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svg is a module for iText7 that allows you to integrate SVG images in your PDF creation and manipulation process
/*
This file is part of the iText (R) project.
Copyright (c) 1998-2018 iText Group NV
Authors: iText Software.
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.
See the GNU Affero General Public License for more details.
You should have received a copy of the GNU Affero General Public License
along with this program; if not, see http://www.gnu.org/licenses or write to
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
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These activities include: offering paid services to customers as an ASP,
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*/
package com.itextpdf.svg.utils;
import com.itextpdf.kernel.geom.AffineTransform;
import com.itextpdf.styledxmlparser.css.util.CssUtils;
import com.itextpdf.svg.exceptions.SvgLogMessageConstant;
import com.itextpdf.svg.exceptions.SvgProcessingException;
import java.util.ArrayList;
import java.util.List;
import java.util.StringTokenizer;
/**
* Utility class responsible for converting Strings containing transformation declarations
* into AffineTransform objects.
*
* This class only supports the transformations as described in the SVG specification:
* - matrix
* - rotate
* - scale
* - skewX
* - skewY
* - translate
*/
public final class TransformUtils {
/**
* Keyword for matrix transformations. Accepts 6 values.
*
* matrix(0 1 2 3 4 5)
*/
private static final String MATRIX = "MATRIX";
/**
* Keyword for rotation transformation. Accepts either 1 or 3 values.
* In the case of 1 value, x and y are assumed to be the origin of the user space.
*
* rotate(angle x y)
* rotate(angle)
*/
private static final String ROTATE = "ROTATE";
/**
* Keyword for scale transformation. Accepts either 1 or 2 values.
* In the case of 1 value, the second value is assumed to be the same as the first one.
*
* scale(x y)
* scale(x)
*/
private static final String SCALE = "SCALE";
/**
* Keyword for skewX transformation. Accepts 1 value.
*
* skewX(angle)
*/
private static final String SKEWX = "SKEWX";
/**
* Keyword for skewY transformation. Accepts 1 value.
*
* skewY(angle)
*/
private static final String SKEWY = "SKEWY";
/**
* Keyword for translate transformation. Accepts either 1 or 2 values.
* In the case of 1 value, the y value is assumed to be 0.
*
* translate(x y)
* translate(x)
*/
private static final String TRANSLATE = "TRANSLATE";
private TransformUtils() {}
/**
* Converts a string containing a transform declaration into an AffineTransform object.
* This class only supports the transformations as described in the SVG specification:
* - matrix
* - translate
* - skewx
* - skewy
* - rotate
* - scale
*
* @param transform value to be parsed
* @return the AffineTransform object
*/
public static AffineTransform parseTransform(String transform) {
if (transform == null ) {
throw new SvgProcessingException(SvgLogMessageConstant.TRANSFORM_NULL);
}
if (transform.isEmpty()) {
throw new SvgProcessingException(SvgLogMessageConstant.TRANSFORM_EMPTY);
}
AffineTransform matrix = new AffineTransform();
List listWithTransformations = splitString(transform);
for (String transformation : listWithTransformations) {
AffineTransform newMatrix = transformationStringToMatrix(transformation);
if (newMatrix != null) {
matrix.concatenate(newMatrix);
}
}
return matrix;
}
/**
* A transformation attribute can encompass multiple transformation operation (e.g. "translate(10,20) scale(30,40)".
* This method splits the original transformation string into multiple strings so that they can be handled separately.
*
* @param transform the transformation value
* @return a list containing strings describing a single transformation operation
*/
private static List splitString(String transform) {
ArrayList list = new ArrayList<>();
StringTokenizer tokenizer = new StringTokenizer(transform, ")", false);
while (tokenizer.hasMoreTokens()) {
list.add(tokenizer.nextToken().trim() + ")");
}
return list;
}
/**
* This method decides which transformation operation the given transformation strings maps onto.
*
* @param transformation string containing a transformation operation
* @return the mapped AffineTransform object
*/
private static AffineTransform transformationStringToMatrix(String transformation) {
String name = getNameFromString(transformation).toUpperCase();
if ( name.isEmpty() ) {
throw new SvgProcessingException(SvgLogMessageConstant.INVALID_TRANSFORM_DECLARATION);
}
switch (name) {
case MATRIX:
return createMatrixTransformation(getValuesFromTransformationString(transformation));
case TRANSLATE:
return createTranslateTransformation(getValuesFromTransformationString(transformation));
case SCALE:
return createScaleTransformation(getValuesFromTransformationString(transformation));
case ROTATE:
return createRotationTransformation(getValuesFromTransformationString(transformation));
case SKEWX:
return createSkewXTransformation(getValuesFromTransformationString(transformation));
case SKEWY:
return createSkewYTransformation(getValuesFromTransformationString(transformation));
default:
throw new SvgProcessingException(SvgLogMessageConstant.UNKNOWN_TRANSFORMATION_TYPE);
}
}
/**
* Creates a skewY transformation.
