PDF/A: Add check for Default Color Space

DEVSIX-2801

Author: vitali.prudnikovich

kernel/src/main/java/com/itextpdf/kernel/pdf/canvas/PdfCanvas.java

@@ -51,6 +51,7 @@ This file is part of the iText (R) project.
 import com.itextpdf.io.image.ImageType;
 import com.itextpdf.io.source.ByteUtils;
 import com.itextpdf.io.util.StreamUtil;
+import com.itextpdf.kernel.colors.DeviceGray;
 import com.itextpdf.kernel.exceptions.PdfException;
 import com.itextpdf.kernel.colors.Color;
 import com.itextpdf.kernel.colors.PatternColor;
@@ -174,6 +175,10 @@ public class PdfCanvas {
 
     private static final float IDENTITY_MATRIX_EPS = 1e-4f;
 
+    // Flag showing whether to check the color on drawing or not
+    // Normally the color is checked on setColor but not the default one which is DeviceGray.BLACK
+    private boolean defaultDeviceGrayBlackColorCheckRequired = true;
+
     /**
      * a LIFO stack of graphics state saved states.
      */
@@ -539,6 +544,8 @@ public PdfCanvas newlineText() {
      * @return current canvas.
      */
     public PdfCanvas newlineShowText(String text) {
+        checkDefaultDeviceGrayBlackColor(getColorKeyForText());
+
         showTextInt(text);
         contentStream.getOutputStream()
                 .writeByte('\'')
@@ -555,6 +562,8 @@ public PdfCanvas newlineShowText(String text) {
      * @return current canvas.
      */
     public PdfCanvas newlineShowText(float wordSpacing, float charSpacing, String text) {
+        checkDefaultDeviceGrayBlackColor(getColorKeyForText());
+
         contentStream.getOutputStream()
                 .writeFloat(wordSpacing)
                 .writeSpace()
@@ -702,6 +711,8 @@ public PdfCanvas setTextMatrix(float x, float y) {
      * @return current canvas.
      */
     public PdfCanvas showText(String text) {
+        checkDefaultDeviceGrayBlackColor(getColorKeyForText());
+
         showTextInt(text);
         contentStream.getOutputStream().writeBytes(Tj);
         return this;
@@ -726,7 +737,9 @@ public PdfCanvas showText(GlyphLine text) {
      * @return current canvas.
      */
     public PdfCanvas showText(GlyphLine text, Iterator<GlyphLine.GlyphLinePart> iterator) {
+        checkDefaultDeviceGrayBlackColor(getColorKeyForText());
         document.checkIsoConformance(currentGs, IsoKey.FONT_GLYPHS, null, contentStream);
+
         PdfFont font;
         if ((font = currentGs.getFont()) == null) {
             throw new PdfException(
@@ -898,7 +911,9 @@ private float getWordSpacingAddition(Glyph glyph) {
      * @return current canvas.
      */
     public PdfCanvas showText(PdfArray textArray) {
+        checkDefaultDeviceGrayBlackColor(getColorKeyForText());
         document.checkIsoConformance(currentGs, IsoKey.FONT_GLYPHS, null, contentStream);
+
         if (currentGs.getFont() == null)
             throw new PdfException(
                     KernelExceptionMessageConstant.FONT_AND_SIZE_MUST_BE_SET_BEFORE_WRITING_ANY_TEXT, currentGs);
@@ -1269,6 +1284,8 @@ public PdfCanvas closePath() {
      * @return current canvas.
      */
     public PdfCanvas closePathEoFillStroke() {
+        checkDefaultDeviceGrayBlackColor(CheckColorMode.FILL_AND_STROKE);
+
         contentStream.getOutputStream().writeBytes(bStar);
         return this;
     }
@@ -1279,6 +1296,8 @@ public PdfCanvas closePathEoFillStroke() {
      * @return current canvas.
      */
     public PdfCanvas closePathFillStroke() {
+        checkDefaultDeviceGrayBlackColor(CheckColorMode.FILL_AND_STROKE);
+
         contentStream.getOutputStream().writeBytes(b);
         return this;
     }
@@ -1299,6 +1318,8 @@ public PdfCanvas endPath() {
      * @return current canvas.
      */
     public PdfCanvas stroke() {
+        checkDefaultDeviceGrayBlackColor(CheckColorMode.STROKE);
+
         contentStream.getOutputStream().writeBytes(S);
         return this;
     }
@@ -1341,6 +1362,8 @@ public PdfCanvas closePathStroke() {
      * @return current canvas.
      */
     public PdfCanvas fill() {
+        checkDefaultDeviceGrayBlackColor(CheckColorMode.FILL);
+
         contentStream.getOutputStream().writeBytes(f);
         return this;
     }
@@ -1351,6 +1374,8 @@ public PdfCanvas fill() {
      * @return current canvas.
      */
     public PdfCanvas fillStroke() {
+        checkDefaultDeviceGrayBlackColor(CheckColorMode.FILL_AND_STROKE);
+
         contentStream.getOutputStream().writeBytes(B);
         return this;
     }
@@ -1361,6 +1386,8 @@ public PdfCanvas fillStroke() {
      * @return current canvas.
      */
     public PdfCanvas eoFill() {
+        checkDefaultDeviceGrayBlackColor(CheckColorMode.FILL);
+
         contentStream.getOutputStream().writeBytes(fStar);
         return this;
     }
@@ -1371,6 +1398,8 @@ public PdfCanvas eoFill() {
      * @return current canvas.
      */
     public PdfCanvas eoFillStroke() {
+        checkDefaultDeviceGrayBlackColor(CheckColorMode.FILL_AND_STROKE);
+
         contentStream.getOutputStream().writeBytes(BStar);
         return this;
     }
@@ -2479,6 +2508,40 @@ private PdfCanvas drawArc(double x1, double y1, double x2, double y2,
         return this;
     }
 
