Help with JLabels and JTextFields

I'm experimenting with JLabels and JTextFields in a basic JFrame. What I am trying to accomplish (without success) is to align a JLabel above and centered on a JTextField. The tutorials are confusing me. Any help would be greatly appreciated. a Sample of code is ...
JLabel myTextLabel = new JLabel("Who's text Field?");
JTextField myTextField = new JTextField("My Text Field");...after reading the tutorial I thought that I needed to assign L&F variables to the JLabel ... i.e.
JLabel myTextLabel = new JLabel("Who's text field?:", JLabel.CENTER, JLabel.TOP); but this results in an error when compiling. (cannot find symbol), so I thought I need to assign the JLabel to the JTextField. i.e.
myTextLabel.setLabelFor(myTextField);Then I get "identifier" expected. So now being completely confused I am here asking "How do I?" :)
Thanks in advance!

Most likely, you need to think a little more about using a layout manager to hlp you along the way. If memory serves, the default layout manager for a JPanel is FlowLayout and that will simply place the components you add to the panel one after another and allow each to adopt it's preferred size.
One way to ensure that the two compoenets were sized equally, would be to use the GridLayout layout manager and create either one row with two columns, or two rows with one column on each. Then add the compoennets to each of the 'cells' so to speak and that should ensure that they are both the same size.
As to making the text centered in each, both the JLabel and JtextField classes have amethod called setHorizontalAlignment(); it can be used to aligh the text as you require.
Simply create an instance of the class;
JLabel aLabel = new JLabel("Some Text");
// Then set the alignment
aLabel.setHorizontalAlignment(SwingConstants.CENTER);Or, do the whole operation i one step
JLabel aLabel = new JLabel("Sone Text", SwingConstants.CENTER);and then add the componenet to the panel once you have set the layout manager.
Remember that the label.textfield will have to be wide enought to make it obvious that the text is centered!

Similar Messages

Problem with PropertyChangeListener and JTextField

I'm having a problem with PropertyChangeListener and JTextField.
I can not seem to get the propertychange event to fire.
Anyone have any idea why the code below doesn't work?
* NewJFrame.java
* Created on May 15, 2005, 4:21 PM
import java.beans.*;
import javax.swing.*;
* @author wolfgray
public class NewJFrame extends javax.swing.JFrame
implements PropertyChangeListener {
/** Creates new form NewJFrame */
public NewJFrame() {
initComponents();
jTextField1.addPropertyChangeListener( this );
public void propertyChange(PropertyChangeEvent e) {
System.out.println(e);
/** This method is called from within the constructor to
* initialize the form.
* WARNING: Do NOT modify this code. The content of this method is
* always regenerated by the Form Editor.
private void initComponents() {
jTextField1 = new javax.swing.JTextField();
jScrollPane1 = new javax.swing.JScrollPane();
jFormattedTextField1 = new javax.swing.JFormattedTextField();
setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
jTextField1.setText("jTextField1");
getContentPane().add(jTextField1, java.awt.BorderLayout.NORTH);
jFormattedTextField1.setText("jFormattedTextField1");
jScrollPane1.setViewportView(jFormattedTextField1);
getContentPane().add(jScrollPane1, java.awt.BorderLayout.CENTER);
pack();
* @param args the command line arguments
public static void main(String args[]) {
java.awt.EventQueue.invokeLater(new Runnable() {
public void run() {
new NewJFrame().setVisible(true);
// Variables declaration - do not modify
private javax.swing.JFormattedTextField jFormattedTextField1;
private javax.swing.JScrollPane jScrollPane1;
private javax.swing.JTextField jTextField1;
// End of variables declaration
}

If you want to listen to changes in the textfield's contents you should use a DocumentListener and not a PropertyChangeListener:
http://java.sun.com/docs/books/tutorial/uiswing/events/documentlistener.html
And please use [co[/i]de] tags when you are posting code (press the code button above the message window).

