Admin: 1 версия

2010-06-01T05:58:00Z

1 версия

в 18:01, 31 мая 2010

2010-05-31T18:01:43Z

Новая страница

== ActionEvent.getActionCommand() ==



<source lang="java">

import java.awt.FlowLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JFrame;
class ButtonDemo implements ActionListener {
JButton jbtnA = new JButton("Alpha");
JButton jbtnB = new JButton("Beta");
ButtonDemo() {
JFrame jfrm = new JFrame("A Button Example");
jfrm.setLayout(new FlowLayout());
jfrm.setSize(220, 90);
jfrm.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
jbtnA.addActionListener(this);
jbtnB.addActionListener(this);
jfrm.add(jbtnA);
jfrm.add(jbtnB);
jfrm.setVisible(true);
}
public void actionPerformed(ActionEvent ae) {
String ac = ae.getActionCommand();
if (ac.equals("Alpha")) {
if (jbtnB.isEnabled()) {
System.out.println("Alpha pressed. Beta is disabled.");
jbtnB.setEnabled(false);
} else {
System.out.println("Alpha pressed. Beta is enabled.");
jbtnB.setEnabled(true);
}
} else if (ac.equals("Beta"))
System.out.println("Beta pressed.");
}
public static void main(String args[]) {
new ButtonDemo();
}
}

</source>



== Adding an InputMap to a Component ==



<source lang="java">

import javax.swing.InputMap;
import javax.swing.JButton;
import javax.swing.JComponent;
import javax.swing.KeyStroke;
public class Main {
public static void main(String[] argv) throws Exception {
InputMap inputMap = new InputMap();
inputMap.put(KeyStroke.getKeyStroke("F2"), "actionName");
JButton component = new JButton("button");

inputMap.setParent(component.getInputMap(JComponent.WHEN_FOCUSED));
component.setInputMap(JComponent.WHEN_FOCUSED, inputMap);
}
}

</source>



== Event object has information about an event, that has happened. ==



<source lang="java">

import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.text.DateFormat;
import java.util.Calendar;
import java.util.Date;
import java.util.Locale;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
public class EventObject {
public static void main(String[] args) {
JFrame f = new JFrame();
JButton ok = new JButton("Ok");
ok.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent event) {
Calendar cal = Calendar.getInstance();
cal.setTimeInMillis(event.getWhen());
Locale locale = Locale.getDefault();
String s = DateFormat.getTimeInstance(DateFormat.SHORT, locale).format(new Date());
if (event.getID() == ActionEvent.ACTION_PERFORMED)
System.out.println(" Event Id: ACTION_PERFORMED");
System.out.println(" Time: " + s);
String source = event.getSource().getClass().getName();
System.out.println(" Source: " + source);
int mod = event.getModifiers();
if ((mod & ActionEvent.ALT_MASK) > 0)
System.out.println("Alt ");
if ((mod & ActionEvent.SHIFT_MASK) > 0)
System.out.println("Shift ");
if ((mod & ActionEvent.META_MASK) > 0)
System.out.println("Meta ");
if ((mod & ActionEvent.CTRL_MASK) > 0)
System.out.println("Ctrl ");
}
});
f.add(ok);
f.setSize(420, 250);
f.setLocationRelativeTo(null);
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
f.setVisible(true);
}
}

</source>



== Event source and listener ==



<source lang="java">

import java.util.ArrayList;
import java.util.EventListener;
import java.util.EventObject;
abstract class TestEventSource {
public abstract void addListener(TestEventListener l);
public abstract void removeListener(TestEventListener l);
public abstract void fireEvent(java.util.EventObject o);
public void test() {
addListener(new TestEventListener("A"));
fireEvent(new java.util.EventObject(this));
}
}
class TestEventListener implements EventListener {
String id;
public TestEventListener(String id) {
this.id = id;
}
public void handleEvent(EventObject o) {
System.out.println(id + " called");
if (id.equals("C")) {
((TestEventSource) o.getSource()).removeListener(this);
}
}
}
public class Main extends TestEventSource {
ArrayList listeners = new ArrayList();
public void addListener(TestEventListener l) {
listeners.add(l);
}
public void removeListener(TestEventListener l) {
listeners.remove(l);
}
public void fireEvent(EventObject o) {
for (int i = 0; i < listeners.size(); i++) {
TestEventListener l = (TestEventListener) listeners.get(i);
l.handleEvent(o);
}
}
public static void main(String[] args) {
Main pfles = new Main();
pfles.test();
}
}

