Java Tutorial/Swing/JLayeredPane
Содержание
Implement buttons at different layers
<source lang="java">
import java.awt.Color; import javax.swing.JButton; import javax.swing.JFrame; import javax.swing.JLayeredPane; public class Main extends JFrame {
public Main() {
setSize(200, 150);
setDefaultCloseOperation(EXIT_ON_CLOSE);
JLayeredPane lp = getLayeredPane();
JButton top = new JButton();
top.setBackground(Color.white);
top.setBounds(20, 20, 50, 50);
JButton middle = new JButton();
middle.setBackground(Color.gray);
middle.setBounds(40, 40, 50, 50);
JButton bottom = new JButton();
bottom.setBackground(Color.black);
bottom.setBounds(60, 60, 50, 50);
lp.add(middle, new Integer(2));
lp.add(top, new Integer(3));
lp.add(bottom, new Integer(1));
setVisible(true);
}
public static void main(String[] args) {
new Main();
}
}</source>
JLayeredPane Layer Constants
ConstantDescriptionFRAME_CONTENT_LAYERLevel -30,000 for holding the menu bar and content pane; not normally used by developersDEFAULT_LAYERLevel 0 for the normal component levelPALETTE_LAYERLevel 100 for holding floating toolbarsMODAL_LAYERLevel 200 for holding pop-up dialog boxes, on top of palettes, and below pop-upsPOPUP_LAYERLevel 300 for holding pop-up menus and tooltipsDRAG_LAYERLevel 400 for ensuring that dragged objects remain on top
Moves an image of Duke around within a layered pane in response to mouse motion events.
<source lang="java">
/*
*
* Copyright (c) 1998 Sun Microsystems, Inc. All Rights Reserved.
*
* Sun grants you ("Licensee") a non-exclusive, royalty free, license to use,
* modify and redistribute this software in source and binary code form,
* provided that i) this copyright notice and license appear on all copies of
* the software; and ii) Licensee does not utilize the software in a manner
* which is disparaging to Sun.
*
* This software is provided "AS IS," without a warranty of any kind. ALL
* EXPRESS OR IMPLIED CONDITIONS, REPRESENTATIONS AND WARRANTIES, INCLUDING ANY
* IMPLIED WARRANTY OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE OR
* NON-INFRINGEMENT, ARE HEREBY EXCLUDED. SUN AND ITS LICENSORS SHALL NOT BE
* LIABLE FOR ANY DAMAGES SUFFERED BY LICENSEE AS A RESULT OF USING, MODIFYING
* OR DISTRIBUTING THE SOFTWARE OR ITS DERIVATIVES. IN NO EVENT WILL SUN OR ITS
* LICENSORS BE LIABLE FOR ANY LOST REVENUE, PROFIT OR DATA, OR FOR DIRECT,
* INDIRECT, SPECIAL, CONSEQUENTIAL, INCIDENTAL OR PUNITIVE DAMAGES, HOWEVER
* CAUSED AND REGARDLESS OF THE THEORY OF LIABILITY, ARISING OUT OF THE USE OF
* OR INABILITY TO USE SOFTWARE, EVEN IF SUN HAS BEEN ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGES.
*
* This software is not designed or intended for use in on-line control of
* aircraft, air traffic, aircraft navigation or aircraft communications; or in
* the design, construction, operation or maintenance of any nuclear
* facility. Licensee represents and warrants that it will not use or
* redistribute the Software for such purposes.
*/
import java.awt.Color; import java.awt.Dimension; import java.awt.Point; import java.awt.event.ActionEvent; import java.awt.event.ActionListener; import java.awt.event.MouseEvent; import java.awt.event.MouseMotionListener; import javax.swing.BorderFactory; import javax.swing.Box; import javax.swing.BoxLayout; import javax.swing.ImageIcon; import javax.swing.JCheckBox; import javax.swing.JComboBox; import javax.swing.JComponent; import javax.swing.JFrame; import javax.swing.JLabel; import javax.swing.JLayeredPane; import javax.swing.JPanel; public class LayeredPaneDemo extends JPanel implements ActionListener, MouseMotionListener {
private String[] layerStrings = { "Yellow (0)", "Magenta (1)", "Cyan (2)", "Red (3)", "Green (4)" };
private Color[] layerColors = { Color.yellow, Color.magenta, Color.cyan, Color.red, Color.green };
private JLayeredPane layeredPane;
private JLabel dukeLabel;
private JCheckBox onTop;
private JComboBox layerList;
// Action commands
private static String ON_TOP_COMMAND = "ontop";
private static String LAYER_COMMAND = "layer";
// Adjustments to put Duke"s toe at the cursor"s tip.