Help with writing and retrieving data from a table field with type "LCHR"

Hi Experts,
I need help with writing and reading data from a database table field which has a type of "LCHR". I have given an example of the original code but don't know what to change it to in order to fix it and still read in the original data that's stored in the LCHR field.
Basically we have two Function modules, one that saves list data to a database table and one that reads in this data. Both Function modules have an identicle table which has an array of fields from type INT4, CHAR, and type P. The INT4 field is the first one.
Incidentally this worked in the 4.7 non-unicode system but is now dumping in the new ECC6 Unicode system.
Thanks in advance,
C
SAVING THE LIST DATA TO DB
DATA: L_WA(800).
LOOP AT T_TAB into L_WA.
ZDBTAB-DATALEN = STRLEN( L_WA ).
MOVE: L_WA to ZDBTAB-RAWDATA.
ZDBTAB-LINENUM = SY-TABIX.
INSERT ZDBTAB.
READING THE DATA FROM DB
DATA: BEGIN OF T_DATA,
             SEQNR type ZDBTAB-LINENUM,
             DATA type ZDBTAB-RAWDATA,
           END OF T_TAB.
Select the data.
SELECT linenum rawdata from ZDBTAB into table T_DATA
     WHERE repid = w_repname
     AND rundate = w_rundate
     ORDER BY linenum.
Populate calling Internal Table.
LOOP AT T-DATA.
APPEND T_DATA to T_TAB.
ENDLOOP.

Hi Anuj,
The unicode flag is active.
When I run our report and then to try and save the list data a dump is happening at the following point
LOOP AT T_TAB into L_WA.
As I say, T_TAB consists of different fields and field types whereas L_WA is CHAR 800. The dump mentions UC_OBJECTS_NOT_CONVERTIBLE
When I try to load a saved list the dump is happening at the following point
APPEND T_DATA-RAWDATA to T_TAB.
T_DATA-RAWDATA is type LCHR and T_TAB consists of different fields and field types.
In both examples the dumps mention UC_OBJECTS_NOT_CONVERTIBLE
Regards
C

Layout of JLabels and JTextFields

Hi!
I am looking for an easy way to layout JLabels and JTextFields side by side like this:
jlabel             jtextField
small jlabel       jtextField
longer jlabel      jtextFieldAny ideas on how to do this?
Peter

Read this section from the Swing tutorial on "Using Layout Managers":
http://java.sun.com/docs/books/tutorial/uiswing/layout/using.html
The easiest way is to use a GridLayout.
JPanel panel = new JPanel();
panel.setLayout( new GridLayout(0, 2) );
panel.add( new JLabel("...") );
panel.add( new JTextField(10) );
panel.add( new JLabel("...") );
panel.add( new JTextField(10) );
A more complicated, but more flexible way is to use a GridBagLayout. Something like this:
public class ActivityPanel extends JPanel
     public ActivityPanel()
          setBorder( new EmptyBorder(5, 5, 5, 5) );
          setLayout( new GridBagLayout() );
          GridBagConstraints gbc = new GridBagConstraints();
          gbc.insets = new Insets(5, 10, 5, 10);
          // add street
          JLabel lStreet = new JLabel("Street");
          JTextField cStreet = new JTextField(32);
          addRow(gbc, lStreet, cStreet);
          // add city
          JLabel lCity = new JLabel("City");
          JTextField cCity = new JTextField(32);
          addRow(gbc, lCity, cCity);
     private void addRow(GridBagConstraints gbc, Component left, Component right)
          gbc.gridx = GridBagConstraints.RELATIVE;
          gbc.gridy = GridBagConstraints.RELATIVE;
          gbc.gridheight = 1;
          gbc.gridwidth = 1;
          gbc.anchor = GridBagConstraints.EAST;
          add(left, gbc);
          gbc.gridwidth = GridBagConstraints.REMAINDER;
          gbc.anchor = GridBagConstraints.WEST;
          add(right, gbc);
}

