i am doing one project related to swings in this i am facing one problem like some 5 check boxes are there in this if i delete two non immediate check boxes (or) single check box i am able to delete but if i delete two immediate check boxes i am not able to delete i.e i have check boxes like 1,2,3,4,5 if i delete 1 and 3 , 1 and 4 , or 3 and 5 etc... (or) 1,2,3 etc.. if i delete using this combination i am able to delete but if i delete 1 and 2 or 2 and 3 or
4 and 5 like immediate check boxes i am not able to delete i am new to swings i don't no what's happening wrong and where. when i am searching for the answer i found this link
Deleting check boxes
The same program i am using the different approach, Here i am creating my own custom classes here my program:
import java.awt.*;
import java.util.*;
import javax.swing.*;
#SuppressWarnings("serial")
public class ListModels extends JDialog {
#SuppressWarnings("rawtypes")
private JList list;
private JPanel rightPanel;
JButton cancel = new JButton("Cancel");
JButton delbtn = new JButton("Delete");
public ListModels() {
createList();
createButtons();
initUI();
}
public ListModels(List<String> values) {
}
#SuppressWarnings({ "unchecked", "rawtypes" })
private void createList() {
myModel mModel = new myModel(new CheckListItem[] {
new CheckListItem("78"), new CheckListItem("79"),
new CheckListItem("80"), new CheckListItem("81"),
new CheckListItem("82") });
list = new JList(mModel);
list.setCellRenderer(new CheckListRenderer());
list.setSelectionMode(ListSelectionModel.SINGLE_SELECTION);
list.addMouseListener(new MouseAdapter() {
public void mouseClicked(MouseEvent event) {
JList list = (JList) event.getSource();
// Get index of item clicked
int index = list.locationToIndex(event.getPoint());
CheckListItem item = (CheckListItem) list.getModel()
.getElementAt(index);
if (item.isSelected) {
System.out.println("i am selected ");
}
// Toggle selected state
item.setSelected(!item.isSelected());
// Repaint cell
list.repaint(list.getCellBounds(index, index));
}
});
}
private void createButtons() {
rightPanel = new JPanel();
// JButton cancel = new JButton("Cancel");
cancel.setMaximumSize(cancel.getMaximumSize());
// JButton delbtn = new JButton("Delete");
delbtn.setMaximumSize(cancel.getMaximumSize());
// Cancel button
cancel.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent event) {
System.exit(0);
}
});
// Cancel
delbtn.addActionListener(new ActionListener() {
#SuppressWarnings("rawtypes")
public void actionPerformed(ActionEvent event) {
// CheckListItem item = (CheckListItem)
// list.getModel().getElementAt(index);
int dialogButton = JOptionPane.YES_NO_OPTION;
int dialogResult = JOptionPane.showConfirmDialog(null,
"Are you sure you want to delete the selected map",
"Delete", dialogButton);
myModel mModel = (myModel) list.getModel();
ListModel currentModel = list.getModel();
for (int i = 0; i < mModel.getSize(); i++) {
CheckListItem item = (CheckListItem) mModel.getElementAt(i);
if(!item.isSelected)
{
System.out.println("i am in not selected item "+item);
}
else if (item.isSelected()) {
System.out.println("i am selected item "+item);
if (dialogResult == JOptionPane.YES_OPTION) {
// Location loc=(Location) mModel.getElementAt(i);
mModel.removeAt(i);
mModel.fireIntervalRemoved(this, i,mModel.getSize());
}
}
}
}
});
// JPanel buttonPane = new JPanel();
rightPanel.setLayout(new BoxLayout(rightPanel, BoxLayout.LINE_AXIS));
rightPanel.setBorder(BorderFactory.createEmptyBorder(0, 4, 4, 4));
rightPanel.add(Box.createHorizontalStrut(60));
rightPanel.add(delbtn);
rightPanel.add(Box.createRigidArea(new Dimension(10, 0)));
rightPanel.add(cancel);
}
private void initUI() {
// JScroll Panel
JScrollPane listScroller = new JScrollPane(list);
listScroller.setPreferredSize(new Dimension(250, 80));
listScroller.setAlignmentX(LEFT_ALIGNMENT);
// Lay out the label and scroll pane from top to bottom.
JPanel listPane = new JPanel();
listPane.setLayout(new BoxLayout(listPane, BoxLayout.PAGE_AXIS));
// Add all to the panel
listPane.add(Box.createRigidArea(new Dimension(0, 5)));
listPane.add(listScroller);
listPane.setBorder(BorderFactory.createEmptyBorder(10, 10, 10, 10));
// Lay out the buttons from left to right.
JPanel buttonPane = new JPanel();
buttonPane.setLayout(new BoxLayout(buttonPane, BoxLayout.LINE_AXIS));
buttonPane.setBorder(BorderFactory.createEmptyBorder(0, 10, 10, 10));
buttonPane.add(Box.createHorizontalStrut(60));
buttonPane.add(delbtn);
buttonPane.add(Box.createRigidArea(new Dimension(10, 0)));
buttonPane.add(cancel);
listPane.add(buttonPane);
// Put everything together, using the content pane's BorderLayout.
