/**
* Copyright (C) 2001-2017 by RapidMiner and the contributors
*
* Complete list of developers available at our web site:
*
* http://rapidminer.com
*
* This program is free software: you can redistribute it and/or modify it under the terms of the
* GNU Affero General Public License as published by the Free Software Foundation, either version 3
* of the License, or (at your option) any later version.
*
* This program 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
* Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License along with this program.
* If not, see http://www.gnu.org/licenses/.
*/
package com.rapidminer.operator.nio.model;
import java.util.LinkedList;
import java.util.List;
import javax.swing.table.AbstractTableModel;
import com.rapidminer.operator.OperatorException;
import com.rapidminer.operator.nio.ImportWizardUtils;
import com.rapidminer.tools.ProgressListener;
/**
* Data container and table model for previews. Reads a few lines from a {@link DataResultSet} to
* display them. This should be only used in case where no more efficient implementation for the
* TableModel is available.
*
* @author Simon Fischer
*
*/
public class DefaultPreview extends AbstractTableModel {
private static final long serialVersionUID = 1L;
private String[][] data;
private String[] columnNames;
private int previewSize = ImportWizardUtils.getPreviewLength();
/**
* Maximum number of characters visible in a single cell. The number of characters is limited in
* order to prevent possible GUI freezes.
*/
private static final int CELL_MAX_LENGTH = 100;
public DefaultPreview(DataResultSet resultSet, ProgressListener l) throws OperatorException, ParseException {
read(resultSet, l);
}
public void read(DataResultSet resultSet, ProgressListener listener) throws OperatorException, ParseException {
if (listener != null) {
listener.setTotal(previewSize);
}
List<String[]> dataList = new LinkedList<String[]>();
resultSet.reset(listener);
while (resultSet.hasNext() && dataList.size() < previewSize) {
resultSet.next(listener);
String[] row = new String[resultSet.getNumberOfColumns()];
for (int i = 0; i < row.length; i++) {
row[i] = shortenDisplayValue(resultSet.getString(i));
}
dataList.add(row);
if (listener != null) {
listener.setCompleted(dataList.size());
}
}
// copy to array since will be accessed by index
this.data = dataList.toArray(new String[dataList.size()][]);
columnNames = resultSet.getColumnNames();
if (listener != null) {
listener.complete();
}
}
@Override
public int getRowCount() {
return data.length;
}
@Override
public String getColumnName(int column) {
return columnNames[column];
}
@Override
public int getColumnCount() {
if (columnNames != null) {
return columnNames.length;
} else {
if (data != null && data.length > 0) {
return data[0].length;
} else {
return 1;
}
}
}
@Override
public Object getValueAt(int rowIndex, int columnIndex) {
final String[] row = data[rowIndex];
if (row == null) {
return null;
} else if (columnIndex >= row.length) {
return null;
} else {
return row[columnIndex];
}
}
/**
* Shortens the provided value to a maximum length of {@link #CELL_MAX_LENGTH} so we do not run
* into any displaying issues.
*
* @param displayValue
* the value to be shortened. Can be <code>null</code>.
* @return the full value of length below {@link #CELL_MAX_LENGTH} or a value with only
* {@link #CELL_MAX_LENGTH} characters
*/
public static final String shortenDisplayValue(String displayValue) {
if (displayValue != null && displayValue.length() > CELL_MAX_LENGTH) {
// chop text and end with "..."
return displayValue.substring(0, CELL_MAX_LENGTH - 1) + "\u2026";
} else {
return displayValue;
}
}
}