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 * Copyright (c) 2011, 2012, 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
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 */

package javafx.geometry;

/**
 * A class representing four different radius values, one for the
 * top-left, top-right, bottom-right, and bottom-left corners of
 * some rectangle. This class does not allow for negative numbers.
 */
public final class Radii {
    /**
     * Empty radii. An {@code Radii} instance with all offsets equal to zero.
     */
    public static final Radii EMPTY = new Radii(0);

    /**
     * The inset on the topLeft side
     */
    public final double getTopLeft() { return topLeft; }
    private double topLeft;

    /**
     * The inset on the topRight side
     */
    public final double getTopRight() { return topRight; }
    private double topRight;

    /**
     * The inset on the bottomRight side
     */
    public final double getBottomRight() { return bottomRight; }
    private double bottomRight;

    /**
     * The inset on the bottomLeft side
     */
    public final double getBottomLeft() { return bottomLeft; }
    private double bottomLeft;

    /**
     * The cached hash code, used to improve performance in situations where
     * we cache gradients, such as in the CSS routines.
     */
    private int hash = 0;

    /**
     * Constructs a new Radii instance with four different offsets.
     *
     * @param topLeft the topLeft offset
     * @param topRight the topRight offset
     * @param bottomRight the bottomRight offset
     * @param bottomLeft the bottomLeft offset
     */
    public Radii(double topLeft, double topRight, double bottomRight, double bottomLeft) {
        if (topLeft < 0 || topRight < 0 || bottomRight < 0 || bottomLeft < 0) {
            throw new IllegalArgumentException("No radius can be < 0");
        }

        this.topLeft = topLeft;
        this.topRight = topRight;
        this.bottomRight = bottomRight;
        this.bottomLeft = bottomLeft;
    }

    /**
     * Constructs a new Radii instance with same value for all four offsets.
     *
     * @param radius the value used for topLeft, bottomRight, topRight and bottomLeft
     * offset
     */
    public Radii(double radius) {
        if (radius < 0) {
            throw new IllegalArgumentException("The radius cannot be < 0");
        }

        this.topLeft = radius;
        this.topRight = radius;
        this.bottomRight = radius;
        this.bottomLeft = radius;
    }

    /**
     * Indicates whether some other object is "equal to" this one.
     *
     * @param obj the reference object with which to compare
     * @return true if this object is the same as the obj argument; false otherwise
     */
    @Override public boolean equals(Object obj) {
        if (obj == this) return true;
        if (obj instanceof Radii) {
            Radii other = (Radii) obj;
            return topLeft == other.topLeft
                    && topRight == other.topRight
                    && bottomRight == other.bottomRight
                    && bottomLeft == other.bottomLeft;
        } else return false;
    }

    /**
     * Returns a hash code value for the Radii.
     * @return a hash code value for the Radii.
     */
    @Override public int hashCode() {
        if (hash == 0) {
            long bits = 17L;
            bits = 37L * bits + Double.doubleToLongBits(topLeft);
            bits = 37L * bits + Double.doubleToLongBits(topRight);
            bits = 37L * bits + Double.doubleToLongBits(bottomRight);
            bits = 37L * bits + Double.doubleToLongBits(bottomLeft);
            hash = (int) (bits ^ (bits >> 32));
        }
        return hash;
    }

    /**
     * Returns a string representation for the Radii.
     * @return a string representation for the Radii.
     */
    @Override public String toString() {
        return "Radii [topLeft=" + topLeft + ", topRight=" + topRight + ", bottomRight="
                + bottomRight + ",bottomLeft=" + bottomLeft + "]";
    }
}