StringStack.java

/**
 * H2GIS is a library that brings spatial support to the H2 Database Engine
 * <http://www.h2database.com>. H2GIS is developed by CNRS
 * <http://www.cnrs.fr/>.
 *
 * This code is part of the H2GIS project. H2GIS 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;
 * version 3.0 of the License.
 *
 * H2GIS 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 <http://www.gnu.org/licenses/>.
 *
 *
 * For more information, please consult: <http://www.h2gis.org/>
 * or contact directly: info_at_h2gis.org
 */

package org.h2gis.functions.io.gpx.model;

/**
 * This class is a stack to keep in memory the structure of the GPX file.
 *
 * @author Erwan Bocher and Antonin Piasco
 */
public final class StringStack {

    private String[] stack;
    // Indicates the level of the stack
    private int stackTop = 0;

    /**
     * Instantiates a StringStack with chosen max size.
     *
     * @param capacity max size
     */
    public StringStack(int capacity) {
        stack = new String[capacity];
    }

    /**
     * Puts string in the stack.
     *
     * @param newText A new string to put in the stack
     * @return false if the stack is full
     */
    public boolean push(String newText) {
        if (stackTop < stack.length - 1) {
            stack[stackTop++] = newText;
            return true;
        } else {
            return false;
        }
    }

    /**
     * Removes the last string of the stack.
     *
     * @return the last string of the stack, null if the stack is empty
     */
    public String pop() {
        if (stackTop == 0) {
            return (null);
        } else {
            return (stack[--stackTop]);
        }
    }
}