Support stroke-opacity at layout level for text elements

DEVSIX-8774

Author: AnhelinaM

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

@@ -1514,9 +1514,6 @@ public PdfCanvas setMiterLimit(float miterLimit) {
      */
     public PdfCanvas setLineDash(float phase) {
         PdfArray dashPattern = getDashPatternArray(phase);
-        if (dashPattern == null) {
-            return this;
-        }
         currentGs.setDashPattern(dashPattern);
         contentStream.getOutputStream().writeByte('[').writeByte(']').writeSpace()
                 .writeFloat(phase).writeSpace()

layout/src/main/java/com/itextpdf/layout/ElementPropertyContainer.java

@@ -604,20 +604,62 @@ public T setTextRenderingMode(int textRenderingMode) {
      * The stroke color is the color of the outlines or edges of a shape.
      *
      * @return the current stroke color
+     *
+     * @deprecated in favour of {@link #getTransparentStrokeColor()} which should be renamed to {@code getStrokeColor}
+     * after this method will be removed
      */
+    @Deprecated
     public Color getStrokeColor() {
-        return this.<Color>getProperty(Property.STROKE_COLOR);
+        return this.<TransparentColor>getProperty(Property.STROKE_COLOR).getColor();
+    }
+
+    /**
+     * Gets the stroke color for the current element.
+     * The stroke color is the color of the outlines or edges of a shape.
+     *
+     * @return the current stroke color
+     */
+    public TransparentColor getTransparentStrokeColor() {
+        return this.<TransparentColor>getProperty(Property.STROKE_COLOR);
     }
 
     /**
      * Sets the stroke color for the current element.
      * The stroke color is the color of the outlines or edges of a shape.
      *
      * @param strokeColor a new stroke color
-     * @return this Element.
+     *
+     * @return this element
      */
     public T setStrokeColor(Color strokeColor) {
-        setProperty(Property.STROKE_COLOR, strokeColor);
+        return setStrokeColor(strokeColor, 1f);
+    }
+
+    /**
+     * Sets the stroke color for the current element.
+     * The stroke color is the color of the outlines or edges of a shape.
+     *
+     * @param strokeColor a {@link Color} for the stroke
+     * @param opacity an opacity for the stroke color; a float between 0 and 1, where 1 stands for fully opaque color
+     *                and 0 - for fully transparent
+     *
+     * @return this element
+     */
+    public T setStrokeColor(Color strokeColor, float opacity) {
+        setProperty(Property.STROKE_COLOR, strokeColor != null ? new TransparentColor(strokeColor, opacity) : null);
+        return (T) (Object) this;
+    }
+
+    /**
+     * Sets the stroke color for the current element.
+     * The stroke color is the color of the outlines or edges of a shape.
+     *
+     * @param transparentColor a new stroke color with transparency
+     *
+     * @return this element
+     */
+    public T setStrokeColor(TransparentColor transparentColor) {
+        setProperty(Property.STROKE_COLOR, transparentColor);
         return (T) (Object) this;
     }
 

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

@@ -23,6 +23,7 @@ This file is part of the iText (R) project.
 package com.itextpdf.layout;
 
 import com.itextpdf.io.font.constants.StandardFonts;
+import com.itextpdf.kernel.colors.Color;
 import com.itextpdf.kernel.colors.ColorConstants;
 import com.itextpdf.kernel.font.PdfFont;
 import com.itextpdf.kernel.font.PdfFontFactory;
@@ -131,6 +132,78 @@ public void textRenderingModeTest01() throws IOException, InterruptedException {
         Assertions.assertNull(new CompareTool().compareByContent(outFileName, cmpFileName, destinationFolder, "diff"));
     }
 