Container contentPane = getContentPane();
contentPane.add(listPane, BorderLayout.CENTER);
contentPane.add(buttonPane, BorderLayout.PAGE_END);
add(listPane);
add(listPane);
setTitle("Delete Map");
setSize(300, 250);
setLocationRelativeTo(null);
}
class CheckListItem {
private String label;
private boolean isSelected = false;
public CheckListItem(String label) {
this.label = label;
}
public boolean isSelected() {
return isSelected;
}
public void setSelected(boolean isSelected) {
this.isSelected = isSelected;
}
public String toString() {
return label;
}
}
#SuppressWarnings({ "rawtypes" })
class CheckListRenderer extends JCheckBox implements ListCellRenderer {
public Component getListCellRendererComponent(JList list, Object value,
int index, boolean isSelected, boolean hasFocus) {
setEnabled(list.isEnabled());
setSelected(((CheckListItem) value).isSelected());
setFont(list.getFont());
setBackground(list.getBackground());
setForeground(list.getForeground());
setText(value.toString());
return this;
}
}
class myModel extends AbstractListModel<CheckListItem> {
private List<CheckListItem> items;
public myModel(CheckListItem[] items) {
super();
this.items = new ArrayList<ListModels.CheckListItem>();
for (CheckListItem item : items) {
this.items.add(item);
}
}
/*
* #Override protected void fireContentsChanged(Object Source, int
* index0, int index1) { super.fireContentsChanged(Source, index0,
* index1); }
*/
#Override
public CheckListItem getElementAt(int index) {
return items.get(index);
}
#Override
protected void fireIntervalRemoved(Object Source, int index0, int index1) {
// TODO Auto-generated method stub
super.fireIntervalRemoved(Source, index0, index1);
}
#Override
public int getSize() {
return items.size();
}
public void removeAt(int item) {
items.remove(item);
}
public void addAt(int index, CheckListItem item) {
items.set(index, item);
}
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
#Override
public void run() {
List<String> values = new ArrayList<String>();
values.addAll(newList);
ListModels ex = new ListModels();
ex.setVisible(true);
}
});
}
}
Finally in this program i am loading the check boxes through my custom class directly giving numbers ,I want to call this class from my main method and pass the numbers through Array list or array. Any HELP IS WELCOME and THANKS.
for (int i = 0; i < mModel.getSize(); i++)
You need to start at the end of the list and work backwards:
for (int i = mModel.getSize() - 1; i >=0; i--)
because if you start at 0, all the rows will shift down by one when the row is removed.
Related
I'm very new to programming, and I can't add JCheckbox to the JList. There is no error but nothing is displayed.
JFrame f=new JFrame();
String[] labels={"a","b","c","d","e"};
JCheckBox[] ch=new JCheckBox[labels.length];
JList list=new JList();
for (int i = 0; i < labels.length; i++) {
ch[i]=new JCheckBox("CheckBox"+i);
list.add(ch[i]);
}
JScrollPane pane=new JScrollPane(list);
f.add(pane);
f.setVisible(true);
As an alternative to the JTable solution that trashgod posted, you can also create the appearance of JCheckBoxes in a JList by:
Use a custom renderer for your JList that will show each item as a JCheckBox
Use a custom object in your JList that maintains it's boolean "checked" state
Add a MouseListener to the JList that will set/unset the checked state of each item.
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.border.*;
public class JCheckBoxListDemo implements Runnable
{
private JList jlist;
public static void main(String args[])
{
SwingUtilities.invokeLater(new JCheckBoxListDemo());
}
public void run()
{
Object[] items = new CheckListItem[] {
new CheckListItem("Apple"),
new CheckListItem("Banana"),
new CheckListItem("Carrot"),
new CheckListItem("Date"),
new CheckListItem("Eggplant"),
new CheckListItem("Fig"),
new CheckListItem("Guava"),
};
jlist = new JList(items);
jlist.setCellRenderer(new CheckBoxListRenderer());
jlist.setSelectionMode(ListSelectionModel.SINGLE_SELECTION);
jlist.setVisibleRowCount(5);
jlist.addMouseListener(new MouseAdapter()
{
#Override
public void mouseClicked(MouseEvent event)
{
selectItem(event.getPoint());
}
});
KeyStroke keyStroke = KeyStroke.getKeyStroke(KeyEvent.VK_SPACE, 0);
Object mapKey = keyStroke.toString();
jlist.getInputMap().put(keyStroke, mapKey);
jlist.getActionMap().put(mapKey, new AbstractAction()
{
public void actionPerformed(ActionEvent event)
{
toggleSelectedItem();
}
});
JFrame frame = new JFrame();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.getContentPane().add(new JScrollPane(jlist));
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
private void selectItem(Point point)
{
int index = jlist.locationToIndex(point);
if (index >= 0)
{
CheckListItem item = (CheckListItem)jlist.getModel().getElementAt(index);
item.setSelected(!item.isSelected());
jlist.repaint(jlist.getCellBounds(index, index));
}
}
private void toggleSelectedItem()
{
int index = jlist.getSelectedIndex();
if (index >= 0)
{
CheckListItem item = (CheckListItem)jlist.getModel().getElementAt(index);
item.setSelected(!item.isSelected());
jlist.repaint(jlist.getCellBounds(index, index));
}
}
private class CheckListItem
{
private Object item;
private boolean selected;
public CheckListItem(Object item)
{
this.item = item;
}
#SuppressWarnings("unused")
public Object getItem()
{
return item;
}
public boolean isSelected()
{
return selected;
}
public void setSelected(boolean isSelected)
{
this.selected = isSelected;
}
#Override
public String toString()
{
return item.toString();
}
}
private class CheckBoxListRenderer extends JCheckBox
implements ListCellRenderer
{
public Component getListCellRendererComponent(JList comp, Object value,
int index, boolean isSelected, boolean hasFocus)
{
setEnabled(comp.isEnabled());
setSelected(((CheckListItem) value).isSelected());
setFont(comp.getFont());
setText(value.toString());
if (isSelected)
{
setBackground(comp.getSelectionBackground());
setForeground(comp.getSelectionForeground());
}
else
{
setBackground(comp.getBackground());
setForeground(comp.getForeground());
}
return this;
}
}
}
A JList renderer can draw a checkbox, but JList does not support a cell editor. Instead, consider a one-column JTable. The default renderer & editor for a column of type Boolean.class is a JCheckBox, for example.
