Java tutorial
/* * Copyright (c) 2011, Oracle and/or its affiliates. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * - Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * * - Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * - Neither the name of Oracle or the names of its * contributors may be used to endorse or promote products derived * from this software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ import java.awt.*; import java.awt.event.*; import javax.swing.*; import javax.swing.plaf.LayerUI; public class Diva { public static void main(String[] args) { javax.swing.SwingUtilities.invokeLater(new Runnable() { public void run() { createUI(); } }); } public static void createUI() { JFrame f = new JFrame("Diva"); LayerUI<JPanel> layerUI = new SpotlightLayerUI(); JPanel panel = createPanel(); JLayer<JPanel> jlayer = new JLayer<JPanel>(panel, layerUI); f.add(jlayer); f.setSize(300, 200); f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); f.setLocationRelativeTo(null); f.setVisible(true); } private static JPanel createPanel() { JPanel p = new JPanel(); ButtonGroup entreeGroup = new ButtonGroup(); JRadioButton radioButton; p.add(radioButton = new JRadioButton("Beef", true)); entreeGroup.add(radioButton); p.add(radioButton = new JRadioButton("Chicken")); entreeGroup.add(radioButton); p.add(radioButton = new JRadioButton("Vegetable")); entreeGroup.add(radioButton); p.add(new JCheckBox("Ketchup")); p.add(new JCheckBox("Mustard")); p.add(new JCheckBox("Pickles")); p.add(new JLabel("Special requests:")); p.add(new JTextField(20)); JButton orderButton = new JButton("Place Order"); p.add(orderButton); return p; } } class SpotlightLayerUI extends LayerUI<JPanel> { private boolean mActive; private int mX, mY; @Override public void installUI(JComponent c) { super.installUI(c); JLayer jlayer = (JLayer) c; jlayer.setLayerEventMask(AWTEvent.MOUSE_EVENT_MASK | AWTEvent.MOUSE_MOTION_EVENT_MASK); } @Override public void uninstallUI(JComponent c) { JLayer jlayer = (JLayer) c; jlayer.setLayerEventMask(0); super.uninstallUI(c); } @Override public void paint(Graphics g, JComponent c) { Graphics2D g2 = (Graphics2D) g.create(); // Paint the view. super.paint(g2, c); if (mActive) { // Create a radial gradient, transparent in the middle. java.awt.geom.Point2D center = new java.awt.geom.Point2D.Float(mX, mY); float radius = 72; float[] dist = { 0.0f, 1.0f }; Color[] colors = { new Color(0.0f, 0.0f, 0.0f, 0.0f), Color.BLACK }; RadialGradientPaint p = new RadialGradientPaint(center, radius, dist, colors); g2.setPaint(p); g2.setComposite(AlphaComposite.getInstance(AlphaComposite.SRC_OVER, .6f)); g2.fillRect(0, 0, c.getWidth(), c.getHeight()); } g2.dispose(); } @Override protected void processMouseEvent(MouseEvent e, JLayer l) { if (e.getID() == MouseEvent.MOUSE_ENTERED) mActive = true; if (e.getID() == MouseEvent.MOUSE_EXITED) mActive = false; l.repaint(); } @Override protected void processMouseMotionEvent(MouseEvent e, JLayer l) { Point p = SwingUtilities.convertPoint(e.getComponent(), e.getPoint(), l); mX = p.x; mY = p.y; l.repaint(); } }