Add ability to set null values for SignedAppearanceText

Author: AnhelinaM

forms/src/main/java/com/itextpdf/forms/fields/properties/SignedAppearanceText.java

@@ -79,7 +79,10 @@ public String getReasonLine() {
      * @return this same {@link SignedAppearanceText} instance.
      */
     public SignedAppearanceText setReasonLine(String reason) {
-        this.reason = reason.trim();
+        if (reason != null) {
+            reason = reason.trim();
+        }
+        this.reason = reason;
         return this;
     }
 
@@ -99,12 +102,15 @@ public String getLocationLine() {
      * Note, that this location won't be passed to the signature dictionary. If none is set, value set by
      * {@code PdfSigner#setLocation} will be used.
      *
-     * @param location new signing location.
+     * @param location new signing location
      *
-     * @return this same {@link SignedAppearanceText} instance.
+     * @return this same {@link SignedAppearanceText} instance
      */
     public SignedAppearanceText setLocationLine(String location) {
-        this.location = location.trim();
+        if (location != null) {
+            location = location.trim();
+        }
+        this.location = location;
         return this;
     }
 
@@ -114,19 +120,22 @@ public SignedAppearanceText setLocationLine(String location) {
      * <p>
      * Note, that the signer name will be replaced by the one from the signing certificate during the actual signing.
      *
-     * @param signedBy name of the signer.
+     * @param signedBy name of the signer
      *
-     * @return this same {@link SignedAppearanceText} instance.
+     * @return this same {@link SignedAppearanceText} instance
      */
     public SignedAppearanceText setSignedBy(String signedBy) {
-        this.signedBy = signedBy.trim();
+        if (signedBy != null) {
+            signedBy = signedBy.trim();
+        }
+        this.signedBy = signedBy;
         return this;
     }
 
     /**
      * Gets the name of the signer from the certificate.
      *
-     * @return signedBy name of the signer.
+     * @return signedBy name of the signer
      */
     public String getSignedBy() {
         return signedBy;
@@ -147,8 +156,9 @@ public java.util.Calendar getSignDate() {
      * <p>
      * Note, that the signing date will be replaced by the one from the {@code PdfSigner} during the signing.
      *
-     * @param signDate new signature date.
-     * @return this same {@link SignedAppearanceText} instance.
+     * @param signDate new signature date
+     *
+     * @return this same {@link SignedAppearanceText} instance
      */
     public SignedAppearanceText setSignDate(java.util.Calendar signDate) {
         this.signDate = signDate;
@@ -159,7 +169,7 @@ public SignedAppearanceText setSignDate(java.util.Calendar signDate) {
     /**
      * Generates the signature description text based on the provided parameters.
      *
-     * @return signature description.
+     * @return signature description
      */
     public String generateDescriptionText() {
         final StringBuilder buf = new StringBuilder();

forms/src/test/java/com/itextpdf/forms/form/element/SignatureFieldAppearanceTest.java

@@ -165,6 +165,44 @@ public void customizedSigFieldTest() throws IOException, InterruptedException {
         Assertions.assertNull(new CompareTool().compareByContent(outPdf, cmpPdf, DESTINATION_FOLDER));
     }
 
+    @Test
+    public void emptySigFieldAppearanceTest() throws IOException, InterruptedException {
+        String outPdf = DESTINATION_FOLDER + "emptySigFieldAppearance.pdf";
+        String cmpPdf = SOURCE_FOLDER + "cmp_emptySigFieldAppearance.pdf";
+
+        try (Document document = new Document(new PdfDocument(new PdfWriter(outPdf)))) {
+            SignedAppearanceText description = new SignedAppearanceText()
+                    .setSignedBy(null).setLocationLine(null).setReasonLine(null);
+
+            SignatureFieldAppearance formSigField = new SignatureFieldAppearance("Signature1").setContent(description);
+            formSigField.setBackgroundColor(ColorConstants.LIGHT_GRAY);
+            formSigField.setBorder(new SolidBorder(ColorConstants.GREEN, 2));
+            formSigField.setHeight(100).setWidth(200);
+            document.add(formSigField);
+        }
+
+        Assertions.assertNull(new CompareTool().compareByContent(outPdf, cmpPdf, DESTINATION_FOLDER));
+    }
+
+    @Test
+    public void ignoreSignDateAndReasonInAppearanceTest() throws IOException, InterruptedException {
+        String outPdf = DESTINATION_FOLDER + "ignoreSignDateAndReasonInAppearance.pdf";
+        String cmpPdf = SOURCE_FOLDER + "cmp_ignoreSignDateAndReasonInAppearance.pdf";
+
+        try (Document document = new Document(new PdfDocument(new PdfWriter(outPdf)))) {
+            SignedAppearanceText description = new SignedAppearanceText()
+                    .setSignedBy("Signer Name").setLocationLine("Test Location").setReasonLine(null);
+
+            SignatureFieldAppearance formSigField = new SignatureFieldAppearance("Signature1").setContent(description);
+            formSigField.setBackgroundColor(ColorConstants.LIGHT_GRAY);
+            formSigField.setBorder(new SolidBorder(ColorConstants.GREEN, 2));
+            formSigField.setHeight(100).setWidth(200);
+            document.add(formSigField);
+        }
+
+        Assertions.assertNull(new CompareTool().compareByContent(outPdf, cmpPdf, DESTINATION_FOLDER));
+    }
+
     @Test
     @LogMessages(messages = @LogMessage(messageTemplate = IoLogMessageConstant.CLIP_ELEMENT))
     public void signatureFieldVerticalAlignmentTest() throws IOException, InterruptedException {

