Java tutorial
/* * Copyright (c) 2010, 2017, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. Oracle designates this * particular file as subject to the "Classpath" exception as provided * by Oracle in the LICENSE file that accompanied this code. * * This code 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 * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. */ package javafx.scene.paint; import java.util.ArrayList; import java.util.Arrays; import java.util.Collections; import java.util.List; import javafx.beans.NamedArg; /** * Defines one element of the ramp of colors to use on a gradient. * For more information see {@code javafx.scene.paint.LinearGradient} and * {@code javafx.scene.paint.RadialGradient}. * * <p>Example:</p> * <pre>{@code * // object bounding box relative (proportional:true, default) * Stop[] stops = { new Stop(0, Color.WHITE), new Stop(1, Color.BLACK)}; * LinearGradient lg = new LinearGradient(0, 0, 1, 0, true, CycleMethod.NO_CYCLE, stops); * Rectangle r = new Rectangle(); * r.setFill(lg); * }</pre> * @since JavaFX 2.0 */ public final class Stop { static final List<Stop> NO_STOPS = Collections .unmodifiableList(Arrays.asList(new Stop(0.0, Color.TRANSPARENT), new Stop(1.0, Color.TRANSPARENT))); static List<Stop> normalize(Stop stops[]) { List<Stop> stoplist = (stops == null ? null : Arrays.asList(stops)); return normalize(stoplist); } static List<Stop> normalize(List<Stop> stops) { if (stops == null) { return NO_STOPS; } Stop zerostop = null; Stop onestop = null; List<Stop> newlist = new ArrayList<Stop>(stops.size()); for (Stop s : stops) { if (s == null || s.getColor() == null) continue; double off = s.getOffset(); if (off <= 0.0) { if (zerostop == null || off >= zerostop.getOffset()) { zerostop = s; } } else if (off >= 1.0) { if (onestop == null || off < onestop.getOffset()) { onestop = s; } } else if (off == off) { // non-NaN for (int i = newlist.size() - 1; i >= 0; i--) { Stop s2 = newlist.get(i); if (s2.getOffset() <= off) { if (s2.getOffset() == off) { if (i > 0 && newlist.get(i - 1).getOffset() == off) { newlist.set(i, s); } else { newlist.add(i + 1, s); } } else { newlist.add(i + 1, s); } s = null; break; } } if (s != null) { newlist.add(0, s); } } } if (zerostop == null) { Color zerocolor; if (newlist.isEmpty()) { if (onestop == null) { return NO_STOPS; } zerocolor = onestop.getColor(); } else { zerocolor = newlist.get(0).getColor(); if (onestop == null && newlist.size() == 1) { // Special case for a single color with a non-0,1 offset. // If we leave the color in there we end up with a 3-color // gradient with all the colors being identical and we // will not catch the optimization to a solid color. newlist.clear(); } } zerostop = new Stop(0.0, zerocolor); } else if (zerostop.getOffset() < 0.0) { zerostop = new Stop(0.0, zerostop.getColor()); } newlist.add(0, zerostop); if (onestop == null) { onestop = new Stop(1.0, newlist.get(newlist.size() - 1).getColor()); } else if (onestop.getOffset() > 1.0) { onestop = new Stop(1.0, onestop.getColor()); } newlist.add(onestop); return Collections.unmodifiableList(newlist); } /** * The {@code offset} variable is a number ranging from {@code 0} to {@code 1} * that indicates where this gradient stop is placed. For linear gradients, * the {@code offset} variable represents a location along the gradient vector. * For radial gradients, it represents a percentage distance from * the focus point to the edge of the outermost/largest circle. * * @defaultValue 0.0 */ private double offset; /** * Gets a number ranging from {@code 0} to {@code 1} * that indicates where this gradient stop is placed. For linear gradients, * the {@code offset} variable represents a location along the gradient vector. * For radial gradients, it represents a percentage distance from * the focus point to the edge of the outermost/largest circle. * * @return position of the Stop within the gradient * (ranging from {@code 0} to {@code 1}) */ public final double getOffset() { return offset; } /** * The color of the gradient at this offset. * * @defaultValue Color.BLACK */ private Color color; /** * Gets the color of the gradient at this offset. * @return the color of the gradient at this offset */ public final Color getColor() { return color; } /** * The cached hash code, used to improve performance in situations where * we cache gradients, such as in the CSS routines. */ private int hash = 0; /** * Creates a new instance of Stop. * @param offset Stop's position (ranging from {@code 0} to {@code 1} * @param color Stop's color */ public Stop(@NamedArg("offset") double offset, @NamedArg(value = "color", defaultValue = "BLACK") Color color) { this.offset = offset; this.color = color; } /** * Indicates whether some other object is "equal to" this one. * @param obj the reference object with which to compare. * @return {@code true} if this object is equal to the {@code obj} argument; {@code false} otherwise. */ @Override public boolean equals(Object obj) { if (obj == null) return false; if (obj == this) return true; if (obj instanceof Stop) { Stop other = (Stop) obj; return offset == other.offset && (color == null ? other.color == null : color.equals(other.color)); } else return false; } /** * Returns a hash code for this {@code Stop} object. * @return a hash code for this {@code Stop} object. */ @Override public int hashCode() { if (hash == 0) { long bits = 17L; bits = 37L * bits + Double.doubleToLongBits(offset); bits = 37L * bits + color.hashCode(); hash = (int) (bits ^ (bits >> 32)); } return hash; } /** * Returns a string representation of this {@code Stop} object. * @return a string representation of this {@code Stop} object. */ @Override public String toString() { return color + " " + offset * 100 + "%"; } }