</source>



== int java.awt.event.WindowEvent.WINDOW_OPENED ==



<source lang="java">

import java.awt.AWTEvent;
import java.awt.Toolkit;
import java.awt.event.AWTEventListener;
import java.awt.event.ActionEvent;
import java.awt.event.ruponentEvent;
import java.awt.event.WindowEvent;
import javax.swing.AbstractAction;
import javax.swing.JFrame;
import javax.swing.JMenu;
import javax.swing.JMenuBar;
public class Main implements AWTEventListener {
public void eventDispatched(AWTEvent evt) {
if (evt.getID() == WindowEvent.WINDOW_OPENED) {
ComponentEvent cev = (ComponentEvent) evt;
if (cev.getComponent() instanceof JFrame) {
System.out.println("event: " + evt);
JFrame frame = (JFrame) cev.getComponent();
loadSettings(frame);
}
}
}
public static void loadSettings(JFrame frame) {
System.out.println("loading");
}
public static void saveSettings() {
System.out.println("saving");
}
public static void main(String[] args) throws Exception {
Toolkit tk = Toolkit.getDefaultToolkit();
final Main main = new Main();
tk.addAWTEventListener(main, AWTEvent.WINDOW_EVENT_MASK);
final JFrame frame = new JFrame("");
frame.setName("your frame");
JMenuBar mb = new JMenuBar();
JMenu menu = new JMenu("File");
menu.add(new AbstractAction("Quit") {
public void actionPerformed(ActionEvent evt) {
try {
main.saveSettings();
System.exit(0);
} catch (Exception ex) {
System.out.println(ex);
}
}
});
mb.add(menu);
frame.setJMenuBar(mb);
frame.pack();
frame.setVisible(true);
}
}

</source>



== JComponent.WHEN_IN_FOCUSED_WINDOW ==



<source lang="java">

import java.awt.event.ActionEvent;
import javax.swing.AbstractAction;
import javax.swing.Action;
import javax.swing.JButton;
import javax.swing.JComponent;
import javax.swing.KeyStroke;
public class Main {
public static void main(String[] argv) throws Exception {
JButton component = new JButton();
MyAction action = new MyAction();
component.getInputMap(JComponent.WHEN_IN_FOCUSED_WINDOW).put(KeyStroke.getKeyStroke("F2"),
action.getValue(Action.NAME));
}
}
class MyAction extends AbstractAction {
public MyAction() {
super("my action");
}
public void actionPerformed(ActionEvent e) {
System.out.println("hi");
}
}

</source>



== Multiple sources: A listener can be plugged into several sources. ==



<source lang="java">

import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
class ButtonListener implements ActionListener {
public void actionPerformed(ActionEvent e) {
JButton o = (JButton) e.getSource();
String label = o.getText();
System.out.println(label + " button clicked");
}
}
public class MultipleSources {
public static void main(String[] args) {
JPanel panel = new JPanel();
JButton close = new JButton("Close");
close.addActionListener(new ButtonListener());
JButton open = new JButton("Open");
open.addActionListener(new ButtonListener());
JButton find = new JButton("Find");
find.addActionListener(new ButtonListener());
JButton save = new JButton("Save");
save.addActionListener(new ButtonListener());
panel.add(close);
panel.add(open);
panel.add(find);
panel.add(save);
JFrame f = new JFrame();
f.add(panel);
f.setSize(400, 300);
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
f.setVisible(true);
}
}

</source>



== Register action ==



<source lang="java">

import java.awt.event.ActionEvent;
import javax.swing.AbstractAction;
import javax.swing.Action;
import javax.swing.JButton;
public class Main {
public static void main(String[] argv) throws Exception {
JButton component = new JButton();
MyAction action = new MyAction();
component.getActionMap().put(action.getValue(Action.NAME), action);
}
}
class MyAction extends AbstractAction {
public MyAction() {
super("my action");
}
public void actionPerformed(ActionEvent e) {
System.out.println("hi");
}
}

</source>



== Register several listeners for one event. ==



<source lang="java">

import java.awt.BorderLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JSpinner;
public class MultipleListeners {
JLabel statusbar = new JLabel("0");
JSpinner spinner = new JSpinner();
static int count = 0;
class ButtonListener1 implements ActionListener {
public void actionPerformed(ActionEvent e) {
Integer val = (Integer) spinner.getValue();
spinner.setValue(++val);
}
}
class ButtonListener2 implements ActionListener {
public void actionPerformed(ActionEvent e) {
statusbar.setText(Integer.toString(++count));
}
}
public MultipleListeners() {
JPanel panel = new JPanel();
JButton add = new JButton("+");
add.addActionListener(new ButtonListener1());
add.addActionListener(new ButtonListener2());
panel.add(add);
panel.add(spinner);
JFrame f = new JFrame();
f.add(panel);
f.add(statusbar, BorderLayout.SOUTH);
f.setSize(300, 200);
f.setLocationRelativeTo(null);
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
f.setVisible(true);
}
public static void main(String[] args) {
new MultipleListeners();
}
}

