In this code, perfs is a String[] and model is a DefaultTableModel associated to a JTable.
for(int i =0; i<100000; i++){
model.addRow(perfs);
}
I would like the rows to appear as they are added, but they only appear once the loop is over. Could this have something to do with te fact the table is in a JScrollPane ?
Here's the full code in case it might be useful
import javax.swing.*;
import javax.swing.table.DefaultTableModel;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
public class gwy implements ActionListener{
private JFrame frame;
private JPanel panel;
private JButton button;
String[] nomsColonnes = {"INSTANCE","Solvabilité","Profondeur(ms)","Largeur(ms)", "Heur. basique(ms)", "Heur. opérations variées", "Heur. distances au carré"};
private DefaultTableModel model = new DefaultTableModel(nomsColonnes, 0);
private JTable tableResultats = new JTable(model);
JScrollPane scrollPane;
public gwy(){
frame = new JFrame();
button = new JButton("Résoudre");
button.addActionListener(this);
scrollPane = new JScrollPane(tableResultats);
tableResultats.setFillsViewportHeight(true);
panel = new JPanel();
panel.setSize(70,50);
panel.setBorder(BorderFactory.createEmptyBorder(10, 10, 10,10));
panel.setLayout(new BoxLayout(panel,BoxLayout.PAGE_AXIS));
panel.add(button);
panel.add(scrollPane);
frame.add(panel, BorderLayout.CENTER);
//frame.setSize(500,500);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setTitle("GUI");
frame.pack();
frame.setVisible(true);
}
public static void main(String[] args){
new gwy();
}
#Override
public void actionPerformed(ActionEvent e) {
for(int i =0; i<10000000; i++){
model.addRow(nomsColonnes);
}
}
}
The problem is, Swing is single threaded. This means that until your loops completes, it's blocking the Event Dispatching Thread from processing any new events, which would otherwise update the UI.
Swing is also not thread safe, meaning you should not update the UI, or any state the UI depends on, from out the context of the Event Dispatching Thread.
See Concurrency in Swing for more details.
A common way to achieve this would be to use a SwingWorker which can be used to create new rows in a seperate thread, but which can sync the updates back to the Event Dispatching Thread safely.
See Worker Threads and SwingWorker for more details
Runnable example
import java.awt.BorderLayout;
import java.awt.EventQueue;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.ArrayList;
import java.util.List;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTable;
import javax.swing.SwingWorker;
import javax.swing.event.TableModelEvent;
import javax.swing.event.TableModelListener;
import javax.swing.table.AbstractTableModel;
public class Main {
public static void main(String[] args) {
new Main();
}
public Main() {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
JFrame frame = new JFrame();
frame.add(new TestPane());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
public class TestPane extends JPanel {
private MyTableModel model;
public TestPane() {
setLayout(new BorderLayout());
model = new MyTableModel();
JTable table = new JTable(model);
model.addTableModelListener(new TableModelListener() {
#Override
public void tableChanged(TableModelEvent e) {
if (e.getType() == TableModelEvent.INSERT) {
int row = e.getFirstRow();
table.scrollRectToVisible(table.getCellRect(row, 0, true));
}
}
});
add(new JScrollPane(table));
JButton populate = new JButton("Populate");
populate.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
populate.setEnabled(false);
PopulateWorker worker = new PopulateWorker(model);
worker.execute();
}
});
add(populate, BorderLayout.SOUTH);
}
}
public class PopulateWorker extends SwingWorker<Void, MyRowData> {
private MyTableModel model;
public PopulateWorker(MyTableModel model) {
this.model = model;
}
public MyTableModel getModel() {
return model;
}
#Override
protected void process(List<MyRowData> chunks) {
for (MyRowData row : chunks) {
model.addRow(row);
}
}
#Override
protected Void doInBackground() throws Exception {
for (int index = 0; index < 10_000; index++) {
publish(new MyRowData(Integer.toString(index)));
// Decrease this to make it faster
Thread.sleep(125);
}
return null;
}
}
public class MyRowData {
private String identifer;
public MyRowData(String identifer) {
this.identifer = identifer;
}
public String getIdentifer() {
return identifer;
}
}
public class MyTableModel extends AbstractTableModel {
private String[] columnNames = new String[]{"INSTANCE"};
private List<MyRowData> data = new ArrayList<>(32);
#Override
public int getRowCount() {
return data.size();
}
#Override
public int getColumnCount() {
return columnNames.length;
}
#Override
public String getColumnName(int column) {
return columnNames[column];
}
#Override
public Class<?> getColumnClass(int columnIndex) {
return String.class;
}
#Override
public Object getValueAt(int rowIndex, int columnIndex) {
MyRowData row = data.get(rowIndex);
switch (columnIndex) {
case 0: return row.getIdentifer();
}
return null;
}
public void addRow(MyRowData row) {
data.add(row);
fireTableRowsInserted(data.size() - 1, data.size() - 1);
}
}
}
nb:: There is a Thread.sleep inside the doInBackground method of the SwingWorker, this is very important. If you remove it, the worker will complete before the UI get's updated. Instead, you can modify the Thread.sleep to increase or decrease the speed at which the updates occur. Just beware, if it's low enough, you might end up with multiple rows appearing at the same time, depending on the thread load.