forms/src/test/resources/com/itextpdf/forms/form/element/SignatureFieldAppearanceTest/cmp_emptySigFieldAppearance.pdf

@@ -94,6 +94,7 @@ This file is part of the iText (R) project.
 import java.security.cert.X509Certificate;
 import java.util.ArrayList;
 import java.util.Arrays;
+import java.util.Calendar;
 import java.util.Collection;
 import java.util.HashMap;
 import java.util.List;
@@ -623,7 +624,10 @@ public void signDetached(IExternalDigest externalDigest, IExternalSignature exte
         dic.setLocation(this.signerProperties.getLocation());
         dic.setSignatureCreator(this.signerProperties.getSignatureCreator());
         dic.setContact(this.signerProperties.getContact());
-        dic.setDate(new PdfDate(this.signerProperties.getClaimedSignDate())); // time-stamp will over-rule this
+        Calendar claimedSignDate = this.signerProperties.getClaimedSignDate();
+        if (claimedSignDate != TimestampConstants.UNDEFINED_TIMESTAMP_DATE) {
+            dic.setDate(new PdfDate(claimedSignDate)); // time-stamp will over-rule this
+        }
         cryptoDictionary = dic;
 
         Map<PdfName, Integer> exc = new HashMap<>();
@@ -1357,8 +1361,9 @@ PdfSignature createSignatureDictionary(boolean includeDate) {
         dic.setLocation(this.signerProperties.getLocation());
         dic.setSignatureCreator(this.signerProperties.getSignatureCreator());
         dic.setContact(this.signerProperties.getContact());
-        if (includeDate) {
-            dic.setDate(new PdfDate(this.signerProperties.getClaimedSignDate())); // time-stamp will over-rule this
+        Calendar claimedSignDate = this.signerProperties.getClaimedSignDate();
+        if (includeDate && claimedSignDate != TimestampConstants.UNDEFINED_TIMESTAMP_DATE) {
+            dic.setDate(new PdfDate(claimedSignDate)); // time-stamp will over-rule this
         }
         return dic;
     }
@@ -1412,25 +1417,34 @@ private void setContent() {
     }
 
     private SignedAppearanceText generateSignatureText() {
-        return new SignedAppearanceText()
-                .setSignedBy(signerName)
-                .setSignDate(this.signerProperties.getClaimedSignDate())
-                .setReasonLine("Reason: " + this.signerProperties.getReason())
-                .setLocationLine("Location: " + this.signerProperties.getLocation());
+        SignedAppearanceText signedAppearanceText = new SignedAppearanceText();
+        fillInAppearanceText(signedAppearanceText);
+        return signedAppearanceText;
     }
 
     private void populateExistingModelElement() {
         this.signerProperties.getSignatureAppearance().setSignerName(signerName);
-        SignedAppearanceText signedAppearanceText =
-                this.signerProperties.getSignatureAppearance().getSignedAppearanceText();
-        if (signedAppearanceText != null) {
-            signedAppearanceText.setSignedBy(signerName).setSignDate(this.signerProperties.getClaimedSignDate());
-            if (signedAppearanceText.getReasonLine().isEmpty()) {
-                signedAppearanceText.setReasonLine("Reason: " + this.signerProperties.getReason());
-            }
-            if (signedAppearanceText.getLocationLine().isEmpty()) {
-                signedAppearanceText.setLocationLine("Location: " + this.signerProperties.getLocation());
-            }
+        SignedAppearanceText appearanceText = this.signerProperties.getSignatureAppearance().getSignedAppearanceText();
+        if (appearanceText != null) {
+            fillInAppearanceText(appearanceText);
+        }
+    }
+
+    private void fillInAppearanceText(SignedAppearanceText appearanceText) {
+        appearanceText.setSignedBy(signerName);
+        Calendar claimedSignDate = this.signerProperties.getClaimedSignDate();
+        if (claimedSignDate != TimestampConstants.UNDEFINED_TIMESTAMP_DATE) {
+            appearanceText.setSignDate(claimedSignDate);
+        }
+        String reason = signerProperties.getReason();
+        boolean setReason = appearanceText.getReasonLine() != null && appearanceText.getReasonLine().isEmpty();
+        if (setReason && reason != null && !reason.isEmpty()) {
+            appearanceText.setReasonLine("Reason: " + reason);
+        }
+        String location = signerProperties.getLocation();
+        boolean setLocation = appearanceText.getLocationLine() != null && appearanceText.getLocationLine().isEmpty();
+        if (setLocation && location != null && !location.isEmpty()) {
+            appearanceText.setLocationLine("Location: " + location);
         }
     }
 

