I am a new, terribly green user of Swing. I managed to create a table class using examples from java.sun tutorials, and I managed to load data dynamically into it. I want to be able to react to a click on a row by displaying a dialog box. How do I add the event Handler that will identify the selected row number?
The main function code:
public static void main(String[] args) {
javax.swing.SwingUtilities.invokeLater(new Runnable() {
public void run() {
try {
MainWindow window = new MainWindow();
window.frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
//Create and set up the content pane.
createAndShowGUI();
//...
}
}
}
}
and
private static void createAndShowGUI() {
//Create and set up the window.
JFrame frame = new JFrame("Data Table");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
//Create and set up data of the content pane.
TableClass mainTable = new TableClass(fh.getColNames(), fh.getTableContent());
mainTable.setOpaque(true);
frame.setContentPane(mainTable);
//Display the window.
frame.pack();
frame.setVisible(true);
}
Thank you
table.addMouseListener(new MouseAdapter() {
#Override
public void mouseClicked(MouseEvent e) {
if (SwingUtilities.isLeftMouseButton(e) && e.getClickCount() == 1) {
int selectedRowIndex = table.getSelectedRow();
//show your dialog with the selected row's contents
}
}
});
A couple of points.
The answer from Bozhidar Batsov is correct. However, you may not necessarily have a reference to the table (if for example your mouse listener is in another class or something). Point is, the table can be found from the MouseEvent's getSource() method. You can safely cast it to a JTable.
Also, table.getSelectedRow() may return a -1 if no row has actually been selected on the table yet. That would happen if the user, for example, clicks in the "whitespace" of the table (the area outside of the grid, but still in the text area). Just be sure to test for a -1 in your code.
Related
I'm trying to create a program that displays a table with data on it, called a Time Log program. I'm having trouble expanding a Jtable to fill a JPanel, since it's currently looking like this:
You can see the huge white gap below the table, but I want the rows to be evenly distributed among the space.
Below is my code.
This is a class I call TimeLogApplication, which has main method and creates a JFrame.
public static void main(String[] args) {
/* Create a new frame */
JFrame guiFrame = new JFrame("Time Log Program");
/* Set size of the frame */
guiFrame.setSize(FRAME_WIDTH, FRAME_HEIGHT);
/* Add the panel */
guiFrame.add(new TimeLogPanel());
/* Exit normally on closing the window */
guiFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
/* Show the frame */
guiFrame.setVisible(true);
}
The JFrame calls TimeLogPanel class that creates a JPanel. This panel has a Border Layout. The table is added to the center panel, which also has Border Layout.
public TimeLogPanel() {
// Set layout, add table panel
setLayout(new BorderLayout(20, 20));
add(tablePanel);
// Create table panel and set layout
tablePanel = new JPanel();
tablePanel.setLayout(new BorderLayout());
// Create a new table with row and column number
table = new JTable(rowNum, colNum);
table.setShowGrid(true);
table.setGridColor(Color.BLACK);
// Set a raised border
table.setBorder(new EtchedBorder(EtchedBorder.RAISED));
// Add table to table panel
tablePanel.add(table);
}
I have tried to get the panel height but since it is not created until the frame is created, the panel height is zero.
Thanks in advance for any suggestions!
UPDATE:
I tried out the suggestions and it worked beautifully (adding ComponentListener to the JPanel that holds the JTable). This is what I did:
tablePanel.addComponentListener(new ComponentListener() {
#Override
public void componentResized(ComponentEvent e) {
tablePanelSize = tablePanel.getHeight();
table.setRowHeight(tablePanel.getHeight()/rowNum); //RowNum is the number of rows
}
// Below methods are not used but must be there, as a requirement when adding a listener
#Override
public void componentMoved(ComponentEvent e) {
}
#Override
public void componentShown(ComponentEvent e) {
}
#Override
public void componentHidden(ComponentEvent e) {
}
});
I think you have to add a ComponentListener (componentResized event), calculate the row height and then call JTable.setRowHeight.
I have a JPanel holding a JButton and JScrollPane (in turn holding a JTable) and am currently running into two issues which I believe are related:
The JButton listener's actionPerformed() method is not invoked upon click. The only way in which I can get it to be invoked is by calling doClick() on the JButton. The JButton color changes upon hover but no click animation is shown when the mouse is pressed.
Secondly, if a cell is clicked within the JTable, the cell located 2 rows down in the same column registers the click instead. This offset does not occur when clicking in the column headers (i.e. to adjust cell widths), only when within the cell area.