Related
I just started using Java Swing, and I was going through the following post: Dynamic fields addition in java/swing form.
I implement the code in this post with some modification, and it worked fine. As mentioned in the post, JPanel is not resizing itself when we add more rows. Can someone throw more light on this issue with easy to understand explanation that how can we resize JPanel as soon as we hit +/- button? Here is the code :
Row class
import java.awt.event.ActionEvent;
import javax.swing.AbstractAction;
import javax.swing.JButton;
import javax.swing.JPanel;
import javax.swing.JTextField;
#SuppressWarnings("serial")
public class Row extends JPanel {
private JTextField quantity;
private JTextField item;
private JTextField price;
private JButton plus;
private JButton minus;
private RowList parent;
public Row(String initialQuantity, String initalPrice, String initialItem, RowList list) {
this.parent = list;
this.plus = new JButton(new AddRowAction());
this.minus = new JButton(new RemoveRowAction());
this.quantity = new JTextField(10);
this.item = new JTextField(10);
this.price = new JTextField(10);
this.quantity.setText(initialQuantity);
this.price.setText(initalPrice);
this.item.setText(initialItem);
add(this.plus);
add(this.minus);
add(this.quantity);
add(this.item);
add(this.price);
}
public class AddRowAction extends AbstractAction {
public AddRowAction() {
super("+");
}
public void actionPerformed(ActionEvent e) {
parent.cloneRow(Row.this);
}
}
public class RemoveRowAction extends AbstractAction {
public RemoveRowAction() {
super("-");
}
public void actionPerformed(ActionEvent e) {
parent.removeItem(Row.this);
}
}
public void enableAdd(boolean enabled) {
this.plus.setEnabled(enabled);
}
public void enableMinus(boolean enabled) {
this.minus.setEnabled(enabled);
}
}
RowList class
import java.util.ArrayList;
import java.util.List;
import javax.swing.JButton;
import javax.swing.JLabel;
import javax.swing.JPanel;
#SuppressWarnings("serial")
public class RowList extends JPanel{
private List<Row> rows;
public RowList() {
this.rows = new ArrayList<Row>();
Row initial = new Row("1","0.00","", this);
//addHeaders();
//addGenerateBillButton();
addItem(initial);
}
public void addHeaders(){
JLabel qty = new JLabel("Quantity");
//qty.setBounds(10, 0, 80, 25);
add(qty);
JLabel item = new JLabel("Item");
//item.setBounds(70, 0, 80, 25);
add(item);
JLabel price = new JLabel("Price");
//price.setBounds(120, 0, 80, 25);
add(price);
}
public void addGenerateBillButton(){
JButton billGenerationButton = new JButton("Generate Bill");
add(billGenerationButton);
}
public void cloneRow(Row row) {
Row theClone = new Row("1","0.00","", this);
addItem(theClone);
}
private void addItem(Row row) {
rows.add(row);
add(row);
refresh();
}
public void removeItem(Row entry) {
rows.remove(entry);
remove(entry);
refresh();
}
private void refresh() {
revalidate();
repaint();
if (rows.size() == 1) {
rows.get(0).enableMinus(false);
}
else {
for (Row e : rows) {
e.enableMinus(true);
}
}
}
}
Main class
import javax.swing.JFrame;
public class Main {
public static void main(String[] args) {
JFrame frame = new JFrame("Enter Items");
RowList panel = new RowList();
frame.getContentPane().add(panel);
frame.pack();
frame.setVisible(true);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
}
You can call the pack() of the frame again.
