Implement architecture for creating PDF/UA document

* Add checkpoint 1 checks for mattarhorn protocol

DEVSIX-7895

Author: guustysebie

commons/src/main/java/com/itextpdf/commons/datastructures/Tuple2.java

@@ -0,0 +1,74 @@
+/*
+    This file is part of the iText (R) project.
+    Copyright (c) 1998-2023 Apryse Group NV
+    Authors: Apryse Software.
+
+    This program is offered under a commercial and under the AGPL license.
+    For commercial licensing, contact us at https://itextpdf.com/sales.  For AGPL licensing, see below.
+
+    AGPL licensing:
+    This program is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Affero General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Affero General Public License for more details.
+
+    You should have received a copy of the GNU Affero General Public License
+    along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+package com.itextpdf.commons.datastructures;
+
+/**
+ * Simple tuple container that holds two elements.
+ *
+ * @param <T1> type of the first element
+ * @param <T2> type of the second element
+ */
+public class Tuple2<T1, T2> {
+    private final T1 first;
+    private final T2 second;
+
+    /**
+     * Creates a new instance of {@link Tuple2} with given elements.
+     *
+     * @param first  the first element
+     * @param second the second element
+     */
+    public Tuple2(T1 first, T2 second) {
+        this.first = first;
+        this.second = second;
+    }
+
+    /**
+     * Get the first element.
+     *
+     * @return the first element
+     */
+    public T1 getFirst() {
+        return first;
+    }
+
+    /**
+     * Get the second element.
+     *
+     * @return the second element
+     */
+    public T2 getSecond() {
+        return second;
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    @Override
+    public String toString() {
+        return "Tuple2{" +
+                "first=" + first +
+                ", second=" + second +
+                '}';
+    }
+}

commons/src/main/java/com/itextpdf/commons/utils/DIContainer.java

@@ -87,6 +87,15 @@ public <T> T getInstance(Class<T> clazz) {
         return (T) supplier;
     }
 
-
+    /**
+     * Checks if an instance is registered for a class.
+     * If the class is registered but the value is null, it will still return {@code true}.
+     *
+     * @param clazz the class
+     *
+     * @return {@code true} if an instance is registered, {@code false} otherwise
+     */
+    public boolean isRegistered(Class<?> clazz) {
+        return localInstances.containsKey(clazz) || instances.containsKey(clazz);
+    }
 }
-

commons/src/test/java/com/itextpdf/commons/datastructures/Tuple2Test.java

@@ -0,0 +1,55 @@
+/*
+    This file is part of the iText (R) project.
+    Copyright (c) 1998-2023 Apryse Group NV
+    Authors: Apryse Software.
+
+    This program is offered under a commercial and under the AGPL license.
+    For commercial licensing, contact us at https://itextpdf.com/sales.  For AGPL licensing, see below.
+
+    AGPL licensing:
+    This program is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Affero General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Affero General Public License for more details.
+
+    You should have received a copy of the GNU Affero General Public License
+    along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+package com.itextpdf.commons.datastructures;
+
+import com.itextpdf.test.ExtendedITextTest;
+import com.itextpdf.test.annotations.type.UnitTest;
+
+import org.junit.Test;
+import org.junit.experimental.categories.Category;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNull;
+
+@Category(UnitTest.class)
+public class Tuple2Test extends ExtendedITextTest {
+
+    @Test
+    public void testTuple2_StringInt() {
+        Tuple2<String, Integer> tuple = new Tuple2<>("test", 1);
+        assertEquals("test", tuple.getFirst());
+        assertEquals(Integer.valueOf(1), tuple.getSecond());
+    }
+
+    @Test
+    public void testTuple2_ToString() {
+        Tuple2<String, Integer> tuple = new Tuple2<>("test", 1);
+        assertEquals("Tuple2{first=test, second=1}", tuple.toString());
+    }
+
+    @Test
+    public void testTuple2_TestWithNullFirstValue() {
+        Tuple2<String, Integer> tuple = new Tuple2<>(null, 1);
+        assertNull(tuple.getFirst());
+        assertEquals(Integer.valueOf(1), tuple.getSecond());
+    }
+}

forms/src/main/java/com/itextpdf/forms/form/renderer/AbstractFormFieldRenderer.java