Here is what you might be looking for:
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
class CheckBo
{
public static void main(String[] args)
{
JFrame f=new JFrame();
String[]labels={"a","b","c","d","e"};
JCheckBox[]ch=new JCheckBox[labels.length];
final DefaultListModel model = new DefaultListModel();
JList list=new JList(model);
list.setCellRenderer(new CheckListRenderer());
for (int i = 0; i < labels.length; i++) {
//ch[i]=new JCheckBox("CheckBox"+i);
model.addElement(new CheckListItem("CheckBox"+i));
}
JScrollPane pane=new JScrollPane(list);
list.addMouseListener(new MouseAdapter()
{
public void mouseClicked(MouseEvent event)
{
JList list = (JList) event.getSource();
// Get index of item clicked
int index = list.locationToIndex(event.getPoint());
CheckListItem item = (CheckListItem)
list.getModel().getElementAt(index);
// Toggle selected state
item.setSelected(! item.isSelected());
// Repaint cell
list.repaint(list.getCellBounds(index, index));
}
});
f.add(pane);
f.pack();
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
f.setVisible(true);
}
static class CheckListItem
{
private String label;
private boolean isSelected = false;
public CheckListItem(String label)
{
this.label = label;
}
public boolean isSelected()
{
return isSelected;
}
public void setSelected(boolean isSelected)
{
this.isSelected = isSelected;
}
public String toString()
{
return label;
}
}
static class CheckListRenderer extends JCheckBox implements ListCellRenderer
{
public Component getListCellRendererComponent(JList list, Object value, int index,boolean isSelected, boolean hasFocus)
{
setEnabled(list.isEnabled());
setSelected(((CheckListItem)value).isSelected());
setFont(list.getFont());
setBackground(list.getBackground());
setForeground(list.getForeground());
setText(value.toString());
return this;
}
}
}
Source for above code is this
This is homework. I included relevant code at the bottom.
Problem:
In an attempted to allow the user to resize the grid, the grid is now being drawn severely overpopuated.
Screen Shots:
"Overpopulation" -
http://i.imgur.com/zshAC6n.png
"Desired Population" -
http://i.imgur.com/5Rf6P42.png
Background:
It's a version of Conway's Game of Life. In class we completed 3 classes: LifeState which handles the game logic, LifePanel which is a JPanel that contains the game, and a driver that created a JFrame and added the LifePanel. The assignment was to develop it into a full GUI application with various requirements. My solution was to extend JFrame and do most of my work in that class.
Initializing the LifePanel outside of the actionlistener yields normal population, but intializing the LifePanel in the actionlistener "overpopulates" the grid.
Question: Why is the overpopulation occurring?
