de.openali.odysseus.chart.ext.base.axisrenderer.DateTimeTickCalculator.java Source code

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Here is the source code for de.openali.odysseus.chart.ext.base.axisrenderer.DateTimeTickCalculator.java

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/*----------------    FILE HEADER KALYPSO ------------------------------------------
 *
 *  This file is part of kalypso.
 *  Copyright (C) 2004 by:
 *
 *  Technical University Hamburg-Harburg (TUHH)
 *  Institute of River and coastal engineering
 *  Denickestrae 22
 *  21073 Hamburg, Germany
 *  http://www.tuhh.de/wb
 *
 *  and
 *
 *  Bjoernsen Consulting Engineers (BCE)
 *  Maria Trost 3
 *  56070 Koblenz, Germany
 *  http://www.bjoernsen.de
 *
 *  This library is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU Lesser General Public
 *  License as published by the Free Software Foundation; either
 *  version 2.1 of the License, or (at your option) any later version.
 *
 *  This library 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
 *  Lesser General Public License for more details.
 *
 *  You should have received a copy of the GNU Lesser General Public
 *  License along with this library; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 *  Contact:
 *
 *  E-Mail:
 *  belger@bjoernsen.de
 *  schlienger@bjoernsen.de
 *  v.doemming@tuhh.de
 *
 *  ---------------------------------------------------------------------------*/
package de.openali.odysseus.chart.ext.base.axisrenderer;

import java.util.ArrayList;
import java.util.List;

import org.eclipse.swt.graphics.GC;
import org.eclipse.swt.graphics.Point;
import org.joda.time.DateTimeField;
import org.joda.time.DateTimeZone;
import org.joda.time.DurationField;
import org.joda.time.chrono.GregorianChronology;
import org.kalypso.core.KalypsoCorePlugin;

import de.openali.odysseus.chart.framework.model.data.IDataRange;
import de.openali.odysseus.chart.framework.model.mapper.IAxis;

/**
 * @author kimwerner
 */
public class DateTimeTickCalculator implements ITickCalculator {

    private final IDateTimeAxisFieldProvider m_fieldTypeProvider;

    public DateTimeTickCalculator(final IDateTimeAxisFieldProvider dateTimeFieldProvider) {
        m_fieldTypeProvider = dateTimeFieldProvider;
    }

    private long getFirstRollValue(final IDateTimeAxisField axisField, final long start, final long end) {
        final DateTimeZone jodaTZ = DateTimeZone.forTimeZone(KalypsoCorePlugin.getDefault().getTimeZone());
        final DateTimeField field = axisField.getFieldType().getField(GregorianChronology.getInstance(jodaTZ));
        final long firstRoll = field.roundFloor(start);
        if (firstRoll + end - start <= start)
            // out of range, precision too small so we return without adjustment
            // maybe try roundCeil instead
            return start;
        final int fieldValue = field.get(firstRoll);
        if (fieldValue == 0)
            return firstRoll;

        final int[] beginners = axisField.getBeginners();
        for (int i = 1; i < beginners.length; i++) {
            if (fieldValue < beginners[i]) {
                return field.add(firstRoll, beginners[i - 1] - fieldValue);
            }
        }

        return field.add(firstRoll, -fieldValue);
    }

    /**
     * @see org.kalypso.chart.ext.test.axisrenderer.ITickCalculator#calcTicks(org.eclipse.swt.graphics.GC,
     *      org.kalypso.chart.framework.model.mapper.IAxis)
     */
    /**
     * Calculates the ticks shown for the given Axis
     */
    @SuppressWarnings("rawtypes")
    @Override
    public Double[] calcTicks(final GC gc, final IAxis axis, final Number minDisplayInterval,
            final Point ticklabelSize) {
        final IDataRange<Number> numRange = axis.getNumericRange();
        if (numRange == null || numRange.getMin() == null || numRange.getMax() == null)
            return new Double[] {};

        final long start = numRange.getMin().longValue();
        final long end = numRange.getMax().longValue();

        final IDateTimeAxisField axisField = m_fieldTypeProvider.getDateTimeAxisField(numRange);

        final DateTimeZone jodaTZ = DateTimeZone.forTimeZone(KalypsoCorePlugin.getDefault().getTimeZone());
        final DurationField field = axisField.getFieldType().getDurationType()
                .getField(GregorianChronology.getInstance(jodaTZ));

        final int tickCount = Math.max(1, field.getDifference(end, start));
        final int maximumTickCount = axis.getScreenHeight() / (ticklabelSize.x + 2/* Pixel */);
        final int[] rollOvers = axisField.getRollovers();

        final int rollOver = calculateRollover(tickCount, maximumTickCount, rollOvers);

        final List<Double> ticks = new ArrayList<>();
        Long tick = getFirstRollValue(axisField, start, end);
        ticks.add(tick.doubleValue());
        while (tick < end) {
            tick = field.add(tick, rollOver);
            ticks.add(tick.doubleValue());
        }

        return ticks.toArray(new Double[ticks.size()]);
    }

    private int calculateRollover(final int tickCount, final int maximumTickCount, final int[] rollOvers) {
        if (maximumTickCount < 0)
            return 1;

        if (tickCount <= maximumTickCount)
            return 1;

        int rollOver = 1;
        for (final int i : rollOvers) {
            if (tickCount / i < maximumTickCount) {
                rollOver = i;
                break;
            }
            rollOver = i;
        }

        // TODO: why can it be 0 at all?
        if (rollOver == 0)
            return 1;

        while (tickCount / rollOver > maximumTickCount) {
            rollOver = 2 * rollOver;
        }

        return rollOver;
    }
}