Java tutorial
/* * JCommon : a free general purpose class library for the Java(tm) platform * * * (C) Copyright 2000-2009, by Object Refinery Limited and Contributors. * * Project Info: http://www.jfree.org/jcommon/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. * * [Java is a trademark or registered trademark of Sun Microsystems, Inc. * in the United States and other countries.] * * ----------------------- * StrokeChooserPanel.java * ----------------------- * (C) Copyright 2000-2009, by Object Refinery Limited. * * Original Author: David Gilbert (for Object Refinery Limited); * Contributor(s): Dirk Zeitz; * * $Id: StrokeChooserPanel.java,v 1.8 2009/02/27 13:58:41 mungady Exp $ * * Changes (from 26-Oct-2001) * -------------------------- * 26-Oct-2001 : Changed package to com.jrefinery.ui.*; * 14-Oct-2002 : Fixed errors reported by Checkstyle (DG); * 16-Mar-2004 : Fix for focus problems (DZ); * 27-Feb-2009 : Fixed bug 2612649, NullPointerException (DG); * */ import java.awt.BorderLayout; import java.awt.Component; import java.awt.Dimension; import java.awt.Graphics; import java.awt.Graphics2D; import java.awt.Insets; import java.awt.RenderingHints; import java.awt.Stroke; import java.awt.event.ActionEvent; import java.awt.event.ActionListener; import java.awt.geom.Ellipse2D; import java.awt.geom.Line2D; import java.awt.geom.Point2D; import javax.swing.DefaultComboBoxModel; import javax.swing.JComboBox; import javax.swing.JComponent; import javax.swing.JList; import javax.swing.JPanel; import javax.swing.ListCellRenderer; /** * A component for choosing a stroke from a list of available strokes. * * @author David Gilbert */ public class StrokeChooserPanel extends JPanel { /** A combo for selecting the stroke. */ private JComboBox selector; /** * Creates a panel containing a combo-box that allows the user to select * one stroke from a list of available strokes. * * @param current the current stroke sample. * @param available an array of 'available' stroke samples. */ public StrokeChooserPanel(StrokeSample current, StrokeSample[] available) { setLayout(new BorderLayout()); // we've changed the behaviour here to populate the combo box // with Stroke objects directly - ideally we'd change the signature // of the constructor too...maybe later. DefaultComboBoxModel model = new DefaultComboBoxModel(); for (int i = 0; i < available.length; i++) { model.addElement(available[i].getStroke()); } this.selector = new JComboBox(model); this.selector.setSelectedItem(current.getStroke()); this.selector.setRenderer(new StrokeSample(null)); add(this.selector); // Changes due to focus problems!! DZ this.selector.addActionListener(new ActionListener() { public void actionPerformed(final ActionEvent evt) { getSelector().transferFocus(); } }); } /** * Returns the selector component. * * @return Returns the selector. */ protected final JComboBox getSelector() { return this.selector; } /** * Returns the selected stroke. * * @return The selected stroke (possibly <code>null</code>). */ public Stroke getSelectedStroke() { return (Stroke) this.selector.getSelectedItem(); } } /* * JCommon : a free general purpose class library for the Java(tm) platform * * * (C) Copyright 2000-2009, by Object Refinery Limited and Contributors. * * Project Info: http://www.jfree.org/jcommon/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. * * [Java is a trademark or registered trademark of Sun Microsystems, Inc. * in the United States and other countries.] * * ----------------- * StrokeSample.java * ----------------- * (C) Copyright 2000-2009, by Object Refinery Limited. * * Original Author: David Gilbert (for Object Refinery Limited); * Contributor(s): -; * * $Id: StrokeSample.java,v 1.5 2009/02/27 13:58:41 mungady Exp $ * * Changes (from 26-Oct-2001) * -------------------------- * 26-Oct-2001 : Changed package to com.jrefinery.ui.*; * 14-Oct-2002 : Fixed errors reported by Checkstyle (DG); * 21-Mar-2003 : Fixed null pointer exception, bug 705126 (DG); * */ /** * A panel that displays a stroke sample. * * @author David Gilbert */ class StrokeSample extends JComponent implements ListCellRenderer { /** The stroke being displayed (may be null). */ private Stroke stroke; /** The preferred size of the component. */ private Dimension preferredSize; /** * Creates a StrokeSample for the specified stroke. * * @param stroke the sample stroke (<code>null</code> permitted). */ public StrokeSample(final Stroke stroke) { this.stroke = stroke; this.preferredSize = new Dimension(80, 18); setPreferredSize(this.preferredSize); } /** * Returns the current Stroke object being displayed. * * @return The stroke (possibly <code>null</code>). */ public Stroke getStroke() { return this.stroke; } /** * Sets the stroke object being displayed and repaints the component. * * @param stroke the stroke (<code>null</code> permitted). */ public void setStroke(final Stroke stroke) { this.stroke = stroke; repaint(); } /** * Returns the preferred size of the component. * * @return the preferred size of the component. */ public Dimension getPreferredSize() { return this.preferredSize; } /** * Draws a line using the sample stroke. * * @param g the graphics device. */ public void paintComponent(final Graphics g) { final Graphics2D g2 = (Graphics2D) g; g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON); final Dimension size = getSize(); final Insets insets = getInsets(); final double xx = insets.left; final double yy = insets.top; final double ww = size.getWidth() - insets.left - insets.right; final double hh = size.getHeight() - insets.top - insets.bottom; // calculate point one final Point2D one = new Point2D.Double(xx + 6, yy + hh / 2); // calculate point two final Point2D two = new Point2D.Double(xx + ww - 6, yy + hh / 2); // draw a circle at point one final Ellipse2D circle1 = new Ellipse2D.Double(one.getX() - 5, one.getY() - 5, 10, 10); final Ellipse2D circle2 = new Ellipse2D.Double(two.getX() - 6, two.getY() - 5, 10, 10); // draw a circle at point two g2.draw(circle1); g2.fill(circle1); g2.draw(circle2); g2.fill(circle2); // draw a line connecting the points final Line2D line = new Line2D.Double(one, two); if (this.stroke != null) { g2.setStroke(this.stroke); g2.draw(line); } } /** * Returns a list cell renderer for the stroke, so the sample can be * displayed in a list or combo. * * @param list the list. * @param value the value. * @param index the index. * @param isSelected selected? * @param cellHasFocus focussed? * * @return the component for rendering. */ public Component getListCellRendererComponent(JList list, Object value, int index, boolean isSelected, boolean cellHasFocus) { if (value instanceof Stroke) { setStroke((Stroke) value); } else { setStroke(null); } return this; } }