+    private void checkDefaultDeviceGrayBlackColor(CheckColorMode checkColorMode) {
+        if (defaultDeviceGrayBlackColorCheckRequired) {
+            // It's enough to check DeviceGray.BLACK once for fill color or stroke color
+            // But it's still important to do not check fill color if it's not used and vice versa
+            if (currentGs.getFillColor() == DeviceGray.BLACK &&
+                    (checkColorMode == CheckColorMode.FILL || checkColorMode == CheckColorMode.FILL_AND_STROKE)) {
+                document.checkIsoConformance(currentGs, IsoKey.FILL_COLOR, resources, contentStream);
+                defaultDeviceGrayBlackColorCheckRequired = false;
+            } else if (currentGs.getStrokeColor() == DeviceGray.BLACK &&
+                    (checkColorMode == CheckColorMode.STROKE || checkColorMode == CheckColorMode.FILL_AND_STROKE)) {
+                document.checkIsoConformance(currentGs, IsoKey.STROKE_COLOR, resources, contentStream);
+                defaultDeviceGrayBlackColorCheckRequired = false;
+            } else {
+                // Nothing
+            }
+        }
+    }
+
+    private CheckColorMode getColorKeyForText() {
+        switch (currentGs.getTextRenderingMode()) {
+            case PdfCanvasConstants.TextRenderingMode.FILL:
+            case PdfCanvasConstants.TextRenderingMode.FILL_CLIP:
+                return CheckColorMode.FILL;
+            case PdfCanvasConstants.TextRenderingMode.STROKE:
+            case PdfCanvasConstants.TextRenderingMode.STROKE_CLIP:
+                return CheckColorMode.STROKE;
+            case PdfCanvasConstants.TextRenderingMode.FILL_STROKE:
+            case PdfCanvasConstants.TextRenderingMode.FILL_STROKE_CLIP:
+                return CheckColorMode.FILL_AND_STROKE;
+            default:
+                return CheckColorMode.NONE;
+        }
+    }
+
     private static PdfStream getPageStream(PdfPage page) {
         PdfStream stream = page.getLastContentStream();
         return stream == null || stream.getOutputStream() == null || stream.containsKey(PdfName.Filter) ? page.newContentStreamAfter() : stream;
@@ -2508,4 +2571,11 @@ private static boolean isIdentityMatrix(float a, float b, float c, float d, floa
         return Math.abs(1 - a) < IDENTITY_MATRIX_EPS && Math.abs(b) < IDENTITY_MATRIX_EPS && Math.abs(c) < IDENTITY_MATRIX_EPS &&
                 Math.abs(1 - d) < IDENTITY_MATRIX_EPS && Math.abs(e) < IDENTITY_MATRIX_EPS && Math.abs(f) < IDENTITY_MATRIX_EPS;
     }
+
+    private enum CheckColorMode {
+        NONE,
+        FILL,
+        STROKE,
+        FILL_AND_STROKE
+    }
 }

