Table Header is not displaying on Java Swing

Table Header is not displaying on Java Swing - java

I add full code Here. Check the following code which I am using to create the table.
While executing the program, Values are displaying clearly, but the header is not displaying.
public class Table extends JFrame implements ActionListener {
JFrame f;
JPanel p1;
JPanel jPanel1;
JTable jTable1;
Table() {
f=new JFrame("Home123");
f.setSize(getMaximumSize());
f.setVisible(true);
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
f.setLayout(null);
p1=new JPanel();
p1.setBackground(Color.red);
p1.setVisible(true);
p1.setLayout(null);
f.add(p1);
String[] headers = {"First Name","Last Name","Age"};
Object[][] data = {
{"Kathy", "Smith",new Integer(25)},
};
jTable1 =new JTable(data, headers);
JScrollPane scrollPane = new JScrollPane(jTable1);
p1.add(jTable1);
p1.setBounds(200, 100, 500, 500);
jTable1.setBounds(70,250, 375,80);
}
public static void main(String[] args) {
new Table();
}
}

public class TableExample extends JFrame implements ActionListener {
JFrame f;
JPanel p1;
JPanel jPanel1;
JTable jTable1;
TableExample() {
JFrame f;
JPanel p1;
JPanel jPanel1;
JTable jTable1;
f = new JFrame("Home123");
f.setSize(getMaximumSize());
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
p1 = new JPanel();
p1.setBackground(Color.red);
p1.setLayout(new BorderLayout());
f.add(p1);
String[] headers = {"First Name", "Last Name", "Age"};
Object[][] data = {
{"Kathy", "Smith", new Integer(25)},};
jTable1 = new JTable(data, headers);
JScrollPane scrollPane = new JScrollPane(jTable1);
scrollPane.setSize(500,500);
jTable1.setSize(500,500);
p1.add(scrollPane);
f.pack();
f.setVisible(true);
}
public static void main(String[] args) {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
new TableExample();
}
});
}
#Override
public void actionPerformed(ActionEvent e) {
try {
System.out.println("");
} catch (Exception ex) {
ex.printStackTrace();
}
}
}
try this its working and showing all thing that u need.

to #Sergiy Medvynskyy and #Krishna about 1. f.setVisible(true); 2. Initial Thread 3. p1.setVisible(true);
e.g.
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.EventQueue;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTable;
public class Table /*extends JFrame implements ActionListener*/ {
private JFrame f;
private JPanel p1;
private JPanel jPanel1;
private JTable jTable1;
public Table() {
p1 = new JPanel();
p1.setBackground(Color.red);
p1.setLayout(new BorderLayout(5, 5));
String[] headers = {"First Name", "Last Name", "Age"};
Object[][] data = {
{"Kathy", "Smith", new Integer(25)},};
jTable1 = new JTable(data, headers);
JScrollPane scrollPane = new JScrollPane(jTable1);
jTable1.setPreferredScrollableViewportSize(jTable1.getPreferredSize());
p1.add(scrollPane);
f = new JFrame("Home123");
//f.setSize(getMaximumSize());
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
f.add(p1);
f.pack();
f.setVisible(true);
}
public static void main(String[] args) {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
new Table();
}
});
}
}

You're adding the table directly to the frame's panel, instead of adding the scroll pane wrapping the table, and displaying the headers.
Change
p1.add(jTable1);
to
p1.add(scrollPane);
And definitely stop using a null layout and setting bounds. Learn using layout managers.

You should add scroll pane to panel
import java.awt.BorderLayout;
import java.awt.Color;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTable;
public class Table extends JFrame {
JFrame f;
JPanel p1;
JPanel jPanel1;
JTable jTable1;
Table() {
p1=new JPanel();
p1.setBackground(Color.red);
p1.setVisible(true);
p1.setLayout(new BorderLayout());
final String[] headers = {"First Name","Last Name","Age"};
final Object[][] data = {
{"Kathy", "Smith",new Integer(25)},
};
jTable1 =new JTable(data, headers);
final JScrollPane scrollPane = new JScrollPane(jTable1);
p1.add(scrollPane);
f=new JFrame("Home123");
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
f.add(p1);
f.pack();
f.setVisible(true);
}
public static void main(String[] args) {
new Table();
}
}
P.S. Never use null-layout.

