So I have 2 different panels, the first panel works like it should but the Actionlistener might be needed to solve my issue:
class knopHandler implements ActionListener
{
public void actionPerformed ( ActionEvent e )
{
JFrame frame2 = new JFrame ( "Total Hours" );
frame2.setSize ( 600, 500 );
JPanel uitvoerpanel = new uitvoerpanel();
frame2.setContentPane( uitvoerpanel );
frame2.setVisible( true );
frame1.setVisible( false );
String invoerstring1 = maandaginvoer.getText();
int getal1 = Integer.parseInt( invoerstring1 );
String invoerstring2 = dinsdaginvoer.getText();
int getal2 = Integer.parseInt( invoerstring2 );
String invoerstring3 = woensdaginvoer.getText();
int getal3 = Integer.parseInt( invoerstring3 );
String invoerstring4 = donderdaginvoer.getText();
int getal4 = Integer.parseInt( invoerstring4 );
String invoerstring5 = vrijdaginvoer.getText();
int getal5 = Integer.parseInt( invoerstring5 );
String invoerstring6 = zaterdaginvoer.getText();
int getal6 = Integer.parseInt( invoerstring6 );
String invoerstring7 = zondaginvoer.getText();
int getal7 = Integer.parseInt( invoerstring7 );
int resultaat = getal1 + getal2 + getal3 + getal4 + getal5 + getal6 + getal7;
}
}
The relevant part of the second panel looks like this :
public uitvoerpanel()
{
setLayout( null );
naamvak = new JTextField ( 20 );
naamvak.setHorizontalAlignment ( JTextField.LEFT );
naamvak.setEditable ( false );
naamvak.setText( naaminvoer.getText() );
badgevak = new JTextField ( 20 );
badgevak.setHorizontalAlignment ( JTextField.LEFT );
badgevak.setEditable ( false );
badgevak.setText( badgeinvoer.getText() ) ;
totaalurenvak = new JTextField ( 20 );
totaalurenvak.setHorizontalAlignment ( JTextField.LEFT );
totaalurenvak.setEditable ( false );
totaalurenvak.setText( "" + resultaat );
The first panel has a few textfields where people can type something, I want the text from those textfields to appear in the textfields in the second panel but I am at a loss. When I run the program now nothing appears in the textfields in the second panel.
The "int resultaat" from the actionlistener should also appear in one of the textfields but I have also not been able to get this to work.
Am I putting the setter/getter in the right place or should this be in the actionlistener for example? Or am I missing a different piece of code?
Say, your button is jButton1 and your textFields are jTextField1 and jTextField2
Add an actionListner for your button as:
jButton1.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
jButton1ActionPerformed(evt);
}
});
Then simply implement this method:
private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) {
String s=jTextField1.getText();
jTextField2.setText(s);
}
Event handling with Action Listeners in Swing is straightforward.
As mentioned in the docs, you need to perform the following steps:
Declare an event handler class and specify that the class either
implements an ActionListener interface or extends a class that
implements an ActionListener interface. For example:
public class MyClass implements ActionListener {
Register an instance of the event
handler class as a listener on one or more components. For example:
someComponent.addActionListener(instanceOfMyClass);
Include code that
implements the methods in listener interface. For example:
public void actionPerformed(ActionEvent e) {
...//code that reacts to the action... }
I see that you are already trying to do some of these.
The problem in your method is that you cannot have an action listener on a panel which is a container of components. You need to define your action listener for individual components e.g. in your case, the text field maandaginvoer. You need to register (step 2) your listener with the text field on the panel 1.
Once you fix this problem, you should be able to see your desired output.
Related
I am trying to implement a listener to detect the closing of a window. My main class is extending other classes so I am unable to extend JFrame which is not allowing me to use addWindowListener.
I have tried the code below but it is not working.
public class PowerPanel extends AnotherPanel implements ActionListener, PropertyChangeListener {
// logic …
this.addWindowListener(new WindowAdapter() {
public void windowClosing (WindowEvent e ) {
// do things
}
});
}
The error I am getting is indicating that addWindowListener is "undefined for the type PowerPanel."