pdfa/src/main/java/com/itextpdf/pdfa/exceptions/PdfAConformanceException.java

@@ -105,7 +105,7 @@ public class PdfAConformanceException extends PdfException {
     public static final String GRAPHICS_STATE_STACK_DEPTH_IS_GREATER_THAN_28 = "Graphics state stack depth is greater than 28";
     public static final String HALFTONES_SHALL_NOT_CONTAIN_HALFTONENAME = "Halftones shall not contain halftonename";
     public static final String IF_DEVICE_RGB_CMYK_GRAY_USED_IN_FILE_THAT_FILE_SHALL_CONTAIN_PDFA_OUTPUTINTENT = "If device rgb cmyk gray used in file, that file shall contain pdfa outputintent";
-    public static final String IF_DEVICE_RGB_CMYK_GRAY_USED_IN_FILE_THAT_FILE_SHALL_CONTAIN_PDFA_OUTPUTINTENT_OR_DEFAULT_RGB_CMYK_GRAY_IN_USAGE_CONTEXT = "If device rgb cmyk gray used in file that file shall contain pdfa outputintent orDefaultRgb Cmyk Gray in usage context";
+    public static final String IF_DEVICE_RGB_CMYK_GRAY_USED_IN_FILE_THAT_FILE_SHALL_CONTAIN_PDFA_OUTPUTINTENT_OR_DEFAULT_RGB_CMYK_GRAY_IN_USAGE_CONTEXT = "If device rgb cmyk gray used in file that file shall contain pdfa outputintent or DefaultRgb Cmyk Gray in usage context";
     public static final String IF_OUTPUTINTENTS_ARRAY_HAS_MORE_THAN_ONE_ENTRY_WITH_DESTOUTPUTPROFILE_KEY_THE_SAME_INDIRECT_OBJECT_SHALL_BE_USED_AS_THE_VALUE_OF_THAT_OBJECT = "If outputintents array has more than one entry with destoutputprofile key the same indirect object shall be used as the value of that object";
     public static final String IF_SPECIFIED_RENDERING_SHALL_BE_ONE_OF_THE_FOLLOWING_RELATIVECOLORIMETRIC_ABSOLUTECOLORIMETRIC_PERCEPTUAL_OR_SATURATION = "If specified rendering shall be one of the following relativecolorimetric absolutecolorimetric perceptual or saturation";
     public static final String INTEGER_NUMBER_IS_OUT_OF_RANGE = "Integer number is out of range";

