I have some problem with creating back button. Now in form there is list, I need create button which be on this form in the lower right corner, and when scrolling list, button remains in its place(the lower right corner).
I was trying create container in for lower of the screen and do his invisible. But its not helped because list does not appear under container.
You can try this...
import com.sun.lwuit.Command;
import com.sun.lwuit.Form;
import com.sun.lwuit.Display;
import com.sun.lwuit.events.ActionEvent;
import com.sun.lwuit.events.ActionListener;
public class FirstApp extends MIDlet implements ActionListener{
Form f;
Command exitCommand;
public FirstApp()
{
//display form
Display.init(this);
f = new Form("myForm");
f.setLayout(new BoxLayout(BoxLayout.Y_AXIS));
}
public void pauseApp()
{
}
public void destroyApp(boolean unconditional)
{
}
public void commandAction(Command c, Displayable dis)
{
}
protected void startApp() throws MIDletStateChangeException
{
//add exit button
Command exitCommand;
exitCommand = new Command("EXIT")
{
public void actionPerformed(ActionEvent e) {
notifyDestroyed();
}
};
f.addCommand(exitCommand);
f.setBackCommand(exitCommand);
}
You need to use in Object Command.
Command cmd = new Command(searchText) {
public void actionPerformed(ActionEvent evt) {
//TODO - implement back
}
};
and than adding him to Form
f.addCommand(command);
Related
I'm working on a small personal project.
I have two JFrame windows, Viewer and Console.
Viewer only contains a subclass of JPanel, and it should respond to mouse input (clicking, mostly).
Console contains a button, a JTextField (the input), and a JTextArea (the output).
I need to make sure than when I press keys on my keyboard, the corresponding text appears in the Console JTextField, not only when the focus is held by the JTextField, but also when it's held any other component in my app.
In other words, I want the JTextField to accept input even right after I clicked on the Viewer frame.
Is this feasible?
In case that matters, I'm running win 8 x64 and I don't really care about portability (I'm the only one that will ever look at or use this code).
EDIT: here is an example of my code:
import java.awt.Color;
import java.awt.Graphics;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JTextField;
public class main {
public static Viewer v;
public static Console c;
public static void main(String[] args) {
v=new Viewer();
c=new Console();
}
static class Viewer extends JFrame {
public Viewer(){
setSize(600,600);
getContentPane().add(new myPanel());
addMouseListener(new mouse());
setVisible(true);
}
}
static class myPanel extends JPanel{
public void paintComponent(Graphics g){
g.setColor(new Color((int)(Math.random()*255),(int)(Math.random()*255),(int)(Math.random()*255)));
g.fillRect(0, 0, 600, 600);
}
}
static class Console extends JFrame {
public Console(){
setSize(600,200);
JTextField text=new JTextField();
getContentPane().add(text);
setVisible(true);
}
}
static class mouse implements MouseListener{
#Override
public void mouseClicked(MouseEvent arg0) {
v.repaint();
}
#Override
public void mouseEntered(MouseEvent arg0) {
}
#Override
public void mouseExited(MouseEvent arg0) {
}
#Override
public void mousePressed(MouseEvent arg0) {
}
#Override
public void mouseReleased(MouseEvent arg0) {
}
}
}
In this example, after I click on the big window to change its color, if I want to write stuff in the other window I have to click on it first.
Can I suggest the KeyboardFocusManager? I've found this to be the easiest way to achieve what I believe you are trying to achieve
KeyboardFocusManager.getCurrentKeyboardFocusManager().addKeyEventDispatcher(
new KeyEventDispatcher() {
public void dispatchKeyEvent(KeyEvent ke) {
//TODO: fill this in
}
});
One inelegant solution is to create a KeyListener, which feeds typed characters to your console, although how exactly this happens depends on how you create your components. For the sake of this example I'll pretend to do it through a static method in your Console class (preferably you'd have access to an instance of Console):
public class ApplicationKeyListener implements KeyListener {
public ApplicationKeyListener() {
}
// Other necessary methods...
public void keyPressed(KeyEvent e) {
char pressed = e.getKeyChar();
Console.feedChar(pressed);
}
}
And then in Console, make sure your JTextField object is global and static, then set up the feedChar() method.
public class Console extends JFrame {
private static JTextField consoleTextField;
public Console() {
consoleTextField = new JTextField();
// ...