Align JLabels and JTextFields vertically in different areas

I like to have 3 TitledBorders for 3 different areas of my frame.
Each area has its own components - JLabels, JTextField, etc.
How to align JLabels and JTextFields vertically in different areas?
e.g. for the following test program, how to configure label1, label2, label3 so that their right sides all align vertically and
tf1, tf2, tf3 so that their left sides all align vertically?
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.GridLayout;
import java.awt.Insets;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JTextField;
import javax.swing.border.TitledBorder;
public class TitledBorderDemo extends JFrame {
public TitledBorderDemo() {
    super("TitledBorderDemo");
    JTextField tf1 = new JTextField("hello", 6);
    JTextField tf2 = new JTextField("hello", 12);
    JTextField tf3 = new JTextField("test");
    JTextField tf4 = new JTextField("test2");
    JLabel label1 = new JLabel("1234567890ertyuiyup label");
    JLabel label2 = new JLabel("zzzzzzzzzzzzzzzzzzzzzzzzzzzzzz long label");
    JLabel label3 = new JLabel("short label");
    JLabel label4 = new JLabel("test");
    JPanel panel_tf = new JPanel(new GridBagLayout());
    JPanel panel_pf = new JPanel(new GridBagLayout());
    JPanel panel_ftf = new JPanel(new GridBagLayout());
    GridBagConstraints constraints = new GridBagConstraints(0, 0, 3, 3,
            0.0, 0.0, GridBagConstraints.WEST, GridBagConstraints.NONE,
            new Insets(10, 10, 10, 10), 0, 0);
    constraints.gridx = 0;
    constraints.gridy = 0;
    constraints.gridwidth = 2;
    constraints.anchor = GridBagConstraints.WEST;
    panel_tf.add(label1, constraints);
    constraints.gridx = 2;
    constraints.gridwidth = 1;
    constraints.anchor = GridBagConstraints.EAST;
    panel_tf.add(tf1, constraints);
    constraints.gridx = 0;
    constraints.gridy = 1;
    constraints.gridwidth = 2;
    constraints.anchor = GridBagConstraints.WEST;
    panel_pf.add(label2, constraints);
    constraints.gridx = 2;
    constraints.gridwidth = 1;
    constraints.anchor = GridBagConstraints.EAST;
    panel_pf.add(tf2, constraints);
    constraints.gridx = 0;
    constraints.gridy = 2;
    constraints.gridwidth = 2;
    constraints.anchor = GridBagConstraints.WEST;
    panel_ftf.add(label3, constraints);
    constraints.gridx = 2;
    constraints.gridwidth = 1;
    constraints.anchor = GridBagConstraints.EAST;
    panel_ftf.add(tf3, constraints);
    constraints.gridx = 3;
    constraints.gridwidth = 1;
    constraints.anchor = GridBagConstraints.WEST;
    panel_ftf.add(label4, constraints);
    constraints.gridx = 4;
    constraints.anchor = GridBagConstraints.EAST;
    panel_ftf.add(tf4, constraints);
    panel_tf.setBorder(new TitledBorder("JTextField1"));
    panel_pf.setBorder(new TitledBorder("JTextField2"));
    panel_ftf.setBorder(new TitledBorder("JTextField3"));
    JPanel pan = new JPanel(new GridLayout(3, 1, 10, 10));
    pan.add(panel_tf);
    pan.add(panel_pf);
    pan.add(panel_ftf);
    this.add(pan);
public static void main(String args[]) {
    JFrame frame = new TitledBorderDemo();
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    frame.setSize(600, 450);
    frame.setVisible(true);
}