forms/src/test/resources/com/itextpdf/forms/form/element/SignatureFieldAppearanceTest/cmp_ignoreSignDateAndReasonInAppearance.pdf

@@ -35,6 +35,12 @@ This file is part of the iText (R) project.
  * Properties to be used in signing operations.
  */
 public class SignerProperties {
+    /**
+     * This string could be used to create the {@link SignatureFieldAppearance} instance which will be used for signing
+     * since its ID will be ignored anyway in that case, and specified ID won't override the field name.
+     *
+     * @see #setSignatureAppearance(SignatureFieldAppearance)
+     */
     public static final String IGNORED_ID = "";
 
     private PdfSigFieldLock fieldLock;

sign/src/main/java/com/itextpdf/signatures/PdfSigner.java

@@ -61,6 +61,7 @@ This file is part of the iText (R) project.
 import com.itextpdf.signatures.PdfSigner;
 import com.itextpdf.signatures.PrivateKeySignature;
 import com.itextpdf.signatures.SignerProperties;
+import com.itextpdf.signatures.TimestampConstants;
 import com.itextpdf.signatures.testutils.PemFileHelper;
 import com.itextpdf.signatures.testutils.SignaturesCompareTool;
 import com.itextpdf.test.ExtendedITextTest;
@@ -75,9 +76,11 @@ This file is part of the iText (R) project.
 import java.security.cert.Certificate;
 import java.security.cert.CertificateException;
 import java.util.Arrays;
+import java.util.Calendar;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
+
 import org.junit.jupiter.api.Assertions;
 import org.junit.jupiter.api.BeforeAll;
 import org.junit.jupiter.api.BeforeEach;
@@ -132,6 +135,41 @@ public void defaultSignedAppearanceTextTest() throws GeneralSecurityException, I
         Assertions.assertNull(SignaturesCompareTool.compareSignatures(outPdf, cmpPdf));
     }
 
+    @Test
+    public void noReasonLocationSignDateInAppearanceTextTest() throws GeneralSecurityException, IOException, InterruptedException {
+        String srcFile = SOURCE_FOLDER + "simpleDocument.pdf";
+        String cmpPdf = SOURCE_FOLDER + "cmp_noReasonLocationSignDateInAppearanceText.pdf";
+        String outPdf = DESTINATION_FOLDER + "noReasonLocationSignDateInAppearanceText.pdf";
+
+        Rectangle rect = new Rectangle(36, 648, 200, 100);
+
+        String fieldName = "Signature1";
+        SignatureFieldAppearance appearance = new SignatureFieldAppearance(SignerProperties.IGNORED_ID)
+                .setContent(new SignedAppearanceText().setReasonLine(null).setLocationLine(null));
+
+        PdfSigner signer = new PdfSigner(new PdfReader(srcFile), FileUtil.getFileOutputStream(outPdf),
+                new StampingProperties());
+
+        SignerProperties signerProperties = new SignerProperties()
+                .setCertificationLevel(AccessPermissions.UNSPECIFIED)
+                .setFieldName(fieldName)
+                .setReason("Test 1")
+                .setLocation("TestCity 1")
+                .setSignatureAppearance(appearance)
+                .setClaimedSignDate((Calendar) TimestampConstants.UNDEFINED_TIMESTAMP_DATE)
+                .setPageRect(rect);
+        signer.setSignerProperties(signerProperties);
+
+        // Creating the signature
+        IExternalSignature pks = new PrivateKeySignature(pk, DigestAlgorithms.SHA256, FACTORY.getProviderName());
+        signer.signDetached(new BouncyCastleDigest(), pks, chain, null, null, null, 0, PdfSigner.CryptoStandard.CADES);
+
+        Assertions.assertNull(new CompareTool().compareVisually(outPdf, cmpPdf, DESTINATION_FOLDER, "diff_",
+                getTestMap(new Rectangle(36, 676, 200, 15))));
+
+        Assertions.assertNull(SignaturesCompareTool.compareSignatures(outPdf, cmpPdf));
+    }
+
     @Test
     public void signPDFADocumentWithoutSettingFont() throws IOException {
         String srcFile = DESTINATION_FOLDER + "simplePDFA.pdf";