You can't add window listener to your panel - you need to add it into the java.awt.Window instance which in your case is a JFrame.
If it is hard for you to pass your JFrame instance into the panel - you can access it in a different way:
public class SamplePanel extends JPanel
{
/**
* Simple panel example that has no idea about it's parent window.
*/
public SamplePanel ()
{
super ();
// Your custom window listener
final WindowAdapter windowAdapter = new WindowAdapter ()
{
#Override
public void windowClosing ( final WindowEvent e )
{
System.out.println ( "Window is closing" );
}
};
// Ancestor availability listener
// It will make sure that whenever component appears on some visible window
// and is displayable container - we will add our window listener to it
addAncestorListener ( new AncestorAdapter ()
{
/**
* Saved window to remove listener from later on.
*/
private Window window = null;
#Override
public void ancestorAdded ( final AncestorEvent event )
{
// Component appeared on some window, we can add our listener now
addListener ();
}
#Override
public void ancestorMoved ( final AncestorEvent event )
{
// Re-adding listener to potentially new parent window
removeListener ();
addListener ();
}
#Override
public void ancestorRemoved ( final AncestorEvent event )
{
// Component was hidden or removed, we need to remove our listener
removeListener ();
}
/**
* Adds window listener.
*/
protected void addListener ()
{
window = SwingUtilities.getWindowAncestor ( SamplePanel.this );
if ( window != null )
{
window.addWindowListener ( windowAdapter );
}
}
/**
* Removes window listener.
*/
protected void removeListener ()
{
if ( window != null )
{
window.removeWindowListener ( windowAdapter );
window = null;
}
}
} );
}
/**
* Sample main method for runing the example.
*
* #param args arguments
*/
public static void main ( final String[] args )
{
SwingUtilities.invokeLater ( new Runnable ()
{
#Override
public void run ()
{
final JFrame frame = new JFrame ();
final SamplePanel panel = new SamplePanel ();
panel.add ( new JLabel ( "Sample panel content" ) );
frame.add ( panel );
frame.pack ();
frame.setDefaultCloseOperation ( JFrame.DISPOSE_ON_CLOSE );
frame.setLocationRelativeTo ( null );
frame.setVisible ( true );
}
} );
}
}
With this code your panel will automatically register window listener on it's parent window whenever it is displayed. It will also automatically remove the listener once panel is hidden or removed from the window, so potentially this is the best solution you can have.
Be careful though, if you will use that panel multiple times on the same window - all of the instances will add their own listener and will all perform on-close action separately. If you want to perform your on-close operation just once per window/frame/dialog instance - you need to add the listener on the window itself, preferably where it is created not to make it obscure.
You might also notice that in my example there is actually a method that retrieves panel's parent window directly:
window = SwingUtilities.getWindowAncestor ( SamplePanel.this );
Although you can't use it in your panel directly, because at the moment when panel is created it is not yet added into any container, let alone visible window. That is why the solution with ancestor listener that i've shown is required.
I'm creating a form in Java Swing, and one of the fields is a JTextArea. When I use the Tab key on all other fields, it gives the focus to the next widget, but in the JTextArea, it inserts a tab character (horizontal space) in the text.
How can I modify this behavior?
/*
This is my understanding of how tabbing works. The focus manager
recognizes the following default KeyStrokes for tabbing:
forwards: TAB or Ctrl-TAB
backwards: Shift-TAB or Ctrl-Shift-TAB
In the case of JTextArea, TAB and Shift-TAB have been removed from
the defaults which means the KeyStroke is passed to the text area.
The TAB KeyStroke inserts a tab into the Document. Shift-TAB seems
to be ignored.
This example shows different approaches for tabbing out of a JTextArea
Also, a text area is typically added to a scroll pane. So when
tabbing forward the vertical scroll bar would get focus by default.
Each approach shows how to prevent the scrollbar from getting focus.
