I'm trying to add an ActionListener to my ComboBox. I want to open a form when a item is selected from the box. I successfully implemented it on a JButton but I can't figure out how to do it in a combobox. Can someone please help me out?
JComboBox<String> valBox = new JComboBox<>();
valBox.addItem("Apparat");
valBox.addItem("Smycke");
valBox.addItem("Aktie");
södra.add(valBox);
valBox.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
if (valBox.getSelectedIndex() == 0)
nyLyss.ApparatForm.form1();
}
});
The code that I wan't to execute when the first item is selected is this one:
class nyLyss implements ActionListener{
public void actionPerformed(ActionEvent ae) {
try{
ApparatForm form1 = new ApparatForm();
int svar = JOptionPane.showConfirmDialog(Layout.this, form1);
if(svar != JOptionPane.OK_OPTION)
return;
String namn = form1.getNamn();
int inköpspris = form1.getPris();
int slitage = form1.getPris();
// saker ap = new saker(namn, inköpspris, slitage);
// alla.add(ap);
}catch(NumberFormatException e){
JOptionPane.showMessageDialog(Layout.this, "Felaktig indata!");
}
}
}
Thanks! :)
I would solve the problem with a ItemStateChanged listener on my combobox. Here a short example with a combobox called "mycombobox".
private void mycomboboxItemStateChanged(java.awt.event.ItemEvent evt) {
System.out.println(mycombobox.getSelectedItem());
}
The result is, that the application is printing out the selected item after every change of the selected item in the combobox "mycombobox".
Related
How can I make the comboBox available when the checkBox was uncheck (vice versa)
Why the comboBox is still disable after I unChecked the checkBox?
choice [] = {"A","B","C"};
JComboBox a = new JComboBox(choice);
JCheckBox chk = new JCheckBox("choice");
...
a.addActionListener(this);
chk.addActionListener(this);
...
public void actionPerformed(ActionEvent e) {
//disable the a comboBox when the checkBox chk was checked
if(e.getSource()==chk)
a.setEnabled(false);
//enable the a comboBox when the checkBox chk was unchecked
else if(e.getSource()!=chk)
a.setEnabled(true);
}
If I understand you correctly I think all that you need to do is to change the enabled state of the combo box based on the current value of the checkbox:
public void actionPerformed(ActionEvent e) {
if (e.getSource()==chk) {
a.setEnabled(chk.isSelected());
}
}
I have a similar set up, and I use an Item Listener, like so:
CheckBox.addItemListener(new ItemListener() {
public void itemStateChanged(ItemEvent e) {
if(e.getStateChange()==ItemEvent.SELECTED){
ComboBox.setEnabled(true);
}else if(e.getStateChange()==ItemEvent.DESELECTED){
ComboBox.setSelectedIndex(-1);
ComboBox.setEnabled(false);
}
}
});
This way the behaviour is different when selected and deselected.
I treid this and worked..
public class JF extends JFrame implements ActionListener {
String choice [] = {"A","B","C"};
JComboBox a = new JComboBox(choice);
JCheckBox chk = new JCheckBox("choice");
JF()
{
this.add(a, BorderLayout.NORTH);
this.add(chk, BorderLayout.CENTER);
setDefaultCloseOperation(EXIT_ON_CLOSE);
a.addActionListener(this);
chk.addActionListener(this);
}
public void actionPerformed(ActionEvent e) {
//NOTE THE FOLLOWING LINE!!!!
if(e.getSource()==chk)
a.setEnabled(chk.isSelected());
}
public static void main(String[] args) {
new JF().setVisible(true);
}
}
Your old code didn't work because, even unchecking a checkbox triggers the event. The source of the trigger is the checkbox.. so both while checking and unchecking the event source was chk
if (e.getSource() == chckbxModificar) {
if (chckbxModificar.isSelected()) {
cbxImpuesto.setEnabled(true);
cbxMoneda.setEnabled(true);
txtPorcentaje.setEditable(true);
txtSimbolo.setEditable(true);
} else {
cbxImpuesto.setEnabled(false);
cbxMoneda.setEnabled(false);
txtPorcentaje.setEditable(false);
txtSimbolo.setEditable(false);
}
}
I have a array of Jradiobuttons.i am trying to have java anonymous class that implement ActionListener so when the user press on a radio button I can do something but since this is an array i cant give the array index using a while loop so how to identify what Jradiobutton I am using.and I want to get the text of that radio button and save it in a another variable...How can I do this?
This is what so far I have done :
if(count!=0) {
rs=pst.executeQuery();
JRadioButton a []=new JRadioButton[count];
jPanel3.setLayout(new GridLayout());
int x=0;
ButtonGroup bg=new ButtonGroup();
while(rs.next()) {
a[x]=new JRadioButton(rs.getString("name"));
bg.add(a[x]);
jPanel3.add(a[x]);
a[x].setVisible(true);
a[x].addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
JOptionPane.showMessageDialog(null,a[x].getText()); //here i cant use this x...even though i make x global value of x always will be 6 becouse of while loop.