Related

JTable in JTabbedPane_TabPanel

I have made a little minimum example.
I have a jTabbedPane with two tabs.
After pressing a button in TabPanel2 a table shut showing up.
But the table does not appear.
Please help me. Thank you.
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.event.*;
import javax.swing.table.DefaultTableModel;
public class test extends JFrame {
private JButton jButton1 = new JButton();
private JTabbedPane jTabbedPane1 = new JTabbedPane();
private JPanel jTabbedPane1TabPanel1 = new JPanel(null, true);
private JPanel jTabbedPane1TabPanel2 = new JPanel(null, true);
private JButton jButton2 = new JButton();
public void jButton2_ActionPerformed(ActionEvent evt) {
DefaultTableModel tableModel = new DefaultTableModel(0,2);
tableModel.addRow(new Object[] {"string1","string2"});
JTable table1 = new JTable(tableModel);
jTabbedPane1TabPanel2.add(table1);
}
}

`public class test extends JFrame implements ActionListener {
private JButton jButton1 = new JButton("button1");
private JTabbedPane jTabbedPane1 = new JTabbedPane();
private JPanel jTabbedPane1TabPanel1 = new JPanel();
private JPanel jTabbedPane1TabPanel2 = new JPanel();
private JButton jButton2 = new JButton("button2");
public test() {
jTabbedPane1TabPanel1.add(jButton1);
jTabbedPane1TabPanel2.add(jButton2, BorderLayout.PAGE_START);
jTabbedPane1.addTab("1", jTabbedPane1TabPanel1);
jTabbedPane1.addTab("2", jTabbedPane1TabPanel2);
jButton2.addActionListener(this);
JFrame frame = new JFrame();
frame.setContentPane(jTabbedPane1);
frame.pack();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setVisible(true);
}
public void actionPerformed(ActionEvent evt) {
DefaultTableModel tableModel = new DefaultTableModel(0, 2);
tableModel.addRow(new Object[] {
"string1", "string2"
});
JTable table1 = new JTable(tableModel);
// System.out.println(table1.getColumnCount());
// System.out.println(table1.getRowCount());
jTabbedPane1TabPanel2.add(table1, BorderLayout.CENTER);
}
public static void main(String[] args) {
new test();
}
}`

How to make a Blank JList at a specified size? Without empty elements

I am trying to create a BLANK JList for the user to see befor elements are added. Over all what is happening is I am using JFileChooser to select txt documents to be added to a list, then the vowels in each txt document are counted and displayed in the other list. The list must be visible before the user selects anything and the list must be blank. Yes there are two empty JList but obviously if I can get help with one the other is easy. So far nowhere on the internet touches on this particular subject.
Setting row count(visible) does not work, nor setsize(). Unless I am using it wrong. Please explain with examples. Thanks in advance!
An example below:
Code:
import java.awt.BorderLayout;
import java.awt.Container;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.*;
import javax.swing.*;
public class VowelCounterApp extends JFrame implements ActionListener
{
/**
*
*/
private static final long serialVersionUID = 1L;
JPanel panel1 = new JPanel();
JPanel panel2 = new JPanel();
JScrollPane scrollPane = new JScrollPane();
JList selectList = new JList();
JList showList = new JList();
JFileChooser fileChooser = new JFileChooser();
JButton addFiles = new JButton("Add Files");
JButton process = new JButton("Process");
JButton clear = new JButton("Clear");
JButton help = new JButton("Help");
public VowelCounterApp()
{
JFrame appWindow = new JFrame("Vowel Counter");
appWindow.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
appWindow.setSize(1500, 600);
appWindow.setLayout(new BorderLayout());
appWindow.setVisible(true);
appWindow.add(panel1, BorderLayout.WEST);
appWindow.add(panel2, BorderLayout.EAST);
panel1.add(selectList);
selectList.add(scrollPane);
panel2.add(showList);
showList.add(scrollPane);
}
public void actionPerformed(ActionEvent e)
{
}
public static void main(String[] args)
{
new VowelCounterApp();
}
}