LifePanel class
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.util.Random;
public class LifePanel extends JPanel implements MouseListener
{
private int row;
private int col;
private int scale;
private LifeState life;
boolean state;
boolean wrap;
int delay;
Timer timer;
public LifePanel(int r, int c, int s, int d)
{
row = r;
col = c;
scale = s;
delay = d;
life = new LifeState(row,col);
Random rnd = new Random();
for(int i=0;i<row;i++)
for(int j=0;j<col;j++)
life.setCell(i,j,rnd.nextBoolean());
timer = new Timer(delay, new UpdateListener());
setPreferredSize( new Dimension(scale*row, scale*col));
addMouseListener(this);
timer.start();
}
public void paintComponent(Graphics g)
{
super.paintComponent(g);
for(int i=0;i<row;i++)
for(int j=0;j<col;j++)
if(life.getCell(i,j))
g.fillRect(scale*i,scale*j,scale,scale);
}
public int getRow() {
return row;
}
public void setRow(int row) {
this.row = row;
}
public int getCol() {
return col;
}
public void setCol(int col) {
this.col = col;
}
public int getScale() {
return scale;
}
public void setScale(int scale) {
this.scale = scale;
}
public int getDelay() {
return delay;
}
public void setDelay(int delay) {
this.delay = delay;
timer.setDelay(delay);
}
public void pauseGame(){
timer.stop();
}
public void playGame(){
timer.restart();
}
public void setInitState(boolean set){
state = set;
if(state){
timer.stop();
}
}
public void setWrap(boolean set){
wrap = set;
if(wrap){
//implement allow wrap
}
}
#Override
public void mouseClicked(MouseEvent e) {
if(state){
int x=e.getX();
int y=e.getY();
boolean isFilled;
isFilled = life.getCell(x,y);
//Test pop-up
JOptionPane.showMessageDialog(this, x+","+y+"\n"+life.getCell(x,y));
if(isFilled){
life.setCell(x,y,false);
}else{
life.setCell(x,y,true);
}
repaint();
}
}
#Override
public void mousePressed(MouseEvent e) {}
#Override
public void mouseReleased(MouseEvent e) {}
#Override
public void mouseEntered(MouseEvent e) {}
#Override
public void mouseExited(MouseEvent e) {}
private class UpdateListener implements ActionListener
{
public void actionPerformed(ActionEvent e)
{
life.iterate();
repaint();
}
}
}
LifeFrame class
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
public class LifeFrame extends JFrame implements ActionListener{
JMenuBar menuBar;
JMenu mainMenu, helpMenu;
JMenuItem restartItem, quitItem, helpItem;
JButton stopButton, playButton, pauseButton, startButton;
CardLayout cardLayout = new MyCardLayout();
CardLayout cardLayout2 = new MyCardLayout();
SetupPanel setupPanel; //panel for input
LifePanel gamePanel; //game panel
JPanel controls = new JPanel(); //controls for game
JPanel controls2 = new JPanel(); //controls for input panel
JPanel cardPanel = new JPanel(cardLayout);
JPanel cardPanel2 = new JPanel(cardLayout2);
int gridRow=480;
int gridCol=480;
int scale=1;
int delay=2;
boolean setState = false;
boolean setWrap = false;
public LifeFrame() {
setTitle("Game of Life");
setLayout(new BorderLayout());
//Add the Panels
setupPanel = new SetupPanel();
gamePanel = new LifePanel(gridRow,gridCol,scale,delay);
cardPanel.add(setupPanel, "1");
cardPanel.add(gamePanel, "2");
add(cardPanel, BorderLayout.NORTH);
cardPanel2.add(controls2, "1");
cardPanel2.add(controls, "2");
add(cardPanel2, BorderLayout.SOUTH);
//init menu
menuBar = new JMenuBar();
//button listener setup
stopButton = new JButton("Stop");
pauseButton = new JButton("Pause");
playButton = new JButton("Play");
startButton = new JButton("Start");
stopButton.addActionListener(this);
pauseButton.addActionListener(this);
playButton.addActionListener(this);
startButton.addActionListener(this);
//menu listener setup
restartItem = new JMenuItem("Restart", KeyEvent.VK_R);
quitItem = new JMenuItem("Quit", KeyEvent.VK_Q);
helpItem = new JMenuItem("Help", KeyEvent.VK_H);
restartItem.addActionListener(this);
quitItem.addActionListener(this);
helpItem.addActionListener(this);
//add buttons
controls.add(stopButton);
controls.add(pauseButton);
controls.add(playButton);
controls2.add(startButton);
//build the menus
mainMenu = new JMenu("Menu");
mainMenu.setMnemonic(KeyEvent.VK_M);
helpMenu = new JMenu("Help");
helpMenu.setMnemonic(KeyEvent.VK_H);
menuBar.add(mainMenu);
menuBar.add(helpMenu);
setJMenuBar(menuBar);
//add JMenuItems
restartItem.getAccessibleContext().setAccessibleDescription("Return to setup screen");
mainMenu.add(restartItem);
mainMenu.add(quitItem);
helpMenu.add(helpItem);
this.addWindowListener(new WindowAdapter(){
public void windowClosing(WindowEvent e){
System.exit(0);
}
});
pack();
setLocationRelativeTo(null);
setVisible(true);
setDefaultCloseOperation(EXIT_ON_CLOSE);
}
#Override
public void actionPerformed(ActionEvent e) {
try{
gridRow = setupPanel.getRowSize();
gridCol = setupPanel.getColSize();
scale = setupPanel.getScale();
delay = setupPanel.getDelay();
setWrap = setupPanel.getSetWrap();
setState = setupPanel.getSetState();
}catch (NumberFormatException n){
JOptionPane.showMessageDialog(LifeFrame.this, "Make sure the fields contain only digits and are completed!");
return;
}
if(e.getSource() == pauseButton){
gamePanel.pauseGame();
}else if(e.getSource() == playButton){
gamePanel.playGame();
}else if(e.getSource() == quitItem){
System.exit(0);
}else if(e.getSource() == restartItem || e.getSource() == stopButton){
cardLayout.show(cardPanel, "1");
cardLayout2.show(cardPanel2, "1");
pack();
setLocationRelativeTo(null);
}else if(e.getSource() == helpItem){
String helpText = "Help\nPlease make sure every field is completed and contains only digits\nCurrent Stats:\nGrid Size: "+gamePanel.getRow()+" by "+gamePanel.getCol()+"\nScale: "+ gamePanel.getScale() +"\nDelay: "+gamePanel.getDelay()+"\nManual Initial State: "+setState+"\nEnable Wrapping: "+setWrap;
JOptionPane.showMessageDialog(LifeFrame.this, helpText);
}else if(e.getSource() == startButton){
gamePanel = new LifePanel(gridRow,gridCol,scale,delay);
cardPanel.add(gamePanel, "2");
/*
* Alternate solution, throws array index out of bounds due to array usage in the LifePanel, but properly
* populates the grid.
