Extract part of the margin box handling logic to tag worker and css applier

This allows customization of margin boxes processing.
See new tests that show examples of how it is done.

DEVSIX-1563

Author: yulian-gaponenko

src/main/java/com/itextpdf/html2pdf/LogMessageConstant.java

@@ -49,24 +49,17 @@ public final class LogMessageConstant {
 
     /** The Constant CONTENT_PROPERTY_INVALID. */
     public static final String CONTENT_PROPERTY_INVALID = "Content property \"{0}\" is either invalid or uses unsupported function.";
-
     /** The Constant CSS_PROPERTY_IN_PERCENTS_NOT_SUPPORTED. */
     public static final String CSS_PROPERTY_IN_PERCENTS_NOT_SUPPORTED = "Css property {0} in percents is not supported";
-
     public static final String DEFAULT_VALUE_OF_CSS_PROPERTY_UNKNOWN = "Default value of the css property \"{0}\" is unknown.";
-
     /** The Constant ERROR_LOADING_FONT. */
     public static final String ERROR_LOADING_FONT = "Error while loading font";
-
     /** The Constant ERROR_PARSING_CSS_SELECTOR. */
     public static final String ERROR_PARSING_CSS_SELECTOR = "Error while parsing css selector: {0}";
-
     /** The Constant ERROR_RESOLVING_PARENT_STYLES. */
     public static final String ERROR_RESOLVING_PARENT_STYLES = "Element parent styles are not resolved. Styles for current element might be incorrect.";
-
     /** The Constant ERROR_WHILE_LAYOUT_OF_FORM_FIELD. */
     public static final String ERROR_WHILE_LAYOUT_OF_FORM_FIELD = "Cannot layout form field field. It won't be displayed";
-
     /** The Constant ERROR_WHILE_LAYOUT_OF_FORM_FIELD_WITH_TYPE. */
     public static final String ERROR_WHILE_LAYOUT_OF_FORM_FIELD_WITH_TYPE = "Error during layout of form filed with type {0}.";
     /** The Constant HEIGHT_VALUE_IN_PERCENT_NOT_SUPPORTED. */
@@ -77,13 +70,10 @@ public final class LogMessageConstant {
     public static final String INPUT_SUPPORTS_ONLY_POINT_WIDTH = "Input field supports only point width";
     /** The Constant INPUT_TYPE_IS_NOT_SUPPORTED. */
     public static final String INPUT_TYPE_IS_NOT_SUPPORTED = "Input type {0} is not supported";
-
     /** The Constant INVALID_CSS_PROPERTY_DECLARATION. */
     public static final String INVALID_CSS_PROPERTY_DECLARATION = "Invalid css property declaration: {0}";
-
     /** The Constant MARGIN_VALUE_IN_PERCENT_NOT_SUPPORTED. */
     public static final String MARGIN_VALUE_IN_PERCENT_NOT_SUPPORTED = "Margin value in percents not supported";
-
     /** The Constant NOT_SUPPORTED_LIST_STYLE_TYPE. */
     public static final String NOT_SUPPORTED_LIST_STYLE_TYPE = "Not supported list style type: {0}";
     /** The Constant NO_CONSUMER_FOUND_FOR_CONTENT. */
@@ -94,10 +84,10 @@ public final class LogMessageConstant {
     public static final String NO_IPROPERTYCONTAINER_RESULT_FOR_THE_TAG = "Tag worker does not produce IPropertyContainer for \"{0}\" tag. An outline for \"{0}\" tag will not be created.";
     /** The Constant NO_WORKER_FOUND_FOR_TAG. */
     public static final String NO_WORKER_FOUND_FOR_TAG = "No worker found for tag {0}";
-
     /** The Constant PADDING_VALUE_IN_PERCENT_NOT_SUPPORTED. */
     public static final String PADDING_VALUE_IN_PERCENT_NOT_SUPPORTED = "Padding value in percents not supported";
     public static final String PAGE_MARGIN_BOX_CONTENT_CANNOT_BE_DRAWN = "Page margin box {0} content cannot be drawn.";
+    public static final String PAGE_MARGIN_BOX_SOME_PROPERTIES_NOT_PROCESSED = "Page margin box margin, padding, height and width properties are not processed. Passed styles container shall be of PageMarginBoxContextNode type.";
     /** The Constant PAGE_SIZE_VALUE_IS_INVALID. */
     public static final String PAGE_SIZE_VALUE_IS_INVALID = "Page size value {0} is invalid.";
     /** The Constant QUOTES_PROPERTY_INVALID. */