The JList API will show you two key methods:
public void setVisibleRowCount(int rowCount)
public void setPrototypeCellValue(E prototype)
So simply give your list an adequate row visible count and an adequately long enough prototype value, and then its enclosing JScrollPane's viewport will automatically size its viewport accordingly.
For example:
import java.awt.GridLayout;
import javax.swing.*;
public class JListExample extends JPanel {
private JList<String> list1 = new JList<>();
private JList<String> list2 = new JList<>();
public JListExample() {
list1.setVisibleRowCount(20);
list2.setVisibleRowCount(20);
list1.setPrototypeCellValue(String.format("%60s", ""));
list2.setPrototypeCellValue(String.format("%60s", ""));
setLayout(new GridLayout(1, 2));
add(new JScrollPane(list1));
add(new JScrollPane(list2));
}
private static void createAndShowGui() {
JListExample mainPanel = new JListExample();
JFrame frame = new JFrame("JList Example");
frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
frame.getContentPane().add(mainPanel);
frame.pack();
frame.setLocationByPlatform(true);
frame.setVisible(true);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
createAndShowGui();
}
});
}
}
Or better to avoid "magic" numbers:
public class JListExample extends JPanel {
private static final int LIST_ROW_COUNT = 20;
private static final int LIST_CHAR_WIDTH = 80;
private static final String LIST_PROTOTYPE = "%" + LIST_CHAR_WIDTH + "s";
private JList<String> list1 = new JList<>();
private JList<String> list2 = new JList<>();
public JListExample() {
list1.setVisibleRowCount(LIST_ROW_COUNT);
list2.setVisibleRowCount(LIST_ROW_COUNT);
list1.setPrototypeCellValue(String.format(LIST_PROTOTYPE, ""));
list2.setPrototypeCellValue(String.format(LIST_PROTOTYPE, ""));
Here, now you can see the lists better by my wrapping them and their JScrollPane in a JPanel that uses a TitledBorder:
import java.awt.BorderLayout;
import java.awt.GridLayout;
import javax.swing.*;
public class JListExample extends JPanel {
private static final int LIST_ROW_COUNT = 20;
private static final int LIST_CHAR_WIDTH = 80;
private static final String LIST_PROTOTYPE = "%" + LIST_CHAR_WIDTH + "s";
private JList<String> list1 = new JList<>();
private JList<String> list2 = new JList<>();
public JListExample() {
list1.setVisibleRowCount(LIST_ROW_COUNT);
list2.setVisibleRowCount(LIST_ROW_COUNT);
list1.setPrototypeCellValue(String.format(LIST_PROTOTYPE, ""));
list2.setPrototypeCellValue(String.format(LIST_PROTOTYPE, ""));
setLayout(new GridLayout(1, 2));
add(createListWrapper(list1, "JList 1"));
add(createListWrapper(list2, "JList 2"));
}
private JComponent createListWrapper(JList<String> list, String title) {
JScrollPane scrollPane = new JScrollPane(list);
scrollPane.setVerticalScrollBarPolicy(JScrollPane.VERTICAL_SCROLLBAR_ALWAYS);
JPanel wrapperPanel = new JPanel(new BorderLayout());
wrapperPanel.add(scrollPane);
wrapperPanel.setBorder(BorderFactory.createTitledBorder(title));
return wrapperPanel;
}
private static void createAndShowGui() {
JListExample mainPanel = new JListExample();
JFrame frame = new JFrame("JList Example");
frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
frame.getContentPane().add(mainPanel);
frame.pack();
frame.setLocationByPlatform(true);
frame.setVisible(true);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
createAndShowGui();
}
});
}
}
Edit
As MadProgrammer states in comment:
I'd also be careful with prototypeCellValue, unless the value matches the expected length of your data, it could truncate your data when it's displayed, just need to be careful