*
gamePanel.setRow(gridRow);
gamePanel.setCol(gridCol);
gamePanel.setScale(scale);
gamePanel.setDelay(delay);
*/
if(setWrap){
gamePanel.setWrap(true);
gamePanel.playGame();
}else if(setState){
gamePanel.setInitState(true);
}else{
gamePanel.setWrap(false);
gamePanel.setInitState(false);
gamePanel.playGame();
}
gamePanel.repaint();
cardLayout.show(cardPanel, "2");
cardLayout2.show(cardPanel2, "2");
pack();
setLocationRelativeTo(null);
}
}
public static class MyCardLayout extends CardLayout {
#Override
public Dimension preferredLayoutSize(Container parent) {
Component current = findCurrentComponent(parent);
if (current != null) {
Insets insets = parent.getInsets();
Dimension pref = current.getPreferredSize();
pref.width += insets.left + insets.right;
pref.height += insets.top + insets.bottom;
return pref;
}
return super.preferredLayoutSize(parent);
}
public Component findCurrentComponent(Container parent) {
for (Component comp : parent.getComponents()) {
if (comp.isVisible()) {
return comp;
}
}
return null;
}
}
}
Thanks for reading all this, and in advance for any help/advice you offer.
EDIT: Added screen shots and refined question.
Based on how you initialize LifePanel
Random rnd = new Random();
for(int i=0;i<row;i++)
for(int j=0;j<col;j++)
life.setCell(i,j,rnd.nextBoolean());
what you call "overpopulation" is the expected state. The above code will set about 1/2 of the cells to "alive" (or "occupied"), which is what your "overpopulated" state looks like.
The "desired population" screenshot contains many "life" artifacts such as "beehives", "gliders", "traffic lights", etc, and was either manually constructed or is the result of running several iterations on an initially 50% random population. With a 50% occupied population the first generation will result in wholesale clearing ("death") of many, many cells due to the proximity rules.
Most crucially, consider that, when starting up, your program does not paint the initial configuration. At least one iteration occurs before the first repaint() call.
I don't think your code is broken at all, just your expectation for what the initial population looks like.
I need a Jtable having Add Button on the header.When add is clicked..then it must add a row containing 4 columns of 3 textfields and delete button. When delete button is clicked, then the corresponding row should deleted.. Thanks in advance..
public class UserTableInfo {
private JFrame frame;
private JTable CompTable = null;
private PanelTableModel CompModel = null;
private JButton delButton=null;
private JButton button=null;
public static void main(String args[]) {
try {
UIManager.setLookAndFeel("com.sun.java.swing.plaf.nimbus.NimbusLookAndFeel");
} catch (Exception fail) {
}
SwingUtilities.invokeLater(new Runnable() {
#Override
public void run() {
new UserTableInfo().makeUI();
}
}); }
public void makeUI() {
CompTable = CreateCompTable();
JScrollPane CompTableScrollpane = new JScrollPane(CompTable,
JScrollPane.VERTICAL_SCROLLBAR_AS_NEEDED,
JScrollPane.HORIZONTAL_SCROLLBAR_NEVER);
JPanel bottomPanel = CreateBottomPanel();
frame = new JFrame("Comp Table Test");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(CompTableScrollpane, BorderLayout.CENTER);
frame.add(bottomPanel, BorderLayout.SOUTH);
frame.setPreferredSize(new Dimension(800, 400));
frame.setLocation(150, 150);
frame.pack();
frame.setVisible(true);
}public JTable CreateCompTable() {
CompModel = new PanelTableModel();
button=new JButton("Add Row");
button.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
CompModel.addRow();
}
});
JTable table = new JTable(CompModel);
table.setRowHeight(new CompCellPanel().getPreferredSize().height);
JTableHeader header = table.getTableHeader();
header.setLayout(new FlowLayout(FlowLayout.TRAILING, 5, 0));
header.add(button);
PanelCellEditorRenderer PanelCellEditorRenderer = new
PanelCellEditorRenderer();
table.setDefaultRenderer(Object.class, PanelCellEditorRenderer);
table.setDefaultEditor(Object.class, PanelCellEditorRenderer);
return table;
} public JPanel CreateBottomPanel() {
delButton=new JButton("Exit");
delButton.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent ae) {
Object source = ae.getSource();
if (source == delButton) {
System.exit(1);
}
}
}); JPanel panel = new JPanel(new GridBagLayout());
panel.add(delButton);