src/main/java/com/itextpdf/html2pdf/attach/impl/DefaultTagWorkerMapping.java

@@ -2,15 +2,15 @@
     This file is part of the iText (R) project.
     Copyright (c) 1998-2017 iText Group NV
     Authors: Bruno Lowagie, Paulo Soares, et al.
-    
+
     This program is free software; you can redistribute it and/or modify
     it under the terms of the GNU Affero General Public License version 3
     as published by the Free Software Foundation with the addition of the
     following permission added to Section 15 as permitted in Section 7(a):
     FOR ANY PART OF THE COVERED WORK IN WHICH THE COPYRIGHT IS OWNED BY
     ITEXT GROUP. ITEXT GROUP DISCLAIMS THE WARRANTY OF NON INFRINGEMENT
     OF THIRD PARTY RIGHTS
-    
+
     This program is distributed in the hope that it will be useful, but
     WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
     or FITNESS FOR A PARTICULAR PURPOSE.
@@ -20,23 +20,23 @@ This file is part of the iText (R) project.
     the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
     Boston, MA, 02110-1301 USA, or download the license from the following URL:
     http://itextpdf.com/terms-of-use/
-    
+
     The interactive user interfaces in modified source and object code versions
     of this program must display Appropriate Legal Notices, as required under
     Section 5 of the GNU Affero General Public License.
-    
+
     In accordance with Section 7(b) of the GNU Affero General Public License,
     a covered work must retain the producer line in every PDF that is created
     or manipulated using iText.
-    
+
     You can be released from the requirements of the license by purchasing
     a commercial license. Buying such a license is mandatory as soon as you
     develop commercial activities involving the iText software without
     disclosing the source code of your own applications.
     These activities include: offering paid services to customers as an ASP,
     serving PDFs on the fly in a web application, shipping iText with a closed
     source product.
-    
+
     For more information, please contact iText Software Corp. at this
     address: sales@itextpdf.com
  */
@@ -63,6 +63,7 @@ This file is part of the iText (R) project.
 import com.itextpdf.html2pdf.attach.impl.tags.MetaTagWorker;
 import com.itextpdf.html2pdf.attach.impl.tags.PTagWorker;
 import com.itextpdf.html2pdf.attach.impl.tags.PageCountWorker;
+import com.itextpdf.html2pdf.attach.impl.tags.PageMarginBoxWorker;
 import com.itextpdf.html2pdf.attach.impl.tags.PreTagWorker;
 import com.itextpdf.html2pdf.attach.impl.tags.SpanTagWorker;
 import com.itextpdf.html2pdf.attach.impl.tags.TableFooterTagWorker;
@@ -75,6 +76,7 @@ This file is part of the iText (R) project.
 import com.itextpdf.html2pdf.attach.impl.tags.TrTagWorker;
 import com.itextpdf.html2pdf.attach.impl.tags.UlOlTagWorker;
 import com.itextpdf.html2pdf.css.CssConstants;
+import com.itextpdf.html2pdf.css.page.PageMarginBoxContextNode;
 import com.itextpdf.html2pdf.css.pseudo.CssPseudoElementUtil;
 import com.itextpdf.html2pdf.css.resolve.func.counter.PageCountElementNode;
 import com.itextpdf.html2pdf.html.TagConstants;
@@ -208,6 +210,7 @@ private DefaultTagWorkerMapping() {
 
         // custom elements mapping, implementation-specific
         workerMapping.putMapping(PageCountElementNode.PAGE_COUNTER_TAG, PageCountWorker.class);
+        workerMapping.putMapping(PageMarginBoxContextNode.PAGE_MARGIN_BOX_TAG, PageMarginBoxWorker.class);
     }
 
     /**