@@ -289,7 +289,10 @@ protected PdfAConformanceLevel getConformanceLevel(PdfDocument document) {
         if (document == null) {
             return null;
         }
-        return document.getConformanceLevel();
+        if (document.getConformanceLevel() instanceof PdfAConformanceLevel) {
+            return (PdfAConformanceLevel) document.getConformanceLevel();
+        }
+        return null;
     }
 
     /**

forms/src/main/java/com/itextpdf/forms/form/renderer/AbstractSelectFieldRenderer.java

@@ -242,7 +242,10 @@ protected PdfAConformanceLevel getConformanceLevel(PdfDocument document) {
         if (document == null) {
             return null;
         }
-        return document.getConformanceLevel();
+        if (document.getConformanceLevel() instanceof PdfAConformanceLevel) {
+            return (PdfAConformanceLevel) document.getConformanceLevel();
+        }
+        return null;
     }
 
     protected List<IRenderer> getOptionsMarkedSelected(IRenderer optionsSubTree) {

itextcore/pom.xml

@@ -130,5 +130,10 @@
       <artifactId>bouncy-castle-connector</artifactId>
       <version>${project.version}</version>
     </dependency>
+    <dependency>
+      <groupId>com.itextpdf</groupId>
+      <artifactId>pdfua</artifactId>
+      <version>${project.version}</version>
+    </dependency>
   </dependencies>
 </project>

kernel/src/main/java/com/itextpdf/kernel/pdf/IConformanceLevel.java

@@ -0,0 +1,35 @@
+/*
+    This file is part of the iText (R) project.
+    Copyright (c) 1998-2023 Apryse Group NV
+    Authors: Apryse Software.
+
+    This program is offered under a commercial and under the AGPL license.
+    For commercial licensing, contact us at https://itextpdf.com/sales.  For AGPL licensing, see below.
+
+    AGPL licensing:
+    This program is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Affero General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Affero General Public License for more details.
+
+    You should have received a copy of the GNU Affero General Public License
+    along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+package com.itextpdf.kernel.pdf;
+
+
+/**
+ * Interface for PDF conformance level.
+ * <p>
+ *
+ * Conformance levels are extended PDF specifications that define subsets of PDF
+ * functionality. An example of a conformance level is PDF/A, which is used for long-term archiving
+ * and PDF/UA, which is used for accessible documents.
+ */
+public interface IConformanceLevel {
+}

kernel/src/main/java/com/itextpdf/kernel/pdf/IsoKey.java

@@ -26,6 +26,7 @@ This file is part of the iText (R) project.
  * Type of object to conform.
  */
 public enum IsoKey {
+    // PDF/A Enums
     CANVAS_STACK,
     FILL_COLOR,
     EXTENDED_GRAPHICS_STATE,
@@ -40,5 +41,8 @@ public enum IsoKey {
     SIGNATURE,
     SIGNATURE_TYPE,
     CRYPTO,
-    FONT
+    FONT,
+    // PDF/UA Enums
+    CANVAS_BEGIN_MARKED_CONTENT,
+    CANVAS_WRITING_CONTENT
 }

kernel/src/main/java/com/itextpdf/kernel/pdf/PdfAConformanceLevel.java

@@ -31,7 +31,7 @@ This file is part of the iText (R) project.
 /**
  * Enumeration of all the PDF/A conformance levels.
  */
-public class PdfAConformanceLevel {
+public class PdfAConformanceLevel implements IConformanceLevel {
 
