Fix preserveAspectRatio application

Add support for different preserveAspectRatio attribute values
Add unit tests

DEVSIX-2240

Author: BlackEgoist

forms/src/main/java/com/itextpdf/forms/xfdf/XfdfObject.java

@@ -83,7 +83,6 @@ public void setFields(FieldsObject fields) {
         this.fields = fields;
     }
 
-
     public AnnotsObject getAnnots() {
         return annots;
     }

svg/src/main/java/com/itextpdf/svg/SvgConstants.java

@@ -849,18 +849,13 @@ public static final class Values {
         /**
          * Value representing the default aspect ratio: xmidymid.
          */
-        public static final String DEFAULT_ASPECT_RATIO = "xmidymid";
+        public static final String DEFAULT_ASPECT_RATIO = Values.XMID_YMID;
 
         /**
          * Value representing how to preserve the aspect ratio when dealing with images.
          */
         public static final String DEFER = "defer";
 
-        /**
-         * Value representing the text-alignment end for text objects
-         */
-        public static final String TEXT_ANCHOR_END = "end";
-
         /**
          * Value representing the fill rule "even odd".
          */
@@ -872,25 +867,41 @@ public static final class Values {
         public static final String FILL_RULE_NONZERO = "nonzero";
 
         /**
-         * Value representing the text-alignment middle for text objects
+         * Value representing the meet for preserve aspect ratio calculations.
          */
-        public static final String TEXT_ANCHOR_MIDDLE = "middle";
+        public static final String MEET = "meet";
 
         /**
          * Value representing the "none" value".
          */
         public static final String NONE = "none";
 
         /**
-         * Value representing the text-alignment start for text objects
+         * The value representing slice for the preserve aspect ratio calculations;
          */
-        public static final String TEXT_ANCHOR_START = "start";
+        public static final String SLICE = "slice";
 
         /**
-         * The value corresponding with the namespace url for SVG
+         * The value corresponding with the namespace url for SVG. Will be removed since version 7.2.
          */
+        @Deprecated
         public static final String SVGNAMESPACEURL = "http://www.w3.org/2000/svg";
 
+        /**
+         * Value representing the text-alignment end for text objects
+         */
+        public static final String TEXT_ANCHOR_END = "end";
+
+        /**
+         * Value representing the text-alignment middle for text objects
+         */
+        public static final String TEXT_ANCHOR_MIDDLE = "middle";
+
+        /**
+         * Value representing the text-alignment start for text objects
+         */
+        public static final String TEXT_ANCHOR_START = "start";
+
         /**
          * Value representing how to align when scaling.
          */
@@ -906,6 +917,11 @@ public static final class Values {
          */
         public static final String XMIN_YMAX = "xminymax";
 
+        /**
+         * Value representing how to align when scaling.
+         */
+        public static final String XMID_YMID = "xmidymid";
+
         /**
          * Value representing how to align when scaling.
          */

svg/src/main/java/com/itextpdf/svg/converter/SvgConverter.java

@@ -667,7 +667,9 @@ public static PdfFormXObject convertToXObject(InputStream stream, PdfDocument do
     //Private converter for unification
     private static PdfFormXObject convertToXObject(ISvgProcessorResult processorResult, PdfDocument document, ISvgConverterProperties props) {
         String baseUri = "";
-        if (props != null) baseUri = props.getBaseUri();
+        if (props != null) {
+            baseUri = props.getBaseUri();
+        }
         SvgDrawContext drawContext = new SvgDrawContext(new ResourceResolver(baseUri), processorResult.getFontProvider());
         drawContext.setTempFonts(processorResult.getTempFonts());
         drawContext.addNamedObjects(processorResult.getNamedObjects());