Open new JFrame with JButton Click - Java Swing

I am trying to open a new JFrame window with a button click event. There is lots of info on this site but nothing that helps me because I think it is not so much the code I have, but the order it is executed (however I am uncertain).
This is the code for the frame holding the button that I want to initiate the event:
package messing with swing;
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.io.*;
import java.util.*;
import javax.swing.border.EmptyBorder;
public class ReportGUI extends JFrame{
//Fields
private JButton viewAllReports = new JButton("View All Program Details");
private JButton viewPrograms = new JButton("View Programs and Majors Associated with this course");
private JButton viewTaughtCourses = new JButton("View Courses this Examiner Teaches");
private JLabel courseLabel = new JLabel("Select a Course: ");
private JLabel examinerLabel = new JLabel("Select an Examiner: ");
private JPanel panel = new JPanel(new GridLayout(6,2,4,4));
private ArrayList<String> list = new ArrayList<String>();
private ArrayList<String> courseList = new ArrayList<String>();
public ReportGUI(){
reportInterface();
allReportsBtn();
examinnerFileRead();
courseFileRead();
comboBoxes();
}
private void examinnerFileRead(){
try{
Scanner scan = new Scanner(new File("Examiner.txt"));
while(scan.hasNextLine()){
list.add(scan.nextLine());
}
scan.close();
}
catch (FileNotFoundException e){
e.printStackTrace();
}
}
private void courseFileRead(){
try{
Scanner scan = new Scanner(new File("Course.txt"));
while(scan.hasNextLine()){
courseList.add(scan.nextLine());
}
scan.close();
}
catch (FileNotFoundException e){
e.printStackTrace();
}
}
private void reportInterface(){
setTitle("Choose Report Specifications");
setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
JPanel panel = new JPanel(new FlowLayout());
add(panel, BorderLayout.CENTER);
setSize(650,200);
setVisible(true);
setResizable(false);
setLocationRelativeTo(null);
}
private void allReportsBtn(){
JPanel panel = new JPanel(new GridLayout(1,1));
panel.setBorder(new EmptyBorder(70, 50, 70, 25));
panel.add(viewAllReports);
viewAllReports.addActionListener(new ActionListener(){
#Override
public void actionPerformed(ActionEvent e){
JFrame AllDataGUI = new JFrame();
new AllDataGUI();
}
});
add(panel, BorderLayout.LINE_END);
}
private void comboBoxes(){
panel.setBorder(new EmptyBorder(0, 5, 5, 10));
String[] comboBox1Array = list.toArray(new String[list.size()]);
JComboBox comboBox1 = new JComboBox(comboBox1Array);
panel.add(examinerLabel);
panel.add(comboBox1);
panel.add(viewTaughtCourses);
viewTaughtCourses.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
JFrame ViewCourseGUI = new JFrame();
new ViewCourseGUI();
}
});
String[] comboBox2Array = courseList.toArray(new String[courseList.size()]);
JComboBox comboBox2 = new JComboBox(comboBox2Array);
panel.add(courseLabel);
panel.add(comboBox2);
panel.add(viewPrograms);
add(panel, BorderLayout.LINE_START);
}
If you don't want to delve into the above code, the button ActionListener is here:
panel.add(viewTaughtCourses);
viewTaughtCourses.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
JFrame ViewCourseGUI = new JFrame();
new ViewCourseGUI();
}
});
This is the code in the class holding the JFrame I want to open:
package messing with swing;
import java.awt.BorderLayout;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTextArea;
import javax.swing.border.EmptyBorder;
public class ViewCourseGUI extends JFrame{
private JButton saveCloseBtn = new JButton("Save Changes and Close");
private JButton closeButton = new JButton("Exit Without Saving");
private JFrame frame=new JFrame("Courses taught by this examiner");
private JTextArea textArea = new JTextArea();
public void ViewCoursesGUI(){
panels();
}
private void panels(){
JPanel panel = new JPanel(new GridLayout(1,1));
panel.setBorder(new EmptyBorder(5, 5, 5, 5));
JPanel rightPanel = new JPanel(new GridLayout(15,0,10,10));
rightPanel.setBorder(new EmptyBorder(15, 5, 5, 10));
JScrollPane scrollBarForTextArea=new JScrollPane(textArea,JScrollPane.VERTICAL_SCROLLBAR_AS_NEEDED,JScrollPane.HORIZONTAL_SCROLLBAR_AS_NEEDED);
panel.add(scrollBarForTextArea);
frame.add(panel);
frame.getContentPane().add(rightPanel,BorderLayout.EAST);
rightPanel.add(saveCloseBtn);
rightPanel.add(closeButton);
frame.setSize(1000, 700);
frame.setVisible(true);
frame.setLocationRelativeTo(null);
}
}
Could someone please point me in the right direction?