}
public static feedChar(char c) {
consoleTextField.setText(consoleTextField.getText() + c.toString());
}
}
Then finally you'd have to add this listener to all JFrames and their children.
public class Viewer extends JFrame {
public Viewer() {
ApplicationKeyListener kl = new ApplicationKeyListener();
addKeyListener(kl);
for (Component child : this.getComponents()) {
child.addKeyListener(kl);
}
}
}
i'm doing a class that does a sort of "file explorer",
in the constructor i create the frame ,panel ecc.. but than i want to say to the main program that calls this class that the user has finish the selection, i know i can call a static method that is in the main from this class,but i want to make a action listener because i want to use this class for different programs
For Example if FileEx is my class:
public class FileEx()
{
public FileEx()
{
//program that do something
if(done == true)
//here i want to call the action
}
public void addActionListener(ActionListener ac) //i don't know if it's correct
//but i want something like this
{
}
}
public static void main(String[] args)
{
FileEx fileex = new FileEx();
fileex.addActionListener(new ActionListener(){
#Override
public void actionPerformed(ActionEvent e)
{
//when done is true i want this block of code to be called
}
});
}
ActionListeners will only work when added to components that allow them to be added and that notify listeners with them such as JButtons, JMenuItems, JComboBoxes and such. We have no idea what type of class FileEx is or why it should accept an ActionListener and a little more information would be qutie helpful. If you want to notify another object that an event occurs, such as that a calculation is done, use another type of listener such as a PropertyChangeListener. Alternatively you could do the processing in a modal JDialog window, which will notify the calling window that it is done performing its duties by returning code flow to the calling window.
For example, please look at my answers to similar questions:
Drawing with paintComponent after value of Jbutton changed in another class
JTextField data in different frames, with data stored in global variable?
Loop making program freeze
EDIT
For example, if you wanted your FileEx to allow other classes to listen for changes to a String called selection (the so-called "bound" property) you could create it to look something like:
import java.beans.PropertyChangeEvent;
import java.beans.PropertyChangeListener;
public class TestFileEx {
public static void main(String[] args) {
final FileEx fileEx = new FileEx();
fileEx.addPropertyChangeListener(FileEx.SELECTION, new PropertyChangeListener() {
#Override
public void propertyChange(PropertyChangeEvent evt) {
// TODO code to call when fileEx has changed selections
String fileExSelection = evt.getNewValue().toString();
// or
String fileExSelection2 = fileEx.getSelection();
}
});
}
}
and
import java.beans.PropertyChangeEvent;
import java.beans.PropertyChangeListener;
import javax.swing.event.SwingPropertyChangeSupport;
publicclass FileEx {
public static final String SELECTION = "selection";
private SwingPropertyChangeSupport propertyChangeSupport = new SwingPropertyChangeSupport(
this);
private String selection;
public void someMethodThatChangesSelection() {
}
public String getSelection() {
return selection;
}
public void setSelection(String selection) {
String oldValue = this.selection;
String newValue = selection;
this.selection = selection;
// notify the listeners of change
propertyChangeSupport.firePropertyChange(SELECTION, oldValue, newValue);
}
public void addPropertyChangeListener(PropertyChangeListener listener) {
propertyChangeSupport.addPropertyChangeListener(listener);
}
public void addPropertyChangeListener(String propertyName, PropertyChangeListener listener) {
propertyChangeSupport.addPropertyChangeListener(propertyName, listener);
}
public void removePropertyChangeListener(PropertyChangeListener listener) {
propertyChangeSupport.removePropertyChangeListener(listener);
}
public void rem(String propertyName, PropertyChangeListener listener) {
propertyChangeSupport.removePropertyChangeListener(propertyName, listener);
}
}
Here is the code based on your example which adds actionlisteners and calls them:
public class FileEx()
{
private final List<ActionListener> listeners = new ArrayList<>();
public FileEx()
{
//program that do something
if(done == true) {
notifyListeners();
}
}
public void addActionListener(ActionListener ac)
{
listeners.add(ac);
}
private void notifyListeners()
{
for (final ActionListener listener: listeners)
{
listener.actionPerformed(null);//You can create event if you want.