Try this: Add this in your Row class
public class AddRowAction extends AbstractAction
{
public AddRowAction()
{
super("+");
}
public void actionPerformed(ActionEvent e)
{
parent.cloneRow(Row.this);
((JFrame) SwingUtilities.getRoot(parent)).pack(); // <--- THIS LINE
}
}
public class RemoveRowAction extends AbstractAction
{
public RemoveRowAction()
{
super("-");
}
public void actionPerformed(ActionEvent e)
{
parent.removeItem(Row.this);
((JFrame) SwingUtilities.getRoot(parent)).pack(); // <--- THIS LINE
}
}
You can get the root component (JFrame) using the SwingUtilities.getRoot(comp) from the child component and call the pack() method after your new Row is added to your RowList.
This would resize your JPanel. But your RowList will be horizontal. This is where LayoutManager comes into play.
You can know more about different LayoutManagers here.
To fix this problem, in your RowList panel, set your layout to:
setLayout(new BoxLayout(this, BoxLayout.Y_AXIS));
Within your refresh method call doLayout() method after revalidate()
I want to change the action of the button to delete. I have this code:
package buttonexample;
import java.awt.BorderLayout;
import java.awt.Component;
import java.awt.Dimension;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import javax.swing.*;
import javax.swing.table.AbstractTableModel;
import javax.swing.table.DefaultTableModel;
import javax.swing.table.TableCellRenderer;
import javax.swing.table.TableModel;
public class ButtonExample {
public JTable table;
public static void main(String[] args) {
final ButtonExample example = new ButtonExample();
javax.swing.SwingUtilities.invokeLater(new Runnable() {
public void run() {
example.createAndShowGUI();
}
});
}
private void createAndShowGUI() {
JFrame frame = new JFrame("Button Example");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
table = new JTable(new JTableModel());
JScrollPane scrollPane = new JScrollPane(table);
table.setFillsViewportHeight(true);
TableCellRenderer buttonRenderer = new JTableButtonRenderer();
//table.getColumn("Button1").setCellRenderer(buttonRenderer);
table.getColumn("Button2").setCellRenderer(buttonRenderer);
table.addMouseListener(new JTableButtonMouseListener(table));
frame.getContentPane().add(scrollPane, BorderLayout.CENTER);
frame.getContentPane().setPreferredSize(new Dimension(500, 200));
frame.pack();
frame.setVisible(true);
}
public static class JTableModel extends AbstractTableModel {
private static final long serialVersionUID = 1L;
private static final String[] COLUMN_NAMES = new String[] {"Id", "Stuff", "Asdfsdf", "Button2"};
private static final Class<?>[] COLUMN_TYPES = new Class<?>[] {Integer.class, String.class, String.class, JButton.class};
#Override public int getColumnCount() {
return COLUMN_NAMES.length;
}
#Override public int getRowCount() {
return 4;
}
#Override public String getColumnName(int columnIndex) {
return COLUMN_NAMES[columnIndex];
}
#Override public Class<?> getColumnClass(int columnIndex) {
return COLUMN_TYPES[columnIndex];
}
#Override public Object getValueAt(final int rowIndex, final int columnIndex) {
switch (columnIndex) {
case 0: return rowIndex;
case 1: return "Text for "+rowIndex;
case 2: return "Column for "+rowIndex;
case 3: final JButton button = new JButton(COLUMN_NAMES[columnIndex]);
button.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent arg0) {
// When this is clicked the whole row will be deleted.