Left-hand panel. Click position circled
public class InventoryPanel extends JPanel {
// Parent Business object reference for communication and JFrame
private Business parent;
private AddItemPanel addItemPanel;
// Inventory table items
private DefaultTableModel inventoryModel;
private JTable inventoryTable;
private JScrollPane inventoryScrollPane;
private JLabel updateLbl;
private JButton addItemBtn;
// Columns for inventory table
private static final String[] INVENTORY_COLUMNS = {"Item","Stock","Restocking Level","Edit"};
public InventoryPanel(Business parent) {
this.parent = parent;
initGUI();
new Thread(new Runnable() {
#Override
public void run() {
while (true) {
//doStuff
try {
Thread.sleep(5000);
} catch (InterruptedException e) {
e.printStackTrace(new PrintStream(System.out));
}
}
}
}).start();
}
// INITIALISES GUI
public void initGUI() {
this.setLayout(new BoxLayout(this,BoxLayout.PAGE_AXIS));
this.setBorder(BorderFactory.createLineBorder(Color.BLACK));
JLabel titleLabel = new JLabel("<html><B>Inventory</B></html>");
this.add(titleLabel);
// Create empty inventory table
inventoryModel = new DefaultTableModel(new Object[3][4],INVENTORY_COLUMNS);
inventoryTable = new JTable(inventoryModel);
inventoryScrollPane = new JScrollPane(inventoryTable);
// Create button to allow items to be added
addItemBtn = new JButton("Add item");
addItemBtn.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
System.out.println("ADD ITEM PRESSED");
}
});
updateLbl = new JLabel("Loading inventory...");
this.add(addItemBtn);
this.add(inventoryScrollPane);
this.add(updateLbl);
}
I've tried removing the table from the panel to see if that solves the JButton issue and visa-versa, but no luck. I've also tried changing the project JDK but no luck there either.
There are other JPanels adjacent to the troublesome one in a JFrame which work perfectly fine. Any ideas?
Edit: I can create a working instance of the InventoryPanel alone in a frame in another project, as mentioned in the comments. However the exact same code (no calls being made to other objects/methods) in the current project now produces ClassCastExceptions. After some googling this seems to be due to non-EDT threads updating the GUI.
However there is no use of the Business class, and all GUI operations are performed using the SwingUtilities.invokeLater() method like so:
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
#Override
public void run() {
JFrame frame = new JFrame("test");
frame.add(new InventoryPanel());
frame.pack();
frame.setVisible(true);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
});
}
Note: the no-argument constructor InventoryPanel() just calls initGUI().
Thanks for the help so far...still very confused by this.
I have two Jframes where frame1 has some text fields and when a button on frame1 is clicked, I open another JFrame which contains a search box and a JTable containing search results.
When I click on a result row on JTable, I want that particular values to be reflected in the frame1 text fields.
I tried passing the JFrame1's object as a parameter but I have no clear idea on how to achieve this.
Any help would be highly appreciated.
Thanks
First of all, your program design seems a bit off, as if you are using a JFrame for one of your windows where you should in fact be using a JDialog since it sounds as if one window should be dependent upon the other.
But regardless, you pass references of GUI objects the same as you would standard non-GUI Java code. If one window opens the other (the second often being the dialog), then the first window usually already holds a reference to the second window and can call methods off of it. The key often is when to have the first window call the second's methods to get its state. If the second is a modal dialog, then the when is easy -- immediately after the dialog returns which will be in the code immediately after you set the second dialog visible. If it is not a modal dialog, then you probably want to use a listener of some sort to know when to extract the information.
Having said this, the details will all depend on your program structure, and you'll need to tell us more about this if you want more specific help.
For a simple example that has one window open another, allows the user to enter text into the dialog windows JTextField, and then places the text in the first window's JTextField, please have a look at this:
import java.awt.Window;
import java.awt.Dialog.ModalityType;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.*;
public class WindowCommunication {
private static void createAndShowUI() {
JFrame frame = new JFrame("WindowCommunication");
frame.getContentPane().add(new MyFramePanel());
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
// let's be sure to start Swing on the Swing event thread
public static void main(String[] args) {
java.awt.EventQueue.invokeLater(new Runnable() {
public void run() {
createAndShowUI();
}
});
}
}
class MyFramePanel extends JPanel {
private JTextField field = new JTextField(10);
private JButton openDialogeBtn = new JButton("Open Dialog");
// here my main gui has a reference to the JDialog and to the
// MyDialogPanel which is displayed in the JDialog
private MyDialogPanel dialogPanel = new MyDialogPanel();
private JDialog dialog;
public MyFramePanel() {
openDialogeBtn.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
openTableAction();
}
});
field.setEditable(false);
field.setFocusable(false);
add(field);
add(openDialogeBtn);
}
private void openTableAction() {
// lazy creation of the JDialog
if (dialog == null) {
Window win = SwingUtilities.getWindowAncestor(this);
if (win != null) {
dialog = new JDialog(win, "My Dialog",
ModalityType.APPLICATION_MODAL);
dialog.getContentPane().add(dialogPanel);
dialog.pack();
dialog.setLocationRelativeTo(null);
}
}
dialog.setVisible(true); // here the modal dialog takes over
// this line starts *after* the modal dialog has been disposed
// **** here's the key where I get the String from JTextField in the GUI held
// by the JDialog and put it into this GUI's JTextField.
