Introduce way to pass MetaInfo to forms module

DEVSIX-6328

Author: Eugene Bochilo

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

@@ -0,0 +1,12 @@
+package com.itextpdf.commons.utils;
+
+/**
+ * Functional interface which takes 0 parameters and returns nothing.
+ */
+@FunctionalInterface
+public interface Action {
+    /**
+     * Execute action.
+     */
+    void execute();
+}

forms/src/main/java/com/itextpdf/forms/PdfAcroForm.java

@@ -87,6 +87,8 @@ This file is part of the iText (R) project.
  */
 public class PdfAcroForm extends PdfObjectWrapper<PdfDictionary> {
 
+    private static final Logger LOGGER = LoggerFactory.getLogger(PdfAcroForm.class);
+
     /**
      * To be used with {@link #setSignatureFlags}.
      * <br>
@@ -137,7 +139,6 @@ public class PdfAcroForm extends PdfObjectWrapper<PdfDictionary> {
     private PdfDictionary defaultResources;
     private Set<PdfFormField> fieldsForFlattening = new LinkedHashSet<>();
     private XfaForm xfaForm;
-    private static Logger logger = LoggerFactory.getLogger(PdfAcroForm.class);
 
     /**
      * Creates a PdfAcroForm as a wrapper of a dictionary.
@@ -720,7 +721,7 @@ public void flattenFields() {
                     }
                 }
             } else {
-                logger.error(IoLogMessageConstant.N_ENTRY_IS_REQUIRED_FOR_APPEARANCE_DICTIONARY);
+                LOGGER.error(IoLogMessageConstant.N_ENTRY_IS_REQUIRED_FOR_APPEARANCE_DICTIONARY);
             }
 
             PdfArray fFields = getFields();
@@ -861,7 +862,7 @@ public void replaceField(String name, PdfFormField field) {
     protected PdfArray getFields() {
         PdfArray fields = getPdfObject().getAsArray(PdfName.Fields);
         if (fields == null) {
-            logger.warn(IoLogMessageConstant.NO_FIELDS_IN_ACROFORM);
+            LOGGER.warn(IoLogMessageConstant.NO_FIELDS_IN_ACROFORM);
             fields = new PdfArray();
             getPdfObject().put(PdfName.Fields, fields);
         }
@@ -877,12 +878,12 @@ private Map<String, PdfFormField> iterateFields(PdfArray array, Map<String, PdfF
         int index = 1;
         for (PdfObject field : array) {
             if (field.isFlushed()) {
-                logger.info(IoLogMessageConstant.FORM_FIELD_WAS_FLUSHED);
+                LOGGER.info(IoLogMessageConstant.FORM_FIELD_WAS_FLUSHED);
                 continue;
             }
             PdfFormField formField = PdfFormField.makeFormField(field, document);
             if (formField == null) {
-                logger.warn(MessageFormatUtil.format(IoLogMessageConstant.CANNOT_CREATE_FORMFIELD,
+                LOGGER.warn(MessageFormatUtil.format(IoLogMessageConstant.CANNOT_CREATE_FORMFIELD,
                         field.getIndirectReference() == null ? field : field.getIndirectReference()));
                 continue;
             }

forms/src/main/java/com/itextpdf/forms/fields/FormsMetaInfoStaticContainer.java

@@ -0,0 +1,47 @@
+package com.itextpdf.forms.fields;
+
+import com.itextpdf.commons.utils.Action;
+import com.itextpdf.layout.renderer.MetaInfoContainer;
+
+/**
+ * Class to store meta info that will be used in forms module in static context.
+ */
+public final class FormsMetaInfoStaticContainer {
+
+    private static ThreadLocal<MetaInfoContainer> metaInfoForLayout = new ThreadLocal<>();
+
+    private FormsMetaInfoStaticContainer() {
+        // Empty constructor.
+    }
+
+    /**
+     * Sets meta info related to forms into static context, executes the action and then cleans meta info.
+     *
+     * <p>
+     * Keep in mind that this instance will only be accessible from the same thread.
+     *
+     * @param metaInfoContainer instance to be set.
+     * @param action action which will be executed while meta info is set to static context.
+     */
+    // TODO DEVSIX-6368 We want to prevent customer code being run while meta info is in the static context
+    public static void useMetaInfoDuringTheAction(MetaInfoContainer metaInfoContainer, Action action) {
+        try {
+            metaInfoForLayout.set(metaInfoContainer);
+            action.execute();
+        } finally {
+            metaInfoForLayout.set(null);
+        }
+    }
+
+    /**
+     * Gets meta info which was set previously.
+     *
+     * <p>
+     * Keep in mind that this operation will return meta info instance which was set previously from the same thread.
+     *
+     * @return meta info instance.
+     */
+    static MetaInfoContainer getMetaInfoForLayout() {
+        return metaInfoForLayout.get();
+    }
+}

forms/src/main/java/com/itextpdf/forms/fields/PdfFormField.java

@@ -106,6 +106,7 @@ This file is part of the iText (R) project.
 import com.itextpdf.layout.properties.TransparentColor;
 import com.itextpdf.layout.properties.VerticalAlignment;
 import com.itextpdf.layout.renderer.IRenderer;
+import com.itextpdf.layout.renderer.MetaInfoContainer;
 
 import java.io.ByteArrayOutputStream;
 import java.io.IOException;
@@ -117,6 +118,7 @@ This file is part of the iText (R) project.
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
+
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -2432,6 +2434,8 @@ protected void drawTextAppearance(Rectangle rect, PdfFont font, float fontSize,
         Canvas modelCanvas = new Canvas(canvas, new Rectangle(0, -height, 0, 2 * height));
         modelCanvas.setProperty(Property.APPEARANCE_STREAM_LAYOUT, true);
 