JOptionPane.showMessageDialog(JOptionPane.getFrameForComponent(button),
"Button clicked for row "+rowIndex);
}
});
return button;
default: return "Error";
}
}
}
private static class JTableButtonRenderer implements TableCellRenderer {
#Override public Component getTableCellRendererComponent(JTable table, Object value, boolean isSelected, boolean hasFocus, int row, int column) {
JButton button = (JButton)value;
if (isSelected) {
button.setForeground(table.getSelectionForeground());
button.setBackground(table.getSelectionBackground());
} else {
button.setForeground(table.getForeground());
button.setBackground(UIManager.getColor("Button.background"));
}
return button;
}
}
private static class JTableButtonMouseListener extends MouseAdapter {
private final JTable table;
public JTableButtonMouseListener(JTable table) {
this.table = table;
}
public void mouseClicked(MouseEvent e) {
int column = table.getColumnModel().getColumnIndexAtX(e.getX());
int row = e.getY()/table.getRowHeight();
if (row < table.getRowCount() && row >= 0 && column < table.getColumnCount() &&
column >= 0) {
Object value = table.getValueAt(row, column);
if (value instanceof JButton) {
((JButton)value).doClick();
}
}
}
}
}
But the (DefaultTableModel)someTable.getModel(); model.removeRow(row); I can't make it work because the table model does not have any name and I don't know what to name it. I have tried initializing a table model and I get error saying non-static variable model cannot be reference to a static context. Is there a way to delete the row in a static context?
The example by camickr is probably a more reusable solution, but for the sake of education...
Rendering of cells is the domain of the view
Model's should never contain components, especially if you're thinking about rendering them to the screen, this is simply the wrong approach to take...
You need to set up a TableCellEditor which will act as the means by which you can retrieve notification of the edit actions (mouse click or keypress)
This is a basic example, for simplicity, I've used a DefaultTableModel as it has a nice removeRow method, but conceivably, you could use any TableModel, so long as you provided the means to remove a row and modified by the editor to support it...
import java.awt.BorderLayout;
import java.awt.Component;
import java.awt.Dimension;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.util.EventObject;
import javax.swing.AbstractCellEditor;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JScrollPane;
import javax.swing.JTable;
import javax.swing.UIManager;
import javax.swing.event.CellEditorListener;
import javax.swing.table.AbstractTableModel;
import javax.swing.table.DefaultTableModel;
import javax.swing.table.TableCellEditor;
import javax.swing.table.TableCellRenderer;
import javax.swing.table.TableModel;
public class ButtonExample {
public JTable table;
public static void main(String[] args) {
final ButtonExample example = new ButtonExample();
javax.swing.SwingUtilities.invokeLater(new Runnable() {
public void run() {
example.createAndShowGUI();
}
});
}
private void createAndShowGUI() {
JFrame frame = new JFrame("Button Example");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
table = new JTable(new ExampleTableModel());
JScrollPane scrollPane = new JScrollPane(table);
table.setFillsViewportHeight(true);
table.getColumn("action").setCellRenderer(new ButtonCellRenderer());
table.getColumn("action").setCellEditor(new ButtonCellEditor());
frame.getContentPane().add(scrollPane, BorderLayout.CENTER);
frame.pack();
frame.setVisible(true);
}
public static class ExampleTableModel extends DefaultTableModel {
public ExampleTableModel() {
super(new Object[]{"id", "stuff", "blah", "action"}, 0);
for (int index = 0; index < 10; index++) {
addRow(new Object[]{index, "Text for " + index, "Na na", index});
}
}
#Override
public boolean isCellEditable(int rowIndex, int columnIndex) {
return columnIndex == 3;
}
}
public static class ButtonCellRenderer extends JButton implements TableCellRenderer {
#Override
public Component getTableCellRendererComponent(JTable table, Object value, boolean isSelected, boolean hasFocus, int row, int column) {
if (value != null) {
setText("Delete row " + value.toString());
} else {
setText("Delete Me");
}
if (isSelected) {
setForeground(table.getSelectionForeground());
setBackground(table.getSelectionBackground());
} else {
setForeground(table.getForeground());
setBackground(UIManager.getColor("Button.background"));
}
return this;
}
}
public static class ButtonCellEditor extends AbstractCellEditor implements TableCellEditor {
private JButton editor;
private Object value;
private int row;
private JTable table;
public ButtonCellEditor() {
editor = new JButton();
