exceptions.PdfAsException;
-import at.gv.egiz.pdfas.common.exceptions.PdfAsWrappedIOException;
-import at.gv.egiz.pdfas.common.settings.ISettings;
-import at.gv.egiz.pdfas.common.settings.SignatureProfileSettings;
-import at.gv.egiz.pdfas.lib.impl.pdfbox2.PDFBOXObject;
-import at.knowcenter.wag.egov.egiz.pdf.PositioningInstruction;
+import java.io.IOException;
+
 import org.apache.pdfbox.pdmodel.PDDocument;
 import org.apache.pdfbox.pdmodel.PDPage;
 import org.apache.pdfbox.pdmodel.PDPageTree;
@@ -36,7 +32,12 @@ import org.apache.pdfbox.pdmodel.interactive.digitalsignature.visible.PDVisibleS
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
-import java.io.IOException;
+import at.gv.egiz.pdfas.common.exceptions.PdfAsException;
+import at.gv.egiz.pdfas.common.exceptions.PdfAsWrappedIOException;
+import at.gv.egiz.pdfas.common.settings.ISettings;
+import at.gv.egiz.pdfas.common.settings.SignatureProfileSettings;
+import at.gv.egiz.pdfas.lib.impl.pdfbox2.PDFBOXObject;
+import at.knowcenter.wag.egov.egiz.pdf.PositioningInstruction;
 
 public class PDFAsVisualSignatureProperties extends PDVisibleSigProperties {
 
@@ -56,9 +57,13 @@ public class PDFAsVisualSignatureProperties extends PDVisibleSigProperties {
 
 	private String alternativeTableCaption="";
 
+  private boolean buildPreviewOnly;
+
 	public PDFAsVisualSignatureProperties(ISettings settings, PDFBOXObject object, 
-			PdfBoxVisualObject visObj, PositioningInstruction pos, SignatureProfileSettings signatureProfileSettings) {
-		this.settings = settings;
+			PdfBoxVisualObject visObj, PositioningInstruction pos, SignatureProfileSettings signatureProfileSettings, 
+			boolean buildPreviewOnly) {
+		this.buildPreviewOnly = buildPreviewOnly;
+	  this.settings = settings;
 		this.signatureProfileSettings = signatureProfileSettings;
 		try {
 			main = visObj.getTable();
@@ -113,7 +118,7 @@ public class PDFAsVisualSignatureProperties extends PDVisibleSigProperties {
 		PDFAsVisualSignatureBuilder builder = new PDFAsVisualSignatureBuilder(this, this.settings, designer, this.signatureProfileSettings);
 		PDFAsTemplateCreator creator = new PDFAsTemplateCreator(builder);
 		try {
-			setVisibleSignature(creator.buildPDF(designer, this.origDoc));
+			setVisibleSignature(creator.buildPDF(designer, this.origDoc, buildPreviewOnly));
 		} catch (PdfAsException e) {
 			throw new PdfAsWrappedIOException(e);
 		}
diff --git a/pdf-as-pdfbox-2/src/test/java/at/gv/egiz/pdfas/lib/testpdfbox/SignatureFieldsAndPlaceHolderExtractorTest.java b/pdf-as-pdfbox-2/src/test/java/at/gv/egiz/pdfas/lib/testpdfbox/SignatureFieldsAndPlaceHolderExtractorTest.java
index 0d85c82b..40522504 100644
--- a/pdf-as-pdfbox-2/src/test/java/at/gv/egiz/pdfas/lib/testpdfbox/SignatureFieldsAndPlaceHolderExtractorTest.java
+++ b/pdf-as-pdfbox-2/src/test/java/at/gv/egiz/pdfas/lib/testpdfbox/SignatureFieldsAndPlaceHolderExtractorTest.java
@@ -1,16 +1,20 @@
 package at.gv.egiz.pdfas.lib.testpdfbox;
 
-import at.gv.egiz.pdfas.lib.impl.pdfbox2.placeholder.SignatureFieldsAndPlaceHolderExtractor;
-import at.gv.egiz.pdfas.lib.impl.placeholder.SignaturePlaceholderData;
-import org.apache.pdfbox.pdmodel.PDDocument;
-import org.junit.Assert;
-import org.junit.Test;
-
 import java.io.File;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.List;
 
+import org.apache.pdfbox.pdmodel.PDDocument;
+import org.junit.Assert;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.junit.runners.JUnit4;
+
+import at.gv.egiz.pdfas.lib.impl.pdfbox2.placeholder.SignatureFieldsAndPlaceHolderExtractor;
+import at.gv.egiz.pdfas.lib.impl.placeholder.SignaturePlaceholderData;
+
+@RunWith(JUnit4.class)
 public class SignatureFieldsAndPlaceHolderExtractorTest {
 
   public String getPath(String resourceName) {