JavaFX 2.x: Y-axis Logarithmic Scale

We also had these problems with the proposed logarithmic analysis implementation, here is the complete code with fixes that worked for us.

import com.sun.javafx.charts.ChartLayoutAnimator;
import java.text.NumberFormat;
import java.util.ArrayList;
import java.util.LinkedList;
import java.util.List;
import javafx.animation.KeyFrame;
import javafx.animation.KeyValue;
import javafx.beans.binding.DoubleBinding;
import javafx.beans.property.DoubleProperty;
import javafx.beans.property.SimpleDoubleProperty;
import javafx.scene.chart.ValueAxis;
import javafx.util.Duration;

//http://blog.dooapp.com/logarithmic-scale-strikes-back-in-javafx-20
//Edited by Vadim Levit & Benny Lutati for usage in AgentZero ( https://code.google.com/p/azapi-test/ )
public class LogarithmicNumberAxis extends ValueAxis<Number> {

    private Object currentAnimationID;
    private final ChartLayoutAnimator animator = new ChartLayoutAnimator(this);

//Create our LogarithmicAxis class that extends ValueAxis<Number> and define two properties that will represent the log lower and upper bounds of our axis.     
    private final DoubleProperty logUpperBound = new SimpleDoubleProperty();
    private final DoubleProperty logLowerBound = new SimpleDoubleProperty();
//

//we bind our properties with the default bounds of the value axis. But before, we should verify the given range according to the mathematic logarithmic interval definition.
    public LogarithmicNumberAxis() {
        super(1, 10000000);
        bindLogBoundsToDefaultBounds();
    }

    public LogarithmicNumberAxis(double lowerBound, double upperBound) {
        super(lowerBound, upperBound);
        validateBounds(lowerBound, upperBound);
        bindLogBoundsToDefaultBounds();
    }

    public void setLogarithmizedUpperBound(double d) {
        double nd = Math.pow(10, Math.ceil(Math.log10(d)));
        setUpperBound(nd == d ? nd * 10 : nd);
    }

    /**
     * Bind our logarithmic bounds with the super class bounds, consider the
     * base 10 logarithmic scale.
     */
    private void bindLogBoundsToDefaultBounds() {
        logLowerBound.bind(new DoubleBinding() {
            {
                super.bind(lowerBoundProperty());
            }

            @Override
            protected double computeValue() {
                return Math.log10(lowerBoundProperty().get());
            }
        });
        logUpperBound.bind(new DoubleBinding() {
            {
                super.bind(upperBoundProperty());
            }

            @Override
            protected double computeValue() {
                return Math.log10(upperBoundProperty().get());
            }
        });
    }

    /**
     * Validate the bounds by throwing an exception if the values are not
     * conform to the mathematics log interval: ]0,Double.MAX_VALUE]
     *
     * @param lowerBound
     * @param upperBound
     * @throws IllegalLogarithmicRangeException
     */
    private void validateBounds(double lowerBound, double upperBound) throws IllegalLogarithmicRangeException {
        if (lowerBound < 0 || upperBound < 0 || lowerBound > upperBound) {
            throw new IllegalLogarithmicRangeException(
                    "The logarithmic range should be in [0,Double.MAX_VALUE] and the lowerBound should be less than the upperBound");
        }
    }

//Now we have to implement all abstract methods of the ValueAxis class.
//The first one, calculateMinorTickMarks is used to get the list of minor tick marks position that you want to display on the axis. You could find my definition below. It based on the number of minor tick and the logarithmic formula.
    @Override
    protected List<Number> calculateMinorTickMarks() {
        List<Number> minorTickMarksPositions = new ArrayList<>();
        return minorTickMarksPositions;
    }

//Then, the calculateTickValues method is used to calculate a list of all the data values for each tick mark in range, represented by the second parameter. The formula is the same than previously but here we want to display one tick each power of 10.
    @Override
    protected List<Number> calculateTickValues(double length, Object range) {
        LinkedList<Number> tickPositions = new LinkedList<>();
        if (range != null) {
            double lowerBound = ((double[]) range)[0];
            double upperBound = ((double[]) range)[1];

            for (double i = Math.log10(lowerBound); i <= Math.log10(upperBound); i++) {
                tickPositions.add(Math.pow(10, i));
            }

            if (!tickPositions.isEmpty()) {
                if (tickPositions.getLast().doubleValue() != upperBound) {
                    tickPositions.add(upperBound);
                }
            }
        }

        return tickPositions;
    }

    /**
     * The getRange provides the current range of the axis. A basic
     * implementation is to return an array of the lowerBound and upperBound
     * properties defined into the ValueAxis class.
     *
     * @return
     */
    @Override
    protected double[] getRange() {
        return new double[]{
            getLowerBound(),
            getUpperBound()
        };
    }

    /**
     * The getTickMarkLabel is only used to convert the number value to a string
     * that will be displayed under the tickMark. Here I choose to use a number
     * formatter.
     *
     * @param value
     * @return
     */
    @Override
    protected String getTickMarkLabel(Number value) {
        NumberFormat formatter = NumberFormat.getInstance();
        formatter.setMaximumIntegerDigits(10);
        formatter.setMinimumIntegerDigits(1);
        return formatter.format(value);
    }

    /**
     * The method setRange is used to update the range when data are added into
     * the chart. There is two possibilities, the axis is animated or not. The
     * simplest case is to set the lower and upper bound properties directly
     * with the new values.
     *
     * @param range
     * @param animate
     */
    @Override
    protected void setRange(Object range, boolean animate) {
        if (range != null) {
            final double[] rangeProps = (double[]) range;
            final double lowerBound = rangeProps[0];
            final double upperBound = rangeProps[1];

            final double oldLowerBound = getLowerBound();
            setLowerBound(lowerBound);
            setUpperBound(upperBound);
            if (animate) {
                animator.stop(currentAnimationID);
                currentAnimationID = animator.animate(
                        new KeyFrame(Duration.ZERO,
                                new KeyValue(currentLowerBound, oldLowerBound)
                        ),
                        new KeyFrame(Duration.millis(700),
                                new KeyValue(currentLowerBound, lowerBound)
                        )
                );
            } else {
                currentLowerBound.set(lowerBound);
            }
        }
    }

    /**
     * We are almost done but we forgot to override 2 important methods that are
     * used to perform the matching between data and the axis (and the reverse).
     *
     * @param displayPosition
     * @return
     */
    @Override
    public Number getValueForDisplay(double displayPosition) {
        double delta = logUpperBound.get() - logLowerBound.get();
        if (getSide().isVertical()) {
            return Math.pow(10, (((displayPosition - getHeight()) / -getHeight()) * delta) + logLowerBound.get());
        } else {
            return Math.pow(10, (((displayPosition / getWidth()) * delta) + logLowerBound.get()));
        }
    }

    @Override
    public double getDisplayPosition(Number value) {
        double delta = logUpperBound.get() - logLowerBound.get();
        double deltaV = Math.log10(value.doubleValue()) - logLowerBound.get();
        if (getSide().isVertical()) {
            return (1. - ((deltaV) / delta)) * getHeight();
        } else {
            return ((deltaV) / delta) * getWidth();
        }
    }

    /**
     * Exception to be thrown when a bound value isn't supported by the
     * logarithmic axis<br>
     *
     *
     * @author Kevin Senechal mailto: kevin.senechal@dooapp.com
     *
     */
    public class IllegalLogarithmicRangeException extends RuntimeException {

        /**
         * @param string
         */
        public IllegalLogarithmicRangeException(String message) {
            super(message);
        }
    }
}