/*
* GRAL: GRAphing Library for Java(R)
*
* (C) Copyright 2009-2016 Erich Seifert ,
* Michael Seifert
*
* 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 dataListeners;
/** Statistical description of the data values. */
private transient Statistics statistics;
/**
* Iterator that returns each row of the DataSource.
*/
private class DataSourceIterator implements Iterator> {
/** Index of current column. */
private int col;
/** Index of current row. */
private int row;
/**
* Initializes a new iterator instance that starts at (0, 0).
*/
public DataSourceIterator() {
col = 0;
row = 0;
}
/**
* Returns {@code true} if the iteration has more elements.
* (In other words, returns {@code true} if {@code next}
* would return an element rather than throwing an exception.)
* @return {@code true} if the iterator has more elements.
*/
public boolean hasNext() {
return (col < getColumnCount()) && (row < getRowCount());
}
/**
* Returns the next element in the iteration.
* @return the next element in the iteration.
* @exception NoSuchElementException iteration has no more elements.
*/
public Comparable next() {
if (!hasNext()) {
throw new NoSuchElementException();
}
Comparable value = get(col, row);
if (++col >= getColumnCount()) {
col = 0;
++row;
}
return value;
}
/**
* Method that theoretically removes a cell from a data source.
* However, this is not supported.
*/
public void remove() {
throw new UnsupportedOperationException();
}
}
public AbstractDataSource() {
this(null, new Class[0]);
}
/**
* Initializes a new instance with the specified name, number of columns, and
* column types.
* @param name name of the DataSource
* @param types type for each column
*/
public AbstractDataSource(String name, Class>... types) {
this.name = name;
setColumnTypes(types);
dataListeners = new LinkedHashSet();
}
/**
* Initializes a new instance with the specified number of columns and
* column types.
* @param types type for each column
*/
public AbstractDataSource(Class>... types) {
this(null, types);
}
public AbstractDataSource(Column... remainingColumns) {
Class>[] columnTypes = new Class[remainingColumns.length];
for (int columnIndex = 0; columnIndex < remainingColumns.length; columnIndex++) {
Column column = remainingColumns[columnIndex];
columnTypes[columnIndex] = column.getType();
}
setColumnTypes(columnTypes);
dataListeners = new LinkedHashSet();
}
/**
* Retrieves a object instance that contains various statistical
* information on the current data source.
* @return statistical information
*/
public Statistics getStatistics() {
if (statistics == null) {
statistics = new Statistics(this);
}
return statistics;
}
public DataSource getColumnStatistics(String key) {
Class[] columnTypes = new Class[getColumnCount()];
Arrays.fill(columnTypes, Double.class);
DataTable statisticsTable = new DataTable(columnTypes);
List colStatistics = new ArrayList(columnTypes.length);
for (int colIndex = 0; colIndex < getColumnCount(); colIndex++) {
Column col = getColumn(colIndex);
colStatistics.add(col.getStatistics(key));
}
if (!colStatistics.isEmpty()) {
statisticsTable.add(colStatistics);
}
return statisticsTable;
}
public DataSource getRowStatistics(String key) {
DataTable statisticsTable = getRowCount() != 0 ? new DataTable(Double.class) : new DataTable();
for (int rowIndex = 0; rowIndex < getRowCount(); rowIndex++) {
Record row = getRecord(rowIndex);
statisticsTable.add(new Statistics(row).get(key));
}
return statisticsTable;
}
/**
* Adds the specified {@code DataListener} to this data source.
* @param dataListener listener to be added.
*/
public void addDataListener(DataListener dataListener) {
dataListeners.add(dataListener);
}
/**
* Removes the specified {@code DataListener} from this data source.
* @param dataListener listener to be removed.
*/
public void removeDataListener(DataListener dataListener) {
dataListeners.remove(dataListener);
}
/**
* Returns an iterator over a set of elements of type T.
*
* @return an Iterator.
*/
public Iterator> iterator() {
return new DataSourceIterator();
}
/**
* Notifies all registered listeners that data values have been added.
* @param events Event objects describing all values that have been added.
*/
protected void notifyDataAdded(DataChangeEvent... events) {
List listeners = new LinkedList(dataListeners);
for (DataListener dataListener : listeners) {
dataListener.dataAdded(this, events);
}
}
/**
* Notifies all registered listeners that data values have been removed.
* @param events Event objects describing all values that have been removed.
*/
protected void notifyDataRemoved(DataChangeEvent... events) {
List listeners = new LinkedList(dataListeners);
for (DataListener dataListener : listeners) {
dataListener.dataRemoved(this, events);
}
}
/**
* Notifies all registered listeners that data values have changed.
* @param events Event objects describing all values that have changed.
*/
protected void notifyDataUpdated(DataChangeEvent... events) {
List listeners = new LinkedList(dataListeners);
for (DataListener dataListener : listeners) {
dataListener.dataUpdated(this, events);
}
}
/**
* Returns the column with the specified index.
* @param col index of the column to return
* @return the specified column of the data source
*/
@Override
public Column getColumn(int col) {
Class> columnType = getColumnTypes()[col];
List> columnData = new LinkedList>();
for (int rowIndex = 0; rowIndex < getRowCount(); rowIndex++) {
Record record = getRecord(rowIndex);
columnData.add(record.get(col));
}
return new Column(columnType, columnData.toArray(new Comparable[0]));
}
@Override
public String getName() {
return name;
}
@Override
public Record getRecord(int row) {
return new Record(getRow(row).toArray(null));
}
// Allows DataTable to reuse the name property
protected void setName(String name) {
this.name = name;
}
/**
* Returns the number of columns of the data source.
* @return number of columns in the data source.
*/
public int getColumnCount() {
return columnCount;
}
/**
* Returns the data types of all columns.
* @return The data types of all column in the data source
*/
public Class>[] getColumnTypes() {
Class>[] types =
Arrays.copyOf(this.types, this.types.length);
return types;
}
/**
* Returns whether the column at the specified index contains numbers.
* @param columnIndex Index of the column to test.
* @return {@code true} if the column is numeric, otherwise {@code false}.
*/
public boolean isColumnNumeric(int columnIndex) {
if (columnIndex < 0 || columnIndex >= types.length) {
return false;
}
Class columnType = types[columnIndex];
return Number.class.isAssignableFrom(columnType);
}
/**
* Sets the data types of all columns. This also changes the number of
* columns.
* @param types Data types.
*/
protected void setColumnTypes(Class>... types) {
this.types = Arrays.copyOf(types, types.length);
columnCount = types.length;
}
/**
* Returns the row with the specified index.
* @param row Index of the row to return
* @return the Specified row of the data source
*/
public Row getRow(int row) {
return new Row(this, row);
}
/**
* Custom deserialization method.
* @param in Input stream.
* @throws ClassNotFoundException if a serialized class doesn't exist anymore.
* @throws IOException if there is an error while reading data from the
* input stream.
*/
private void readObject(ObjectInputStream in)
throws ClassNotFoundException, IOException {
// Normal deserialization
in.defaultReadObject();
// Handle transient fields
dataListeners = new HashSet();
// Statistics can be omitted. It's created using a lazy getter.
}
}
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