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jtstand-common is a library derived from jcommon, used by jtstand-chart, which is derived from jfreechart

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/*
 * Copyright (c) 2009 Albert Kurucz. 
 *
 * This file, ObjectTable.java is part of JTStand.
 *
 * JTStand 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.
 *
 * JTStand 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 GTStand.  If not, see .
 */

package org.jfree.util;

import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.Serializable;
import java.util.Arrays;

/**
 * A lookup table for objects. This implementation is not synchronized, it is up
 * to the caller to synchronize it properly.
 *
 * @author Thomas Morgner
 */
public class ObjectTable implements Serializable
{

  /**
   * For serialization.
   */
  private static final long serialVersionUID = -3968322452944912066L;

  /**
   * The number of rows.
   */
  private int rows;

  /**
   * The number of columns.
   */
  private int columns;

  /**
   * An array of objects.  The array may contain null values.
   */
  private transient Object[][] data;

  /**
   * Defines how many object-slots get reserved each time we run out of
   * space.
   */
  private int rowIncrement;

  /**
   * Defines how many object-slots get reserved each time we run out of
   * space.
   */
  private int columnIncrement;

  /**
   * Creates a new table.
   */
  public ObjectTable()
  {
    this(5, 5);
  }

  /**
   * Creates a new table.
   *
   * @param increment the row and column size increment.
   */
  public ObjectTable(final int increment)
  {
    this(increment, increment);
  }

  /**
   * Creates a new table.
   *
   * @param rowIncrement the row size increment.
   * @param colIncrement the column size increment.
   */
  public ObjectTable(final int rowIncrement, final int colIncrement)
  {
    if (rowIncrement < 1)
    {
      throw new IllegalArgumentException("Increment must be positive.");
    }

    if (colIncrement < 1)
    {
      throw new IllegalArgumentException("Increment must be positive.");
    }

    this.rows = 0;
    this.columns = 0;
    this.rowIncrement = rowIncrement;
    this.columnIncrement = colIncrement;

    this.data = new Object[rowIncrement][];
  }

  /**
   * Returns the column size increment.
   *
   * @return the increment.
   */
  public int getColumnIncrement()
  {
    return this.columnIncrement;
  }

  /**
   * Returns the row size increment.
   *
   * @return the increment.
   */
  public int getRowIncrement()
  {
    return this.rowIncrement;
  }

  /**
   * Checks that there is storage capacity for the specified row and resizes
   * if necessary.
   *
   * @param row the row index.
   */
  protected void ensureRowCapacity(final int row)
  {

    // does this increase the number of rows?  if yes, create new storage
    if (row >= this.data.length)
    {

      final Object[][] enlarged = new Object[row + this.rowIncrement][];
      System.arraycopy(this.data, 0, enlarged, 0, this.data.length);
      // do not create empty arrays - this is more expensive than checking
      // for null-values.
      this.data = enlarged;
    }
  }

  /**
   * Ensures that there is storage capacity for the specified item.
   *
   * @param row    the row index.
   * @param column the column index.
   */
  public void ensureCapacity(final int row, final int column)
  {

    if (row < 0)
    {
      throw new IndexOutOfBoundsException("Row is invalid. " + row);
    }
    if (column < 0)
    {
      throw new IndexOutOfBoundsException("Column is invalid. " + column);
    }

    ensureRowCapacity(row);

    final Object[] current = this.data[row];
    if (current == null)
    {
      final Object[] enlarged
          = new Object[Math.max(column + 1, this.columnIncrement)];
      this.data[row] = enlarged;
    }
    else if (column >= current.length)
    {
      final Object[] enlarged = new Object[column + this.columnIncrement];
      System.arraycopy(current, 0, enlarged, 0, current.length);
      this.data[row] = enlarged;
    }
  }

  /**
   * Returns the number of rows in the table.
   *
   * @return The row count.
   */
  public int getRowCount()
  {
    return this.rows;
  }

  /**
   * Returns the number of columns in the table.
   *
   * @return The column count.
   */
  public int getColumnCount()
  {
    return this.columns;
  }

  /**
   * Returns the object from a particular cell in the table. Returns null, if
   * there is no object at the given position.
   * 