editor.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
if (table != null) {
fireEditingStopped();
TableModel model = table.getModel();
if (model instanceof DefaultTableModel) {
((DefaultTableModel) model).removeRow(row);
}
}
}
});
}
#Override
public boolean isCellEditable(EventObject e) {
return true;
}
#Override
public Object getCellEditorValue() {
return value;
}
#Override
public Component getTableCellEditorComponent(JTable table, Object value, boolean isSelected, int row, int column) {
this.table = table;
this.row = row;
this.value = value;
if (value != null) {
editor.setText("Delete row " + value.toString());
} else {
editor.setText("Delete Me");
}
if (isSelected) {
editor.setForeground(table.getSelectionForeground());
editor.setBackground(table.getSelectionBackground());
} else {
editor.setForeground(table.getForeground());
editor.setBackground(UIManager.getColor("Button.background"));
}
return editor;
}
}
}
Take a closer look at How to Use Tables for more details
This is just a personal preference, but I prefer to use a toolbar or menu item and key bindings to provide this support. Buttons in a table just seem so...dated - IMHO
Probably a noob question, but im new to java. I have a need for a checkbox list which I found is not supported in swing, but I found this custom control here
http://www.devx.com/tips/Tip/5342
So I created a class file named CheckBoxList, and copied the code from the link into it:
import javax.swing.*;
import javax.swing.border.*;
import java.awt.*;
import java.awt.event.*;
public class CheckBoxList extends JList
{
protected static Border noFocusBorder =
new EmptyBorder(1, 1, 1, 1);
public CheckBoxList()
{
setCellRenderer(new CellRenderer());
addMouseListener(new MouseAdapter()
{
public void mousePressed(MouseEvent e)
{
int index = locationToIndex(e.getPoint());
if (index != -1) {
JCheckBox checkbox = (JCheckBox)
getModel().getElementAt(index);
checkbox.setSelected(
!checkbox.isSelected());
repaint();
}
}
}
);
setSelectionMode(ListSelectionModel.SINGLE_SELECTION);
}
protected class CellRenderer implements ListCellRenderer
{
public Component getListCellRendererComponent(
JList list, Object value, int index,
boolean isSelected, boolean cellHasFocus)
{
JCheckBox checkbox = (JCheckBox) value;
checkbox.setBackground(isSelected ?
getSelectionBackground() : getBackground());
checkbox.setForeground(isSelected ?
getSelectionForeground() : getForeground());
checkbox.setEnabled(isEnabled());
checkbox.setFont(getFont());
checkbox.setFocusPainted(false);
checkbox.setBorderPainted(true);
checkbox.setBorder(isSelected ?
UIManager.getBorder(
"List.focusCellHighlightBorder") : noFocusBorder);
return checkbox;
}
}
}
The problem is I don't know how to implement it in my GUI file. I tried a lot of code, but they never showed an example. Just
To use the class, simply instantiate it, then pass it an array of
JCheckBox objects (or subclasses of JCheckBox objects) by calling
setListData
So does that mean that I will not see the control in the Graphical Design view? My client wants to be able to edit it himself and add stuff so I want it to be easy and graphical if possible. If someone could show an example of instantiating it or give a good hint I would appreciate it. Thanks!
Can you just tell me how?
Use a one column JTable and an appropriate renderer and editor. Based on this example, the code below relies on the default renderer for a data value of type Boolean.Class. A more general example is cited here.
import java.awt.Component;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.GridLayout;
import java.util.ArrayList;
import java.util.List;
import java.util.Set;
import java.util.TreeSet;
import javax.swing.BorderFactory;
import javax.swing.DefaultListModel;
import javax.swing.JCheckBox;
import javax.swing.JFrame;
import javax.swing.JList;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTable;
import javax.swing.event.TableModelEvent;
import javax.swing.event.TableModelListener;
import javax.swing.table.AbstractTableModel;
import javax.swing.table.TableCellRenderer;
/** #see https://stackoverflow.com/a/13919878/230513 */
public class CheckTable {
private static final CheckModel model = new CheckModel(5000);
private static final JTable table = new JTable(model) {
#Override
public Dimension getPreferredScrollableViewportSize() {
return new Dimension(150, 300);
}
#Override
public Component prepareRenderer(TableCellRenderer renderer, int row, int column) {
JCheckBox jcb = (JCheckBox) super.prepareRenderer(renderer, row, column);
jcb.setHorizontalTextPosition(JCheckBox.LEADING);
jcb.setText(String.valueOf(row));
return jcb;
}
};
public static void main(String[] args) {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