*/
import java.awt.*;
import java.util.*;
import java.awt.event.*;
import javax.swing.*;
public class TextAreaTab extends JFrame
{
public TextAreaTab()
{
Container contentPane = getContentPane();
contentPane.setLayout(new BoxLayout(contentPane, BoxLayout.Y_AXIS));
contentPane.add( nullTraversalKeys() );
contentPane.add( writeYourOwnAction() );
contentPane.add( useKeyListener() );
contentPane.add( addTraversalKeys() );
}
// Reset the text area to use the default tab keys.
// This is probably the best solution.
private JComponent nullTraversalKeys()
{
JTextArea textArea = new JTextArea(3, 30);
textArea.setText("Null Traversal Keys\n2\n3\n4\n5\n6\n7\n8\n9");
JScrollPane scrollPane = new JScrollPane( textArea );
// scrollPane.getVerticalScrollBar().setFocusable(false);
textArea.setFocusTraversalKeys(KeyboardFocusManager.FORWARD_TRAVERSAL_KEYS, null);
textArea.setFocusTraversalKeys(KeyboardFocusManager.BACKWARD_TRAVERSAL_KEYS, null);
return scrollPane;
}
// Replace the Tab Actions. A little more complicated but this is the
// only solution that will place focus on the component, not the
// vertical scroll bar, when tabbing backwards (unless of course you
// have manually prevented the scroll bar from getting focus).
private JComponent writeYourOwnAction()
{
JTextArea textArea = new JTextArea(3, 30);
textArea.setText("Write Your Own Tab Actions\n2\n3\n4\n5\n6\n7\n8\n9");
JScrollPane scrollPane = new JScrollPane( textArea );
InputMap im = textArea.getInputMap();
KeyStroke tab = KeyStroke.getKeyStroke("TAB");
textArea.getActionMap().put(im.get(tab), new TabAction(true));
KeyStroke shiftTab = KeyStroke.getKeyStroke("shift TAB");
im.put(shiftTab, shiftTab);
textArea.getActionMap().put(im.get(shiftTab), new TabAction(false));
return scrollPane;
}
// Use a KeyListener
private JComponent useKeyListener()
{
JTextArea textArea = new JTextArea(3, 30);
textArea.setText("Use Key Listener\n2\n3\n4\n5\n6\n7\n8\n9");
JScrollPane scrollPane = new JScrollPane( textArea );
scrollPane.getVerticalScrollBar().setFocusable(false);
textArea.addKeyListener(new KeyAdapter()
{
public void keyPressed(KeyEvent e)
{
if (e.getKeyCode() == KeyEvent.VK_TAB)
{
e.consume();
KeyboardFocusManager.
getCurrentKeyboardFocusManager().focusNextComponent();
}
if (e.getKeyCode() == KeyEvent.VK_TAB
&& e.isShiftDown())
{
e.consume();
KeyboardFocusManager.
getCurrentKeyboardFocusManager().focusPreviousComponent();
}
}
});
return scrollPane;
}
// Add Tab and Shift-Tab KeyStrokes back as focus traversal keys.
// Seems more complicated then just using null, but at least
// it shows how to add a KeyStroke as a focus traversal key.
