content: // ===============================================================================
  // Authors: AFRL/RQQD
  // Organization: Air Force Research Laboratory, Aerospace Systems Directorate, Power and Control Division
  // 
  // Copyright (c) 2017 Government of the United State of America, as represented by
  // the Secretary of the Air Force.  No copyright is claimed in the United States under
  // Title 17, U.S. Code.  All Other Rights Reserved.
  // ===============================================================================
  
  /*
   * GRAL: GRAphing Library for Java(R)
   *
   * (C) Copyright 2009-2013 Erich Seifert <dev[at]erichseifert.de>,
   * Michael Seifert <mseifert[at]error-reports.org>
   *
   * This file is part of GRAL.
   *
   * GRAL 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 3 of the License, or
   * (at your option) any later version.
   *
   * GRAL 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 GRAL.  If not, see <http://www.gnu.org/licenses/>.
   */
  package de.erichseifert.gral.util;
  
  import java.io.Serializable;
  import java.util.Locale;
  
  /**
   * Abstract class that stores insets for all four directions.
   * <p>Please use this instead of java.awt.Insets, as the java class does not
   * support double values.</p>
   */
  public abstract class Insets2D implements Serializable {
  	/** Version id for serialization. */
  	private static final long serialVersionUID = 8685228413052838087L;
  
  	/**
  	 * Creates a new Insets2D object.
  	 */
  	public Insets2D() {
  	}
  
  	/**
  	 * Returns the insets at the top.
  	 * @return Top insets.
  	 */
  	public abstract double getTop();
  
  	/**
  	 * Returns the insets at the left.
  	 * @return Left insets.
  	 */
  	public abstract double getLeft();
  
  	/**
  	 * Returns the insets at the bottom.
  	 * @return Bottom insets.
  	 */
  	public abstract double getBottom();
  
  	/**
  	 * Returns the insets at the right.
  	 * @return Right insets.
  	 */
  	public abstract double getRight();
  
  	/**
  	 * Returns the sum of horizontal insets.
  	 * @return Horizontal insets.
  	 */
  	public double getHorizontal() {
  		return getRight() + getLeft();
  	}
  
  	/**
  	 * Returns the sum of vertical insets.
  	 * @return Vertical insets.
  	 */
  	public double getVertical() {
  		return getTop() + getBottom();
  	}
  
  	/**
  	 * Sets the insets according to the specified insets.
  	 * @param insets Insets to be set.
  	 */
  	public abstract void setInsets(Insets2D insets);
  
  	/**
  	 * Sets the insets to the specified values.
  	 * @param top Top insets.
  	 * @param left Left insets.
  	 * @param bottom Bottom insets.
  	 * @param right Right insets.
  	 */
  	public abstract void setInsets(double top, double left,
  			double bottom, double right);
  
  	/**
  	 * Class that stores insets as double values.
  	 */
  	public static class Double extends Insets2D {
  		/** Version id for serialization. */
  		private static final long serialVersionUID = -6637052175330595647L;
  
  		/** Top. */
  		private double top;
  		/** Left. */
  		private double left;
  		/** Bottom. */
  		private double bottom;
  		/** Right. */
  		private double right;
  
  		/**
  		 * Creates a new Insets2D object with zero insets.
  		 */
  		public Double() {
  			this(0.0);
  		}
  
  		/**
  		 * Creates a new Insets2D object with the specified insets in all
  		 * directions.
  		 * @param inset Inset value.
  		 */
  		public Double(double inset) {
  			this(inset, inset, inset, inset);
  		}
  
  		/**
  		 * Creates a new Insets2D object with the specified insets.
  		 * @param top Top insets.
  		 * @param left Left insets.
  		 * @param bottom Bottom insets.
  		 * @param right Right insets.
  		 */
  		public Double(double top, double left, double bottom, double right) {
  			setInsets(top, left, bottom, right);
  		}
  
  		@Override
  		public double getTop() {
  			return top;
  		}
  
  		@Override
  		public double getLeft() {
  			return left;
  		}
  
  		@Override
  		public double getBottom() {
  			return bottom;
  		}
  
  		@Override
  		public double getRight() {
  			return right;
  		}
  
  		@Override
  		public void setInsets(Insets2D insets) {
  			if (insets == null) {
  				return;
  			}
  			setInsets(insets.getTop(), insets.getLeft(),
  					insets.getBottom(), insets.getRight());
  		}
  
  		@Override
  		public void setInsets(double top, double left,
  				double bottom, double right) {
  			this.top = top;
  			this.left = left;
  			this.bottom = bottom;
  			this.right = right;
  		}
  
  		@Override
  		public String toString() {
  			return String.format(Locale.US,
  				"%s[top=%f, left=%f, bottom=%f, right=%f]", //$NON-NLS-1$
  				getClass().getName(), top, left, bottom, right);
  		}
  
  		@Override
  		public boolean equals(Object obj) {
  			if (!(obj instanceof Insets2D)) {
  				return false;
  			}
  			Insets2D insets = (Insets2D) obj;
  			return (getTop() == insets.getTop())
  				&& (getLeft() == insets.getLeft())
  				&& (getBottom() == insets.getBottom())
  				&& (getRight() == insets.getRight());
  		}
  
  		@Override
  		public int hashCode() {
  			long bits = java.lang.Double.doubleToLongBits(getTop());
  			bits += java.lang.Double.doubleToLongBits(getLeft()) * 37;
  			bits += java.lang.Double.doubleToLongBits(getBottom()) * 43;
  			bits += java.lang.Double.doubleToLongBits(getRight()) * 47;
  			return ((int) bits) ^ ((int) (bits >> 32));
  		}
  	}
  
  }
  