Support 'viewbox' and `preserveAspectRatio' attribute for SVG pattern element

DEVSIX-4782

Author: ar3em

svg/src/main/java/com/itextpdf/svg/exceptions/SvgExceptionMessageConstant.java

@@ -50,8 +50,15 @@ public class SvgExceptionMessageConstant {
     public static final String CURVE_TO_EXPECTS_FOLLOWING_PARAMETERS_GOT_0 = "(x1 y1 x2 y2 x y)+ parameters are expected for curves. Got: {0}";
     public static final String INVALID_SMOOTH_CURVE_USE = "The smooth curve operations (S, s, T, t) may not be used as a first operator in path.";
     public static final String QUADRATIC_CURVE_TO_EXPECTS_FOLLOWING_PARAMETERS_GOT_0 = "(x1 y1 x y)+ parameters are expected for quadratic curves. Got: {0}";
+    public static final String MEET_OR_SLICE_ARGUMENT_IS_INCORRECT =
+            "The meetOrSlice argument is incorrect. It must be `meet`, `slice` or null.";
     public static final String MOVE_TO_EXPECTS_FOLLOWING_PARAMETERS_GOT_0 = "(x y)+ parameters are expected for moveTo operator. Got: {0}";
     public static final String LINE_TO_EXPECTS_FOLLOWING_PARAMETERS_GOT_0 = "(x y)+ parameters are expected for lineTo operator. Got: {0}";
 
     public static final String COULD_NOT_DETERMINE_MIDDLE_POINT_OF_ELLIPTICAL_ARC = "Could not determine the middle point of the ellipse traced by this elliptical arc";
+
+    public static final String VIEWBOX_APPLYING_COULD_NOT_BE_PROCESSED =
+            "The viewBox or the current viewport is null. The viewBox applying could not be processed.";
+
+
 }

svg/src/main/java/com/itextpdf/svg/exceptions/SvgLogMessageConstant.java

@@ -60,7 +60,9 @@ public final class SvgLogMessageConstant {
     @Deprecated
     public static final String FLOAT_PARSING_NAN = "The passed value is not a number.";
     public static final String FONT_NOT_FOUND = "The font wasn't found.";
-    /** Message in case the font provider doesn't know about any fonts. */
+    /**
+     * Message in case the font provider doesn't know about any fonts.
+     */
     @Deprecated
     public static final String FONT_PROVIDER_CONTAINS_ZERO_FONTS = "Font Provider contains zero fonts. At least one font shall be present";
     public static final String GRADIENT_INVALID_GRADIENT_UNITS_LOG = "Could not recognize gradient units value {0}";
@@ -69,19 +71,24 @@ public final class SvgLogMessageConstant {
     public static final String INVALID_CLOSEPATH_OPERATOR_USE = "The close path operator (Z) may not be used before a move to operation (M)";
     public static final String INVALID_PATH_D_ATTRIBUTE_OPERATORS = "Invalid operators found in path data attribute: {0}";
     public static final String INVALID_TRANSFORM_DECLARATION = "Transformation declaration is not formed correctly.";
-    public static final String LOOP ="Loop detected";
+    public static final String LOOP = "Loop detected";
     public static final String MARKER_HEIGHT_IS_NEGATIVE_VALUE = "markerHeight has negative value. Marker will not be rendered.";
     public static final String MARKER_HEIGHT_IS_ZERO_VALUE = "markerHeight has zero value. Marker will not be rendered.";
     public static final String MARKER_WIDTH_IS_NEGATIVE_VALUE = "markerWidth has negative value. Marker will not be rendered.";
     public static final String MARKER_WIDTH_IS_ZERO_VALUE = "markerWidth has zero value. Marker will not be rendered.";
-    public static final String MISSING_WIDTH="Top Svg tag has no defined width attribute and viewbox width is not present, so browser default of 300px is used";
-    public static final String MISSING_HEIGHT="Top Svg tag has no defined height attribute and viewbox height is not present, so browser default of 150px is used";
+    public static final String MISSING_WIDTH = "Top Svg tag has no defined width attribute and viewbox width is not present, so browser default of 300px is used";
+    public static final String MISSING_HEIGHT = "Top Svg tag has no defined height attribute and viewbox height is not present, so browser default of 150px is used";
     public static final String NAMED_OBJECT_NAME_NULL_OR_EMPTY = "The name of the named object can't be null or empty.";
     public static final String NAMED_OBJECT_NULL = "A named object can't be null.";
     public static final String NONINVERTIBLE_TRANSFORMATION_MATRIX_USED_IN_CLIP_PATH = "Non-invertible transformation matrix was used in a clipping path context. Clipped elements may show undefined behavior.";
     public static final String NOROOT = "No root found";
     public static final String PATTERN_INVALID_PATTERN_UNITS_LOG = "Could not recognize patternUnits value {0}";
-    public static final String PATTERN_INVALID_PATTERN_CONTENT_UNITS_LOG = "Could not recognize patternContentUnits value {0}";
+    public static final String PATTERN_INVALID_PATTERN_CONTENT_UNITS_LOG =
+            "Could not recognize patternContentUnits value {0}";
+    public static final String PATTERN_WIDTH_OR_HEIGHT_IS_ZERO =
+            "Pattern width or height is zero. This pattern will not be rendered.";
+    public static final String PATTERN_WIDTH_OR_HEIGHT_IS_NEGATIVE =
+            "Pattern width or height is negative value. This pattern will not be rendered.";
     public static final String PATH_WRONG_NUMBER_OF_ARGUMENTS = "Path operator {0} has received {1} arguments, but expects between {2} and {3} arguments. \n Resulting SVG will be incorrect.";
     public static final String PARAMETER_CANNOT_BE_NULL = "Parameters for this method cannot be null.";
     public static final String POINTS_ATTRIBUTE_INVALID_LIST = "Points attribute {0} on polyline tag does not contain a valid set of points";
@@ -97,6 +104,13 @@ public final class SvgLogMessageConstant {
     public static final String UNABLE_TO_RETRIEVE_FONT = "Unable to retrieve font:\n {0}";
     public static final String UNMAPPEDTAG = "Could not find implementation for tag {0}";
     public static final String UNKNOWN_TRANSFORMATION_TYPE = "Unsupported type of transformation.";
+    public static final String VIEWBOX_VALUE_MUST_BE_FOUR_NUMBERS =
+            "The viewBox value must be 4 numbers. This viewBox=\"{0}\" will not be processed.";
+    public static final String VIEWBOX_WIDTH_AND_HEIGHT_CANNOT_BE_NEGATIVE =
+            "The viewBox width and height cannot be negative. This viewBox=\"{0}\" will not be processed.";
+    public static final String VIEWBOX_WIDTH_OR_HEIGHT_IS_ZERO =
+            "The viewBox width or height is zero. The element with this viewBox will not be rendered.";
 
