Interesting things using JInternalFrames, JDesktopPane, and DesktopManager 2
/*
Java Swing, 2nd Edition
By Marc Loy, Robert Eckstein, Dave Wood, James Elliott, Brian Cole
ISBN: 0-596-00408-7
Publisher: O'Reilly
*/
// SampleDesktop.java
//Another example that shows how to do a few interesting things using
//JInternalFrames, JDesktopPane, and DesktopManager.
//
import java.awt.Dimension;
import java.awt.event.ActionEvent;
import java.beans.PropertyChangeEvent;
import java.beans.PropertyVetoException;
import java.beans.VetoableChangeListener;
import javax.swing.AbstractAction;
import javax.swing.DefaultDesktopManager;
import javax.swing.ImageIcon;
import javax.swing.JComponent;
import javax.swing.JDesktopPane;
import javax.swing.JFrame;
import javax.swing.JInternalFrame;
import javax.swing.JLabel;
import javax.swing.JMenu;
import javax.swing.JMenuBar;
public class SampleDesktop extends JFrame {
private JDesktopPane desk;
private IconPolice iconPolice = new IconPolice();
public SampleDesktop(String title) {
super(title);
setDefaultCloseOperation(EXIT_ON_CLOSE);
// Create a desktop and set it as the content pane. Don't set the
// layered
// pane, since it needs to hold the menu bar too.
desk = new JDesktopPane();
setContentPane(desk);
// Install our custom desktop manager.
desk.setDesktopManager(new SampleDesktopMgr());
createMenuBar();
loadBackgroundImage();
}
// Create a menu bar to show off a few things.
protected void createMenuBar() {
JMenuBar mb = new JMenuBar();
JMenu menu = new JMenu("Frames");
menu.add(new AddFrameAction(true)); // add "upper" frame
menu.add(new AddFrameAction(false)); // add "lower" frame
menu.add(new TileAction(desk)); // add tiling capability
setJMenuBar(mb);
mb.add(menu);
}
// Here we load a background image for our desktop.
protected void loadBackgroundImage() {
ImageIcon icon = new ImageIcon("images/matterhorn.gif");
JLabel l = new JLabel(icon);
l.setBounds(0, 0, icon.getIconWidth(), icon.getIconHeight());
// Place the image in the lowest possible layer so nothing
// can ever be painted under it.
desk.add(l, new Integer(Integer.MIN_VALUE));
}
// This class adds a new JInternalFrame when requested.
class AddFrameAction extends AbstractAction {
public AddFrameAction(boolean upper) {
super(upper ? "Add Upper Frame" : "Add Lower Frame");
if (upper) {
this.layer = new Integer(2);
this.name = "Up";
} else {
this.layer = new Integer(1);
this.name = "Lo";
}
}
public void actionPerformed(ActionEvent ev) {
JInternalFrame f = new JInternalFrame(name, true, true, true, true);
f.addVetoableChangeListener(iconPolice);
f.setBounds(0, 0, 120, 60);
desk.add(f, layer);
f.setVisible(true); // Needed since 1.3
}
private Integer layer;
private String name;
}
// A simple vetoable change listener that insists that there is always at
// least one noniconified frame (just as an example of the vetoable
// properties).
class IconPolice implements VetoableChangeListener {
public void vetoableChange(PropertyChangeEvent ev)
throws PropertyVetoException {
String name = ev.getPropertyName();
if (name.equals(JInternalFrame.IS_ICON_PROPERTY)
&& (ev.getNewValue() == Boolean.TRUE)) {
JInternalFrame[] frames = desk.getAllFrames();
int count = frames.length;
int nonicons = 0; // how many are not icons?
for (int i = 0; i < count; i++) {
if (!frames[i].isIcon()) {
nonicons++;
}
}
if (nonicons <= 1) {
throw new PropertyVetoException("Invalid Iconification!",
ev);
}
}
}
}
// A simple test program.
public static void main(String[] args) {
SampleDesktop td = new SampleDesktop("Sample Desktop");
td.setSize(300, 220);
td.setVisible(true);
}
}
//TileAction.java
//An action that tiles all internal frames when requested.
//
class TileAction extends AbstractAction {
private JDesktopPane desk; // the desktop to work with
public TileAction(JDesktopPane desk) {
super("Tile Frames");
this.desk = desk;
}
public void actionPerformed(ActionEvent ev) {
// How many frames do we have?
JInternalFrame[] allframes = desk.getAllFrames();
int count = allframes.length;
if (count == 0)
return;
// Determine the necessary grid size
int sqrt = (int) Math.sqrt(count);
int rows = sqrt;
int cols = sqrt;
if (rows * cols < count) {
cols++;
if (rows * cols < count) {
rows++;
}
}
// Define some initial values for size & location.
Dimension size = desk.getSize();
int w = size.width / cols;
int h = size.height / rows;
int x = 0;
int y = 0;
// Iterate over the frames, deiconifying any iconified frames and then
// relocating & resizing each.
for (int i = 0; i < rows; i++) {
for (int j = 0; j < cols && ((i * cols) + j < count); j++) {
JInternalFrame f = allframes[(i * cols) + j];
if (!f.isClosed() && f.isIcon()) {
try {
f.setIcon(false);
} catch (PropertyVetoException ignored) {
}
}
desk.getDesktopManager().resizeFrame(f, x, y, w, h);
x += w;
}
y += h; // start the next row
x = 0;
}
}
}
//SampleDesktopMgr.java
//A DesktopManager that keeps its frames inside the desktop.
class SampleDesktopMgr extends DefaultDesktopManager {
// This is called anytime a frame is moved. This
// implementation keeps the frame from leaving the desktop.
public void dragFrame(JComponent f, int x, int y) {
if (f instanceof JInternalFrame) { // Deal only w/internal frames
JInternalFrame frame = (JInternalFrame) f;
JDesktopPane desk = frame.getDesktopPane();
Dimension d = desk.getSize();
// Nothing all that fancy below, just figuring out how to adjust
// to keep the frame on the desktop.
if (x < 0) { // too far left?
x = 0; // flush against the left side
} else {
if (x + frame.getWidth() > d.width) { // too far right?
x = d.width - frame.getWidth(); // flush against right side
}
}
if (y < 0) { // too high?
y = 0; // flush against the top
} else {
if (y + frame.getHeight() > d.height) { // too low?
y = d.height - frame.getHeight(); // flush against the
// bottom
}
}
}
// Pass along the (possibly cropped) values to the normal drag handler.
super.dragFrame(f, x, y);
}
}
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