pdfa/src/test/java/com/itextpdf/pdfa/PdfA2GraphicsCheckTest.java

@@ -55,13 +55,15 @@ This file is part of the iText (R) project.
 import com.itextpdf.kernel.pdf.PdfAConformanceLevel;
 import com.itextpdf.kernel.pdf.PdfArray;
 import com.itextpdf.kernel.pdf.PdfDictionary;
+import com.itextpdf.kernel.pdf.PdfDocument;
 import com.itextpdf.kernel.pdf.PdfName;
 import com.itextpdf.kernel.pdf.PdfNumber;
 import com.itextpdf.kernel.pdf.PdfOutputIntent;
 import com.itextpdf.kernel.pdf.PdfPage;
 import com.itextpdf.kernel.pdf.PdfWriter;
 import com.itextpdf.kernel.pdf.canvas.PdfCanvas;
 import com.itextpdf.kernel.pdf.canvas.PdfCanvasConstants;
+import com.itextpdf.kernel.pdf.canvas.PdfCanvasConstants.TextRenderingMode;
 import com.itextpdf.kernel.pdf.colorspace.PdfCieBasedCs;
 import com.itextpdf.kernel.pdf.colorspace.PdfColorSpace;
 import com.itextpdf.kernel.pdf.colorspace.PdfDeviceCs;
@@ -292,6 +294,78 @@ public void colorCheckTest7() throws IOException, InterruptedException {
                 e.getMessage());
     }
 
+    @Test
+    public void defaultTextColorCheckTest() throws IOException {
+        String outPdf = destinationFolder + "defaultColorCheck.pdf";
+
+        PdfDocument pdfDocument = new PdfADocument(new PdfWriter(outPdf), PdfAConformanceLevel.PDF_A_2B, null);
+        PdfFont font = PdfFontFactory.createFont(sourceFolder + "FreeSans.ttf",
+                "Identity-H", EmbeddingStrategy.FORCE_EMBEDDED);
+
+        PdfPage page = pdfDocument.addNewPage();
+        PdfCanvas canvas = new PdfCanvas(page);
+        canvas.saveState();
+        canvas.beginText()
+                .moveText(36, 750)
+                .setFontAndSize(font, 16)
+                .showText("some text")
+                .endText()
+                .restoreState();
+
+        Exception e = Assert.assertThrows(PdfAConformanceException.class, () -> pdfDocument.close());
+        Assert.assertEquals(MessageFormatUtil.format(PdfAConformanceException.IF_DEVICE_RGB_CMYK_GRAY_USED_IN_FILE_THAT_FILE_SHALL_CONTAIN_PDFA_OUTPUTINTENT_OR_DEFAULT_RGB_CMYK_GRAY_IN_USAGE_CONTEXT),
+                e.getMessage());
+    }
+
+    @Test
+    public void defaultTextColorCheckForInvisibleTextTest() throws IOException, InterruptedException {
+        String outPdf = destinationFolder + "defaultColorCheckInvisibleText.pdf";
+        String cmpPdf = cmpFolder + "cmp_pdfA2b_defaultColorCheckInvisibleText.pdf";
+
+        PdfDocument pdfDocument = new PdfADocument(new PdfWriter(outPdf), PdfAConformanceLevel.PDF_A_2B, null);
+        PdfFont font = PdfFontFactory.createFont(sourceFolder + "FreeSans.ttf",
+                "Identity-H", EmbeddingStrategy.FORCE_EMBEDDED);
+
+        PdfPage page = pdfDocument.addNewPage();
+        PdfCanvas canvas = new PdfCanvas(page);
+        canvas.saveState();
+        canvas.beginText()
+                .setTextRenderingMode(TextRenderingMode.INVISIBLE)
+                .moveText(36, 750)
+                .setFontAndSize(font, 16)
+                .showText("some text")
+                .endText()
+                .restoreState();
+
+        pdfDocument.close();
+        compareResult(outPdf, cmpPdf);
+    }
+
+    @Test
+    public void defaultStrokeColorCheckTest() throws IOException {
+        String outPdf = destinationFolder + "defaultColorCheck.pdf";
+
+        PdfDocument pdfDocument = new PdfADocument(new PdfWriter(outPdf), PdfAConformanceLevel.PDF_A_2B, null);
+        PdfPage page = pdfDocument.addNewPage();
+        PdfCanvas canvas = new PdfCanvas(page);
+        canvas.saveState();
+        float[] whitePoint = {0.9505f, 1f, 1.089f};
+        float[] gamma = {2.2f, 2.2f, 2.2f};
+        float[] matrix = {0.4124f, 0.2126f, 0.0193f, 0.3576f, 0.7152f, 0.1192f, 0.1805f, 0.0722f, 0.9505f};
+        PdfCieBasedCs.CalRgb calRgb = new PdfCieBasedCs.CalRgb(whitePoint, null, gamma, matrix);
+        canvas.getResources().setDefaultRgb(calRgb);
+        canvas.setFillColor(ColorConstants.BLUE);
+        canvas.moveTo(pdfDocument.getDefaultPageSize().getLeft(), pdfDocument.getDefaultPageSize().getBottom());
+        canvas.lineTo(pdfDocument.getDefaultPageSize().getRight(), pdfDocument.getDefaultPageSize().getBottom());
+        canvas.lineTo(pdfDocument.getDefaultPageSize().getRight(), pdfDocument.getDefaultPageSize().getTop());
+        canvas.stroke();
+
+        // We set fill color but stroked so the exception should be thrown
+        Exception e = Assert.assertThrows(PdfAConformanceException.class, () -> pdfDocument.close());
+        Assert.assertEquals(MessageFormatUtil.format(PdfAConformanceException.IF_DEVICE_RGB_CMYK_GRAY_USED_IN_FILE_THAT_FILE_SHALL_CONTAIN_PDFA_OUTPUTINTENT_OR_DEFAULT_RGB_CMYK_GRAY_IN_USAGE_CONTEXT),
+                e.getMessage());
+    }
+
     @Test
     public void egsCheckTest1() throws IOException {
         PdfWriter writer = new PdfWriter(new ByteArrayOutputStream());

