Java tutorial
/* =========================================================== * JFreeChart : a free chart library for the Java(tm) platform * =========================================================== * * (C) Copyright 2000-2014, by Object Refinery Limited and Contributors. * * Project Info: http://www.jfree.org/jfreechart/index.html * * 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, * USA. * * [Oracle and Java are registered trademarks of Oracle and/or its affiliates. * Other names may be trademarks of their respective owners.] * * ----------------------- * GradientBarPainter.java * ----------------------- * (C) Copyright 2008-2014, by Object Refinery Limited. * * Original Author: David Gilbert (for Object Refinery Limited); * Contributor(s): -; * * Changes: * -------- * 19-Jun-2008 : Version 1 (DG); * 15-Aug-2008 : Use outline paint and shadow paint (DG); * 17-Sep-2013 : Fix coordinate error in gradient (DG); * */ package org.jfree.chart.renderer.category; 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 java.io.Serializable; import org.jfree.chart.HashUtilities; import org.jfree.ui.RectangleEdge; /** * An implementation of the {@link BarPainter} interface that uses several * gradient fills to enrich the appearance of the bars. * * @since 1.0.11 */ public class GradientBarPainter implements BarPainter, Serializable { /** 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 GradientBarPainter() { this(0.10, 0.20, 0.80); } /** * Creates a new instance. * * @param g1 percentage value defining the line between regions 1 and 2. * @param g2 percentage value defining the line between regions 2 and 3. * @param g3 percentage value defining the line between regions 3 and 4. */ public GradientBarPainter(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, BarRenderer 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.TOP || base == RectangleEdge.BOTTOM) { 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.LEFT || base == RectangleEdge.RIGHT) { 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].getMaxY(), 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() /*&& state.getBarWidth() > renderer.BAR_OUTLINE_WIDTH_THRESHOLD*/) { 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, BarRenderer 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(renderer.getShadowPaint()); 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; } /** * Tests this instance for equality with an arbitrary object. * * @param obj the obj (<code>null</code> permitted). * * @return A boolean. */ @Override public boolean equals(Object obj) { if (obj == this) { return true; } if (!(obj instanceof GradientBarPainter)) { return false; } GradientBarPainter that = (GradientBarPainter) obj; if (this.g1 != that.g1) { return false; } if (this.g2 != that.g2) { return false; } if (this.g3 != that.g3) { return false; } return true; } /** * Returns a hash code for this instance. * * @return A hash code. */ @Override public int hashCode() { int hash = 37; hash = HashUtilities.hashCode(hash, this.g1); hash = HashUtilities.hashCode(hash, this.g2); hash = HashUtilities.hashCode(hash, this.g3); return hash; } }