JFrame f = new JFrame("CheckTable");
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
f.setLayout(new GridLayout(1, 0));
f.add(new JScrollPane(table));
f.add(new DisplayPanel(model));
f.pack();
f.setLocationRelativeTo(null);
f.setVisible(true);
}
});
}
private static class DisplayPanel extends JPanel {
private DefaultListModel dlm = new DefaultListModel();
private JList list = new JList(dlm);
public DisplayPanel(final CheckModel model) {
super(new GridLayout());
this.setBorder(BorderFactory.createTitledBorder("Checked"));
this.add(new JScrollPane(list));
model.addTableModelListener(new TableModelListener() {
#Override
public void tableChanged(TableModelEvent e) {
dlm.removeAllElements();
for (Integer integer : model.checked) {
dlm.addElement(integer);
}
}
});
}
}
private static class CheckModel extends AbstractTableModel {
private final int rows;
private List<Boolean> rowList;
private Set<Integer> checked = new TreeSet<Integer>();
public CheckModel(int rows) {
this.rows = rows;
rowList = new ArrayList<Boolean>(rows);
for (int i = 0; i < rows; i++) {
rowList.add(Boolean.FALSE);
}
}
#Override
public int getRowCount() {
return rows;
}
#Override
public int getColumnCount() {
return 1;
}
#Override
public String getColumnName(int col) {
return "Column " + col;
}
#Override
public Object getValueAt(int row, int col) {
return rowList.get(row);
}
#Override
public void setValueAt(Object aValue, int row, int col) {
boolean b = (Boolean) aValue;
rowList.set(row, b);
if (b) {
checked.add(row);
} else {
checked.remove(row);
}
fireTableRowsUpdated(row, row);
}
#Override
public Class<?> getColumnClass(int col) {
return getValueAt(0, col).getClass();
}
#Override
public boolean isCellEditable(int row, int col) {
return true;
}
}
}
The code is expecting a list of JCheckBox objects - so this works
CheckBoxList cbList = new CheckBoxList(); // the class you have
JCheckBox check1 = new JCheckBox("One");
JCheckBox check2 = new JCheckBox("two");
JCheckBox[] myList = { check1, check2}; list of checkbox object
cbList.setListData(myList); // set the list data for the object
Small Swing program using your class below
util;
import javax.swing.*;
public class HelloWorldSwing {
private static void createAndShowGUI() {
//Create and set up the window.
JFrame frame = new JFrame("HelloWorldSwing");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
CheckBoxList cbList = new CheckBoxList();
JCheckBox check1 = new JCheckBox("One");
JCheckBox check2 = new JCheckBox("two");
JCheckBox[] myList = { check1, check2};
cbList.setListData(myList);
frame.getContentPane().add(cbList);
//Display the window.
frame.pack();
frame.setVisible(true);
}
public static void main(String[] args) {
//Schedule a job for the event-dispatching thread:
//creating and showing this application's GUI.
javax.swing.SwingUtilities.invokeLater(new Runnable() {
public void run() {
createAndShowGUI();
}
});
}
}
I have following code:
import java.awt.BorderLayout;
import java.awt.Dimension;
import java.util.Vector;
import javax.swing.JFrame;
import javax.swing.JScrollPane;
import javax.swing.JTable;
import javax.swing.SwingUtilities;
import javax.swing.UIManager;
import javax.swing.plaf.nimbus.NimbusLookAndFeel;
import javax.swing.table.DefaultTableModel;
public class NewClass1 extends JFrame {
private JTable table;
private JScrollPane scrollPane;
private DefaultTableModel defaultTableModel;
public NewClass1() {
setLocationByPlatform(true);
setLayout(new BorderLayout());
setPreferredSize(new Dimension(600, 400));
setTitle("Table Issues");
setDefaultCloseOperation(EXIT_ON_CLOSE);
createTableModel();
table = new JTable(defaultTableModel);
scrollPane = new JScrollPane(table);
getContentPane().add(scrollPane, BorderLayout.CENTER);
pack();
}
private void createTableModel() {
Vector cols = new Vector();
cols.add("A");
Vector rows = new Vector();
for (int i = 0; i < 50; i++) {
Vector row = new Vector();
row.add((i + 1) + "");
rows.add(row);
}
defaultTableModel = new DefaultTableModel(rows, cols) {
Class[] types = new Class[]{
String.class
};
#Override
public Class getColumnClass(int columnIndex) {
return types[columnIndex];
}
#Override
public boolean isCellEditable(int row, int column) {
return false;
}
};
}
public static void main(String[] args) {
try {
UIManager.setLookAndFeel(new NimbusLookAndFeel());
} catch (Exception e) {
}
final NewClass1 nc = new NewClass1();
SwingUtilities.invokeLater(new Runnable() {
public void run() {
nc.setVisible(true);
}
});
while (true) {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
int row = (int) (Math.random() * 50);
int move = (int) (Math.random() * 50);
nc.defaultTableModel.moveRow(row, row, move);
}
});
try{
Thread.sleep(1000);
}catch(Exception e){
}
}
}
}
Please run the above code and select row.