As pointed out by PM 77-3
I had:
public void ViewCoursesGUI(){
panels();
}
When I should have had:
public ViewCourseGUI(){
panels();
}
A Combination of syntax and spelling errors.

Set the visibility of the JFrame you want to open, to true in the actionListener:
ViewCourseGUI viewCourseGUI = new ViewCourseGUI();
viewCourseGUI.setVisible(true);
This will open the new JFrame window once you click the button.

Let ReportGUI implement ActionListener. Then you will implement actionPerformed for the button click. On button click, create the second frame (if it doesn't exist). Finally, set the second frame visible (if it is currently not visible):
import java.awt.EventQueue;
import java.awt.FlowLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JFrame;
public class ReportGUI extends JFrame implements ActionListener {
private static final long serialVersionUID = 8679886300517958494L;
private JButton button;
private ViewCourseGUI frame2 = null;
public ReportGUI() {
//frame1 stuff
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setSize(300,200);
setLayout(new FlowLayout());
//create button
button = new JButton("Open other frame");
button.addActionListener(this);
add(button);
}
public static void main(String[] args) {
EventQueue.invokeLater(new Runnable() {
public void run() {
try {
ReportGUI frame = new ReportGUI();
frame.setVisible(true);
} catch (Exception e) {
e.printStackTrace();
}
}
});
}
#Override
public void actionPerformed(ActionEvent e) {
if (e.getSource() == button) {
if (frame2 == null)
frame2 = new ViewCourseGUI();
if (!frame2.isVisible())
frame2.setVisible(true);
}
}
}
This is a simple example. You'll have to add the rest of your code here.

JTable inside a JScrollPane not showing up properly

I am working on a the GUI of a piece of code that I have been patching together. I am stuck at this part of the program where I would like a datafile the user chooses to be displayed in a JTable in a preview manner (i.e. the user should not be able to edit the data on the table).
With a button click from Experiment Parameters tab (see screenshot below), I create and run a "PreviewAction" which creates a new tab, and fills it up with the necessary components. Below is the code for DataPreviewAction. EDIT: I also posted a self-contained, minimal version of this that mimics the conditions in the real project, and exhibits the same behaviour.
import java.awt.BorderLayout;
import java.util.Arrays;
import java.util.LinkedList;
import java.util.List;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTabbedPane;
import javax.swing.JTable;
import javax.swing.SwingUtilities;
import javax.swing.table.DefaultTableModel;
public class MyFrame extends JFrame {
private JPanel panel1;
private JTabbedPane tabs;
private JButton runButton;
public MyFrame() {
tabs = new JTabbedPane();
panel1 = new JPanel();
runButton = new JButton("go!");
runButton.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
runButtonActionPerformed(evt);
}
});
panel1.add(runButton);
tabs.addTab("first tab", panel1);
this.add(tabs);
pack();
}
public static void main(String args[]) {
try {
for (javax.swing.UIManager.LookAndFeelInfo info : javax.swing.UIManager
.getInstalledLookAndFeels()) {
if ("Nimbus".equals(info.getName())) {
javax.swing.UIManager.setLookAndFeel(info.getClassName());
break;
}
}
} catch (ClassNotFoundException ex) {
java.util.logging.Logger.getLogger(MyFrame.class.getName()).log(
java.util.logging.Level.SEVERE, null, ex);
} catch (InstantiationException ex) {
java.util.logging.Logger.getLogger(MyFrame.class.getName()).log(
java.util.logging.Level.SEVERE, null, ex);
} catch (IllegalAccessException ex) {
java.util.logging.Logger.getLogger(MyFrame.class.getName()).log(
java.util.logging.Level.SEVERE, null, ex);
} catch (javax.swing.UnsupportedLookAndFeelException ex) {
java.util.logging.Logger.getLogger(MyFrame.class.getName()).log(
java.util.logging.Level.SEVERE, null, ex);
}
/* Create and display the form */
java.awt.EventQueue.invokeLater(new Runnable() {
public void run() {
MyFrame frame = new MyFrame();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
private void runButtonActionPerformed(java.awt.event.ActionEvent evt) {
/*
* Normally there is more stuff happening here but this much will do for
* the sake of example
*/
List<String[]> data = new LinkedList<String[]>();
for (int i = 1; i < 1000; i++)
data.add(new String[] { "entry1", "value1", "value2", "value3" });
SwingUtilities.invokeLater(new DataPreviewAction(data, tabs));
}
public class DataPreviewAction implements Runnable {
private JTabbedPane contentHolder;
private List<String[]> data;
public DataPreviewAction(List<String[]> data, JTabbedPane comp) {
this.contentHolder = comp;
this.data = data;
}
#Override
public void run() {
DefaultTableModel previewModel = new DefaultTableModel() {
#Override
public boolean isCellEditable(int row, int column) {
return false;
}
};
for (String[] datarow : data) {
previewModel.addRow(Arrays.copyOf(datarow, datarow.length,
Object[].class));
}
JTable table = new JTable(previewModel);
JPanel buttonPanel = new JPanel();
buttonPanel.add(new JButton("A button"));
buttonPanel.add(new JLabel(
"Some description for the awesome table below "));
buttonPanel.add(new JButton("another button"));
JScrollPane tablePanel = new JScrollPane(table);
JPanel container = new JPanel();
container.setLayout(new BorderLayout());
container.add(buttonPanel, BorderLayout.NORTH);
container.add(tablePanel, BorderLayout.CENTER);
contentHolder.addTab("Preview", container);
contentHolder.validate();
contentHolder.repaint();
}
}
}
There are at least two problems here:
The JTable (or the JScrollPane) does not render at all
The JScrollPane is not as wide as the frame itself, I have no idea why
I am not all that good in Swing so I might be missing something fundamental. I have checked that the datafile is read properly, and the data model contains the right amount of rows (1000+). SO the table should not be empty.
Suggestions?