private static final int XFUDGE = 40;
private static final int YFUDGE = 57;
public LayeredPaneDemo() {
setLayout(new BoxLayout(this, BoxLayout.PAGE_AXIS));
// Create and load the duke icon.
final ImageIcon icon = new ImageIcon("yourFile.gif");
// Create and set up the layered pane.
layeredPane = new JLayeredPane();
layeredPane.setPreferredSize(new Dimension(300, 310));
layeredPane.setBorder(BorderFactory.createTitledBorder("Move the Mouse to Move Duke"));
layeredPane.addMouseMotionListener(this);
// This is the origin of the first label added.
Point origin = new Point(10, 20);
// This is the offset for computing the origin for the next label.
int offset = 35;
// Add several overlapping, colored labels to the layered pane
// using absolute positioning/sizing.
for (int i = 0; i < layerStrings.length; i++) {
JLabel label = createColoredLabel(layerStrings[i], layerColors[i], origin);
layeredPane.add(label, new Integer(i));
origin.x += offset;
origin.y += offset;
}
// Create and add the Duke label to the layered pane.
dukeLabel = new JLabel(icon);
if (icon != null) {
dukeLabel.setBounds(15, 225, icon.getIconWidth(), icon.getIconHeight());
} else {
System.err.println("Duke icon not found; using black square instead.");
dukeLabel.setBounds(15, 225, 30, 30);
dukeLabel.setOpaque(true);
dukeLabel.setBackground(Color.BLACK);
}
layeredPane.add(dukeLabel, new Integer(2), 0);
// Add control pane and layered pane to this JPanel.
add(Box.createRigidArea(new Dimension(0, 10)));
add(createControlPanel());
add(Box.createRigidArea(new Dimension(0, 10)));
add(layeredPane);
}
private JLabel createColoredLabel(String text, Color color, Point origin) {
JLabel label = new JLabel(text);
label.setVerticalAlignment(JLabel.TOP);
label.setHorizontalAlignment(JLabel.CENTER);
label.setOpaque(true);
label.setBackground(color);
label.setForeground(Color.black);
label.setBorder(BorderFactory.createLineBorder(Color.black));
label.setBounds(origin.x, origin.y, 140, 140);
return label;
}
// Create the control pane for the top of the frame.
private JPanel createControlPanel() {
onTop = new JCheckBox("Top Position in Layer");
onTop.setSelected(true);
onTop.setActionCommand(ON_TOP_COMMAND);
onTop.addActionListener(this);
layerList = new JComboBox(layerStrings);
layerList.setSelectedIndex(2); // cyan layer
layerList.setActionCommand(LAYER_COMMAND);
layerList.addActionListener(this);
JPanel controls = new JPanel();
controls.add(layerList);
controls.add(onTop);
controls.setBorder(BorderFactory.createTitledBorder("Choose Duke"s Layer and Position"));
return controls;
}
// Make Duke follow the cursor.
public void mouseMoved(MouseEvent e) {
dukeLabel.setLocation(e.getX() - XFUDGE, e.getY() - YFUDGE);
}
public void mouseDragged(MouseEvent e) {
} // do nothing
public void actionPerformed(ActionEvent e) {
String cmd = e.getActionCommand();
if (ON_TOP_COMMAND.equals(cmd)) {
if (onTop.isSelected())
layeredPane.moveToFront(dukeLabel);
else
layeredPane.moveToBack(dukeLabel);
} else if (LAYER_COMMAND.equals(cmd)) {
int position = onTop.isSelected() ? 0 : 1;
layeredPane.setLayer(dukeLabel, layerList.getSelectedIndex(), position);
}
}
public static void main(String[] args) {
JFrame frame = new JFrame("LayeredPaneDemo");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
// Create and set up the content pane.
JComponent newContentPane = new LayeredPaneDemo();
newContentPane.setOpaque(true); // content panes must be opaque
frame.setContentPane(newContentPane);
// Display the window.
frame.pack();
frame.setVisible(true);
}
}</source>
The JLayeredPane serves as the main component container of a JRootPane.
<source lang="java">
Integer layer = new Integer(20); aLayeredPane.add(aComponent, layer);</source>
