Java tutorial
/* =========================================================== * JFreeChart : a free chart library for the Java(tm) platform * =========================================================== * * (C) Copyright 2000-2014, by Object Refinery Limited and Contributors. * * Project Info: http://www.jfree.org/jfreechart/index.html * * This library 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 2.1 of the License, or * (at your option) any later version. * * This library 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 this library; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, * USA. * * [Oracle and Java are registered trademarks of Oracle and/or its affiliates. * Other names may be trademarks of their respective owners.] * * -------------------------------------- * CategoryDatasetSelectionExtension.java * -------------------------------------- * (C) Copyright 2013, 2014, by Michael Zinsmaier. * * Original Author: Michael Zinsmaier; * Contributor(s): -; * * Changes * ------- * 17-Sep-2013 : Version 1 (MZ); * */ package org.jfree.data.extension.impl; import java.util.Iterator; import org.jfree.data.DefaultKeyedValues2D; import org.jfree.data.category.CategoryDataset; import org.jfree.data.extension.DatasetCursor; import org.jfree.data.extension.DatasetIterator; import org.jfree.data.extension.DatasetSelectionExtension; import org.jfree.data.extension.IterableSelection; import org.jfree.data.general.DatasetChangeEvent; import org.jfree.data.general.SelectionChangeListener; /** * Extends a category dataset with a selection state for each data item. * * @author zinsmaie */ public class CategoryDatasetSelectionExtension<ROW_KEY extends Comparable<ROW_KEY>, COLUMN_KEY extends Comparable<COLUMN_KEY>> extends AbstractDatasetSelectionExtension<CategoryCursor<ROW_KEY, COLUMN_KEY>, CategoryDataset> implements IterableSelection<CategoryCursor<ROW_KEY, COLUMN_KEY>> { /** a generated serial id */ private static final long serialVersionUID = 5138359490302459066L; /** * private ref to the stored dataset to avoid casting same as * ({@link AbstractDatasetSelectionExtension#dataset}) */ private CategoryDataset dataset; //could improve here by using own bool data structure /** storage for the selection attributes of the data items. */ private DefaultKeyedValues2D selectionData; /** defines true as byte value */ private final Number TRUE = new Byte((byte) 1); /** defines false as byte value */ private final Number FALSE = new Byte((byte) 0); /** * Creates a separate selection extension for the specified dataset. * * @param dataset the underlying dataset (<code>null</code> not permitted). */ public CategoryDatasetSelectionExtension(CategoryDataset dataset) { super(dataset); this.dataset = dataset; initSelection(); } /** * Creates a separate selection extension for the specified dataset. And * adds an initial selection change listener, e.g. a plot that should be * redrawn on selection changes. * * @param dataset the underlying dataset. * @param initialListener the initial listener. */ public CategoryDatasetSelectionExtension(CategoryDataset dataset, SelectionChangeListener<CategoryCursor<ROW_KEY, COLUMN_KEY>> initialListener) { super(dataset); addChangeListener(initialListener); } /** * Returns the selection status of the data item referenced by the * supplied cursor. * * @param cursor the cursor (<code>null</code> not permitted). * * @return The selection status. */ @Override public boolean isSelected(CategoryCursor<ROW_KEY, COLUMN_KEY> cursor) { return (TRUE == this.selectionData.getValue(cursor.rowKey, cursor.columnKey)); } /** * {@link DatasetSelectionExtension#setSelected(DatasetCursor, boolean)} */ @Override public void setSelected(CategoryCursor<ROW_KEY, COLUMN_KEY> cursor, boolean selected) { if (selected) { selectionData.setValue(TRUE, cursor.rowKey, cursor.columnKey); } else { selectionData.setValue(FALSE, cursor.rowKey, cursor.columnKey); } notifyIfRequired(); } /** * {@link DatasetSelectionExtension#clearSelection()} */ @Override public void clearSelection() { initSelection(); } /** * Receives notification of a change to the underlying dataset, this is * handled by clearing the selection. * * @param event details of the change event. */ @Override public void datasetChanged(DatasetChangeEvent event) { // TODO : we could in fact try to preserve the selection state of // items that still remain in the dataset. initSelection(); } /** * inits the selection attribute storage and sets all data items to * unselected */ private void initSelection() { this.selectionData = new DefaultKeyedValues2D(); for (int i = 0; i < dataset.getRowCount(); i++) { for (int j = 0; j < dataset.getColumnCount(); j++) { if (dataset.getValue(i, j) != null) { selectionData.addValue(FALSE, dataset.getRowKey(i), dataset.getColumnKey(j)); } } } notifyIfRequired(); } //ITERATOR /** * {@link IterableSelection#getIterator()} */ @Override public DatasetIterator<CategoryCursor<ROW_KEY, COLUMN_KEY>> getIterator() { return new CategoryDatasetSelectionIterator(); } /** * {@link IterableSelection#getSelectionIterator(boolean)} */ @Override public DatasetIterator<CategoryCursor<ROW_KEY, COLUMN_KEY>> getSelectionIterator(boolean selected) { return new CategoryDatasetSelectionIterator(selected); } /** * Allows to iterate over all data items or the selected / unselected data * items. Provides on each iteration step a DatasetCursor that defines the * position of the data item. * * @author zinsmaie */ private class CategoryDatasetSelectionIterator implements DatasetIterator<CategoryCursor<ROW_KEY, COLUMN_KEY>> { // could be improved wtr speed by storing selected elements directly for // faster access however storage efficiency would decrease /** a generated serial id */ private static final long serialVersionUID = -6861323401482698708L; /** current row position */ private int row = 0; /** * current column position initialized before the start of the * dataset */ private int column = -1; /** * return all data item positions (null), only the selected (true) or * only the unselected (false) */ private Boolean filter = null; /** * Creates an iterator over all data item positions */ public CategoryDatasetSelectionIterator() { } /** * Creates an iterator that iterates either over all selected or all * unselected data item positions. * * @param selected if true the iterator will iterate over the selected * data item positions */ public CategoryDatasetSelectionIterator(boolean selected) { this.filter = Boolean.valueOf(selected); } /** * {@link Iterator#hasNext() */ @Override public boolean hasNext() { if (nextPosition()[0] != -1) { return true; } return false; } /** * {@link Iterator#next()} */ public CategoryCursor<ROW_KEY, COLUMN_KEY> next() { int[] newPos = nextPosition(); row = newPos[0]; column = newPos[1]; // category datasets are not yet typed therefore the cast is // necessary (and may fail) return new CategoryCursor<ROW_KEY, COLUMN_KEY>((ROW_KEY) dataset.getRowKey(row), (COLUMN_KEY) dataset.getColumnKey(column)); } /** * Iterator remove operation is not supported. */ @Override public void remove() { throw new UnsupportedOperationException(); } /** * Calculates the next position based on the current position * and the filter status. * * @return an array holding the next position [row, column] */ private int[] nextPosition() { int pRow = this.row; int pColumn = this.column; while (pRow < dataset.getRowCount()) { if ((pColumn + 1) >= selectionData.getColumnCount()) { pRow++; pColumn = -1; continue; } if (filter != null) { if (!((filter.equals(Boolean.TRUE) && TRUE.equals(selectionData.getValue(pRow, (pColumn + 1)))) || (filter.equals(Boolean.FALSE) && FALSE.equals(selectionData.getValue(pRow, (pColumn + 1)))))) { pColumn++; continue; } } //success return new int[] { pRow, (pColumn + 1) }; } return new int[] { -1, -1 }; } } }