return panel;
}
}
class PanelCellEditorRenderer extends AbstractCellEditor implements
TableCellRenderer, TableCellEditor {
private static final long serialVersionUID = 1L;
private CompCellPanel renderer = new CompCellPanel();
private CompCellPanel editor = new CompCellPanel();
#Override
public Component getTableCellRendererComponent(JTable table, Object
value, boolean isSelected, boolean hasFocus, int row, int column) {
renderer.setComp((Comp) value);
return renderer;
}
#Override
public Component getTableCellEditorComponent(JTable table, Object
value, boolean isSelected, int row, int column) {
editor.setComp((Comp) value);
return editor;
}
#Override
public Object getCellEditorValue() {
return null;
}
#Override
public boolean isCellEditable(EventObject anEvent) {
return true;
}
#Override
public boolean shouldSelectCell(EventObject anEvent) {
return false;
}
}
class PanelTableModel extends DefaultTableModel {
private static final long serialVersionUID = 1L;
#Override
public int getColumnCount() {
return 1;
}
public void addRow() {
super.addRow(new Object[]{new Comp("")});
}
}
class Comp {
public String upper;
public Comp(String upper) {
this.upper = upper;
}
}
class CompCellPanel extends JPanel {
private static final long serialVersionUID = 1L;
private JLabel label = new JLabel();
private JTextField upperField = new JTextField();
private JButton removeButton = new JButton("remove");
CompCellPanel() {
setLayout(new BoxLayout(this, BoxLayout.X_AXIS));
removeButton.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
JTable table = (JTable)
SwingUtilities.getAncestorOfClass(JTable.class, (Component) e.getSource());
int row = table.getEditingRow();
table.getCellEditor().stopCellEditing();
((DefaultTableModel) table.getModel()).removeRow(row);
} });
upperField.setMaximumSize(new Dimension(Integer.MAX_VALUE, upperField.getPreferredSize().height) );
add(upperField);
label.setMaximumSize(getMaximumSize());
add(label);
add(Box.createHorizontalStrut(10));
add(removeButton);
}
public void setComp(Comp Comp) {
upperField.setText(Comp.upper);
} }
This is much easier if you extend a AbstractTableModel and use that to display your data. You can make an ArrayList of your data and add/remove from that. The TableModel will update the Table automatically when the ArrayList is changed. The ArrayList contains a class which has all the data that you would have in a row. See the Java Tutorials example from Oracle: http://docs.oracle.com/javase/tutorial/displayCode.html?code=http://docs.oracle.com/javase/tutorial/uiswing/examples/components/TableDemoProject/src/components/TableDemo.java
For custom cells, you can detect from the TableModel which column the cell is in and update its content accordingly.
I'm adding a string to a JList with DefaultListModel and it takes seconds to appear. Sometimes, I may have to click on the JList to have the list appear.
I'm using Eclipse Indigo. When I set a breakpoint after adding the element to JList, execution is fast.
I searched the web and SO for JList slow and they all talk about adding many items to the list. I'm adding the first element to the list.
Here's my code fragments:
private DefaultListModel function_list_model = new DefaultListModel();
private JList list_functions = new JList(function_list_model);
//...
// Initialization code:
JPanel panel_function_list = new JPanel();
panel_function_list.setBounds(10, 53, 541, 220);
panel_functions.add(panel_function_list);
panel_function_list.setLayout(null);
JLabel lblFunctions = new JLabel("Functions");
lblFunctions.setHorizontalAlignment(SwingConstants.CENTER);
lblFunctions.setBounds(235, 11, 99, 14);
panel_function_list.add(lblFunctions);
list_functions.setBorder(new LineBorder(new Color(0, 0, 0)));
list_functions.setBounds(10, 42, 492, 177);
list_functions.setFont(new Font("Courier New", Font.PLAIN, 12));
list_functions.setPreferredSize(new Dimension(0, 150));
list_functions.setMinimumSize(new Dimension(32767, 100));
list_functions.setMaximumSize(new Dimension(32767, 100));
JScrollPane scrollPane_functions = new JScrollPane(list_functions);
scrollPane_functions.setBounds(10, 79, 541, 183);
panel_functions.add(scrollPane_functions);
// Code to add a string:
String burger = new String("burger");
function_list_model.addElement(burger);
I'm also using WindowBuilder with Eclipse.