JPanel buttonPanel = new JPanel();
buttonPanel.add(new JButton("A button"));
buttonPanel.add(new JLabel("Some description for the awesome table below "));
buttonPanel.add(new JButton("another button"));
JScrollPane tablePanel = new JScrollPane(table);
JPanel container = new JPanel();
container.add(buttonPanel,BorderLayout.NORTH);
container.add(tablePanel,BorderLayout.SOUTH);
contentHolder.addTab("Preview", container);
//contentHolder.validate(); <- NO good
//contentHolder.repaint(); <- --"---
}
JPanel uses FlowLayout (implemented in API, acceptiong only PreferredSize, by default isn't resizable), correct output as is demonstrated in attn image, you have to change default LayoutManager for JPanel to BorderLayout, then code lines
.
container.add(buttonPanel,BorderLayout.NORTH);
container.add(tablePanel,BorderLayout.SOUTH);
will expands JComponents and can be works as you expecting, but I think tablePanel should be placed in CENTER area
EDIT:
import java.awt.BorderLayout;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTabbedPane;
import javax.swing.JTable;
import javax.swing.table.DefaultTableModel;
public class MyFrame extends JFrame {
private JPanel panel1;
private JTabbedPane tabs;
private JButton runButton;
private JFrame frame = new JFrame();
private String[] columnNames = {"Nama", "Nim", "IP", "Hapus Baris ke"};
private Object[][] data = {
{"igor", "B01_125-358", "1.124.01.125", true},
{"lenka", "B21_002-242", "21.124.01.002", true},
{"peter", "B99_001-358", "99.124.01.001", false},
{"zuza", "B12_100-242", "12.124.01.100", true},
{"jozo", "BUS_011-358", "99.124.01.011", false},
{"nora", "B09_154-358", "9.124.01.154", false},
{"xantipa", "B01_001-358", "1.124.01.001", false},};
private DefaultTableModel model = new DefaultTableModel(data, columnNames) {
private static final long serialVersionUID = 1L;
#Override
public boolean isCellEditable(int row, int column) {
switch (column) {
case 3:
return true;
default:
return false;
}
}
#Override
public Class getColumnClass(int column) {
return getValueAt(0, column).getClass();
}
};
public MyFrame() {
tabs = new JTabbedPane();
panel1 = new JPanel();
runButton = new JButton("go!");
runButton.addActionListener(new java.awt.event.ActionListener() {
#Override
public void actionPerformed(java.awt.event.ActionEvent evt) {
//
}
});
panel1.add(runButton);
tabs.addTab("first tab", panel1);
JTable table = new JTable(model);
JPanel buttonPanel = new JPanel();
buttonPanel.add(new JButton("A button"));
buttonPanel.add(new JLabel("Some description for the awesome table below "));
buttonPanel.add(new JButton("another button"));
JScrollPane tablePanel = new JScrollPane(table);
JPanel container = new JPanel();
container.setLayout(new BorderLayout());
container.add(buttonPanel, BorderLayout.NORTH);
container.add(tablePanel, BorderLayout.CENTER);
tabs.addTab("Preview", container);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(tabs);
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
public static void main(String args[]) {
java.awt.EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
MyFrame frame = new MyFrame();
}
});
}
}
EDIT 2nd. e.g.
from code (included your idea about to fill data to model)
import java.awt.BorderLayout;
import java.util.Arrays;
import java.util.LinkedList;
import java.util.List;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTabbedPane;
import javax.swing.JTable;
import javax.swing.table.DefaultTableModel;
public class MyFrame extends JFrame {
private JPanel panel1;
private JTabbedPane tabs;
private JButton runButton;
private JFrame frame = new JFrame();
private String[] columnNames = {"Nama", "Nim", "IP", "Hapus Baris ke"};
private Object[][] data = {
{"igor", "B01_125-358", "1.124.01.125", "true"},
{"lenka", "B21_002-242", "21.124.01.002", "true"},
{"peter", "B99_001-358", "99.124.01.001", "false"},
{"zuza", "B12_100-242", "12.124.01.100", "true"},
{"jozo", "BUS_011-358", "99.124.01.011", "false"},
{"nora", "B09_154-358", "9.124.01.154", "false"},
{"xantipa", "B01_001-358", "1.124.01.001", "false"},};
private DefaultTableModel model = new DefaultTableModel(data, columnNames) {
private static final long serialVersionUID = 1L;
#Override
public boolean isCellEditable(int row, int column) {
switch (column) {
case 3:
return true;
default:
return false;
}
}
#Override
public Class getColumnClass(int column) {
return getValueAt(0, column).getClass();
}
};
public MyFrame() {
tabs = new JTabbedPane();
panel1 = new JPanel();
runButton = new JButton("go!");
runButton.addActionListener(new java.awt.event.ActionListener() {
#Override
public void actionPerformed(java.awt.event.ActionEvent evt) {
List<String[]> data = new LinkedList<String[]>();
for (int i = 1; i < 10; i++) {
data.add(new String[]{"entry1", "value1", "value2", "value3"});
}
for (String[] datarow : data) {
model.addRow(Arrays.copyOf(datarow, datarow.length, Object[].class));
}
}
});
panel1.add(runButton);
tabs.addTab("first tab", panel1);
JTable table = new JTable(model);
JPanel buttonPanel = new JPanel();
buttonPanel.add(new JButton("A button"));
buttonPanel.add(new JLabel("Some description for the awesome table below "));
buttonPanel.add(new JButton("another button"));
JScrollPane tablePanel = new JScrollPane(table);
JPanel container = new JPanel();
container.setLayout(new BorderLayout());
container.add(buttonPanel, BorderLayout.NORTH);
container.add(tablePanel, BorderLayout.CENTER);
tabs.addTab("Preview", container);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(tabs);
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
public static void main(String args[]) {
java.awt.EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
MyFrame frame = new MyFrame();
}
});
}
}