+    @Test
+    public void textStrokeTest() throws IOException, InterruptedException {
+        String outFileName = destinationFolder + "textStrokeTest.pdf";
+        String cmpFileName = sourceFolder + "cmp_textStrokeTest.pdf";
+        try (PdfDocument pdfDocument = new PdfDocument(new PdfWriter(outFileName));
+        Document document = new Document(pdfDocument)) {
+            Text text1 = new Text("Red stroke text via color setter")
+                    .setTextRenderingMode(PdfCanvasConstants.TextRenderingMode.STROKE)
+                    .setStrokeColor(ColorConstants.RED)
+                    .setStrokeWidth(0.1f);
+            document.add(new Paragraph().add(text1));
+
+            Text text2 = new Text("Red transparent stroke text via setter with 2 parameters")
+                    .setTextRenderingMode(PdfCanvasConstants.TextRenderingMode.STROKE)
+                    .setStrokeColor(ColorConstants.RED, 0.5f)
+                    .setStrokeWidth(0.1f);
+            document.add(new Paragraph().add(text2));
+
+            Text text3 = new Text("Red transparent stroke text via transparent color setter")
+                    .setTextRenderingMode(PdfCanvasConstants.TextRenderingMode.STROKE)
+                    .setStrokeColor(new TransparentColor(ColorConstants.RED, 0.5f))
+                    .setStrokeWidth(0.1f);
+            document.add(new Paragraph().add(text3));
+
+            Text text4 = new Text("Red transparent stroke text via transparent color property")
+                    .setTextRenderingMode(PdfCanvasConstants.TextRenderingMode.STROKE)
+                    .setStrokeWidth(0.1f);
+            text4.setProperty(Property.STROKE_COLOR, new TransparentColor(ColorConstants.RED, 0.5f));
+            document.add(new Paragraph().add(text4));
+
+            Text text5 = new Text("Red transparent stroke text via color property")
+                    .setTextRenderingMode(PdfCanvasConstants.TextRenderingMode.STROKE)
+                    .setStrokeWidth(0.1f);
+            text5.setProperty(Property.STROKE_COLOR, ColorConstants.RED);
+            document.add(new Paragraph().add(text5));
+        }
+        Assertions.assertNull(new CompareTool().compareByContent(outFileName, cmpFileName, destinationFolder, "diff"));
+    }
+
+    @Test
+    public void textFillStrokeTest() throws IOException, InterruptedException {
+        String outFileName = destinationFolder + "textFillStrokeTest.pdf";
+        String cmpFileName = sourceFolder + "cmp_textFillStrokeTest.pdf";
+        try (PdfDocument pdfDocument = new PdfDocument(new PdfWriter(outFileName));
+             Document document = new Document(pdfDocument)) {
+            Text text1 = new Text("Pink text with null stroke color (so font color is used)")
+                    .setTextRenderingMode(PdfCanvasConstants.TextRenderingMode.FILL_STROKE)
+                    .setFontColor(ColorConstants.PINK)
+                    .setStrokeColor((Color) null)
+                    .setStrokeWidth(2)
+                    .setFontSize(50);
+            document.add(new Paragraph().add(text1));
+
+            Text text2 = new Text("Pink text with red half-transparent stroke")
+                    .setTextRenderingMode(PdfCanvasConstants.TextRenderingMode.FILL_STROKE)
+                    .setFontColor(ColorConstants.PINK)
+                    .setStrokeColor(ColorConstants.RED, 0.5f)
+                    .setStrokeWidth(2)
+                    .setFontSize(50);
+            document.add(new Paragraph().add(text2));
+
+            Text text3 = new Text("Pink text with fully transparent stroke")
+                    .setTextRenderingMode(PdfCanvasConstants.TextRenderingMode.FILL_STROKE)
+                    .setFontColor(ColorConstants.PINK)
+                    .setStrokeColor(new TransparentColor(ColorConstants.RED, 0f))
+                    .setStrokeWidth(2)
+                    .setFontSize(50);
+            document.add(new Paragraph().add(text3));
+        }
+        Assertions.assertNull(new CompareTool().compareByContent(outFileName, cmpFileName, destinationFolder, "diff"));
+    }
+
     @Test
     public void leadingTest01() throws IOException, InterruptedException {
         String outFileName = destinationFolder + "leadingTest01.pdf";
@@ -365,12 +438,13 @@ public void strokedUnderlineTest() throws IOException, InterruptedException {
                     .setDashPattern(new float[]{5, 5, 10, 5}, 5);
             p.setUnderline(underline);
 
+            TransparentColor strokeColor = new TransparentColor(ColorConstants.GREEN, 0.5f);
             Paragraph p2 = new Paragraph("Text with line-through and default underline.")
                     .setFontSize(50).setStrokeWidth(1).setFontColor(ColorConstants.DARK_GRAY)
-                    .setStrokeColor(ColorConstants.GREEN);
+                    .setStrokeColor(strokeColor);
             Underline underline2 = new Underline(ColorConstants.DARK_GRAY, 0, 0.1f, 0, 0.3f,
                     PdfCanvasConstants.LineCapStyle.BUTT)
-                    .setStrokeWidth(1).setStrokeColor(new TransparentColor(ColorConstants.GREEN));
+                    .setStrokeWidth(1).setStrokeColor(strokeColor);
             p2.setUnderline(underline2);
             p2.setUnderline();
 

layout/src/test/java/com/itextpdf/layout/TextWritingTest.java

@@ -968,7 +968,7 @@ public void drawTextRenderingModeFillStrokeTest() {
                     .setBackgroundColor(ColorConstants.YELLOW)
                     .setWidth(10)
                     .setStrokeWidth(1f)
-                    .setStrokeColor(null)
+                    .setStrokeColor((TransparentColor) null)
                     .setBorder(new SolidBorder(1));
             paragraph.setNextRenderer(new TextRenderer(text) {
                 @Override

layout/src/test/java/com/itextpdf/layout/renderer/TextRendererIntegrationTest.java

@@ -328,6 +328,7 @@ void postDraw(SvgDrawContext context) {
                         }
                     } else {
                         if (doStroke) {
+                            // TODO DEVSIX-8854 Draw SVG elements with transparent stroke in 2 steps
                             currentCanvas.fillStroke();
                         } else {
                             currentCanvas.fill();
@@ -396,6 +397,7 @@ void applyFillAndStrokeProperties(FillProperties fillProperties, StrokePropertie
             currentCanvas.setLineWidth(strokeProperties.getWidth());
 
             if (!CssUtils.compareFloats(strokeProperties.getOpacity(), 1f)) {
+                // TODO DEVSIX-8854 Draw SVG elements with transparent stroke in 2 steps
                 opacityGraphicsState.setStrokeOpacity(strokeProperties.getOpacity());
             }
         }

layout/src/test/resources/com/itextpdf/layout/TextWritingTest/cmp_strokedUnderline.pdf

@@ -143,12 +143,10 @@ private void applyTransform(SvgDrawContext context) {
 
     private void applyGraphicsState(SvgDrawContext context) {
         SvgTextProperties textProperties = context.getSvgTextProperties();
-        // TODO DEVSIX-8774 support stroke-opacity for text at layout level
-        text.setFontColor(textProperties.getFillColor());
+        text.setFontColor(textProperties.getFillColor(), textProperties.getFillOpacity());
         text.setStrokeWidth(textProperties.getLineWidth());
-        text.setStrokeColor(textProperties.getStrokeColor());
+        text.setStrokeColor(textProperties.getStrokeColor(), textProperties.getStrokeOpacity());
         text.setDashPattern(textProperties.getDashArray(), textProperties.getDashPhase());
-        text.setOpacity(textProperties.getFillOpacity());
         text.setProperty(Property.UNDERLINE, textProperties.getTextDecoration());
     }