-    private SvgLogMessageConstant(){}
+    private SvgLogMessageConstant() {
+    }
 }

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

@@ -42,6 +42,7 @@ This file is part of the iText (R) project.
  */
 package com.itextpdf.svg.renderers.impl;
 
+import com.itextpdf.io.util.MessageFormatUtil;
 import com.itextpdf.kernel.geom.AffineTransform;
 import com.itextpdf.kernel.geom.Matrix;
 import com.itextpdf.kernel.geom.NoninvertibleTransformException;
@@ -67,7 +68,6 @@ This file is part of the iText (R) project.
 import java.util.Arrays;
 import java.util.Collections;
 import java.util.List;
-
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -77,8 +77,15 @@ This file is part of the iText (R) project.
  */
 public abstract class AbstractBranchSvgNodeRenderer extends AbstractSvgNodeRenderer implements IBranchSvgNodeRenderer {
 
+    /**
+     * The number of viewBox values.
+     */
+    protected final static int VIEWBOX_VALUES_NUMBER = 4;
+
     private final List<ISvgNodeRenderer> children = new ArrayList<>();
 
+    private static final Logger LOGGER = LoggerFactory.getLogger(AbstractBranchSvgNodeRenderer.class);
+
     /**
      * Method that will set properties to be inherited by this branch renderer's
      * children and will iterate over all children in order to draw them.
@@ -142,14 +149,14 @@ protected void doDraw(SvgDrawContext context) {
      * @param context current svg draw context
      */
     void applyViewBox(SvgDrawContext context) {
-        if (this.attributesAndStyles != null && this.attributesAndStyles.containsKey(SvgConstants.Attributes.VIEWBOX)) {
-            float[] values = getViewBoxValues();
+        float[] viewBoxValues = getViewBoxValues();
+        if (viewBoxValues.length < VIEWBOX_VALUES_NUMBER) {
+            float[] values = {0, 0, context.getCurrentViewPort().getWidth(), context.getCurrentViewPort().getHeight()};
             Rectangle currentViewPort = context.getCurrentViewPort();
             calculateAndApplyViewBox(context, values, currentViewPort);
         } else {
-            float[] values = {0, 0, context.getCurrentViewPort().getWidth(), context.getCurrentViewPort().getHeight()};
             Rectangle currentViewPort = context.getCurrentViewPort();
-            calculateAndApplyViewBox(context, values, currentViewPort);
+            calculateAndApplyViewBox(context, viewBoxValues, currentViewPort);
         }
     }
 
