Java example source code file (Insets.java)

This example Java source code file (Insets.java) is included in the alvinalexander.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Learn more about this Java project at its project page.

Java - Java tags/keywords

cloneable, clonenotsupportedexception, insets, internalerror, object, string

The Insets.java Java example source code

/*
 * Copyright (c) 1995, 2011, 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 java.awt;

/**
 * An <code>Insets object is a representation of the borders
 * of a container. It specifies the space that a container must leave
 * at each of its edges. The space can be a border, a blank space, or
 * a title.
 *
 * @author      Arthur van Hoff
 * @author      Sami Shaio
 * @see         java.awt.LayoutManager
 * @see         java.awt.Container
 * @since       JDK1.0
 */
public class Insets implements Cloneable, java.io.Serializable {

    /**
     * The inset from the top.
     * This value is added to the Top of the rectangle
     * to yield a new location for the Top.
     *
     * @serial
     * @see #clone()
     */
    public int top;

    /**
     * The inset from the left.
     * This value is added to the Left of the rectangle
     * to yield a new location for the Left edge.
     *
     * @serial
     * @see #clone()
     */
    public int left;

    /**
     * The inset from the bottom.
     * This value is subtracted from the Bottom of the rectangle
     * to yield a new location for the Bottom.
     *
     * @serial
     * @see #clone()
     */
    public int bottom;

    /**
     * The inset from the right.
     * This value is subtracted from the Right of the rectangle
     * to yield a new location for the Right edge.
     *
     * @serial
     * @see #clone()
     */
    public int right;

    /*
     * JDK 1.1 serialVersionUID
     */
    private static final long serialVersionUID = -2272572637695466749L;

    static {
        /* ensure that the necessary native libraries are loaded */
        Toolkit.loadLibraries();
        if (!GraphicsEnvironment.isHeadless()) {
            initIDs();
        }
    }

    /**
     * Creates and initializes a new <code>Insets object with the
     * specified top, left, bottom, and right insets.
     * @param       top   the inset from the top.
     * @param       left   the inset from the left.
     * @param       bottom   the inset from the bottom.
     * @param       right   the inset from the right.
     */
    public Insets(int top, int left, int bottom, int right) {
        this.top = top;
        this.left = left;
        this.bottom = bottom;
        this.right = right;
    }

    /**
     * Set top, left, bottom, and right to the specified values
     *
     * @param       top   the inset from the top.
     * @param       left   the inset from the left.
     * @param       bottom   the inset from the bottom.
     * @param       right   the inset from the right.
     * @since 1.5
     */
    public void set(int top, int left, int bottom, int right) {
        this.top = top;
        this.left = left;
        this.bottom = bottom;
        this.right = right;
    }

    /**
     * Checks whether two insets objects are equal. Two instances
     * of <code>Insets are equal if the four integer values
     * of the fields <code>top, left,
     * <code>bottom, and right are all equal.
     * @return      <code>true if the two insets are equal;
     *                          otherwise <code>false.
     * @since       JDK1.1
     */
    public boolean equals(Object obj) {
        if (obj instanceof Insets) {
            Insets insets = (Insets)obj;
            return ((top == insets.top) && (left == insets.left) &&
                    (bottom == insets.bottom) && (right == insets.right));
        }
        return false;
    }

    /**
     * Returns the hash code for this Insets.
     *
     * @return    a hash code for this Insets.
     */
    public int hashCode() {
        int sum1 = left + bottom;
        int sum2 = right + top;
        int val1 = sum1 * (sum1 + 1)/2 + left;
        int val2 = sum2 * (sum2 + 1)/2 + top;
        int sum3 = val1 + val2;
        return sum3 * (sum3 + 1)/2 + val2;
    }

    /**
     * Returns a string representation of this <code>Insets object.
     * This method is intended to be used only for debugging purposes, and
     * the content and format of the returned string may vary between
     * implementations. The returned string may be empty but may not be
     * <code>null.
     *
     * @return  a string representation of this <code>Insets object.
     */
    public String toString() {
        return getClass().getName() + "[top="  + top + ",left=" + left + ",bottom=" + bottom + ",right=" + right + "]";
    }

    /**
     * Create a copy of this object.
     * @return     a copy of this <code>Insets object.
     */
    public Object clone() {
        try {
            return super.clone();
        } catch (CloneNotSupportedException e) {
            // this shouldn't happen, since we are Cloneable
            throw new InternalError(e);
        }
    }
    /**
     * Initialize JNI field and method IDs
     */
    private static native void initIDs();

}