So how do I improve the performance of JList?
if you want I can to generating new Item from Char[] and to call doClick() for JButton("Fire")
import java.awt.*;
import java.awt.event.*;
import java.util.Date;
import javax.swing.*;
import javax.swing.event.*;
public class ListDemo extends JPanel implements ListSelectionListener {
private JList list;
private DefaultListModel listModel;
private static final String hireString = "Hire";
private static final String fireString = "Fire";
private JButton fireButton;
private JTextField employeeName;
private javax.swing.Timer timer = null;
private int delay = 3;
private int count = 0;
public ListDemo() {
super(new BorderLayout());
listModel = new DefaultListModel();
listModel.addElement("Jane Doe");
listModel.addElement("John Smith");
listModel.addElement("Kathy Green");
list = new JList(listModel);
list.setSelectionMode(ListSelectionModel.SINGLE_SELECTION);
list.setSelectedIndex(0);
list.addListSelectionListener(this);
list.setVisibleRowCount(5);
JScrollPane listScrollPane = new JScrollPane(list);
JButton hireButton = new JButton(hireString);
HireListener hireListener = new HireListener(hireButton);
hireButton.setActionCommand(hireString);
hireButton.addActionListener(hireListener);
hireButton.setEnabled(false);
fireButton = new JButton(fireString);
fireButton.setActionCommand(fireString);
fireButton.addActionListener(new FireListener());
employeeName = new JTextField(10);
employeeName.addActionListener(hireListener);
employeeName.getDocument().addDocumentListener(hireListener);
String name = listModel.getElementAt(list.getSelectedIndex()).toString();
JPanel buttonPane = new JPanel();
buttonPane.setLayout(new BoxLayout(buttonPane, BoxLayout.LINE_AXIS));
buttonPane.add(fireButton);
buttonPane.add(Box.createHorizontalStrut(5));
buttonPane.add(new JSeparator(SwingConstants.VERTICAL));
buttonPane.add(Box.createHorizontalStrut(5));
buttonPane.add(employeeName);
buttonPane.add(hireButton);
buttonPane.setBorder(BorderFactory.createEmptyBorder(5, 5, 5, 5));
add(listScrollPane, BorderLayout.CENTER);
add(buttonPane, BorderLayout.PAGE_END);
start();
System.out.println(new Date());
}
private void start() {
timer = new javax.swing.Timer(delay * 10, updateCol());
timer.start();
}
public Action updateCol() {
return new AbstractAction("text load action") {
private static final long serialVersionUID = 1L;
#Override
public void actionPerformed(ActionEvent e) {
listModel.addElement("Jane Doe");
listModel.addElement("John Smith");
listModel.addElement("Kathy Green");
list.ensureIndexIsVisible(listModel.getSize()-1);
count++;
if (count >= 500) {
timer.stop();
System.out.println("update cycle completed");
System.out.println(new Date());
}
}
};
}
class FireListener implements ActionListener {
#Override
public void actionPerformed(ActionEvent e) {
int index = list.getSelectedIndex();
listModel.remove(index);
int size = listModel.getSize();
if (size == 0) { //Nobody's left, disable firing.
fireButton.setEnabled(false);
} else { //Select an index.
if (index == listModel.getSize()) {
index--;
}
list.setSelectedIndex(index);
list.ensureIndexIsVisible(index);
}
}
}
class HireListener implements ActionListener, DocumentListener {
private boolean alreadyEnabled = false;
private JButton button;
HireListener(JButton button) {
this.button = button;
}
#Override
public void actionPerformed(ActionEvent e) {
String name = employeeName.getText();
if (name.isEmpty() || alreadyInList(name)) {
Toolkit.getDefaultToolkit().beep();
employeeName.requestFocusInWindow();
employeeName.selectAll();
return;
}
int index = list.getSelectedIndex(); //get selected index
if (index == -1) { //no selection, so insert at beginning
index = 0;
} else { //add after the selected item
index++;
}
listModel.insertElementAt(employeeName.getText(), index);
//listModel.addElement(employeeName.getText());
employeeName.requestFocusInWindow();
employeeName.setText("");
list.setSelectedIndex(index);
list.ensureIndexIsVisible(index);
}
protected boolean alreadyInList(String name) {
return listModel.contains(name);
}
#Override
public void insertUpdate(DocumentEvent e) {
enableButton();
}
#Override
public void removeUpdate(DocumentEvent e) {
handleEmptyTextField(e);
}
#Override
public void changedUpdate(DocumentEvent e) {
if (!handleEmptyTextField(e)) {
enableButton();
}
}
private void enableButton() {
if (!alreadyEnabled) {
button.setEnabled(true);
}
}
private boolean handleEmptyTextField(DocumentEvent e) {
if (e.getDocument().getLength() <= 0) {
button.setEnabled(false);
alreadyEnabled = false;
return true;
}
return false;
}
}
#Override
public void valueChanged(ListSelectionEvent e) {
if (e.getValueIsAdjusting() == false) {
if (list.getSelectedIndex() == -1) {
fireButton.setEnabled(false);
} else {
fireButton.setEnabled(true);
}
}
}
private static void createAndShowGUI() {
JFrame frame = new JFrame("ListDemo");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
JComponent newContentPane = new ListDemo();
newContentPane.setOpaque(true);
frame.setContentPane(newContentPane);
frame.pack();
frame.setVisible(true);
}
public static void main(String[] args) {
javax.swing.SwingUtilities.invokeLater(new Runnable() {
#Override
public void run() {
createAndShowGUI();
}
});
}
}
I'm trying to create a form with a JList and a button
What I want to do, is select an item from the JList, and then press the button to perform an action dependant on the selection. However, as soon as the button is clicked, the JList loses focus, and the selection disappears, making the button unable to determine what element was selected in the JList.