@@ -349,6 +356,7 @@ void setPartOfClipPath(boolean isPart) {
     }
 
     void calculateAndApplyViewBox(SvgDrawContext context, float[] values, Rectangle currentViewPort) {
+        // TODO DEVSIX-4861 change this method with using of SvgCoordinateUtils#applyViewBox
         String[] alignAndMeet = retrieveAlignAndMeet();
         String align = alignAndMeet[0];
         String meetOrSlice = alignAndMeet[1];
@@ -395,12 +403,35 @@ void calculateAndApplyViewBox(SvgDrawContext context, float[] values, Rectangle
     }
 
     float[] getViewBoxValues() {
+        if (this.attributesAndStyles == null) {
+            return new float[]{};
+        }
         String viewBoxValues = attributesAndStyles.get(SvgConstants.Attributes.VIEWBOX);
+        if (viewBoxValues == null) {
+            return new float[]{};
+        }
         List<String> valueStrings = SvgCssUtils.splitValueList(viewBoxValues);
         float[] values = new float[valueStrings.size()];
         for (int i = 0; i < values.length; i++) {
             values[i] = CssDimensionParsingUtils.parseAbsoluteLength(valueStrings.get(i));
         }
+        // the value for viewBox should be 4 numbers according to the viewBox documentation
+        if (values.length != VIEWBOX_VALUES_NUMBER) {
+            if (LOGGER.isWarnEnabled()) {
+                LOGGER.warn(MessageFormatUtil.format(
+                        SvgLogMessageConstant.VIEWBOX_VALUE_MUST_BE_FOUR_NUMBERS, viewBoxValues));
+            }
+            return new float[]{};
+        }
+        // case when viewBox width or height is negative value is an error and
+        // invalidates the ‘viewBox’ attribute (according to the viewBox documentation)
+        if (values[2] < 0 || values[3] < 0) {
+            if (LOGGER.isWarnEnabled()) {
+                LOGGER.warn(MessageFormatUtil.format(
+                        SvgLogMessageConstant.VIEWBOX_WIDTH_AND_HEIGHT_CANNOT_BE_NEGATIVE, viewBoxValues));
+            }
+            return new float[]{};
+        }
         return values;
     }
 

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

@@ -206,11 +206,8 @@ private void applyUserSpaceScaling(SvgDrawContext context) {
     private void applyCoordinatesTranslation(SvgDrawContext context) {
         float xScale = 1;
         float yScale = 1;
-        if (this.attributesAndStyles.containsKey(SvgConstants.Attributes.VIEWBOX)) {
-            //Parse viewbox parameters stuff
-            String viewBoxValues = attributesAndStyles.get(SvgConstants.Attributes.VIEWBOX);
-            List<String> valueStrings = SvgCssUtils.splitValueList(viewBoxValues);
-            float[] viewBox = getViewBoxValues();
+        float[] viewBox = getViewBoxValues();
+        if (viewBox.length == VIEWBOX_VALUES_NUMBER) {
             xScale = context.getCurrentViewPort().getWidth() / viewBox[2];
             yScale = context.getCurrentViewPort().getHeight() / viewBox[3];
         }
@@ -234,19 +231,14 @@ private void applyCoordinatesTranslation(SvgDrawContext context) {
     }
 
     private float[] getViewBoxValues(float defaultWidth, float defaultHeight) {
-        float[] values;
-        if (this.attributesAndStyles.containsKey(SvgConstants.Attributes.VIEWBOX)) {
-            //Parse viewbox parameters stuff
-            values = super.getViewBoxValues();
+        float[] values = super.getViewBoxValues();
+        if (values.length < VIEWBOX_VALUES_NUMBER) {
+            //If viewBox is not specified or incorrect, it's width and height are the same as passed defaults
+            return new float[] {0, 0, defaultWidth, defaultHeight};
+
         } else {
-            //If viewbox is not specified, it's width and height are the same as passed defaults
-            values = new float[4];
-            values[0] = 0;
-            values[1] = 0;
-            values[2] = defaultWidth;
-            values[3] = defaultHeight;
+            return values;
         }
-        return values;
     }
 }