+        setMetaInfoToCanvas(modelCanvas);
+
         Style paragraphStyle = new Style().setFont(font).setFontSize(fontSize);
         paragraphStyle.setProperty(Property.LEADING, new Leading(Leading.MULTIPLIED, 1));
         if (color != null)
@@ -2489,6 +2493,8 @@ protected void drawMultiLineTextAppearance(Rectangle rect, PdfFont font, String
         Canvas modelCanvas = new Canvas(canvas, areaRect);
         modelCanvas.setProperty(Property.APPEARANCE_STREAM_LAYOUT, true);
 
+        setMetaInfoToCanvas(modelCanvas);
+
         Paragraph paragraph = createParagraphForTextFieldValue(value).setFont(font)
                 .setMargin(0)
                 .setPadding(3)
@@ -2545,6 +2551,9 @@ private void drawChoiceAppearance(Rectangle rect, float fontSize, String value,
 
         Canvas modelCanvas = new Canvas(canvas, new Rectangle(3, 0, Math.max(0, width - widthBorder), Math.max(0, height - heightBorder)));
         modelCanvas.setProperty(Property.APPEARANCE_STREAM_LAYOUT, true);
+
+        setMetaInfoToCanvas(modelCanvas);
+
         Div div = new Div();
         if(getFieldFlag(PdfChoiceFormField.FF_COMBO)) {
             div.setVerticalAlignment(VerticalAlignment.MIDDLE);
@@ -2865,6 +2874,9 @@ protected void drawButton(PdfCanvas canvas, float x, float y, float width, float
                 setVerticalAlignment(VerticalAlignment.MIDDLE);
         Canvas modelCanvas = new Canvas(canvas, new Rectangle(0, -height, width, 2 * height));
         modelCanvas.setProperty(Property.APPEARANCE_STREAM_LAYOUT, true);
+
+        setMetaInfoToCanvas(modelCanvas);
+
         modelCanvas.showTextAligned(paragraph, width / 2, height / 2, TextAlignment.CENTER, VerticalAlignment.MIDDLE);
     }
 
@@ -2922,6 +2934,13 @@ protected void drawPdfACheckBox(PdfCanvas canvas, float width, float height, boo
         }
     }
 
+    static void setMetaInfoToCanvas(Canvas canvas) {
+        MetaInfoContainer metaInfo = FormsMetaInfoStaticContainer.getMetaInfoForLayout();
+        if (metaInfo != null) {
+            canvas.setProperty(Property.META_INFO, metaInfo);
+        }
+    }
+
     private String getRadioButtonValue() {
         for (String state : getAppearanceStates()) {
             if (!"Off".equals(state)) {

forms/src/test/java/com/itextpdf/forms/fields/FormsMetaInfoStaticContainerTest.java