field.setText(dialogPanel.getFieldText());
}
}
class MyDialogPanel extends JPanel {
private JTextField field = new JTextField(10);
private JButton okButton = new JButton("OK");
public MyDialogPanel() {
okButton.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
okButtonAction();
}
});
add(field);
add(okButton);
}
// to allow outside classes to get the text held by the JTextField
public String getFieldText() {
return field.getText();
}
// This button's action is simply to dispose of the JDialog.
private void okButtonAction() {
// win is here the JDialog that holds this JPanel, but it could be a JFrame or
// any other top-level container that is holding this JPanel
Window win = SwingUtilities.getWindowAncestor(this);
if (win != null) {
win.dispose();
}
}
}
You'd do a very similar technique to get information out of a JTable.
And again, if this information doesn't help you, then please tell us more about your program including showing us some of your code. The best code to show is a small compilable example, an SSCCE similar to what I've posted above.
I have two Jframes where frame1 has some text fields and when a button on frame1 is clicked, I open another JFrame which contains a search box and a JTable containing search results.
When I click on a result row on JTable, I want that particular values to be reflected in the frame1 text fields.
I tried passing the JFrame1's object as a parameter but I have no clear idea on how to achieve this.
Any help would be highly appreciated.
Thanks
First of all, your program design seems a bit off, as if you are using a JFrame for one of your windows where you should in fact be using a JDialog since it sounds as if one window should be dependent upon the other.
But regardless, you pass references of GUI objects the same as you would standard non-GUI Java code. If one window opens the other (the second often being the dialog), then the first window usually already holds a reference to the second window and can call methods off of it. The key often is when to have the first window call the second's methods to get its state. If the second is a modal dialog, then the when is easy -- immediately after the dialog returns which will be in the code immediately after you set the second dialog visible. If it is not a modal dialog, then you probably want to use a listener of some sort to know when to extract the information.
Having said this, the details will all depend on your program structure, and you'll need to tell us more about this if you want more specific help.
For a simple example that has one window open another, allows the user to enter text into the dialog windows JTextField, and then places the text in the first window's JTextField, please have a look at this:
import java.awt.Window;
import java.awt.Dialog.ModalityType;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.*;
public class WindowCommunication {
private static void createAndShowUI() {
JFrame frame = new JFrame("WindowCommunication");
frame.getContentPane().add(new MyFramePanel());
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
// let's be sure to start Swing on the Swing event thread
public static void main(String[] args) {
java.awt.EventQueue.invokeLater(new Runnable() {
public void run() {
createAndShowUI();
}
});
}
}
class MyFramePanel extends JPanel {
private JTextField field = new JTextField(10);
private JButton openDialogeBtn = new JButton("Open Dialog");
// here my main gui has a reference to the JDialog and to the
// MyDialogPanel which is displayed in the JDialog
private MyDialogPanel dialogPanel = new MyDialogPanel();
private JDialog dialog;
public MyFramePanel() {
openDialogeBtn.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
openTableAction();
}
});
field.setEditable(false);
field.setFocusable(false);
add(field);
add(openDialogeBtn);
}
private void openTableAction() {
// lazy creation of the JDialog
if (dialog == null) {
Window win = SwingUtilities.getWindowAncestor(this);
if (win != null) {
dialog = new JDialog(win, "My Dialog",
ModalityType.APPLICATION_MODAL);
dialog.getContentPane().add(dialogPanel);
dialog.pack();
dialog.setLocationRelativeTo(null);
}
}
dialog.setVisible(true); // here the modal dialog takes over
// this line starts *after* the modal dialog has been disposed
// **** here's the key where I get the String from JTextField in the GUI held
// by the JDialog and put it into this GUI's JTextField.
field.setText(dialogPanel.getFieldText());
}
}
class MyDialogPanel extends JPanel {
private JTextField field = new JTextField(10);
private JButton okButton = new JButton("OK");
public MyDialogPanel() {
okButton.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
okButtonAction();
}
});
add(field);
add(okButton);
}
// to allow outside classes to get the text held by the JTextField
public String getFieldText() {
return field.getText();
}
// This button's action is simply to dispose of the JDialog.
private void okButtonAction() {
// win is here the JDialog that holds this JPanel, but it could be a JFrame or
// any other top-level container that is holding this JPanel
Window win = SwingUtilities.getWindowAncestor(this);
if (win != null) {
win.dispose();
}
}
}
You'd do a very similar technique to get information out of a JTable.