     public static final PdfAConformanceLevel PDF_A_1A = new PdfAConformanceLevel("1", "A");
     public static final PdfAConformanceLevel PDF_A_1B = new PdfAConformanceLevel("1", "B");

kernel/src/main/java/com/itextpdf/kernel/pdf/PdfDocument.java

@@ -60,6 +60,8 @@ This file is part of the iText (R) project.
 import com.itextpdf.kernel.pdf.statistics.SizeOfPdfStatisticsEvent;
 import com.itextpdf.kernel.pdf.tagging.PdfStructTreeRoot;
 import com.itextpdf.kernel.pdf.tagutils.TagStructureContext;
+import com.itextpdf.kernel.utils.ValidationContainer;
+import com.itextpdf.kernel.utils.ValidationContext;
 import com.itextpdf.kernel.xmp.PdfConst;
 import com.itextpdf.kernel.xmp.XMPConst;
 import com.itextpdf.kernel.xmp.XMPException;
@@ -1153,11 +1155,11 @@ public List<PdfPage> copyPagesTo(int pageFrom, int pageTo, PdfDocument toDocumen
 
 
     /**
-     * Get the {@link PdfAConformanceLevel}
+     * Get the {@link IConformanceLevel}
      *
-     * @return the {@link PdfAConformanceLevel}  will be null if the document is not a PDF/A document
+     * @return the {@link IConformanceLevel}  will be null if the document does not have a conformance level specified
      */
-    public PdfAConformanceLevel getConformanceLevel() {
+    public IConformanceLevel getConformanceLevel() {
         return null;
     }
 
@@ -1573,29 +1575,28 @@ public void addOutputIntent(PdfOutputIntent outputIntent) {
 
     /**
      * Checks whether PDF document conforms a specific standard.
-     * Shall be overridden.
      *
      * @param obj An object to conform.
      * @param key type of object to conform.
      */
     public void checkIsoConformance(Object obj, IsoKey key) {
+        checkIsoConformance(obj, key, null, null);
     }
 
     /**
      * Checks whether PDF document conforms a specific standard.
-     * Shall be overridden.
      *
      * @param obj           an object to conform.
      * @param key           type of object to conform.
      * @param resources     {@link PdfResources} associated with an object to check.
      * @param contentStream current content stream
      */
     public void checkIsoConformance(Object obj, IsoKey key, PdfResources resources, PdfStream contentStream) {
+        checkIsoConformance(obj, key, resources, contentStream, null);
     }
 
     /**
      * Checks whether PDF document conforms a specific standard.
-     * Shall be overridden.
      *
      * @param obj           an object to conform.
      * @param key           type of object to conform.
@@ -1605,6 +1606,14 @@ public void checkIsoConformance(Object obj, IsoKey key, PdfResources resources,
      */
     public void checkIsoConformance(Object obj, IsoKey key, PdfResources resources, PdfStream contentStream,
             Object extra) {
+        if (!this.getDiContainer().isRegistered(ValidationContainer.class)) {
+            return;
+        }
+        ValidationContainer container = this.getDiContainer().getInstance(ValidationContainer.class);
+        if (container == null) {
+            return;
+        }
+        container.validate(obj, key, resources, contentStream, extra);
     }
 
     /**
@@ -1982,10 +1991,20 @@ protected void storeDestinationToReaddress(PdfDestination destination,
     }
 
     /**
-     * Checks whether PDF document conforms a specific standard.
-     * Shall be overridden.
+     * Checks whether PDF document conforms to a specific standard.
      */
     protected void checkIsoConformance() {
+        if (!this.getDiContainer().isRegistered(ValidationContainer.class)) {
+            return;
+        }
+        ValidationContainer container = this.getDiContainer().getInstance(ValidationContainer.class);
+        if (container == null) {
+            return;
+        }
+        ValidationContext context = new ValidationContext()
+                .withPdfDocument(this)
+                .withFonts(getDocumentFonts());
+        container.validate(context);
     }
 
     /**