Java tutorial
/* * This file is part of LibrePlan * * Copyright (C) 2009-2010 Fundacin para o Fomento da Calidade Industrial e * Desenvolvemento Tecnolxico de Galicia * Copyright (C) 2010-2011 Igalia, S.L. * * This program is free software: you can redistribute it and/or modify * it under the terms of the GNU Affero General Public License as published by * the Free Software Foundation, either version 3 of the License, or * (at your option) any later version. * * 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/>. */ package org.zkoss.ganttz; import java.math.BigDecimal; import java.math.RoundingMode; import org.apache.commons.lang3.math.Fraction; import org.joda.time.DateTime; import org.joda.time.Duration; import org.joda.time.LocalDate; import org.joda.time.ReadableDuration; import org.zkoss.ganttz.util.Interval; public class DatesMapperOnInterval implements IDatesMapper { private final int horizontalSize; private final Interval interval; private long millisecondsPerPixel; private Fraction pixelsPerDay; public DatesMapperOnInterval(int horizontalSize, Interval interval) { this.horizontalSize = horizontalSize; this.interval = interval; this.millisecondsPerPixel = interval.getLengthBetween().getMillis() / horizontalSize; this.pixelsPerDay = Fraction.getFraction(horizontalSize, interval.getDaysBetween().getDays()); } @Override public LocalDate toDate(int pixels) { int daysInto = Fraction.getFraction(pixels, 1).divideBy(pixelsPerDay).intValue(); return getInterval().getStart().plusDays(daysInto); } @Override public int toPixels(LocalDate date) { return toPixels(getProportion(date)); } private Fraction getProportion(LocalDate date) { return getProportion(date.toDateTimeAtStartOfDay()); } private Fraction getProportion(DateTime dateTime) { return getInterval().getProportion(dateTime); } private int toPixels(Fraction proportion) { try { return proportion.multiplyBy(Fraction.getFraction(horizontalSize, 1)).intValue(); } catch (ArithmeticException e) { double d = Math.log10(horizontalSize); int scale = (int) d + 1; BigDecimal quotient = new BigDecimal(proportion.getNumerator()) .divide(new BigDecimal(proportion.getDenominator()), scale, RoundingMode.HALF_UP); return quotient.multiply(new BigDecimal(horizontalSize)).intValue(); } } @Override public int toPixels(ReadableDuration duration) { DateTime end = getInterval().getStart().toDateTimeAtStartOfDay().plus(duration); return toPixels(getProportion(end)); } @Override public int toPixelsAbsolute(long milliseconds) { DateTime date = new DateTime(milliseconds); return this.toPixels(getProportion(date)); } @Override public ReadableDuration toDuration(int pixels) { return new Duration(millisecondsPerPixel * pixels); } @Override public long getMilisecondsPerPixel() { return millisecondsPerPixel; } @Override public int getHorizontalSize() { return this.horizontalSize; } public Fraction getPixelsPerDay() { return pixelsPerDay; } public Interval getInterval() { return interval; } }