Java tutorial
/* * * This file is part of the iText (R) project. Copyright (c) 1998-2019 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. * 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 * 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 */ package com.itextpdf.text.pdf.parser; import com.itextpdf.awt.geom.Point2D; import java.util.ArrayList; import java.util.Arrays; import java.util.List; /** * Paths define shapes, trajectories, and regions of all sorts. They shall be used * to draw lines, define the shapes of filled areas, and specify boundaries for clipping * other graphics. A path shall be composed of straight and curved line segments, which * may connect to one another or may be disconnected. * * @since 5.5.6 */ public class Path { private static final String START_PATH_ERR_MSG = "Path shall start with \"re\" or \"m\" operator"; private List<Subpath> subpaths = new ArrayList<Subpath>(); private Point2D currentPoint; public Path() { } public Path(List<? extends Subpath> subpaths) { addSubpaths(subpaths); } /** * @return A {@link java.util.List} of subpaths forming this path. */ public List<Subpath> getSubpaths() { return subpaths; } /** * Adds the subpath to this path. * * @param subpath The subpath to be added to this path. */ public void addSubpath(Subpath subpath) { subpaths.add(subpath); currentPoint = subpath.getLastPoint(); } /** * Adds the subpaths to this path. * * @param subpaths {@link java.util.List} of subpaths to be added to this path. */ public void addSubpaths(List<? extends Subpath> subpaths) { if (subpaths.size() > 0) { this.subpaths.addAll(subpaths); currentPoint = this.subpaths.get(subpaths.size() - 1).getLastPoint(); } } /** * The current point is the trailing endpoint of the segment most recently added to the current path. * * @return The current point. */ public Point2D getCurrentPoint() { return currentPoint; } /** * Begins a new subpath by moving the current point to coordinates <CODE>(x, y)</CODE>. */ public void moveTo(final float x, final float y) { currentPoint = new Point2D.Float(x, y); Subpath lastSubpath = getLastSubpath(); if (lastSubpath != null && lastSubpath.isSinglePointOpen()) { lastSubpath.setStartPoint(currentPoint); } else { subpaths.add(new Subpath(currentPoint)); } } /** * Appends a straight line segment from the current point to the point <CODE>(x, y)</CODE>. */ public void lineTo(final float x, final float y) { if (currentPoint == null) { throw new RuntimeException(START_PATH_ERR_MSG); } Point2D targetPoint = new Point2D.Float(x, y); getLastSubpath().addSegment(new Line(currentPoint, targetPoint)); currentPoint = targetPoint; } /** * Appends a cubic Bezier curve to the current path. The curve shall extend from * the current point to the point <CODE>(x3, y3)</CODE>. */ public void curveTo(final float x1, final float y1, final float x2, final float y2, final float x3, final float y3) { if (currentPoint == null) { throw new RuntimeException(START_PATH_ERR_MSG); } // Numbered in natural order Point2D secondPoint = new Point2D.Float(x1, y1); Point2D thirdPoint = new Point2D.Float(x2, y2); Point2D fourthPoint = new Point2D.Float(x3, y3); List<Point2D> controlPoints = new ArrayList( Arrays.asList(currentPoint, secondPoint, thirdPoint, fourthPoint)); getLastSubpath().addSegment(new BezierCurve(controlPoints)); currentPoint = fourthPoint; } /** * Appends a cubic Bezier curve to the current path. The curve shall extend from * the current point to the point <CODE>(x3, y3)</CODE> with the note that the current * point represents two control points. */ public void curveTo(final float x2, final float y2, final float x3, final float y3) { if (currentPoint == null) { throw new RuntimeException(START_PATH_ERR_MSG); } curveTo((float) currentPoint.getX(), (float) currentPoint.getY(), x2, y2, x3, y3); } /** * Appends a cubic Bezier curve to the current path. The curve shall extend from * the current point to the point <CODE>(x3, y3)</CODE> with the note that the (x3, y3) * point represents two control points. */ public void curveFromTo(final float x1, final float y1, final float x3, final float y3) { if (currentPoint == null) { throw new RuntimeException(START_PATH_ERR_MSG); } curveTo(x1, y1, x3, y3, x3, y3); } /** * Appends a rectangle to the current path as a complete subpath. */ public void rectangle(final float x, final float y, final float w, final float h) { moveTo(x, y); lineTo(x + w, y); lineTo(x + w, y + h); lineTo(x, y + h); closeSubpath(); } /** * Closes the current subpath. */ public void closeSubpath() { Subpath lastSubpath = getLastSubpath(); lastSubpath.setClosed(true); Point2D startPoint = lastSubpath.getStartPoint(); moveTo((float) startPoint.getX(), (float) startPoint.getY()); } /** * Closes all subpathes contained in this path. */ public void closeAllSubpaths() { for (Subpath subpath : subpaths) { subpath.setClosed(true); } } /** * Adds additional line to each closed subpath and makes the subpath unclosed. * The line connects the last and the first points of the subpaths. * * @returns Indices of modified subpaths. */ public List<Integer> replaceCloseWithLine() { List<Integer> modifiedSubpathsIndices = new ArrayList<Integer>(); int i = 0; /* It could be replaced with "for" cycle, because IList in C# provides effective * access by index. In Java List interface has at least one implementation (LinkedList) * which is "bad" for access elements by index. */ for (Subpath subpath : subpaths) { if (subpath.isClosed()) { subpath.setClosed(false); subpath.addSegment(new Line(subpath.getLastPoint(), subpath.getStartPoint())); modifiedSubpathsIndices.add(i); } ++i; } return modifiedSubpathsIndices; } /** * Path is empty if it contains no subpaths. */ public boolean isEmpty() { return subpaths.size() == 0; } private Subpath getLastSubpath() { return subpaths.size() > 0 ? subpaths.get(subpaths.size() - 1) : null; } }