Following the footsteps of mKorbel I ended up doing some debugging. I am providing it here in case others run into the same problem.
It felt quite odd that the table looked OK when the underlying DataModel was supplied a data matrix upon initialisation
private DefaultTableModel model = new DefaultTableModel(data, columnNames)
but it would not show up properly when created with the empty constructor
private DefaultTableModel model = new DefaultTableModel()
and adding rows later with model.addRow(Object[] row);
I started look through the source code, and it turns out with the empty constructor the number of rows and columns for the model (private fields) is initiated to 0 and not updated properly afterwards. I noticed this while debugging since my tables had the dimension of 1370 x 0, which of course does not display properly.
Since I do not want to hardcode the number of rows/cols in advance the best course of action was to convert my "rows" to a matrix and provide the data to the model via constructor (much like mKorbel did). Here comes the fun part, if you want to supply the data then you need to supply the column names as well. THe fact that you have to have column names is counter-intuitive (IMHO), what happens if you dont have/need headers? The data is already in a table form, so I dont understand why column names is so important.
At any rate the following code renders the table at least:
String[] colNames = new String[data[1].length];
for(int i=0; i<colNames.length; i++)
colNames[i] = "C" + i;
DefaultTableModel model = new DefaultTableModel(data,colNames){
#Override
public boolean isCellEditable(int row, int column){
return false;
}};
I am accepting this because it points to the origin of the problem, but I would not be able to pinpoint the problem without mKorbel's answer, so give the upvote to his/her answer :)