Thank you! It works!
I add some labels & components to your demo program.
Most of the components align vertically.
How to align the "Country", "Test2" & "Extension" labels on the right sides?
How to align their corresponding components so that their left sides all align vertically?
How to make the Cancel button stick to the Save button
(i.e. eliminate the gap between the Cancel and the Save button)?
import java.awt.*;
import javax.swing.*;
import javax.swing.border.*;
public class TitledBorderDemoNew extends JFrame {
public TitledBorderDemoNew() {
    super("TitledBorderDemoNew");
    JLabel nameLabel = new JLabel("Name");
    JTextField nameText = new JTextField(20);
    JLabel addressLabel = new JLabel("Address (City & State)");
    JTextField addressText = new JTextField(40);
    JLabel countryLabel = new JLabel("Country");
    JTextField countryText = new JTextField(30);
    JLabel testLabel = new JLabel("Test");
    JTextField testText = new JTextField(20);
    JLabel test2Label = new JLabel("Test2");
    JTextField test2Text = new JTextField(20);
    JLabel phoneLabel = new JLabel("Phone");
    JTextField phoneText = new JTextField(20);
    JLabel extensionLabel = new JLabel("Extension");
    JTextField extensionText = new JTextField(5);
    JLabel postalCodeLabel = new JLabel("Postal Code");
    JTextField postalCodeText = new JTextField(6);
    JButton saveButton = new JButton("Save");
    JButton cancelButton = new JButton("Cancel");
    JButton commentButton = new JButton("Comment");
    int longWidth = addressLabel.getPreferredSize().width;
    GridBagConstraints constraints = new GridBagConstraints();
    JPanel p1 = new JPanel(new GridBagLayout());
    p1.setBorder(createBorder("Name"));
    constraints.gridx = 0;
    constraints.gridy = 0;
    constraints.anchor = GridBagConstraints.EAST;
    constraints.insets = new Insets(4,6,4,6);
    p1.add(nameLabel, constraints);
    constraints.gridx = 1;
    constraints.anchor = GridBagConstraints.WEST;
    p1.add(nameText, constraints);
    constraints.gridx = 2;
    constraints.anchor = GridBagConstraints.WEST;
    constraints.fill = GridBagConstraints.HORIZONTAL;
    constraints.weightx = 1.0;
    p1.add(Box.createHorizontalGlue(), constraints);
    constraints.gridx = 0;
    constraints.gridy = 1;
    constraints.fill = GridBagConstraints.NONE;
    constraints.weightx = 0.0;
    p1.add(Box.createHorizontalStrut(longWidth), constraints);
    JPanel p2 = new JPanel(new GridBagLayout());
    p2.setBorder(createBorder("Address"));
    constraints.gridx = 0;
    constraints.gridy = 0;
    constraints.anchor = GridBagConstraints.EAST;
    constraints.insets = new Insets(4,6,4,6);
    p2.add(addressLabel, constraints);
    constraints.gridx = 1;
    constraints.anchor = GridBagConstraints.WEST;
    p2.add(addressText, constraints);
    // extra label & component
    constraints.gridx = 2;
    constraints.anchor = GridBagConstraints.EAST;
    constraints.insets = new Insets(4,36,4,6);
    p2.add(countryLabel, constraints);
    constraints.gridx = 3;
    constraints.anchor = GridBagConstraints.WEST;
    constraints.insets = new Insets(4,6,4,6);
    p2.add(countryText, constraints);
    constraints.gridx = 0;
    constraints.gridy = 1;
    constraints.anchor = GridBagConstraints.EAST;
    constraints.insets = new Insets(4,6,4,6);
    p2.add(testLabel, constraints);
    constraints.gridx = 1;
    constraints.anchor = GridBagConstraints.WEST;
    p2.add(testText, constraints);
    // extra label & component
    constraints.gridx = 2;
    constraints.anchor = GridBagConstraints.EAST;
    constraints.insets = new Insets(4,36,4,6);
    p2.add(test2Label, constraints);
    constraints.gridx = 3;
    constraints.anchor = GridBagConstraints.WEST;
    constraints.insets = new Insets(4,6,4,6);
    p2.add(test2Text, constraints);
    constraints.gridx = 4;
    constraints.anchor = GridBagConstraints.WEST;