private JComponent addTraversalKeys()
{
JTextArea textArea = new JTextArea(3, 30);
textArea.setText("Add Traversal Keys\n2\n3\n4\n5\n6\n7\n8\n9");
JScrollPane scrollPane = new JScrollPane( textArea );
scrollPane.getVerticalScrollBar().setFocusable(false);
Set set = new HashSet( textArea.getFocusTraversalKeys(
KeyboardFocusManager.FORWARD_TRAVERSAL_KEYS ) );
set.add( KeyStroke.getKeyStroke( "TAB" ) );
textArea.setFocusTraversalKeys(
KeyboardFocusManager.FORWARD_TRAVERSAL_KEYS, set );
set = new HashSet( textArea.getFocusTraversalKeys(
KeyboardFocusManager.BACKWARD_TRAVERSAL_KEYS ) );
set.add( KeyStroke.getKeyStroke( "shift TAB" ) );
textArea.setFocusTraversalKeys(
KeyboardFocusManager.BACKWARD_TRAVERSAL_KEYS, set );
return scrollPane;
}
class TabAction extends AbstractAction
{
private boolean forward;
public TabAction(boolean forward)
{
this.forward = forward;
}
public void actionPerformed(ActionEvent e)
{
if (forward)
tabForward();
else
tabBackward();
}
private void tabForward()
{
final KeyboardFocusManager manager =
KeyboardFocusManager.getCurrentKeyboardFocusManager();
manager.focusNextComponent();
SwingUtilities.invokeLater(new Runnable()
{
public void run()
{
if (manager.getFocusOwner() instanceof JScrollBar)
manager.focusNextComponent();
}
});
}
private void tabBackward()
{
final KeyboardFocusManager manager =
KeyboardFocusManager.getCurrentKeyboardFocusManager();
manager.focusPreviousComponent();
SwingUtilities.invokeLater(new Runnable()
{
public void run()
{
if (manager.getFocusOwner() instanceof JScrollBar)
manager.focusPreviousComponent();
}
});
}
}
public static void main(String[] args)
{
TextAreaTab frame = new TextAreaTab();
frame.setDefaultCloseOperation( EXIT_ON_CLOSE );
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
}
you could use the "NextWidget.grabFocus()" method within keylistener of JTextArea when key "tab" is pressed
With this latter approach the tab character will still get inserted into the JTextArea before the focus is shifted away. If you dont want that behavior you can create a subclass of JTextArea whose isManagingFocus() method always returns false, instead of true. For example:
import javax.swing.*;
public class NoTabTextArea extends JTextArea {
public boolean isManagingFocus() {
return false;
}
}
An instance of NoTabTextArea can be used exactly like a JTextArea, except that the tab key will cause the focus to shift away from it without a tab character being inserted.
You can call the following method in your main JFrame or JPanel constructor.
Use by calling as so: disableTabbingInTextAreas(this)
public static void disableTabbingInTextAreas(Component component){
if(component instanceof Container && !(component instanceof JTextArea)){
for(final Component c : ((Container) component).getComponents() ){
disableTabbingInTextAreas(c);
}
}else if(component instanceof JTextArea){
final Component c = component;
c.addKeyListener(new KeyListener() {
#Override
public void keyTyped(KeyEvent e) {}
#Override
public void keyPressed(KeyEvent e) {
if(e.getKeyChar() == '\t'){
c.transferFocus();
e.consume();
}
}
#Override
public void keyReleased(KeyEvent e) {}
});
}
}
import javax.swing.* ;
import java.awt.event.* ;
/**
* This simple subclass of JTextArea does not allow the 'Tab'
* to be pressed. Instead of putting in 3 blank spaces, the tab
* will transfer focus
*/
/*-----------------------------------------------------------*/
/* */
/* NoTabJTextArea */
/* */
/*-----------------------------------------------------------*/
public class NoTabJTextArea extends JTextArea implements KeyListener {
public NoTabJTextArea ( String text ) {
super ( text ) ;
initialize () ;
}
public NoTabJTextArea ( ) {
super() ;
initialize() ;
}
public NoTabJTextArea ( MaskDocument document ) {
super ( document ) ;
initialize() ;
}
private void initialize () {
addKeyListener ( this ) ;
}
public void keyPressed ( KeyEvent e ) {
switch ( e.getKeyCode() ) {
case KeyEvent.VK_TAB :
e.consume() ;
transferFocus() ;
break ;
}
}
public void keyReleased ( KeyEvent e ) {
switch ( e.getKeyCode() ) {
case KeyEvent.VK_TAB :
System.out.println ( "KEY RELEASED TAB" ) ;
break ;
}
}
public void keyTyped ( KeyEvent e ) {
switch ( e.getKeyCode() ) {
case KeyEvent.VK_TAB :
System.out.println ( "KEY TYPED TAB" ) ;
break ;
}
}
} /* NoTabJTextArea */
As isManagingFocus method is deprecated since 1.4, it is also possible to use setFocusTraversalKeys. The example applies the default "on tab" behaviour to the JTextArea field.
