it.cnr.istc.utils.gui.ReverseGradientXYBarPainter.java Source code

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/*
 * Copyright (C) 2017 Riccardo De Benedictis <riccardo.debenedictis@istc.cnr.it>
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
package it.cnr.istc.utils.gui;

import java.awt.Color;
import java.awt.GradientPaint;
import java.awt.Graphics2D;
import java.awt.Paint;
import java.awt.Stroke;
import java.awt.geom.Rectangle2D;
import java.awt.geom.RectangularShape;
import org.jfree.chart.renderer.xy.XYBarPainter;
import org.jfree.chart.renderer.xy.XYBarRenderer;
import org.jfree.ui.RectangleEdge;

/**
 *
 * @author Riccardo De Benedictis <riccardo.debenedictis@istc.cnr.it>
 */
public class ReverseGradientXYBarPainter implements XYBarPainter {

    /**
     * The division point between the first and second gradient regions.
     */
    private double g1;
    /**
     * The division point between the second and third gradient regions.
     */
    private double g2;
    /**
     * The division point between the third and fourth gradient regions.
     */
    private double g3;

    /**
     * Creates a new instance.
     */
    public ReverseGradientXYBarPainter() {
        this(0.10, 0.20, 0.80);
    }

    /**
     * Creates a new instance.
     *
     * @param g1 the division between regions 1 and 2.
     * @param g2 the division between regions 2 and 3.
     * @param g3 the division between regions 3 and 4.
     */
    public ReverseGradientXYBarPainter(double g1, double g2, double g3) {
        this.g1 = g1;
        this.g2 = g2;
        this.g3 = g3;
    }

    /**
     * Paints a single bar instance.
     *
     * @param g2 the graphics target.
     * @param renderer the renderer.
     * @param row the row index.
     * @param column the column index.
     * @param bar the bar
     * @param base indicates which side of the rectangle is the base of the bar.
     */
    @Override
    public void paintBar(Graphics2D g2, XYBarRenderer renderer, int row, int column, RectangularShape bar,
            RectangleEdge base) {

        Paint itemPaint = renderer.getItemPaint(row, column);

        Color c0, c1;
        if (itemPaint instanceof Color) {
            c0 = (Color) itemPaint;
            c1 = c0.brighter();
        } else if (itemPaint instanceof GradientPaint) {
            GradientPaint gp = (GradientPaint) itemPaint;
            c0 = gp.getColor1();
            c1 = gp.getColor2();
        } else {
            c0 = Color.blue;
            c1 = Color.blue.brighter();
        }

        // as a special case, if the bar colour has alpha == 0, we draw
        // nothing.
        if (c0.getAlpha() == 0) {
            return;
        }

        if (base == RectangleEdge.LEFT || base == RectangleEdge.RIGHT) {
            Rectangle2D[] regions = splitVerticalBar(bar, this.g1, this.g2, this.g3);
            GradientPaint gp = new GradientPaint((float) regions[0].getMinX(), 0.0f, c0,
                    (float) regions[0].getMaxX(), 0.0f, Color.white);
            g2.setPaint(gp);
            g2.fill(regions[0]);

            gp = new GradientPaint((float) regions[1].getMinX(), 0.0f, Color.white, (float) regions[1].getMaxX(),
                    0.0f, c0);
            g2.setPaint(gp);
            g2.fill(regions[1]);

            gp = new GradientPaint((float) regions[2].getMinX(), 0.0f, c0, (float) regions[2].getMaxX(), 0.0f, c1);
            g2.setPaint(gp);
            g2.fill(regions[2]);

            gp = new GradientPaint((float) regions[3].getMinX(), 0.0f, c1, (float) regions[3].getMaxX(), 0.0f, c0);
            g2.setPaint(gp);
            g2.fill(regions[3]);
        } else if (base == RectangleEdge.TOP || base == RectangleEdge.BOTTOM) {
            Rectangle2D[] regions = splitHorizontalBar(bar, this.g1, this.g2, this.g3);
            GradientPaint gp = new GradientPaint(0.0f, (float) regions[0].getMinY(), c0, 0.0f,
                    (float) regions[0].getMaxX(), Color.white);
            g2.setPaint(gp);
            g2.fill(regions[0]);

            gp = new GradientPaint(0.0f, (float) regions[1].getMinY(), Color.white, 0.0f,
                    (float) regions[1].getMaxY(), c0);
            g2.setPaint(gp);
            g2.fill(regions[1]);

            gp = new GradientPaint(0.0f, (float) regions[2].getMinY(), c0, 0.0f, (float) regions[2].getMaxY(), c1);
            g2.setPaint(gp);
            g2.fill(regions[2]);

            gp = new GradientPaint(0.0f, (float) regions[3].getMinY(), c1, 0.0f, (float) regions[3].getMaxY(), c0);
            g2.setPaint(gp);
            g2.fill(regions[3]);
        }

        // draw the outline...
        if (renderer.isDrawBarOutline()) {
            Stroke stroke = renderer.getItemOutlineStroke(row, column);
            Paint paint = renderer.getItemOutlinePaint(row, column);
            if (stroke != null && paint != null) {
                g2.setStroke(stroke);
                g2.setPaint(paint);
                g2.draw(bar);
            }
        }