    constraints.fill = GridBagConstraints.HORIZONTAL;
    constraints.weightx = 1.0;
    p2.add(Box.createHorizontalGlue(), constraints);
    constraints.gridx = 0;
    constraints.gridy = 2;
    constraints.fill = GridBagConstraints.NONE;
    constraints.weightx = 0.0;
    p2.add(Box.createHorizontalStrut(longWidth), constraints);
    JPanel p3 = new JPanel(new GridBagLayout());
    p3.setBorder(createBorder("Phone"));
    constraints.gridx = 0;
    constraints.gridy = 0;
    constraints.anchor = GridBagConstraints.EAST;
    constraints.insets = new Insets(4,6,4,6);
    p3.add(phoneLabel, constraints);
    constraints.gridx = 1;
    constraints.anchor = GridBagConstraints.WEST;
    p3.add(phoneText, constraints);
    constraints.gridx = 2;
    constraints.anchor = GridBagConstraints.EAST;
    constraints.insets = new Insets(4,6,4,6);
    p3.add(extensionLabel, constraints);
    constraints.gridx = 3;
    constraints.anchor = GridBagConstraints.WEST;
    p3.add(extensionText, constraints);
    constraints.gridx = 2;
    constraints.anchor = GridBagConstraints.WEST;
    constraints.fill = GridBagConstraints.HORIZONTAL;
    constraints.weightx = 1.0;
    p3.add(Box.createHorizontalGlue(), constraints);
    constraints.gridx = 0;
    constraints.gridy = 1;
    constraints.fill = GridBagConstraints.NONE;
    constraints.weightx = 0.0;
    p3.add(Box.createHorizontalStrut(longWidth), constraints);
    JPanel p4 = new JPanel(new GridBagLayout());
    p4.setBorder(createBorder("Postal Code"));
    constraints.gridx = 0;
    constraints.gridy = 0;
    constraints.anchor = GridBagConstraints.EAST;
    constraints.insets = new Insets(4,6,4,6);
    p4.add(postalCodeLabel, constraints);
    constraints.gridx = 1;
    constraints.anchor = GridBagConstraints.WEST;
    p4.add(postalCodeText, constraints);
    constraints.gridx = 2;
    constraints.anchor = GridBagConstraints.WEST;
    constraints.fill = GridBagConstraints.HORIZONTAL;
    constraints.weightx = 1.0;
    p4.add(Box.createHorizontalGlue(), constraints);
    constraints.gridx = 0;
    constraints.gridy = 1;
    constraints.fill = GridBagConstraints.NONE;
    constraints.weightx = 0.0;
    p4.add(Box.createHorizontalStrut(longWidth), constraints);
    JPanel p5 = new JPanel(new GridBagLayout());
    constraints.gridx = 0;
    constraints.gridy = 0;
    constraints.anchor = GridBagConstraints.WEST;
    constraints.insets = new Insets(4,6,4,6);
    p5.add(commentButton, constraints);
    constraints.gridx = 1;
    constraints.anchor = GridBagConstraints.WEST;
    constraints.fill = GridBagConstraints.HORIZONTAL;
    constraints.weightx = 1.0;
    p5.add(Box.createHorizontalGlue(), constraints);
    constraints.gridx = 2;
    constraints.gridwidth = GridBagConstraints.RELATIVE;
    constraints.fill = GridBagConstraints.NONE;
    constraints.anchor = GridBagConstraints.EAST;
    p5.add(cancelButton, constraints);
    constraints.gridx = 3;
    constraints.gridwidth = GridBagConstraints.REMAINDER;
    constraints.anchor = GridBagConstraints.EAST;
    p5.add(saveButton, constraints);
    JPanel panel = new JPanel(new GridBagLayout());
    constraints.gridx = 0;
    constraints.gridy = 0;
    constraints.fill = GridBagConstraints.HORIZONTAL;
    constraints.weightx = 1.0;
    panel.add(p1, constraints);
    constraints.gridy = 1;
    panel.add(p2, constraints);
    constraints.gridy = 2;
    panel.add(p3, constraints);
    constraints.gridy = 3;
    panel.add(p4, constraints);
    constraints.gridy = 4;
    panel.add(p5, constraints);
    this.add(new JScrollPane(panel));
private Border createBorder(String title)
    TitledBorder b = new TitledBorder(title);
    b.setTitleColor(Color.RED.darker());
    return b;
public static void main(String args[]) {
    JFrame frame = new TitledBorderDemoNew();
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    frame.pack();
    frame.setVisible(true);
}Edited by: 833768 on 26-Apr-2011 10:32 AM

