LinearColorScale.java

/**
 *  Copyright 2012 Universitat Pompeu Fabra.
 *
 *  Licensed under the Apache License, Version 2.0 (the "License");
 *  you may not use this file except in compliance with the License.
 *  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 *
 *
 */
package org.onexus.website.api.widgets.tableviewer.decorators.scale.scales;

import java.awt.*;

public class LinearColorScale extends AbstractColorScale {

    public LinearColorScale(double minPoint, double maxPoint, Color minColor,
                            Color maxColor) {
        super(minPoint, maxPoint);
        this.minColor = minColor;
        this.maxColor = maxColor;
    }

    public LinearColorScale(double minPoint, double maxPoint) {
        super(minPoint, maxPoint);
    }

    public LinearColorScale() {
        super(0.0, 1.0);
    }

    @Override
    public Color valueColor(Object obj) {

        double value;
        if (obj instanceof Double) {
            value = (Double) obj;
        } else {
            value = Double.valueOf(String.valueOf(obj));
        }


        if (Double.isNaN(value)) {
            return notANumberColor;
        }
        else if (value > maxPoint || value == Double.POSITIVE_INFINITY) {
            return posInfinityColor;
        }
        else if (value < minPoint || value == Double.NEGATIVE_INFINITY) {
            return negInfinityColor;
        }

        double range = maxPoint - minPoint;

        double f = (value - minPoint) / range;

        return f <= 0 ? ColorUtils.mix(minColor, maxColor, -f) : ColorUtils
                .mix(maxColor, minColor, f);
    }

}