</source>



== Use the Event queue to retrieve event ==



<source lang="java">

import java.awt.AWTEvent;
import java.awt.Container;
import java.awt.EventQueue;
import java.awt.Frame;
import java.awt.Graphics;
import java.awt.Point;
import java.awt.Toolkit;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.MouseEvent;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
public class EventQueuePanel extends JPanel implements ActionListener {
EventQueuePanel() {
JButton button = new JButton("Draw line");
add(button);
button.addActionListener(this);
}
public void actionPerformed(ActionEvent evt) {
Graphics g = getGraphics();
displayPrompt(g, "Click to chooose the first point");
Point p = getClick();
g.drawOval(p.x - 2, p.y - 2, 4, 4);
displayPrompt(g, "Click to choose the second point");
Point q = getClick();
g.drawOval(q.x - 2, q.y - 2, 4, 4);
g.drawLine(p.x, p.y, q.x, q.y);
displayPrompt(g, "Done! Press button the start again.");
g.dispose();
}
public void displayPrompt(Graphics g, String s) {
y += 20;
g.drawString(s, 0, y);
}
public Point getClick() {
EventQueue eq = Toolkit.getDefaultToolkit().getSystemEventQueue();
while (true) {
try {
AWTEvent evt = eq.getNextEvent();
if (evt.getID() == MouseEvent.MOUSE_PRESSED) {
MouseEvent mevt = (MouseEvent) evt;
Point p = mevt.getPoint();
Point top = getRootPane().getLocation();
p.x -= top.x;
p.y -= top.y;
return p;
}
} catch (InterruptedException e) {
}
}
}
private int y = 60;
public static void main(String[] args) {
JFrame frame = new JFrame();
frame.setTitle("EventQueueTest");
frame.setSize(300, 200);
frame.addWindowListener(new WindowAdapter() {
public void windowClosing(WindowEvent e) {
System.exit(0);
}
});
Container contentPane = frame.getContentPane();
contentPane.add(new EventQueuePanel());
frame.show();
}
}

</source>



== Using an inner ActionListener class. ==



<source lang="java">

import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JFrame;
public class InnerClass {
class ButtonListener implements ActionListener {
public void actionPerformed(ActionEvent e) {
System.exit(0);
}
}
public InnerClass() {
JButton close = new JButton("Close");
ButtonListener listener = new ButtonListener();
close.addActionListener(listener);
JFrame f = new JFrame();
f.add(close);
f.setSize(300, 200);
f.setLocationRelativeTo(null);
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
f.setVisible(true);
}
public static void main(String[] args) {
new InnerClass();
}
}

</source>



== void java.awt.Toolkit.addAWTEventListener(AWTEventListener listener, long eventMask) ==



<source lang="java">

import java.awt.AWTEvent;
import java.awt.Toolkit;
import java.awt.event.AWTEventListener;
import java.awt.event.ActionEvent;
import java.awt.event.ruponentEvent;
import java.awt.event.WindowEvent;
import javax.swing.AbstractAction;
import javax.swing.JFrame;
import javax.swing.JMenu;
import javax.swing.JMenuBar;
public class Main implements AWTEventListener {
public void eventDispatched(AWTEvent evt) {
if (evt.getID() == WindowEvent.WINDOW_OPENED) {
ComponentEvent cev = (ComponentEvent) evt;
if (cev.getComponent() instanceof JFrame) {
System.out.println("event: " + evt);
JFrame frame = (JFrame) cev.getComponent();
loadSettings(frame);
}
}
}
public static void loadSettings(JFrame frame) {
System.out.println("loading");
}
public static void saveSettings() {
System.out.println("saving");
}
public static void main(String[] args) throws Exception {
Toolkit tk = Toolkit.getDefaultToolkit();
final Main main = new Main();
tk.addAWTEventListener(main, AWTEvent.WINDOW_EVENT_MASK);
final JFrame frame = new JFrame("");
frame.setName("your frame");
JMenuBar mb = new JMenuBar();
JMenu menu = new JMenu("File");
menu.add(new AbstractAction("Quit") {
public void actionPerformed(ActionEvent evt) {
try {
main.saveSettings();
System.exit(0);
} catch (Exception ex) {
System.out.println(ex);
}
}
});
mb.add(menu);
frame.setJMenuBar(mb);
frame.pack();
frame.setVisible(true);
}
}

</source>

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Java/Event/Event Queue - История изменений

Admin: 1 версия

в 18:01, 31 мая 2010