Help with count and sum query

Hi I am using oracle 10g. Trying to aggregate duplicate count records. I have so far:
SELECT 'ST' LEDGER,
CASE
WHEN c.Category = 'E' THEN 'Headcount Exempt'
ELSE 'Headcount Non-Exempt'
END
ACCOUNTS,
CASE WHEN a.COMPANY = 'ZEE' THEN 'OH' ELSE 'NA' END MARKET,
'MARCH_12' AS PERIOD,
COUNT (a.empl_id) head_count
FROM essbase.employee_pubinfo a
LEFT OUTER JOIN MMS_DIST_COPY b
ON a.cost_ctr = TRIM (b.bu)
INNER JOIN MMS_GL_PAY_GROUPS c
ON a.pay_group = c.group_code
WHERE a.employee_status IN ('A', 'L', 'P', 'S')
AND FISCAL_YEAR = '2012'
AND FISCAL_MONTH = 'MARCH'
GROUP BY a.company,
b.district,
a.cost_ctr,
c.category,
a.fiscal_month,
a.fiscal_year;
which gives me same rows with different head_counts. I am trying to combine the same rows as a total (one record). Do I use a subquery?

Hi,
Whenever you have a problem, please post a little sample data (CREATE TABLE and INSERT statements, relevant columns only) from all tables involved.
Also post the results you want from that data, and an explanation of how you get those results from that data, with specific examples.
user610131 wrote:
... which gives me same rows with different head_counts.If they have different head_counts, then the rows are not the same.
I am trying to combine the same rows as a total (one record). Do I use a subquery?Maybe. It's more likely that you need a different GROUP BY clause, since the GROUP BY clause determines how many rows of output there will be. I'll be able to say more after you post the sample data, results, and explanation.
You may want both a sub-query and a different GROUP BY clause. For example:
WITH    got_group_by_columns     AS
     SELECT a.empl_id
     ,     CASE
                    WHEN c.category = 'E'
              THEN 'Headcount Exempt'
                    ELSE 'Headcount Non-Exempt'
            END          AS accounts
     ,      CASE
                    WHEN a.company = 'ZEE'
                    THEN 'OH'
                    ELSE 'NA'
            END          AS market
     FROM              essbase.employee_pubinfo a
     LEFT OUTER JOIN mms_dist_copy             b ON   a.cost_ctr     = TRIM (b.bu)
     INNER JOIN       mms_gl_pay_groups        c ON   a.pay_group      = c.group_code
     WHERE     a.employee_status     IN ('A', 'L', 'P', 'S')
     AND        fiscal_year           = '2012'
     AND        fiscal_month          = 'MARCH'
SELECT    'ST'               AS ledger
,       accounts
,       market
,       'MARCH_12'          AS period
,       COUNT (empl_id)      AS head_count
FROM       got_group_by_columns
GROUP BY accounts
,            market
;But that's just a wild guess.
You said you wanted "Help with count and sum". I see the COUNT, but what do you want with SUM? No doubt this will be clearer after you post the sample data and results.
Edited by: Frank Kulash on Apr 4, 2012 5:31 PM

