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.] * * -------------------------------- * XYDatasetSelectionExtension.java * -------------------------------- * (C) Copyright 2013, 2014, by Michael Zinsmaier and Contributors. * * Original Author: Michael Zinsmaier; * Contributor(s): David Gilbert (for Object Refinery Limited); * * Changes * ------- * 17-Sep-2013 : Version 1 (MZ); * */ package org.jfree.data.extension.impl; import java.util.ArrayList; import java.util.Iterator; 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; import org.jfree.data.xy.XYDataset; /** * Extends a xy dataset with a selection state for each data item. * * @author zinsmaie */ public class XYDatasetSelectionExtension extends AbstractDatasetSelectionExtension<XYCursor, XYDataset> implements IterableSelection<XYCursor> { /** A generated serial id. */ private static final long serialVersionUID = 4859712483757720877L; /** private ref to the stored dataset to avoid casting same as ({@link AbstractDatasetSelectionExtension#dataset})*/ private XYDataset dataset; /** * Storage for the selection attributes of the data items (one list for * each series). */ private ArrayList<Boolean>[] selectionData; /** * Creates a separate selection extension for the specified dataset. * * @param dataset the underlying dataset (<code>null</code> not permitted). */ @SuppressWarnings("unchecked") //can't instantiate selection data with //correct type (array limits) public XYDatasetSelectionExtension(XYDataset dataset) { super(dataset); this.dataset = dataset; this.selectionData = new ArrayList[dataset.getSeriesCount()]; 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 dataset ({@code null} not permitted). * @param initialListener a change listener. */ public XYDatasetSelectionExtension(XYDataset dataset, SelectionChangeListener<XYCursor> initialListener) { super(dataset); addChangeListener(initialListener); } /** * A change of the underlying dataset clears the selection and * reinitializes it. * * @param event the event details. */ @Override public void datasetChanged(DatasetChangeEvent event) { initSelection(); } /** * Returns {@code true} if the data item that the cursor points to is * selected, and {@code false} otherwise. * * @param cursor specifies the position of the data item ({@code null} not * permitted). * * @return A boolean. */ @Override public boolean isSelected(XYCursor cursor) { return (selectionData[cursor.series].get(cursor.item)); } /** * Sets the selection state of a data item. * * @param cursor specifies the position of the data item ({@code null} not * permitted). * @param selected the new selection state. */ @Override public void setSelected(XYCursor cursor, boolean selected) { selectionData[cursor.series].set(cursor.item, selected); notifyIfRequired(); } /** * {@link DatasetSelectionExtension#clearSelection()} */ @Override public void clearSelection() { initSelection(); } /** * inits the selection attribute storage and sets all data items to unselected */ private void initSelection() { for (int i = 0; i < dataset.getSeriesCount(); i++) { selectionData[i] = new ArrayList<Boolean>(dataset.getItemCount(i)); for (int j = 0; j < dataset.getItemCount(i); j++) { selectionData[i].add(Boolean.FALSE); } } notifyIfRequired(); } // ITERATOR IMPLEMENTATION /** * {@link IterableSelection#getIterator()} */ @Override public DatasetIterator<XYCursor> getIterator() { return new XYDatasetSelectionIterator(); } /** * {@link IterableSelection#getSelectionIterator(boolean)} */ @Override public DatasetIterator<XYCursor> getSelectionIterator(boolean selected) { return new XYDatasetSelectionIterator(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 XYDatasetSelectionIterator implements DatasetIterator<XYCursor> { // 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 = 125607273863837608L; /** current series position */ private int series = 0; /** current item position initialized before the start of the dataset */ private int item = -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 XYDatasetSelectionIterator() { } /** * 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 XYDatasetSelectionIterator(boolean selected) { this.filter = selected; } /** {@link Iterator#hasNext() */ @Override public boolean hasNext() { if (nextPosition()[0] != -1) { return true; } return false; } /** * {@link Iterator#next()} */ @Override public XYCursor next() { int[] newPos = nextPosition(); this.series = newPos[0]; this.item = newPos[1]; return new XYCursor(this.series, this.item); } /** * 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 [series, item] */ private int[] nextPosition() { int pSeries = this.series; int pItem = this.item; while (pSeries < selectionData.length) { if ((pItem + 1) >= selectionData[pSeries].size()) { pSeries++; pItem = -1; continue; } if (filter != null) { if (!(filter.equals(selectionData[pSeries].get(pItem + 1)))) { pItem++; continue; } } //success return new int[] { pSeries, (pItem + 1) }; } return new int[] { -1, -1 }; } } }