@@ -0,0 +1,80 @@
+package com.itextpdf.forms.fields;
+
+import com.itextpdf.commons.actions.contexts.IMetaInfo;
+import com.itextpdf.layout.renderer.MetaInfoContainer;
+import com.itextpdf.test.ExtendedITextTest;
+import com.itextpdf.test.annotations.type.UnitTest;
+import org.junit.Assert;
+import org.junit.Test;
+import org.junit.experimental.categories.Category;
+
+@Category(UnitTest.class)
+public class FormsMetaInfoStaticContainerTest extends ExtendedITextTest {
+
+    @Test
+    public void useMetaInfoDuringTheActionOneThreadTest() {
+        MetaInfoContainer metaInfo1 = new MetaInfoContainer(new IMetaInfo() {});
+        MetaInfoContainer metaInfo2 = new MetaInfoContainer(new IMetaInfo() {});
+
+        FormsMetaInfoStaticContainer.useMetaInfoDuringTheAction(metaInfo1, () -> {
+            Assert.assertSame(metaInfo1, FormsMetaInfoStaticContainer.getMetaInfoForLayout());
+
+            FormsMetaInfoStaticContainer.useMetaInfoDuringTheAction(metaInfo2,
+                    () -> Assert.assertSame(metaInfo2, FormsMetaInfoStaticContainer.getMetaInfoForLayout()));
+
+            Assert.assertNull(FormsMetaInfoStaticContainer.getMetaInfoForLayout());
+        });
+
+        Assert.assertNull(FormsMetaInfoStaticContainer.getMetaInfoForLayout());
+    }
+
+    @Test
+    public void useMetaInfoDuringTheActionSeveralThreadsTest() throws InterruptedException {
+        MetaInfoCheckClass metaInfoCheckClass1 = new MetaInfoCheckClass(null);
+        MetaInfoCheckClass metaInfoCheckClass2 = new MetaInfoCheckClass(metaInfoCheckClass1);
+        MetaInfoCheckClass metaInfoCheckClass3 = new MetaInfoCheckClass(metaInfoCheckClass2);
+
+        Thread thread = new Thread(() -> metaInfoCheckClass3.checkMetaInfo());
+        thread.start();
+        thread.join();
+
+        Assert.assertFalse(metaInfoCheckClass1.isCheckFailed());
+        Assert.assertFalse(metaInfoCheckClass2.isCheckFailed());
+        Assert.assertFalse(metaInfoCheckClass3.isCheckFailed());
+    }
+
+    private static class MetaInfoCheckClass {
+
+        private MetaInfoCheckClass metaInfoCheckClass = null;
+        private boolean checkFailed = false;
+
+        public MetaInfoCheckClass(MetaInfoCheckClass metaInfoCheckClass) {
+            this.metaInfoCheckClass = metaInfoCheckClass;
+        }
+
+        public void checkMetaInfo() {
+            MetaInfoContainer metaInfo = new MetaInfoContainer(new IMetaInfo() {
+            });
+
+            FormsMetaInfoStaticContainer.useMetaInfoDuringTheAction(metaInfo, () -> {
+                if (metaInfoCheckClass != null) {
+                    Thread thread = new Thread(() -> metaInfoCheckClass.checkMetaInfo());
+                    thread.start();
+                    try {
+                        thread.join();
+                    } catch (Exception ignored) {
+                        checkFailed = true;
+                    }
+                }
+
+                checkFailed |= metaInfo != FormsMetaInfoStaticContainer.getMetaInfoForLayout();
+            });
+
+            checkFailed |= FormsMetaInfoStaticContainer.getMetaInfoForLayout() != null;
+        }
+
+        public boolean isCheckFailed() {
+            return checkFailed;
+        }
+    }
+}

forms/src/test/java/com/itextpdf/forms/fields/PdfFormFieldUnitTest.java

@@ -22,12 +22,20 @@ This file is part of the iText (R) project.
  */
 package com.itextpdf.forms.fields;
 
+import com.itextpdf.commons.actions.contexts.IMetaInfo;
 import com.itextpdf.forms.exceptions.FormsExceptionMessageConstant;
 import com.itextpdf.io.source.ByteArrayOutputStream;
 import com.itextpdf.kernel.exceptions.PdfException;
+import com.itextpdf.kernel.geom.Rectangle;
 import com.itextpdf.kernel.pdf.PdfDictionary;
 import com.itextpdf.kernel.pdf.PdfDocument;
+import com.itextpdf.kernel.pdf.PdfResources;
+import com.itextpdf.kernel.pdf.PdfStream;
 import com.itextpdf.kernel.pdf.PdfWriter;
+import com.itextpdf.kernel.pdf.canvas.PdfCanvas;
+import com.itextpdf.layout.Canvas;
+import com.itextpdf.layout.properties.Property;
+import com.itextpdf.layout.renderer.MetaInfoContainer;
 import com.itextpdf.test.ExtendedITextTest;
 import com.itextpdf.test.annotations.type.UnitTest;
 
@@ -47,4 +55,32 @@ public void cannotGetRectangleIfKidsIsNullTest() {
                 () -> pdfFormField.getRect(pdfDictionary));
         Assert.assertEquals(FormsExceptionMessageConstant.WRONG_FORM_FIELD_ADD_ANNOTATION_TO_THE_FIELD, exception.getMessage());
     }
+
+    @Test
+    public void setMetaInfoToCanvasMetaInfoUsedTest() {
+        Canvas canvas = createCanvas();
+        MetaInfoContainer metaInfoContainer = new MetaInfoContainer(new IMetaInfo() {
+        });
+        FormsMetaInfoStaticContainer.useMetaInfoDuringTheAction(metaInfoContainer,
+                () -> PdfFormField.setMetaInfoToCanvas(canvas));
+
+        Assert.assertSame(metaInfoContainer, canvas.<MetaInfoContainer>getProperty(Property.META_INFO));
+    }
+
+    @Test
+    public void setMetaInfoToCanvasMetaInfoNotUsedTest() {
+        Canvas canvas = createCanvas();
+        PdfFormField.setMetaInfoToCanvas(canvas);
+
+        Assert.assertNull(canvas.<MetaInfoContainer>getProperty(Property.META_INFO));
+    }
+
+    private static Canvas createCanvas() {
+        try (PdfDocument document = new PdfDocument(new PdfWriter(new ByteArrayOutputStream()))) {
+            PdfStream stream = (PdfStream) new PdfStream().makeIndirect(document);
+            PdfResources resources = new PdfResources();
+            PdfCanvas pdfCanvas = new PdfCanvas(stream, resources, document);
+            return new Canvas(pdfCanvas, new Rectangle(100, 100));
+        }
+    }
 }