MOVED: [Athlon64] Need Help with X64 and Promise 20378

This topic has been moved to Operating Systems.
[Athlon64] Need Help with X64 and Promise 20378

I'm moving this the the Administration Forum. It seems more apporpiate there.

Need help with JTextArea and Scrolling

import java.awt.*;
import java.awt.event.*;
import java.text.DecimalFormat;
import javax.swing.*;
public class MORT_RETRY extends JFrame implements ActionListener
private JPanel keypad;
private JPanel buttons;
private JTextField lcdLoanAmt;
private JTextField lcdInterestRate;
private JTextField lcdTerm;
private JTextField lcdMonthlyPmt;
private JTextArea displayArea;
private JButton CalculateBtn;
private JButton ClrBtn;
private JButton CloseBtn;
private JButton Amortize;
private JScrollPane scroll;
private DecimalFormat calcPattern = new DecimalFormat("$###,###.00");
private String[] rateTerm = {"", "7years @ 5.35%", "15years @ 5.5%", "30years @ 5.75%"};
private JComboBox rateTermList;
double interest[] = {5.35, 5.5, 5.75};
int term[] = {7, 15, 30};
double balance, interestAmt, monthlyInterest, monthlyPayment, monPmtInt, monPmtPrin;
int termInMonths, month, termLoop, monthLoop;
public MORT_RETRY()
Container pane = getContentPane();
lcdLoanAmt = new JTextField();
lcdMonthlyPmt = new JTextField();
displayArea = new JTextArea();//DEFINE COMBOBOX AND SCROLL
rateTermList = new JComboBox(rateTerm);
scroll = new JScrollPane(displayArea);
scroll.setSize(600,170);
scroll.setLocation(150,270);//DEFINE BUTTONS
CalculateBtn = new JButton("Calculate");
ClrBtn = new JButton("Clear Fields");
CloseBtn = new JButton("Close");
Amortize = new JButton("Amortize");//DEFINE PANEL(S)
keypad = new JPanel();
buttons = new JPanel();//DEFINE KEYPAD PANEL LAYOUT
keypad.setLayout(new GridLayout( 4, 2, 5, 5));//SET CONTROLS ON KEYPAD PANEL
keypad.add(new JLabel("Loan Amount$ : "));
keypad.add(lcdLoanAmt);
keypad.add(new JLabel("Term of loan and Interest Rate: "));
keypad.add(rateTermList);
keypad.add(new JLabel("Monthly Payment : "));
keypad.add(lcdMonthlyPmt);
lcdMonthlyPmt.setEditable(false);
keypad.add(new JLabel("Amortize Table:"));
keypad.add(displayArea);
displayArea.setEditable(false);//DEFINE BUTTONS PANEL LAYOUT
buttons.setLayout(new GridLayout( 1, 3, 5, 5));//SET CONTROLS ON BUTTONS PANEL
buttons.add(CalculateBtn);
buttons.add(Amortize);
buttons.add(ClrBtn);
buttons.add(CloseBtn);//ADD ACTION LISTENER
CalculateBtn.addActionListener(this);
ClrBtn.addActionListener(this);
CloseBtn.addActionListener(this);
Amortize.addActionListener(this);
rateTermList.addActionListener(this);//ADD PANELS
pane.add(keypad, BorderLayout.NORTH);
pane.add(buttons, BorderLayout.SOUTH);
pane.add(scroll, BorderLayout.CENTER);
addWindowListener( new WindowAdapter()
public void windowClosing(WindowEvent e)
System.exit(0);
public void actionPerformed(ActionEvent e)
String arg = lcdLoanAmt.getText();
int combined = Integer.parseInt(arg);
if (e.getSource() == CalculateBtn)
try
JOptionPane.showMessageDialog(null, "Got try here", "Error", JOptionPane.ERROR_MESSAGE);
catch(NumberFormatException ev)
JOptionPane.showMessageDialog(null, "Got here", "Error", JOptionPane.ERROR_MESSAGE);
if ((e.getSource() == CalculateBtn) && (arg != null))
try{
if ((e.getSource() == CalculateBtn) && (rateTermList.getSelectedIndex() == 1))
monthlyInterest = interest[0] / (12 * 100);
termInMonths = term[0] * 12;
monthlyPayment = combined * (monthlyInterest / (1 - (Math.pow (1 + monthlyInterest, -termInMonths))));
lcdMonthlyPmt.setText(calcPattern.format(monthlyPayment));
if ((e.getSource() == CalculateBtn) && (rateTermList.getSelectedIndex() == 2))
monthlyInterest = interest[1] / (12 * 100);
termInMonths = term[1] * 12;
monthlyPayment = combined * (monthlyInterest / (1 - (Math.pow (1 + monthlyInterest, -termInMonths))));
lcdMonthlyPmt.setText(calcPattern.format(monthlyPayment));
if ((e.getSource() == CalculateBtn) && (rateTermList.getSelectedIndex() == 3))
monthlyInterest = interest[2] / (12 * 100);
termInMonths = term[2] * 12;
monthlyPayment = combined * (monthlyInterest / (1 - (Math.pow (1 + monthlyInterest, -termInMonths))));
lcdMonthlyPmt.setText(calcPattern.format(monthlyPayment));
catch(NumberFormatException ev)
JOptionPane.showMessageDialog(null, "Invalid Entry!\nPlease Try Again", "Error", JOptionPane.ERROR_MESSAGE);
} //IF STATEMENTS FOR AMORTIZATION
if ((e.getSource() == Amortize) && (rateTermList.getSelectedIndex() == 1))
loopy(7, 5.35);
if ((e.getSource() == Amortize) && (rateTermList.getSelectedIndex() == 2))
loopy(15, 5.5);
if ((e.getSource() == Amortize) && (rateTermList.getSelectedIndex() == 3))
loopy(30, 5.75);
if (e.getSource() == ClrBtn)
rateTermList.setSelectedIndex(0);
lcdLoanAmt.setText(null);
lcdMonthlyPmt.setText(null);
displayArea.setText(null);
if (e.getSource() == CloseBtn)
System.exit(0);
private void loopy(int lTerm,double lInterest)
double total, monthly, monthlyrate, monthint, monthprin, balance, lastint, paid;
int amount, months, termloop, monthloop;
String lcd2 = lcdLoanAmt.getText();
amount = Integer.parseInt(lcd2);
termloop = 1;
paid = 0.00;
monthlyrate = lInterest / (12 * 100);
months = lTerm * 12;
monthly = amount *(monthlyrate/(1-Math.pow(1+monthlyrate,-months)));
total = months * monthly;
balance = amount;
while (termloop <= lTerm)
displayArea.setCaretPosition(0);
displayArea.append("\n");
displayArea.append("Year " + termloop + " of " + lTerm + ": payments\n");
displayArea.append("\n");
displayArea.append("Month\tMonthly\tPrinciple\tInterest\tBalance\n");
monthloop = 1;
while (monthloop <= 12)
monthint = balance * monthlyrate;
monthprin = monthly - monthint;
balance -= monthprin;
paid += monthly;
displayArea.setCaretPosition(0);
displayArea.append(monthloop + "\t" + calcPattern.format(monthly) + "\t" + calcPattern.format(monthprin) + "\t");
displayArea.append(calcPattern.format(monthint) + "\t" + calcPattern.format(balance) + "\n");
monthloop ++;
termloop ++;
public static void main(String args[])
MORT_RETRY f = new MORT_RETRY();
f.setTitle("MORTGAGE PAYMENT CALCULATOR");
f.setBounds(600, 600, 500, 500);
f.setLocationRelativeTo(null);
f.setVisible(true);
}need help with displaying the textarea correctly and the scroll bar please.
Message was edited by:
new2this2020

What's the problem you're having ???
PS.