import javax.swing.*;
import java.awt.*;
public class NoTabTextArea extends JTextArea {
public NoTabTextArea(String text, int rows, int columns) {
super(text, rows, columns);
setFocusTraversalKeys(KeyboardFocusManager.FORWARD_TRAVERSAL_KEYS,
KeyboardFocusManager.getCurrentKeyboardFocusManager()
.getDefaultFocusTraversalKeys(KeyboardFocusManager.FORWARD_TRAVERSAL_KEYS));
setFocusTraversalKeys(KeyboardFocusManager.BACKWARD_TRAVERSAL_KEYS,
KeyboardFocusManager.getCurrentKeyboardFocusManager()
.getDefaultFocusTraversalKeys(KeyboardFocusManager.BACKWARD_TRAVERSAL_KEYS));
}
}
I will run the program, but when I activate the event, the JFrame will not update (it only removes the JLabel ) unless I manually drag the window to resize it, even with the repaint() being called after the event takes place. What's wrong?
public Driver() {
setLayout( new FlowLayout() );
pass = new JPasswordField( 4 );
add( pass );
image = new ImageIcon( "closedD.png" );
label = new JLabel( "Enter the password to enter the journal of dreams" , image , JLabel.LEFT );
add( label );
button = new JButton( "Enter" );
add( button );
event e = new event();
button.addActionListener( e );
setDefaultCloseOperation( JFrame.EXIT_ON_CLOSE );
setVisible( true );
setSize( 1600/2 , 900/2 );
setTitle( "Diary" );
}
//main method
//
//
public static void main( String[] args ) {
win = new Driver();
}
public class event implements ActionListener {
private boolean clickAgain = false;
public void actionPerformed( ActionEvent e ) {
if ( passEquals( password ) && clickAgain == false ) {
image2 = new ImageIcon( "openD.png" );
remove( label );
label = new JLabel( "Good Job! Here is the journal of dreams." , image2 , JLabel.LEFT );
add( label );
clickAgain = true;
}
repaint();
}
}
Any time you add or remove a component, you must tell its container to re-layout the current components it holds. You do this by calling revalidate() on it. You would then call repaint() after the revalidate call to have the container repaint itself.
public void actionPerformed( ActionEvent e ) {
if ( passEquals( password ) && clickAgain == false ) {
image2 = new ImageIcon( "openD.png" );
remove( label );
label = new JLabel( "Good Job! Here is the journal of dreams.",
image2 , JLabel.LEFT );
add( label );
clickAgain = true;
}
revalidate(); // **** added ****
repaint();
}
Note: your question is worded in such a way as if you assume that we know what you're trying to do. Please give us more information next time. The better and more informative the question, the better and more informative the answer.
Edit 2:
I wonder if you could simplify your code a bit. Instead of removing and adding a JLabel, better to just simply set the current JLabel's text and Icon:
public void actionPerformed( ActionEvent e ) {
if ( passEquals( password ) && clickAgain == false ) {
image2 = new ImageIcon( "openD.png" );
// remove( label ); // removed
label.setText( "Good Job! Here is the journal of dreams.");
label.setIcon(image2);
}
}
I'm creating a form in Java Swing, and one of the fields is a JTextArea. When I use the Tab key on all other fields, it gives the focus to the next widget, but in the JTextArea, it inserts a tab character (horizontal space) in the text.
How can I modify this behavior?
/*
This is my understanding of how tabbing works. The focus manager
recognizes the following default KeyStrokes for tabbing:
forwards: TAB or Ctrl-TAB
backwards: Shift-TAB or Ctrl-Shift-TAB
In the case of JTextArea, TAB and Shift-TAB have been removed from
the defaults which means the KeyStroke is passed to the text area.
The TAB KeyStroke inserts a tab into the Document. Shift-TAB seems
to be ignored.
This example shows different approaches for tabbing out of a JTextArea
Also, a text area is typically added to a scroll pane. So when
tabbing forward the vertical scroll bar would get focus by default.
Each approach shows how to prevent the scrollbar from getting focus.