My problem is with row movement, row selection is not moving. It is staying at fixed position. Suppose I selected row with column value 25, selected row must be of column value 25 after row movements.
Please help me on this.
My real problem is, user will select row and clicks menu to perform action, meanwhile other threads may have moved rows, and performed action will be on other row than actual one.
The easiest way is to remember the selected row somewhere outside of the ListSelectionModel and adjust the selection whenever the TableModel changes. For example you could do this:
public class NewClass1 extends JFrame {
private JTable table;
private DefaultTableModel defaultTableModel;
private JScrollPane scrollPane;
private class SelectionHelper implements ListSelectionListener, TableModelListener {
private Object selectedRow;
#Override
public void valueChanged(ListSelectionEvent event) {
if (!event.getValueIsAdjusting()) return;
int selectedIndex = table.getSelectedRow();
if (selectedIndex >= 0) {
selectedRow = defaultTableModel.getDataVector().get(selectedIndex);
} else {
selectedRow = null;
}
}
#Override
public void tableChanged(TableModelEvent event) {
if (selectedRow == null) return;
int selectedIndex = defaultTableModel.getDataVector().indexOf(selectedRow);
table.getSelectionModel().setSelectionInterval(selectedIndex, selectedIndex);
}
}
public NewClass1() {
// ...
createTableModel();
table = new JTable(defaultTableModel);
table.setSelectionMode(ListSelectionModel.SINGLE_SELECTION);
SelectionHelper helper = new SelectionHelper();
table.getModel().addTableModelListener(helper);
table.getSelectionModel().addListSelectionListener(helper);
// ...
}
// ...
}
Note however, that you should adjust this code for production use, for example in regards to thread safety or portability (using the table and defaultTableModel attributes in the inner class is bad style).
I have a JList containing an ArrayList of custom objects and I'm trying to create a drag and drop into fields. I'm having trouble understanding how to package and receive the object in Transferable.
This is about as far as I've gotten:
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.event.*;
import java.util.*;
public class FlightProjectInterface extends JFrame{
//create GUI Objects
private JFrame primaryFrame;
private JPanel createFlightPanel;
private JPanel aircraftLayout;
private JList personsJList, personsOnFlightJList;
private JTextField pilotLabel, coPilotLabel, backseat1Label, backseat2Label;
public FlightProjectInterface(){
//establish frame
super("Create Flight");
setLayout( new FlowLayout());
//aircraftPanel
aircraftLayout = new JPanel();
aircraftLayout.setLayout(new GridLayout(2,2));
pilotLabel = new JTextField("Drag Pilot Here");
//build person load list
DefaultListModel listModel = new DefaultListModel();
for (Person person : Database.persons)
listModel.addElement(person);
personsJList = new JList(listModel);
personsJList.setVisibleRowCount(5);
personsJList.setSelectionMode(ListSelectionModel.SINGLE_SELECTION);
personsJList.setDragEnabled(true);
add( new JScrollPane(personsJList) );
aircraftLayout.add(pilotLabel);
add(aircraftLayout);
}//end constructor
}
Clarification: I'm having trouble taking the object selection from the JList and creating a Transferable out of it. With the code above, the toString representation of the object is simply pasted in the text field, so I'm not able to pull object data from the dropped location. How can I "package" the object itself and drop it into a placeholder that I can reference the object itself from the GUI?
Ideally, there would be 4 fields that each contains an object that can be dropped. The person would be removed from the list if they are dropped, but returned to the list if replaced.
Drag and Drop can be a complex beast, not made any easier by the conflicting information that's available. Personally, I like to avoid the Transfer API, but I'm old school like that.
The glue to DnD really is the DataFlavor. I prefer to roll my own, makes life a lot easier.
In this example, I've used a single TransferHandler, but realistically, you really should have one for dragging and one for dropping, in particular, you should have one for each component you want to drop onto.