pdfa/src/test/java/com/itextpdf/pdfa/PdfATransparencyCheckTest.java

@@ -127,10 +127,11 @@ public void transparentTextWithGroupColorSpaceTest() throws IOException, Interru
         String cmpPdf = cmpFolder + "cmp_transparencyAndCS.pdf";
 
         PdfDocument pdfDocument = new PdfADocument(new PdfWriter(outPdf), PdfAConformanceLevel.PDF_A_3B, null);
-        PdfPage page = pdfDocument.addNewPage();
         PdfFont font = PdfFontFactory.createFont(sourceFolder + "FreeSans.ttf",
                 "Identity-H", EmbeddingStrategy.FORCE_EMBEDDED);
 
+        PdfPage page = pdfDocument.addNewPage();
+        page.getResources().setDefaultGray(new PdfCieBasedCs.CalGray(getCalGrayArray()));
         PdfCanvas canvas = new PdfCanvas(page);
         canvas.saveState();
         PdfExtGState state = new PdfExtGState();
@@ -149,8 +150,8 @@ public void transparentTextWithGroupColorSpaceTest() throws IOException, Interru
         groupObj.put(PdfName.S, PdfName.Transparency);
         page.getPdfObject().put(PdfName.Group, groupObj);
 
-
         PdfPage page2 = pdfDocument.addNewPage();
+        page2.getResources().setDefaultGray(new PdfCieBasedCs.CalGray(getCalGrayArray()));
         canvas = new PdfCanvas(page2);
         canvas.saveState();
         canvas.beginText()
@@ -230,6 +231,7 @@ public void testTransparencyObjectsAbsence() throws IOException, InterruptedExce
                 "Identity-H", EmbeddingStrategy.FORCE_EMBEDDED);
 
         PdfCanvas canvas = new PdfCanvas(page);
+        page.getResources().setDefaultGray(new PdfCieBasedCs.CalGray(getCalGrayArray()));
         canvas.beginText()
                 .moveText(36, 750)
                 .setFontAndSize(font, 16)
@@ -241,8 +243,6 @@ public void testTransparencyObjectsAbsence() throws IOException, InterruptedExce
         groupObj.put(PdfName.S, PdfName.Transparency);
         page.getPdfObject().put(PdfName.Group, groupObj);
 
-        page.getResources().setDefaultGray(new PdfCieBasedCs.CalGray(getCalGrayArray()));
-
         pdfDocument.close();
         compareResult(outPdf, cmpPdf);
     }