And again, if this information doesn't help you, then please tell us more about your program including showing us some of your code. The best code to show is a small compilable example, an SSCCE similar to what I've posted above.
I have a Swing program that does a search based on the contents of some text fields and settings of a pair of radio buttons (in a button group). The program will automatically search when certain of the text fields lose focus. The problem comes in when the lose focus event is triggered by a click on one of the radio buttons. The lost focus event on the text field is getting processed before the radio button isSelected() values have changed, so the search is done with the "wrong" (i.e. old) parameters, instead of the parameters based on the new setting of the radio buttons.
I tried invoking the search using my own invokeWhenIdle method (shown below) to run the search after the event queue had settled down, but it still is using the old setting of the radio buttons.
My only working solution is to delay for 250 milliseconds in the lost focus event before running the search, so that the radio buttons have time to change. This works, but it makes the UI seem sluggish.
Any better ideas?
public static void invokeWhenIdle(final int a_max_retry, final Runnable a_runnable) {
if (a_max_retry <= 0) {
throw new IllegalStateException("invokeWhenIdle: Could not run " + a_runnable);
}
// get the next event on the queue
EventQueue l_queue = Toolkit.getDefaultToolkit().getSystemEventQueue();
AWTEvent l_evt = l_queue.peekEvent();
if (l_evt == null) {
// nothing left on the queue (but us), we can do it
SwingUtilities.invokeLater(a_runnable);
} else {
// still something in the queue, try again
SwingUtilities.invokeLater(new Runnable() {
public void run() {
invokeWhenIdle(a_max_retry - 1, a_runnable);
}
});
}
}
Not an answer, but an explanation about what is happening. Maybe it will spark an idea...
The problem is that a mousePressed arms the button model and the mouseReleased actually changes the selected value of the model.
When you execute the FocusListener code the radio button the model is in an undefined state. Even if you add the FocusListener code to the end of the EDT by using invokeLater the code will still execute before the mouseReleased event is generated.
The following shows how you might code the listener to handle this. It assumes the state of the button is about to change:
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class FocusSSCCE extends JPanel
{
public FocusSSCCE()
{
final JRadioButton radio = new JRadioButton("Radio");
add( radio );
radio.setMnemonic('R');
JTextField textField = new JTextField(10);
add( textField );
JButton button = new JButton("Button");
add( button );
textField.addFocusListener( new FocusAdapter()
{
public void focusLost(FocusEvent e)
{
boolean isSelected = radio.isSelected();
// Assumes selected state will change
if (radio.getModel().isArmed())
isSelected = !isSelected;
System.out.println( isSelected );
}
});
}
private static void createAndShowUI()
{
JFrame frame = new JFrame("FocusSSCCE");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add( new FocusSSCCE() );
frame.pack();
frame.setLocationRelativeTo( null );
frame.setVisible( true );
}
public static void main(String[] args)
{
EventQueue.invokeLater(new Runnable()
{
public void run()
{
createAndShowUI();
}
});
}
}
However, even this approach can't be guaranteed to work. If for some reason the user generates the mousePressed event on the radio button and them moves the mouse away from the radio button before releasing the mouse, then the selected state of the radio button is not changed.
Similiarly, even your original implementation to sleep for 250ms can not be guaranteed to work because the user could theoretically hold down the mouse for more than 250ms which would also generate the wrong value.
My workaround for this was to make the radio buttons non focusable
I can't think of any better approach.
Edit:
I just thought of a wild solution.
textField.addFocusListener( new FocusAdapter()
{
public void focusLost(FocusEvent e)
{
if (e.getOppositeComponent() instanceof JRadioButton)
{
final JRadioButton radio = (JRadioButton)e.getOppositeComponent();
MouseListener ml = new MouseAdapter()
{
public void mouseReleased(MouseEvent e)
{
System.out.println( radio.isSelected() );
radio.removeMouseListener(this);
}
};
radio.addMouseListener( ml );
}
else
System.out.println( radio.isSelected() );
}
});
Basically your processing code won't execute until the mouse has been released when you click on the radio button.