After updating JComboBox, how to refresh length of box

I am trying to create a way to update a JComboBox so that when the user enters something into the text field, some code will process the entry and update the JComboBox accordingly.The one issue that I am having is I can update the JComboBox, but the first time it is opened, the box has not refresh the length of the options in it and as seen in the code below it displays extra white space. I do not know if there is a better different way to do this, but this is what I came up with.
Thanks for the help,
Dan
import java.awt.event.*;
import javax.swing.JComboBox;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JTextField;
public class Catch{
public static JComboBox dropDown;
public static String dropDownOptions[] = {
"Choose",
"1",
"2",
"3"};
public static void main(String[] args) {
dropDown = new JComboBox(dropDownOptions);
final JTextField Update = new JTextField("Update", 10);
final JFrame frame = new JFrame("Subnet Calculator");
final JPanel panel = new JPanel();
frame.setSize(315,430);
frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
Update.addFocusListener(new FocusListener(){
public void focusGained(FocusEvent arg0) {
}
public void focusLost(FocusEvent arg0) {
dropDown.removeAllItems();
dropDown.insertItemAt("0", 0);
dropDown.insertItemAt("1", 1);
dropDown.setSelectedIndex(0);
}
});
panel.add(Update);
panel.add(dropDown);
frame.getContentPane().add(panel);
frame.setVisible(true);
Update.requestFocus();
Update.selectAll();
}
}

1) JTextField listening for ENTER key from ActionListener
2) remove FocusListener
3) example about add new Item as last Item from JTextField to the JList, only you have to modify for JComboBox and add method insertItemAt() correctly
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class ListBottom2 {
private static final long serialVersionUID = 1L;
private JFrame frame = new JFrame();
private DefaultListModel model = new DefaultListModel();
private JList list = new JList(model);
private JTextField textField = new JTextField("Use Enter to Add");
private JPanel panel = new JPanel(new BorderLayout());
public ListBottom2() {
model.addElement("First");
list.setVisibleRowCount(5);
panel.setBackground(list.getBackground());
panel.add(list, BorderLayout.SOUTH);
JScrollPane scrollPane = new JScrollPane(panel);
scrollPane.setPreferredSize(new Dimension(200, 100));
frame.add(scrollPane);
frame.add(textField, BorderLayout.NORTH);
textField.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
JTextField textField = (JTextField) e.getSource();
DefaultListModel model = (DefaultListModel) list.getModel();
model.addElement(textField.getText());
int size = model.getSize() - 1;
list.scrollRectToVisible(list.getCellBounds(size, size));
textField.setText("");
}
});
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
public static void main(String[] args) {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
ListBottom2 frame = new ListBottom2();
}
});
}
}

Develop Reference

Java is a programming language and computing platform first released by Sun Microsystems in 1995.

Table Header is not displaying on Java Swing - java

You're adding the table directly to the frame's panel, instead of adding the scroll pane wrapping the table, and displaying the headers. Change p1.add(jTable1); to p1.add(scrollPane); And definitely stop using a null layout and setting bounds. Learn using layout managers.

Related

JTable in JTabbedPane_TabPanel

How to make a Blank JList at a specified size? Without empty elements

Open new JFrame with JButton Click - Java Swing

JTable inside a JScrollPane not showing up properly

After updating JComboBox, how to refresh length of box

Categories

Resources