    }

    /**
     * Paints a single bar instance.
     *
     * @param g2 the graphics target.
     * @param renderer the renderer.
     * @param row the row index.
     * @param column the column index.
     * @param bar the bar
     * @param base indicates which side of the rectangle is the base of the bar.
     * @param pegShadow peg the shadow to the base of the bar?
     */
    @Override
    public void paintBarShadow(Graphics2D g2, XYBarRenderer renderer, int row, int column, RectangularShape bar,
            RectangleEdge base, boolean pegShadow) {

        // handle a special case - if the bar colour has alpha == 0, it is
        // invisible so we shouldn't draw any shadow
        Paint itemPaint = renderer.getItemPaint(row, column);
        if (itemPaint instanceof Color) {
            Color c = (Color) itemPaint;
            if (c.getAlpha() == 0) {
                return;
            }
        }

        RectangularShape shadow = createShadow(bar, renderer.getShadowXOffset(), renderer.getShadowYOffset(), base,
                pegShadow);
        g2.setPaint(Color.gray);
        g2.fill(shadow);

    }

    /**
     * Creates a shadow for the bar.
     *
     * @param bar the bar shape.
     * @param xOffset the x-offset for the shadow.
     * @param yOffset the y-offset for the shadow.
     * @param base the edge that is the base of the bar.
     * @param pegShadow peg the shadow to the base?
     *
     * @return A rectangle for the shadow.
     */
    private Rectangle2D createShadow(RectangularShape bar, double xOffset, double yOffset, RectangleEdge base,
            boolean pegShadow) {
        double x0 = bar.getMinX();
        double x1 = bar.getMaxX();
        double y0 = bar.getMinY();
        double y1 = bar.getMaxY();
        if (base == RectangleEdge.TOP) {
            x0 += xOffset;
            x1 += xOffset;
            if (!pegShadow) {
                y0 += yOffset;
            }
            y1 += yOffset;
        } else if (base == RectangleEdge.BOTTOM) {
            x0 += xOffset;
            x1 += xOffset;
            y0 += yOffset;
            if (!pegShadow) {
                y1 += yOffset;
            }
        } else if (base == RectangleEdge.LEFT) {
            if (!pegShadow) {
                x0 += xOffset;
            }
            x1 += xOffset;
            y0 += yOffset;
            y1 += yOffset;
        } else if (base == RectangleEdge.RIGHT) {
            x0 += xOffset;
            if (!pegShadow) {
                x1 += xOffset;
            }
            y0 += yOffset;
            y1 += yOffset;
        }
        return new Rectangle2D.Double(x0, y0, (x1 - x0), (y1 - y0));
    }

    /**
     * Splits a bar into subregions (elsewhere, these subregions will have
     * different gradients applied to them).
     *
     * @param bar the bar shape.
     * @param a the first division.
     * @param b the second division.
     * @param c the third division.
     *
     * @return An array containing four subregions.
     */
    private Rectangle2D[] splitVerticalBar(RectangularShape bar, double a, double b, double c) {
        Rectangle2D[] result = new Rectangle2D[4];
        double x0 = bar.getMinX();
        double x1 = Math.rint(x0 + (bar.getWidth() * a));
        double x2 = Math.rint(x0 + (bar.getWidth() * b));
        double x3 = Math.rint(x0 + (bar.getWidth() * c));
        result[0] = new Rectangle2D.Double(bar.getMinX(), bar.getMinY(), x1 - x0, bar.getHeight());
        result[1] = new Rectangle2D.Double(x1, bar.getMinY(), x2 - x1, bar.getHeight());
        result[2] = new Rectangle2D.Double(x2, bar.getMinY(), x3 - x2, bar.getHeight());
        result[3] = new Rectangle2D.Double(x3, bar.getMinY(), bar.getMaxX() - x3, bar.getHeight());
        return result;
    }

    /**
     * Splits a bar into subregions (elsewhere, these subregions will have
     * different gradients applied to them).
     *
     * @param bar the bar shape.
     * @param a the first division.
     * @param b the second division.
     * @param c the third division.
     *
     * @return An array containing four subregions.
     */
    private Rectangle2D[] splitHorizontalBar(RectangularShape bar, double a, double b, double c) {
        Rectangle2D[] result = new Rectangle2D[4];
        double y0 = bar.getMinY();
        double y1 = Math.rint(y0 + (bar.getHeight() * a));
        double y2 = Math.rint(y0 + (bar.getHeight() * b));
        double y3 = Math.rint(y0 + (bar.getHeight() * c));
        result[0] = new Rectangle2D.Double(bar.getMinX(), bar.getMinY(), bar.getWidth(), y1 - y0);
        result[1] = new Rectangle2D.Double(bar.getMinX(), y1, bar.getWidth(), y2 - y1);
        result[2] = new Rectangle2D.Double(bar.getMinX(), y2, bar.getWidth(), y3 - y2);
        result[3] = new Rectangle2D.Double(bar.getMinX(), y3, bar.getWidth(), bar.getMaxY() - y3);
        return result;
    }
}