* Note: throws IndexOutOfBoundsException if row or column is negative. * * @param row the row index (zero-based). * @param column the column index (zero-based). * @return The object. */ protected Object getObject(final int row, final int column) { if (row < this.data.length) { final Object[] current = this.data[row]; if (current == null) { return null; } if (column < current.length) { return current[column]; } } return null; } /** * Sets the object for a cell in the table. The table is expanded if * necessary. * * @param row the row index (zero-based). * @param column the column index (zero-based). * @param object the object. */ protected void setObject(final int row, final int column, final Object object) { ensureCapacity(row, column); this.data[row][column] = object; this.rows = Math.max(this.rows, row + 1); this.columns = Math.max(this.columns, column + 1); } /** * Tests this paint table for equality with another object (typically also * an ObjectTable). * * @param o the other object. * @return A boolean. */ public boolean equals(final Object o) { if (o == null) { return false; } if (this == o) { return true; } if ((o instanceof ObjectTable) == false) { return false; } final ObjectTable ot = (ObjectTable) o; if (getRowCount() != ot.getRowCount()) { return false; } if (getColumnCount() != ot.getColumnCount()) { return false; } for (int r = 0; r < getRowCount(); r++) { for (int c = 0; c < getColumnCount(); c++) { if (ObjectUtilities.equal(getObject(r, c), ot.getObject(r, c)) == false) { return false; } } } return true; } /** * Returns a hash code value for the object. * * @return the hashcode */ public int hashCode() { int result; result = this.rows; result = 29 * result + this.columns; return result; } /** * Handles serialization. * * @param stream the output stream. * @throws java.io.IOException if there is an I/O problem. */ private void writeObject(final ObjectOutputStream stream) throws IOException { stream.defaultWriteObject(); final int rowCount = this.data.length; stream.writeInt(rowCount); for (int r = 0; r < rowCount; r++) { final Object[] column = this.data[r]; stream.writeBoolean(column != null); if (column != null) { final int columnCount = column.length; stream.writeInt(columnCount); for (int c = 0; c < columnCount; c++) { writeSerializedData(stream, column[c]); } } } } /** * Handles the serialization of an single element of this table. * * @param stream the stream which should write the object * @param o the object that should be serialized * @throws IOException if an IO error occured */ protected void writeSerializedData(final ObjectOutputStream stream, final Object o) throws IOException { stream.writeObject(o); } /** * Restores a serialized object. * * @param stream the input stream. * @throws java.io.IOException if there is an I/O problem. * @throws ClassNotFoundException if a class cannot be found. */ private void readObject(final ObjectInputStream stream) throws IOException, ClassNotFoundException { stream.defaultReadObject(); final int rowCount = stream.readInt(); this.data = new Object[rowCount][]; for (int r = 0; r < rowCount; r++) { final boolean isNotNull = stream.readBoolean(); if (isNotNull) { final int columnCount = stream.readInt(); final Object[] column = new Object[columnCount]; this.data[r] = column; for (int c = 0; c < columnCount; c++) { column[c] = readSerializedData(stream); } } } } /** * Handles the deserialization of a single element of the table. * * @param stream the object input stream from which to read the object. * @return the deserialized object * @throws ClassNotFoundException if a class cannot be found. * @throws IOException Any of the usual Input/Output related * exceptions. */ protected Object readSerializedData(final ObjectInputStream stream) throws ClassNotFoundException, IOException { return stream.readObject(); } /** * Clears the table. */ public void clear() { this.rows = 0; this.columns = 0; for (int i = 0; i < this.data.length; i++) { if (this.data[i] != null) { Arrays.fill(this.data[i], null); } } } /** * Copys the contents of the old column to the new column. * * @param oldColumn the index of the old (source) column * @param newColumn the index of the new column */ protected void copyColumn(final int oldColumn, final int newColumn) { for (int i = 0; i < getRowCount(); i++) { setObject(i, newColumn, getObject(i, oldColumn)); } } /** * Copys the contents of the old row to the new row. This uses raw access to * the data and is remarkably faster than manual copying. * * @param oldRow the index of the old row * @param newRow the index of the new row */ protected void copyRow(final int oldRow, final int newRow) { this.ensureCapacity(newRow, getColumnCount()); final Object[] oldRowStorage = this.data[oldRow]; if (oldRowStorage == null) { final Object[] newRowStorage = this.data[newRow]; if (newRowStorage != null) { Arrays.fill(newRowStorage, null); } } else { this.data[newRow] = (Object[]) oldRowStorage.clone(); } } /** * Sets the table data. * * @param data the data. * @param colCount the number of columns. */ protected void setData(final Object[][] data, final int colCount) { if (data == null) { throw new NullPointerException(); } if (colCount < 0) { throw new IndexOutOfBoundsException(); } this.data = data; this.rows = data.length; this.columns = colCount; } /** * Returns the table data. * * @return The table data. */ protected Object[][] getData() { return this.data; } }





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