*/
import java.awt.*;
import java.util.*;
import java.awt.event.*;
import javax.swing.*;
public class TextAreaTab extends JFrame
{
public TextAreaTab()
{
Container contentPane = getContentPane();
contentPane.setLayout(new BoxLayout(contentPane, BoxLayout.Y_AXIS));
contentPane.add( nullTraversalKeys() );
contentPane.add( writeYourOwnAction() );
contentPane.add( useKeyListener() );
contentPane.add( addTraversalKeys() );
}
// Reset the text area to use the default tab keys.
// This is probably the best solution.
private JComponent nullTraversalKeys()
{
JTextArea textArea = new JTextArea(3, 30);
textArea.setText("Null Traversal Keys\n2\n3\n4\n5\n6\n7\n8\n9");
JScrollPane scrollPane = new JScrollPane( textArea );
// scrollPane.getVerticalScrollBar().setFocusable(false);
textArea.setFocusTraversalKeys(KeyboardFocusManager.FORWARD_TRAVERSAL_KEYS, null);
textArea.setFocusTraversalKeys(KeyboardFocusManager.BACKWARD_TRAVERSAL_KEYS, null);
return scrollPane;
}
// Replace the Tab Actions. A little more complicated but this is the
// only solution that will place focus on the component, not the
// vertical scroll bar, when tabbing backwards (unless of course you
// have manually prevented the scroll bar from getting focus).
private JComponent writeYourOwnAction()
{
JTextArea textArea = new JTextArea(3, 30);
textArea.setText("Write Your Own Tab Actions\n2\n3\n4\n5\n6\n7\n8\n9");
JScrollPane scrollPane = new JScrollPane( textArea );
InputMap im = textArea.getInputMap();
KeyStroke tab = KeyStroke.getKeyStroke("TAB");
textArea.getActionMap().put(im.get(tab), new TabAction(true));
KeyStroke shiftTab = KeyStroke.getKeyStroke("shift TAB");
im.put(shiftTab, shiftTab);
textArea.getActionMap().put(im.get(shiftTab), new TabAction(false));
return scrollPane;
}
// Use a KeyListener
private JComponent useKeyListener()
{
JTextArea textArea = new JTextArea(3, 30);
textArea.setText("Use Key Listener\n2\n3\n4\n5\n6\n7\n8\n9");
JScrollPane scrollPane = new JScrollPane( textArea );
scrollPane.getVerticalScrollBar().setFocusable(false);
textArea.addKeyListener(new KeyAdapter()
{
public void keyPressed(KeyEvent e)
{
if (e.getKeyCode() == KeyEvent.VK_TAB)
{
e.consume();
KeyboardFocusManager.
getCurrentKeyboardFocusManager().focusNextComponent();
}
if (e.getKeyCode() == KeyEvent.VK_TAB
&& e.isShiftDown())
{
e.consume();
KeyboardFocusManager.
getCurrentKeyboardFocusManager().focusPreviousComponent();
}
}
});
return scrollPane;
}
// Add Tab and Shift-Tab KeyStrokes back as focus traversal keys.
// Seems more complicated then just using null, but at least
// it shows how to add a KeyStroke as a focus traversal key.