}
});
x++;
}
}
If i understand you correctly, You can set the name of radio button:
a[x]=new JRadioButton(rs.getString("name"));
a[x].setName(rs.getString("name"));
and in ActionPerformed you get the source of action:
public void actionPerformed(ActionEvent e) {
if( e.getSource() instanceof JRadioButton){
String selectedRadioName = ((JRadioButton) e.getSource()).getName();
JOptionPane.showMessageDialog( null, selectedRadioName );
}
You could...
Supply each JRadioButton with a ActionCommand which will be made available via the ActionEvent
a[x]=new JRadioButton(rs.getString("name"));
a[x].setActionCommand(String.valueOf(x));
//...
a[x].addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
String cmd = e.getActionCommand();
int value = Integer.parseInt(cmd);
JOptionPane.showMessageDialog(null, a[value].getText());
}
});
See How to Use Buttons, Check Boxes, and Radio Buttons for more details
You could...
Use the Action API to surround the message and action in a self contained unit of work...
public class MessageAction extends AbstractAction {
private String message;
public MessageAction(String text, String message) {
this.message = message;
putValue(NAME, text);
}
#Override
public void actionPerformed(ActionEvent e) {
JOptionPane.showMessageDialog(null, message);
}
}
And then apply it to your button something like...
a[x] = new JRadioButton(new MessageAction(rs.getString("name"), "Hello from " + x);
See How to Use Actions for more details.
How can I update the state (enable/disable) of my button when the user changes the selected item in a combo box.?
The button has a reference to the combo box, but the combo box does not know anything about the button.
If the button has a reference to the combo box, then the button can register an action listener at the combo box in which you can change the state of your button.
final JButton button = new JButton();
final JComboBox comboBox = new JComboBox();
comboBox.addActionListener( new ActionListener() {
#Override
public void actionPerformed( final ActionEvent event ) {
// Your logic to determine when to enable/disable:
final boolean enabled = comboBox.getSelectedIndex() == 0;
button.setEnabled( enabled );
}
} );
The combobox is not required to know about the button. You need to add a listener to the combobox events like this:
public class ComboBoxDemo ... implements ActionListener {
. . .
petList.addActionListener(this) {
. . .
public void actionPerformed(ActionEvent e) {
JComboBox cb = (JComboBox)e.getSource();
String petName = (String)cb.getSelectedItem();
yourButton.setEnabled(true/false);
}
. . .
}
The JButton could simply add its own ActionListener on the JComboBox and in the ActionListener you could then change the state of the JButton according to the selected item of the combo box.
I have previously written code where enabling or disabling a button depends on filling a textfield and selecting an item of a combobox together. It may be helpful here.
jComboBox.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
jComboBoxActionPerformed(e);
}
});
...
jTextField.getDocument().addDocumentListener(new DocumentListener() {
public void insertUpdate(DocumentEvent e) {
jTextFieldDocumentListener(e);
}
public void removeUpdate(DocumentEvent e) {
jTextFieldDocumentListener(e);
}
public void changedUpdate(DocumentEvent e) {
jTextFieldDocumentListener(e);
}
});
jTextField.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
jTextFieldActionPerformed(e);
}
});
...
private void jComboBoxActionPerformed(ActionEvent e){
if(jComboBox.getSelectedIndex() == -1)
jButton.setEnabled(false);
else if(!jTextField.getText().equals(""))
jButton.setEnabled(true);
}
private void jTextFieldDocumentListener(DocumentEvent e){
if(jTextField.getText().equals("") || jComboBox.getSelectedIndex() == -1){
jButton.setEnabled(false);
}
else{
jButton.setEnabled(true);
}
}
private void jTextFieldActionPerformed(ActionEvent e){
if(jTextField.getText().equals("")){
jButton.setEnabled(false);
}
if(!(jTextField.getText().equals(""))){
jButton.setEnabled(true);
}
}
If the combobox is selected and the textfield is filled, then the button will be enabled. Otherwise it will not be enabled.
My problem is a bit tricky. I am using an Editable JComboBox. It may contain case sensitive items. For example, it may have Item1 and item1. So, these two items should be treated as different in my case.
But the problem is, these two items is treated as same. No matter which Items I have selected, it always select the first one (Item1). I've searched in Google, but didn't find any solution. That's why, I am here.
Code:
//loading of Items
jdcbmItemType = new javax.swing.DefaultComboBoxModel(ItemTypeHandler.getItemTypeComboData(MainFrame.companyId));
private void jcbItemTypeMouseReleased(MouseEvent evt)
{
if (jcbItemType.getSelectedIndex() != -1)
{
loadItemTypeDetails(((ItemObject) jcbItemType.getSelectedItem()).getId());
}
else
{
resetFields();
}
}
public static Vector<ItemObject> getItemTypeComboDataV(BigInteger companyId, BigInteger categoryId, boolean addFirstElement, TriState deleted) throws ExceptionWrapper, EJBException
{
try
{
return (Vector<ItemObject>)lookupItemTypeFacade().getItemTypeComboData(companyId, categoryId, addFirstElement, deleted);
} catch (ExceptionWrapper exceptionWrapper)
{
throw exceptionWrapper;
} catch (EJBException ejbEx)
{
throw ejbEx;
} catch (Exception ex)
{
throw new ExceptionWrapper(ex.getMessage());
}
}
ItemObject is a customClass where one field is BigInteger and another is String.
getItemTypeComboData is functioning properly. So, you can assume to get a list of ItemObject from here and it will nicely convert it to Vector<ItemObject>
jcbItemType.getSelectedIndex() always return the same index for Item1 and item1. But it returns different index for item2.