*
* @param values values of the transformation
* @return AffineTransform for the skew operation
*/
private static AffineTransform createSkewYTransformation(List values) {
if (values.size() != 1) {
throw new SvgProcessingException(SvgLogMessageConstant.TRANSFORM_INCORRECT_NUMBER_OF_VALUES);
}
double tan = Math.tan(Math.toRadians((float)CssUtils.parseFloat(values.get(0))));
//Differs from the notation in the PDF-spec for skews
return new AffineTransform(1, tan,0, 1, 0, 0);
}
/**
* Creates a skewX transformation.
*
* @param values values of the transformation
* @return AffineTransform for the skew operation
*/
private static AffineTransform createSkewXTransformation(List values) {
if (values.size() != 1) {
throw new SvgProcessingException(SvgLogMessageConstant.TRANSFORM_INCORRECT_NUMBER_OF_VALUES);
}
double tan = Math.tan(Math.toRadians((float)CssUtils.parseFloat(values.get(0))));
//Differs from the notation in the PDF-spec for skews
return new AffineTransform(1,0, tan, 1, 0, 0);
}
/**
* Creates a rotate transformation.
*
* @param values values of the transformation
* @return AffineTransform for the rotate operation
*/
private static AffineTransform createRotationTransformation(List values) {
if (values.size() != 1 && values.size() != 3) {
throw new SvgProcessingException(SvgLogMessageConstant.TRANSFORM_INCORRECT_NUMBER_OF_VALUES);
}
double angle = Math.toRadians((float)CssUtils.parseFloat(values.get(0)));
if (values.size() == 3) {
float centerX = CssUtils.parseAbsoluteLength(values.get(1));
float centerY = CssUtils.parseAbsoluteLength(values.get(2));
return AffineTransform.getRotateInstance(angle, centerX, centerY);
}
return AffineTransform.getRotateInstance(angle);
}
/**
* Creates a scale transformation.
*
* @param values values of the transformation
* @return AffineTransform for the scale operation
*/
private static AffineTransform createScaleTransformation(List values) {
if (values.size() == 0 || values.size() > 2) {
throw new SvgProcessingException(SvgLogMessageConstant.TRANSFORM_INCORRECT_NUMBER_OF_VALUES);
}
float scaleX = CssUtils.parseRelativeValue(values.get(0),1);
float scaleY = values.size() == 2 ? CssUtils.parseRelativeValue(values.get(1),1) : scaleX;
return AffineTransform.getScaleInstance(scaleX, scaleY);
}
/**
* Creates a translate transformation.
*
* @param values values of the transformation
* @return AffineTransform for the translate operation
*/
private static AffineTransform createTranslateTransformation(List values) {
if (values.size() == 0 || values.size() > 2) {
throw new SvgProcessingException(SvgLogMessageConstant.TRANSFORM_INCORRECT_NUMBER_OF_VALUES);
}
float translateX = CssUtils.parseAbsoluteLength(values.get(0));
float translateY = values.size() == 2 ? CssUtils.parseAbsoluteLength(values.get(1)) : 0;
return AffineTransform.getTranslateInstance(translateX, translateY);
}
/**
* Creates a matrix transformation.
*
* @param values values of the transformation
* @return AffineTransform for the matrix keyword
*/
private static AffineTransform createMatrixTransformation(List values) {
if (values.size() != 6) {
throw new SvgProcessingException(SvgLogMessageConstant.TRANSFORM_INCORRECT_NUMBER_OF_VALUES);
}
float a = CssUtils.parseAbsoluteLength(values.get(0));
float b = CssUtils.parseAbsoluteLength(values.get(1));
float c = CssUtils.parseAbsoluteLength(values.get(2));
float d = CssUtils.parseAbsoluteLength(values.get(3));
float e = CssUtils.parseAbsoluteLength(values.get(4));
float f = CssUtils.parseAbsoluteLength(values.get(5));
return new AffineTransform(a, b, c, d, e, f);
}
/**
* This method extracts the transformation name given a transformation.
*
* @param transformation the transformation
* @return the name of the transformation
*/
private static String getNameFromString(String transformation) {
int indexOfParenthesis = transformation.indexOf("(");
if ( indexOfParenthesis == -1 ) {
throw new SvgProcessingException(SvgLogMessageConstant.INVALID_TRANSFORM_DECLARATION);
}
return transformation.substring(0, transformation.indexOf("("));
}
/**
* This method extracts the values from a transformation.
*
* @param transformation the transformation
* @return values of the transformation
*/
private static List getValuesFromTransformationString(String transformation) {
String numbers = transformation.substring(transformation.indexOf('(') + 1, transformation.indexOf(')'));
return SvgCssUtils.splitValueList(numbers);
}
}