private JComponent addTraversalKeys()
{
JTextArea textArea = new JTextArea(3, 30);
textArea.setText("Add Traversal Keys\n2\n3\n4\n5\n6\n7\n8\n9");
JScrollPane scrollPane = new JScrollPane( textArea );
scrollPane.getVerticalScrollBar().setFocusable(false);
Set set = new HashSet( textArea.getFocusTraversalKeys(
KeyboardFocusManager.FORWARD_TRAVERSAL_KEYS ) );
set.add( KeyStroke.getKeyStroke( "TAB" ) );
textArea.setFocusTraversalKeys(
KeyboardFocusManager.FORWARD_TRAVERSAL_KEYS, set );
set = new HashSet( textArea.getFocusTraversalKeys(
KeyboardFocusManager.BACKWARD_TRAVERSAL_KEYS ) );
set.add( KeyStroke.getKeyStroke( "shift TAB" ) );
textArea.setFocusTraversalKeys(
KeyboardFocusManager.BACKWARD_TRAVERSAL_KEYS, set );
return scrollPane;
}
class TabAction extends AbstractAction
{
private boolean forward;
public TabAction(boolean forward)
{
this.forward = forward;
}
public void actionPerformed(ActionEvent e)
{
if (forward)
tabForward();
else
tabBackward();
}
private void tabForward()
{
final KeyboardFocusManager manager =
KeyboardFocusManager.getCurrentKeyboardFocusManager();
manager.focusNextComponent();
SwingUtilities.invokeLater(new Runnable()
{
public void run()
{
if (manager.getFocusOwner() instanceof JScrollBar)
manager.focusNextComponent();
}
});
}
private void tabBackward()
{
final KeyboardFocusManager manager =
KeyboardFocusManager.getCurrentKeyboardFocusManager();
manager.focusPreviousComponent();
SwingUtilities.invokeLater(new Runnable()
{
public void run()
{
if (manager.getFocusOwner() instanceof JScrollBar)
manager.focusPreviousComponent();
}
});
}
}
public static void main(String[] args)
{
TextAreaTab frame = new TextAreaTab();
frame.setDefaultCloseOperation( EXIT_ON_CLOSE );
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
}
you could use the "NextWidget.grabFocus()" method within keylistener of JTextArea when key "tab" is pressed
With this latter approach the tab character will still get inserted into the JTextArea before the focus is shifted away. If you dont want that behavior you can create a subclass of JTextArea whose isManagingFocus() method always returns false, instead of true. For example:
import javax.swing.*;
public class NoTabTextArea extends JTextArea {
public boolean isManagingFocus() {
return false;
}
}
An instance of NoTabTextArea can be used exactly like a JTextArea, except that the tab key will cause the focus to shift away from it without a tab character being inserted.
You can call the following method in your main JFrame or JPanel constructor.
Use by calling as so: disableTabbingInTextAreas(this)
public static void disableTabbingInTextAreas(Component component){
if(component instanceof Container && !(component instanceof JTextArea)){
for(final Component c : ((Container) component).getComponents() ){
disableTabbingInTextAreas(c);
}
}else if(component instanceof JTextArea){
final Component c = component;
c.addKeyListener(new KeyListener() {
#Override
public void keyTyped(KeyEvent e) {}
#Override
public void keyPressed(KeyEvent e) {
if(e.getKeyChar() == '\t'){
c.transferFocus();
e.consume();
}
}
#Override
public void keyReleased(KeyEvent e) {}
});
}
}
import javax.swing.* ;
import java.awt.event.* ;
/**
* This simple subclass of JTextArea does not allow the 'Tab'
* to be pressed. Instead of putting in 3 blank spaces, the tab
* will transfer focus
*/
/*-----------------------------------------------------------*/
/* */
/* NoTabJTextArea */
/* */
/*-----------------------------------------------------------*/
public class NoTabJTextArea extends JTextArea implements KeyListener {
public NoTabJTextArea ( String text ) {
super ( text ) ;
initialize () ;
}
public NoTabJTextArea ( ) {
super() ;
initialize() ;
}
public NoTabJTextArea ( MaskDocument document ) {
super ( document ) ;
initialize() ;
}
private void initialize () {
addKeyListener ( this ) ;
}
public void keyPressed ( KeyEvent e ) {
switch ( e.getKeyCode() ) {
case KeyEvent.VK_TAB :
e.consume() ;
transferFocus() ;
break ;
}
}
public void keyReleased ( KeyEvent e ) {
switch ( e.getKeyCode() ) {
case KeyEvent.VK_TAB :
System.out.println ( "KEY RELEASED TAB" ) ;
break ;
}
}
public void keyTyped ( KeyEvent e ) {
switch ( e.getKeyCode() ) {
case KeyEvent.VK_TAB :
System.out.println ( "KEY TYPED TAB" ) ;
break ;
}
}
} /* NoTabJTextArea */
As isManagingFocus method is deprecated since 1.4, it is also possible to use setFocusTraversalKeys. The example applies the default "on tab" behaviour to the JTextArea field.