Is there a solution to this?
Thanks in advance :)
I can't see any issue with example from Oracle JList tutorial
have look at ListSelectionListener
maybe carefully with SelectionModes
can you please to describe whats is your goal
code example
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.event.*;
public class ListDemo extends JPanel implements ListSelectionListener {
private JList list;
private DefaultListModel listModel;
private static final String hireString = "Hire";
private static final String fireString = "Fire";
private JButton fireButton;
private JTextField employeeName;
public ListDemo() {
super(new BorderLayout());
listModel = new DefaultListModel();
listModel.addElement("Jane Doe");
listModel.addElement("John Smith");
listModel.addElement("Kathy Green");
list = new JList(listModel);
list.setSelectionMode(ListSelectionModel.SINGLE_SELECTION);
list.setSelectedIndex(0);
list.addListSelectionListener(this);
list.setVisibleRowCount(5);
JScrollPane listScrollPane = new JScrollPane(list);
JButton hireButton = new JButton(hireString);
HireListener hireListener = new HireListener(hireButton);
hireButton.setActionCommand(hireString);
hireButton.addActionListener(hireListener);
hireButton.setEnabled(false);
fireButton = new JButton(fireString);
fireButton.setActionCommand(fireString);
fireButton.addActionListener(new FireListener());
employeeName = new JTextField(10);
employeeName.addActionListener(hireListener);
employeeName.getDocument().addDocumentListener(hireListener);
String name = listModel.getElementAt(list.getSelectedIndex()).toString();
JPanel buttonPane = new JPanel();
buttonPane.setLayout(new BoxLayout(buttonPane, BoxLayout.LINE_AXIS));
buttonPane.add(fireButton);
buttonPane.add(Box.createHorizontalStrut(5));
buttonPane.add(new JSeparator(SwingConstants.VERTICAL));
buttonPane.add(Box.createHorizontalStrut(5));
buttonPane.add(employeeName);
buttonPane.add(hireButton);
buttonPane.setBorder(BorderFactory.createEmptyBorder(5, 5, 5, 5));
add(listScrollPane, BorderLayout.CENTER);
add(buttonPane, BorderLayout.PAGE_END);
}
class FireListener implements ActionListener {
public void actionPerformed(ActionEvent e) {
int index = list.getSelectedIndex();
listModel.remove(index);
int size = listModel.getSize();
if (size == 0) { //Nobody's left, disable firing.
fireButton.setEnabled(false);
} else { //Select an index.
if (index == listModel.getSize()) {
index--;
}
list.setSelectedIndex(index);
list.ensureIndexIsVisible(index);
}
}
}
class HireListener implements ActionListener, DocumentListener {
private boolean alreadyEnabled = false;
private JButton button;
public HireListener(JButton button) {
this.button = button;
}
public void actionPerformed(ActionEvent e) {
String name = employeeName.getText();
if (name.equals("") || alreadyInList(name)) {
Toolkit.getDefaultToolkit().beep();
employeeName.requestFocusInWindow();
employeeName.selectAll();
return;
}
int index = list.getSelectedIndex(); //get selected index
if (index == -1) { //no selection, so insert at beginning
index = 0;
} else { //add after the selected item
index++;
}
listModel.insertElementAt(employeeName.getText(), index);
//listModel.addElement(employeeName.getText());
employeeName.requestFocusInWindow();
employeeName.setText("");
list.setSelectedIndex(index);
list.ensureIndexIsVisible(index);
}
protected boolean alreadyInList(String name) {
return listModel.contains(name);
}
public void insertUpdate(DocumentEvent e) {
enableButton();
}
public void removeUpdate(DocumentEvent e) {
handleEmptyTextField(e);
}
public void changedUpdate(DocumentEvent e) {
if (!handleEmptyTextField(e)) {
enableButton();
}
}
private void enableButton() {
if (!alreadyEnabled) {
button.setEnabled(true);
}
}
private boolean handleEmptyTextField(DocumentEvent e) {
if (e.getDocument().getLength() <= 0) {
button.setEnabled(false);
alreadyEnabled = false;
return true;
}
return false;
}
}
public void valueChanged(ListSelectionEvent e) {
if (e.getValueIsAdjusting() == false) {
if (list.getSelectedIndex() == -1) {
fireButton.setEnabled(false);
} else {
fireButton.setEnabled(true);
}
}
}
private static void createAndShowGUI() {
JFrame frame = new JFrame("ListDemo");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
JComponent newContentPane = new ListDemo();
newContentPane.setOpaque(true); //content panes must be opaque
frame.setContentPane(newContentPane);
frame.pack();
frame.setVisible(true);
}
public static void main(String[] args) {
javax.swing.SwingUtilities.invokeLater(new Runnable() {
public void run() {
createAndShowGUI();
}
});
}
}
Just have a field that you update every time a selection is made. You could do this by adding a listener on your JList.
private class selectListener extends MouseAdapter {
public void mouseClicked(MouseEvent e) {
if (SwingUtilities.isLeftMouseButton(e)) {
currentSelected = list.getSelectedIndex();
}
}
}
Then use that field when your button is pressed.