}
}
}
public static void main(String[] args)
{
FileEx fileex = new FileEx();
fileex.addActionListener(new ActionListener(){
#Override
public void actionPerformed(ActionEvent e)
{
//when done is true i want this block of code to be called
}
});
}
So I have a swing application where a button opens up a window. It is pretty simple, to open it I use:
private static logPicker logWindow;
static boolean logViewerOpen = false;
if (!logViewerOpen) {
logWindow = new logPicker();
logWindow.frmOpenLog.setVisible(true);
logViewerOpen = true;
}
else {
logWindow.frmOpenLog.requestFocus();
}
I also have a window listener to know when the viewer is closed:
frmOpenLog.addWindowListener(new WindowAdapter() {
#Override
public void windowClosing(WindowEvent arg0) {
indexPage.logViewerOpen = false;
frmOpenLog.dispose();
}
});
I do this because I want to keep track on whether or not the window is already open, because if it is then I have to update information. The window I open has a list of logs that a user can double click on to view the information about that log. The problem right now is, when a user double clicks on the list it gets called however many times I have opened and closed that window. example: I open the log picker window, and then close it. I open it again and double click on the log I want to view, and it will open 2 of those. I have the double click simple do a .doClick() on the Open Log button. The weird thing is, when I use the button to open the log, it does not do this. It will only open the log once. Here is the code for the double click event and the Open Log button.
#Override
public void mouseClicked(MouseEvent arg0) {
if (arg0.getClickCount() == 2) {
btnOpenLog.doClick();
}
}
btnOpenLog.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
logViewer window = new logViewer(log.getSelectedValue());
window.frmLogViewer.setVisible(true);
}
});
#LiverpoolFTW: Please provide a SSCCE demonstrating the problem. Absent sufficient code, I speculate you're (re-)adding the MouseListener/MouseAdapter each time your window is opened. The following example works as desired as-is, incrementing the clickCount once per button press or label double-click. But if you uncomment the indicated section, you'll see that the doClick() is executed twice when you double-click the label. If you have, for example, some component to which you're adding a listener each time the window opens, each of those listeners will be executed.
package example.stackoverflow;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import javax.swing.BoxLayout;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.SwingUtilities;
public class ClickCheck extends JFrame
{
private static final long serialVersionUID = -6446528001976145548L;
private static final JButton btnOpenLog = new JButton("Open Log");
public ClickCheck()
{
JLabel label = new JLabel("Double-Click Me");
label.addMouseListener(new MouseAdapter()
{
#Override
public void mouseClicked(MouseEvent arg0) {
if (arg0.getClickCount() == 2) {
btnOpenLog.doClick();
}
}
});
// Uncomment to demonstrate the effect of multiple listeners
// label.addMouseListener(new MouseAdapter()
// {
// #Override
// public void mouseClicked(MouseEvent arg0) {
// if (arg0.getClickCount() == 2) {
// btnOpenLog.doClick();
// }
// }
// });
btnOpenLog.addActionListener(new ActionListener() {
private int clickCount = 0;
public void actionPerformed(ActionEvent e) {
System.out.println(++clickCount + ": Button clicked");
}
});
setSize(200, 200);
setLayout(new BoxLayout(getContentPane(), BoxLayout.Y_AXIS));
add(btnOpenLog);
add(label);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
public static void main(String[] args)
{
SwingUtilities.invokeLater(new Runnable()
{
public void run()
{
ClickCheck c = new ClickCheck();
c.setVisible(true);
}
});
}
}
To start sorry for my bad english. I am confronted to a problem. I am creating a new java application and I want to put the design code in a class file named Login_Design.java and de code of the buttons and other content in another class file named Login.java.
The 2 files work like that :
Login_Design.java:
public class Login_Design
{
public static JButton jbtnlogin;
public Login_Design()
{
initComponents();
}
public void initComponents()
{
jframelogin = new JFrame();
(...)
jbtnlogin = new JButton();
(...)
jbtnlogin.addActionListener(new java.awt.event.ActionListener()
{
public void actionPerformed(java.awt.event.ActionEvent event)
{
Login.jbtnloginActionPerformed(event);
}
});
jframelogin.add(jbtnlogin);
}
}
Login.java:
package unigamex;
import java.awt.event.ActionEvent;
import unigamex.Login_Design;
public class Login
{
public Login()
{
new Login_Design();
}
protected void jbtnloginActionPerformed(ActionEvent event)
{
System.exit(0);
}
public static void main(String args[])
{
new Login();
}
public void JActionPerformed()
{
Login_Design.jbtnlogin.addActionListener(new java.awt.event.ActionListener()
{
public void actionPerformed(java.awt.event.ActionEvent event)
{
jbtnloginActionPerformed(event);
}
});
}
}
Now the problem is :
1 - If I put that code in the same java file, all works (all the buttons work)
2 - If I do like i am doing right here, all buttons are showed but it is not possible to use them.