import javax.swing.*;
import java.awt.*;
public class NoTabTextArea extends JTextArea {
public NoTabTextArea(String text, int rows, int columns) {
super(text, rows, columns);
setFocusTraversalKeys(KeyboardFocusManager.FORWARD_TRAVERSAL_KEYS,
KeyboardFocusManager.getCurrentKeyboardFocusManager()
.getDefaultFocusTraversalKeys(KeyboardFocusManager.FORWARD_TRAVERSAL_KEYS));
setFocusTraversalKeys(KeyboardFocusManager.BACKWARD_TRAVERSAL_KEYS,
KeyboardFocusManager.getCurrentKeyboardFocusManager()
.getDefaultFocusTraversalKeys(KeyboardFocusManager.BACKWARD_TRAVERSAL_KEYS));
}
}
I'm trying to write an app that goes something like this:
- Display a dialog
- When user clicks OK, close dialog, go to main app
Here are the relevant code snippets:
public class Owari extends JPanel implements ActionListener, MouseListener, Runnable {
// FIELDS
JFrame frame;
JTextField IP;
String IPAddress;
static final int SERVER_MODE = 0;
static final int CLIENT_MODE = 1;
int mode;
OwariBoard board;
public static void main( String[] args ) {
SwingUtilities.invokeLater( new Owari() );
}
Owari() {
setPreferredSize( new Dimension( WIDTH, HEIGHT ) );
board = new OwariBoard();
}
void main() {
this.addMouseListener( this );
frame.dispose();
frame = new JFrame( "Owari" );
frame.setContentPane( this );
frame.pack();
frame.setVisible(true);
if ( mode == SERVER_MODE ) {
server();
}
if ( mode == CLIENT_MODE ) {
client();
}
}
public void run() {
frame = new JFrame( "Owari" );
frame.setDefaultCloseOperation( JFrame.EXIT_ON_CLOSE );
JPanel init = new JPanel( new GridBagLayout() );
frame.setContentPane( init );
add some components to the init panel including a button with
this as its actionListener and OK as its command.
frame.pack();
frame.setVisible( true );
}
public void actionPerformed( ActionEvent e ) {
if ( e.getActionCommand().equals( "Client" ) ) {
mode = CLIENT_MODE;
IP.setVisible( true );
}
else if ( e.getActionCommand().equals( "Server" ) ) {
mode = SERVER_MODE;
IP.setVisible( false );
}
else {
IPAddress = IP.getText();
main();
}
}
public void paintComponent( Graphics g ) {
super.paintComponent( g );
System.out.println( "painting" );
do some paintin
}
void server() {
frame.setTitle( "Owari Server" );
try {
server = new ServerSocket( 666 );
socket = server.accept();
initIO();
} catch ( IOException e ) {}
yourTurn = true;
System.out.println( "Got to end of server()" ); // At this point, the window
DOES get painted
What happens is the following:
The initial dialog displays:
I click the OK button.
The main window gets resized to the preferred size of the main app but it doesn't get painted, it's just transparent (shown here with this page as the background, heh):
http://imgur.com/6Ssij.jpg
I can tell the paintComponent method hasn't been called because "painting" isn't printed to the console.
However, "got to this point in the program" DOES get printed, so the program isn't hanging, it's just not calling paintComponent.
Then when I launch a client and connect, the app finally gets painted, and "painting" and "got a client" get printed to the console.
Also later on in the app, calls to repaint() are delayed (ie paintComponent is actually called later in the program than when the call to repaint() is made).
I also tried replacing the initial dialog using sthing along the lines of
public void main
frame.getRootPane.removeAll()
frame.setContentPane(this)
frame.getRootPane().revalidate()
frame.pack()
Exact same result.
tl;dr paintcomponent isn't being called when i want it to, what do?
Bumping for some more info: the call to repaint() is done before the call to sever.accept() So why does it not repaint() before hanging at the server.accept() call?
openasocketandwaitforaclient
Your code is executing in the Event Dispatch Thread so the blocking socket is preventing the GUI from repainting itself.
YOu need to use a separate Thread for the socket. Read the section from the Swing tutorial on Concurrency for an explanation and a solution.
your code seems to work so, maybe you should try to invoke the repaint() methode of you frame after resizing this frame.
Anhuin