I know, it would be better if I can use itemStateChanged event. But in my case, I can't use it. But my question is, MouseReleased and FocusLost works fine for different name string but not same string with different case. I am really stumbled.
Another way to ask the question:
Does MouseReleased or FocusLost event check for case-sensitive items?
How to resolve this problem?
Thanks.
Here is my SSCCE and this works fine , If this is not what youre looking for, then post your SSCCE for better sooner help!
import javax.swing.*;
import java.awt.event.*;
public class ComboBoxTest {
JComboBox combo;
JTextField txt;
public static void main(String[] args) {
new ComboBoxTest();
}
public ComboBoxTest() {
String items[] = {"Item1", "item1"};
JFrame frame = new JFrame("JComboBox Case-sensitivity Test");
JPanel panel = new JPanel();
combo = new JComboBox(items);
combo.setEditable(true);
txt = new JTextField(10);
panel.add(combo);
panel.add(txt);
frame.add(panel);
combo.addItemListener(new ItemListener() {
#Override
public void itemStateChanged(ItemEvent ie) {
String str = (String) combo.getSelectedItem();
txt.setText(str);
}
});
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setSize(400, 100);
frame.setVisible(true);
}
}
I think you are doing like this :-
String[] items = {"item1", "item2"};
JComboBox cb = new JComboBox(items);
cb.setEditable(true);
Now you have to access the JCombobox elements which you have insert into this as in array form like this:-
MyItemListener actionListener = new MyItemListener();
cb.addItemListener(actionListener);
class MyItemListener implements ItemListener {
// This method is called only if a new item has been selected.
public void itemStateChanged(ItemEvent evt) {
JComboBox cb = (JComboBox)evt.getSource();
// Get the affected item
Object item = evt.getItem();
if (evt.getStateChange() == ItemEvent.SELECTED) {
// Item was just selected
} else if (evt.getStateChange() == ItemEvent.DESELECTED) {
// Item is no longer selected
}
}
}
After adding the itemListener you can do your different tasks with individual JCombobox Item
Try this, it works fine...
use ActionListener() to capture the click... then use getSelectedItem() to capture the item clicked on the JComboBox
try this,
check in your console for the output
myComboBox.addItemListener(new ItemListener() {
#Override
public void itemStateChanged(ItemEvent ie) {
String str = (String) myComboBox.getSelectedItem();
System.out.println(str);
}
I want to make an event which will be triggered after i make the selection to the JComboBox.
the problem I'm now facing is that when i added an ActionListener, it was triggered when the user clicked on the box but BEFORE he actually chose the new item, thus the action listener was activated all the time on the previous value which was selected in the box. what i want to do is simply changing the title of an JTextArea according to the selection.
I tried doing something like this:
jBox.addActionListener(new ActionListener(){
#Override
public void actionPerformed(ActionEvent e) {
String alt = GetAlgoAreaTitleByChoice();
panel.remove(jArea);
currentBest = setArea("",alt);
currentBest.setBounds(50, 350, 1000, 290);
panel.add(jArea);
}
});
and the method inside:
private String GetArgsAreaTitleByChoice(){
String chi = jBox.getSelectedItem().toString();
if(chi.equals(generalChoice)){
return "Hello";
}
else if(chi.equals(algoChoice)){
return "World";
}
else if(chi.equals(argsChoice)){
return "Hello";
}
return null;
}
I've tried using the SELECTED events now like this:
public void itemStateChanged(ItemEvent e) {
JComboBox cb = (JComboBox)e.getSource();
// Get the affected item
String item = cb.getSelectedItem().toString();
if (e.getStateChange() == ItemEvent.SELECTED) {
panel.remove(jBox);
textArea = setArea("", item);
panel.add(jBox);
}
but it seems to remove the area from the panel without adding it back... why is this happening?
Here is a simple demonstration with a sample code :
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
public class Tester {
public Tester(){
JComboBox box = new JComboBox();
box.addItem("One");
box.addItem("Two");
box.addItem("Three");
box.addItemListener(new ItemListener(){
public void itemStateChanged(ItemEvent e){
if(e.getStateChange()==ItemEvent.SELECTED){
e.getItem(); //Do what ever you want :))
}
}
});
JFrame frame = new JFrame();
frame.getContentPane().add(box);
frame.pack();
frame.setVisible(true);
}
public static void main(String [] args) {
Tester tester = new Tester();
}
}
For listening of events from JComboBox is better implements ItemListener, returns two events SELECTED/DESELECTED
EDIT
if you remove/add JComponent(s) on Runtime and in already visible container, then you have to call (as least code lines)
revalidate();
repaint();