3 - Remove the public void JActionPerformed() and putting the code in the Login_Design
initcomponents camp, but he shows me the fallowing message :
Cannot make a static reference to the non-static method jbtnsairActionPerformed(ActionEvent) from the type Login
How can i solve that problem ?
Thanks in advance,
Luis Da Costa
One way to do it would be to make Login implement ActionListener and have it register with the Login_Design object as such. The Login_Design class would setup any registrants as ActionListeners on the buttons.
EDIT:
in Login_Design:
public void addActionListenerToButtons(ActionListener listener){
jbtnlongin.addActionListener(listener);
}
then in Login add this to the Login_Design instance.
public void actionPerformed(java.awt.event.ActionEvent event)
{
Login.jbtnloginActionPerformed(event);
}
You are trying to access a method that can only be accessed via an instance variable (i.e. it is not static).
What you should do is something like the following:
public class Login
{
public Login()
{
new Login_Design(this);
}
protected void jbtnloginActionPerformed(ActionEvent event)
{
System.exit(0);
}
}
public class Login_Design{
private Login login;
public Login_Design(Login login){
this.login = login;
initComponents();
}
public void initComponents()
{
//...
jbtnlogin = new JButton();
jbtnlogin.addActionListener(new java.awt.event.ActionListener()
{
public void actionPerformed(java.awt.event.ActionEvent event)
{
login.jbtnloginActionPerformed(event);
}
}
)
//...
}
}
}
I want to be notified when my JPopupMenu is hidden — whether because an item was selected, the menu was dismissed, or setVisible(false) was called on it. Here is my test code:
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
public class A extends ComponentAdapter implements Runnable, ActionListener {
private JButton b;
public static void main(String[] args) {
EventQueue.invokeLater(new A());
}
public void run() {
JFrame f = new JFrame("Test");
b = new JButton("Click me");
b.addActionListener(this);
f.add(b);
f.pack();
f.setVisible(true);
}
public void actionPerformed(ActionEvent e) {
JPopupMenu pm = new JPopupMenu();
pm.addComponentListener(this);
pm.add("Popup...");
pm.add("...menu!");
pm.show(b, 10, 10);
}
public void componentShown(ComponentEvent e) { System.out.println("componentShown"); }
public void componentHidden(ComponentEvent e) { System.out.println("componentHidden"); }
}
Regardless of how I interact with the menu, neither of the two ComponentListener methods are being called. Why is that? Is there different/better/correct way of finding out when my JPopupMenu is hidden?
Thanks,
Cameron
JPopupMenu has a special listener for visibility change events:
pm.addPopupMenuListener(new PopupMenuListener() {
#Override
public void popupMenuCanceled(PopupMenuEvent e) {
System.out.println("cancelled");
}
#Override
public void popupMenuWillBecomeInvisible(PopupMenuEvent e) {
System.out.println("vanishing");
}
#Override
public void popupMenuWillBecomeVisible(PopupMenuEvent e) {
System.out.println("appearing");
}
});
Note, however, as method names hint, they are called before visibility changes, so if you're calling isVisible() somewhere in the event handlers, you should be aware of that, for example:
#Override
public void popupMenuWillBecomeInvisible(PopupMenuEvent e) {
updateMenu();
}
private void updateMenu() {
if (!menu.isVisible()) { // this won't work!
// perform some updates
}
}
With regards to why ComponentListener isn't sending you events on the menu disappearing, this might explain:
The component-hidden and component-shown events occur only as the result of calls to a Component 's setVisible method. For example, a window might be miniaturized into an icon (iconified) without a component-hidden event being fired.
Source: ComponentListener tutorial (non-canonical perhaps, but from the horse's mouth.)
Consider that in conjunction with JPopupMenu's implementation of setVisible:
public void setVisible(boolean b) {
// Not supported for MenuComponents
}
And you might know how it so happens, but not why it happens (what is the justification and where is that properly documented?)