Add PdfDocument as an argument for build linear gradient

DEVSIX-2086

Author: BezrukovM

kernel/src/main/java/com/itextpdf/kernel/colors/gradients/AbstractLinearGradientBuilder.java

@@ -23,14 +23,15 @@ This file is part of the iText (R) project.
 package com.itextpdf.kernel.colors.gradients;
 
 import com.itextpdf.io.LogMessageConstant;
+import com.itextpdf.kernel.PdfException;
 import com.itextpdf.kernel.colors.Color;
-import com.itextpdf.kernel.colors.DeviceRgb;
 import com.itextpdf.kernel.colors.PatternColor;
 import com.itextpdf.kernel.geom.AffineTransform;
 import com.itextpdf.kernel.geom.NoninvertibleTransformException;
 import com.itextpdf.kernel.geom.Point;
 import com.itextpdf.kernel.geom.Rectangle;
 import com.itextpdf.kernel.pdf.PdfArray;
+import com.itextpdf.kernel.pdf.PdfDocument;
 import com.itextpdf.kernel.pdf.PdfNumber;
 import com.itextpdf.kernel.pdf.colorspace.PdfDeviceCs;
 import com.itextpdf.kernel.pdf.colorspace.PdfPattern;
@@ -123,10 +124,12 @@ public GradientSpreadMethod getSpreadMethod() {
      *                          the current space. The {@code null} value is valid and can be used
      *                          if there is no transformation from base coordinates to current space
      *                          specified, or it is equal to identity transformation.
+     * @param document          the {@link PdfDocument} for which the linear gradient would be built.
      * @return the constructed {@link Color} or {@code null} if no color to be applied
      * or base gradient vector has been specified
      */
-    public Color buildColor(Rectangle targetBoundingBox, AffineTransform contextTransform) {
+    // TODO: DEVSIX-4136 the document argument would be required for opaque gradients (as we would need to create a mask form xObject)
+    public Color buildColor(Rectangle targetBoundingBox, AffineTransform contextTransform, PdfDocument document) {
         Point[] baseCoordinatesVector = getGradientVector(targetBoundingBox, contextTransform);
         if (baseCoordinatesVector == null || this.stops.isEmpty()) {
             // Can not create gradient color with 0 stops or null coordinates vector

kernel/src/test/java/com/itextpdf/kernel/colors/gradients/LinearGradientBuilderTest.java

@@ -57,7 +57,7 @@ public void buildWithNullArgumentsAndWithoutSettersTest() {
         Rectangle targetBoundingBox = new Rectangle(50f, 450f, 300f, 300f);
         AbstractLinearGradientBuilder gradientBuilder = new LinearGradientBuilder();
 
-        Assert.assertNull(gradientBuilder.buildColor(targetBoundingBox, null));
+        Assert.assertNull(gradientBuilder.buildColor(targetBoundingBox, null, null));
     }
 
     @Test
@@ -235,7 +235,7 @@ public void buildWithNullArgumentsAndWithoutStopsTest() {
                         targetBoundingBox.getRight() - 100f, targetBoundingBox.getTop() - 100f)
                 .setSpreadMethod(GradientSpreadMethod.PAD);
 
-        Assert.assertNull(gradientBuilder.buildColor(null, null));
+        Assert.assertNull(gradientBuilder.buildColor(null, null, null));
     }
 
     @Test
@@ -705,7 +705,7 @@ public void buildWithTwoStopsBeforeTheBeginningAndNoneTest() throws IOException,
                 .addColorStop(new GradientColorStop(ColorConstants.RED.getColorValue(), -10d, OffsetType.RELATIVE))
                 .addColorStop(new GradientColorStop(ColorConstants.BLUE.getColorValue(),  -5d, OffsetType.RELATIVE));
 
-        Assert.assertNull(gradientBuilder.buildColor(targetBoundingBox, null));
+        Assert.assertNull(gradientBuilder.buildColor(targetBoundingBox, null, null));
     }
 
     @Test
@@ -718,7 +718,7 @@ public void buildWithTwoStopsAfterEndAndNoneTest() throws IOException, Interrupt
                 .addColorStop(new GradientColorStop(ColorConstants.RED.getColorValue(), 5d, OffsetType.RELATIVE))
                 .addColorStop(new GradientColorStop(ColorConstants.BLUE.getColorValue(),  10d, OffsetType.RELATIVE));
 
-        Assert.assertNull(gradientBuilder.buildColor(targetBoundingBox, null));
+        Assert.assertNull(gradientBuilder.buildColor(targetBoundingBox, null, null));
     }
 