The main reason for this is, I put a trap in my canImport method to reject it if your dragging over a JList, so you can only drop it on the JLabel, this is a little hack and probably not the best idea.
import java.awt.BorderLayout;
import java.awt.Component;
import java.awt.EventQueue;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.datatransfer.DataFlavor;
import java.awt.datatransfer.Transferable;
import java.awt.datatransfer.UnsupportedFlavorException;
import java.awt.dnd.DnDConstants;
import java.io.IOException;
import javax.swing.DefaultListModel;
import javax.swing.JComponent;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JList;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.TransferHandler;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
public class DnDTransferableTest {
public static void main(String[] args) {
new DnDTransferableTest();
}
public DnDTransferableTest() {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
}
JFrame frame = new JFrame("Testing");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setLayout(new BorderLayout());
frame.add(new TestPane());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
#SuppressWarnings("serial")
public class TestPane extends JPanel {
private JList<ListItem> list;
private JLabel label;
public TestPane() {
list = new JList<ListItem>();
list.setDragEnabled(true);
list.setTransferHandler(new ListTransferHandler());
DefaultListModel<ListItem> model = new DefaultListModel<ListItem>();
for (int index = 0; index < 10; index++) {
model.addElement(new ListItem("Item " + index));
}
list.setModel(model);
setLayout(new GridBagLayout());
GridBagConstraints gbc = new GridBagConstraints();
gbc.gridx = 0;
gbc.gridy = 0;
gbc.weighty = 1;
gbc.weightx = 1;
gbc.fill = GridBagConstraints.BOTH;
add(new JScrollPane(list), gbc);
label = new JLabel("Drag on me...");
gbc.gridx++;
gbc.weightx = 1;
gbc.fill = GridBagConstraints.NONE;
add(label, gbc);
label.setTransferHandler(new ListTransferHandler());
}
}
#SuppressWarnings("serial")
public class ListTransferHandler extends TransferHandler {
#Override
public boolean canImport(TransferSupport support) {
return (support.getComponent() instanceof JLabel) && support.isDataFlavorSupported(ListItemTransferable.LIST_ITEM_DATA_FLAVOR);
}
#Override
public boolean importData(TransferSupport support) {
boolean accept = false;
if (canImport(support)) {
try {
Transferable t = support.getTransferable();
Object value = t.getTransferData(ListItemTransferable.LIST_ITEM_DATA_FLAVOR);
if (value instanceof ListItem) {
Component component = support.getComponent();
if (component instanceof JLabel) {
((JLabel)component).setText(((ListItem)value).getText());
accept = true;
}
}
} catch (Exception exp) {
exp.printStackTrace();
}
}
return accept;
}
#Override
public int getSourceActions(JComponent c) {
return DnDConstants.ACTION_COPY_OR_MOVE;
}
#Override
protected Transferable createTransferable(JComponent c) {
Transferable t = null;
if (c instanceof JList) {
#SuppressWarnings("unchecked")
JList<ListItem> list = (JList<ListItem>) c;
Object value = list.getSelectedValue();
if (value instanceof ListItem) {
ListItem li = (ListItem) value;
t = new ListItemTransferable(li);
}
}
return t;
}
#Override
protected void exportDone(JComponent source, Transferable data, int action) {
System.out.println("ExportDone");
// Here you need to decide how to handle the completion of the transfer,
// should you remove the item from the list or not...
}
}
public static class ListItemTransferable implements Transferable {
public static final DataFlavor LIST_ITEM_DATA_FLAVOR = new DataFlavor(ListItem.class, "java/ListItem");
private ListItem listItem;
public ListItemTransferable(ListItem listItem) {
this.listItem = listItem;
}
#Override
public DataFlavor[] getTransferDataFlavors() {
return new DataFlavor[]{LIST_ITEM_DATA_FLAVOR};
}
#Override
public boolean isDataFlavorSupported(DataFlavor flavor) {
return flavor.equals(LIST_ITEM_DATA_FLAVOR);
}
#Override
public Object getTransferData(DataFlavor flavor) throws UnsupportedFlavorException, IOException {
return listItem;
}
}
public static class ListItem {
private String text;
public ListItem(String text) {
this.text = text;
}
public String getText() {
return text;
}
#Override
public String toString() {
return getText();
}
}
}