     @Test
@@ -731,7 +731,7 @@ public void buildWithTwoEqualOffsetsStopsAndNoneTest() throws IOException, Inter
                 .addColorStop(new GradientColorStop(ColorConstants.RED.getColorValue(), 0.5d, OffsetType.RELATIVE))
                 .addColorStop(new GradientColorStop(ColorConstants.BLUE.getColorValue(),  0.5d, OffsetType.RELATIVE));
 
-        Assert.assertNull(gradientBuilder.buildColor(targetBoundingBox, null));
+        Assert.assertNull(gradientBuilder.buildColor(targetBoundingBox, null, null));
     }
 
     @Test
@@ -770,7 +770,7 @@ private void generateAndComparePdfs(String fileName, Rectangle toDraw, AffineTra
                 canvas.concatMatrix(transform);
             }
 
-            canvas.setFillColor(gradientBuilder.buildColor(toDraw, transform))
+            canvas.setFillColor(gradientBuilder.buildColor(toDraw, transform, pdfDoc))
                     .setStrokeColor(ColorConstants.BLACK)
                     .rectangle(toDraw)
                     .fillStroke();
@@ -786,7 +786,7 @@ private void generateAndComparePdfsWithoutArgumentToBuild(String fileName, Recta
         try (PdfDocument pdfDoc = new PdfDocument(new PdfWriter(new File(outPdfPath)))) {
             PdfCanvas canvas = new PdfCanvas(pdfDoc.addNewPage());
 
-            canvas.setFillColor(gradientBuilder.buildColor(null, null))
+            canvas.setFillColor(gradientBuilder.buildColor(null, null, pdfDoc))
                     .setStrokeColor(ColorConstants.BLACK)
                     .rectangle(toDraw)
                     .fillStroke();

kernel/src/test/java/com/itextpdf/kernel/colors/gradients/StrategyBasedLinearGradientBuilderTest.java

@@ -59,7 +59,7 @@ public static void beforeClass() {
     @Test
     public void noSettersTest() {
         Assert.assertNull(new StrategyBasedLinearGradientBuilder()
-                .buildColor(new Rectangle(50f, 450f, 500f, 300f), null));
+                .buildColor(new Rectangle(50f, 450f, 500f, 300f), null, null));
     }
 
     @Test
@@ -68,7 +68,7 @@ public void noRectangleTest() {
                 .addColorStop(new GradientColorStop(ColorConstants.RED.getColorValue(), 0d, OffsetType.RELATIVE))
                 .addColorStop(new GradientColorStop(ColorConstants.GREEN.getColorValue(), 0.5, OffsetType.RELATIVE))
                 .addColorStop(new GradientColorStop(ColorConstants.BLUE.getColorValue(), 1d, OffsetType.RELATIVE))
-                .buildColor(null, null));
+                .buildColor(null, null, null));
     }
 
     @Test
@@ -276,7 +276,7 @@ private void generateAndComparePdfs(String fileName, AffineTransform transform,
             }
 
             Rectangle toDraw = new Rectangle(50f, 450f, 500f, 300f);
-            canvas.setFillColor(gradientBuilder.buildColor(toDraw, transform))
+            canvas.setFillColor(gradientBuilder.buildColor(toDraw, transform, pdfDoc))
                     .setStrokeColor(ColorConstants.BLACK)
                     .rectangle(toDraw)
                     .fillStroke();

layout/src/main/java/com/itextpdf/layout/renderer/AbstractRenderer.java

@@ -588,7 +588,7 @@ public static PdfFormXObject createXObject(AbstractLinearGradientBuilder linearG
         Rectangle formBBox = new Rectangle(0, 0, xObjectArea.getWidth(), xObjectArea.getHeight());
         PdfFormXObject xObject = new PdfFormXObject(formBBox);
         if (linearGradientBuilder != null) {
-            Color gradientColor = linearGradientBuilder.buildColor(formBBox, null);
+            Color gradientColor = linearGradientBuilder.buildColor(formBBox, null, document);
             if (gradientColor != null) {
                 new PdfCanvas(xObject, document)
                         .setColor(gradientColor, true)

svg/src/main/java/com/itextpdf/svg/renderers/impl/LinearGradientSvgNodeRenderer.java

@@ -71,7 +71,7 @@ public Color createColor(SvgDrawContext context, Rectangle objectBoundingBox, fl
 
         return builder.buildColor(
                 objectBoundingBox.applyMargins(objectBoundingBoxMargin, objectBoundingBoxMargin, objectBoundingBoxMargin, objectBoundingBoxMargin, true),
-                context.getCurrentCanvasTransform()
+                context.getCurrentCanvasTransform(), context.getCurrentCanvas().getDocument()
         );
     }