Help with BufferedImage and JPanel

I have a program that should display some curves, but thats not the problem, the real problem is when i copy the image contained in the JPanel to the buffered image then i draw something there and draw it back to the JPanel. My panel initialy its white but after the operation it gets gray
Please if some one could help with this
here is my code divided in three classes
//class VentanaPrincipal
package gui;
import java.awt.BorderLayout;
import java.awt.FlowLayout;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.Insets;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.image.BufferedImage;
import javax.swing.BorderFactory;
import javax.swing.JButton;
import javax.swing.JLabel;
import javax.swing.JSeparator;
import javax.swing.border.LineBorder;
import javax.swing.JMenuItem;
import javax.swing.JPanel;
import javax.swing.JMenu;
import javax.swing.JMenuBar;
* This code was edited or generated using CloudGarden's Jigloo
* SWT/Swing GUI Builder, which is free for non-commercial
* use. If Jigloo is being used commercially (ie, by a corporation,
* company or business for any purpose whatever) then you
* should purchase a license for each developer using Jigloo.
* Please visit www.cloudgarden.com for details.
* Use of Jigloo implies acceptance of these licensing terms.
* A COMMERCIAL LICENSE HAS NOT BEEN PURCHASED FOR
* THIS MACHINE, SO JIGLOO OR THIS CODE CANNOT BE USED
* LEGALLY FOR ANY CORPORATE OR COMMERCIAL PURPOSE.
public class VentanaPrincipal extends javax.swing.JFrame {
          //Set Look & Feel
          try {
               javax.swing.UIManager.setLookAndFeel("com.sun.java.swing.plaf.windows.WindowsLookAndFeel");
          } catch(Exception e) {
               e.printStackTrace();
     private JMenuItem helpMenuItem;
     private JMenu jMenu5;
     private JMenuItem deleteMenuItem;
     private JSeparator jSeparator1;
     private JMenuItem pasteMenuItem;
     private JLabel jLabel4;
     private JLabel jLabel5;
     private JLabel jLabel3;
     private JLabel jLabel2;
     private JLabel jLabel1;
     private JButton jSPLineButton;
     private JButton jHermiteButton;
     private JButton jBezierButton;
     private JPanel jPanel2;
     private JPanel jPanel1;
     private JMenuItem jResetMenuItem1;
     private JMenuItem copyMenuItem;
     private JMenuItem cutMenuItem;
     private JMenu jMenu4;
     private JMenuItem exitMenuItem;
     private JSeparator jSeparator2;
     private JMenu jMenu3;
     private JMenuBar jMenuBar1;
      * Variables no autogeneradas
     private int botonSeleccionado;
     * Auto-generated main method to display this JFrame
     public static void main(String[] args) {
          VentanaPrincipal inst = new VentanaPrincipal();
          inst.setVisible(true);
     public VentanaPrincipal() {
          super();
          initGUI();
     private void initGUI() {
          try {
                    this.setTitle("Info3 TP 2");
                         jPanel1 = new pizarra();
                         getContentPane().add(jPanel1, BorderLayout.WEST);
                         jPanel1.setPreferredSize(new java.awt.Dimension(373, 340));
                         jPanel1.setMinimumSize(new java.awt.Dimension(10, 342));
                         jPanel1.setBackground(new java.awt.Color(0,0,255));
                         jPanel1.setBorder(BorderFactory.createCompoundBorder(
                              new LineBorder(new java.awt.Color(0, 0, 0), 1, true),
                              null));
                         BufferedImage bufimg = (BufferedImage)jPanel1.createImage(jPanel1.getWidth(), jPanel1.getHeight());
                         ((pizarra) jPanel1).setBufferedImage(bufimg);
                         jPanel2 = new JPanel();
                         getContentPane().add(jPanel2, BorderLayout.CENTER);
                         GridBagLayout jPanel2Layout = new GridBagLayout();
                         jPanel2Layout.rowWeights = new double[] {0.0, 0.0, 0.0, 0.0};
                         jPanel2Layout.rowHeights = new int[] {69, 74, 76, 71};
                         jPanel2Layout.columnWeights = new double[] {0.0, 0.0, 0.1};
                         jPanel2Layout.columnWidths = new int[] {83, 75, 7};
                         jPanel2.setLayout(jPanel2Layout);
                              jBezierButton = new JButton();
                              jPanel2.add(jBezierButton, new GridBagConstraints(1, 0, 1, 1, 0.0, 0.0, GridBagConstraints.CENTER, GridBagConstraints.BOTH, new Insets(0, 0, 0, 0), 0, 0));
                              jBezierButton.setText("Bezier");
                              jBezierButton.setFont(new java.awt.Font("Tahoma",0,10));
                              jBezierButton.addActionListener(new ActionListener() {
                                   public void actionPerformed(ActionEvent evt) {
                                        bezierActionPerformed();
                              jHermiteButton = new JButton();
                              jPanel2.add(jHermiteButton, new GridBagConstraints(1, 1, 1, 1, 0.0, 0.0, GridBagConstraints.CENTER, GridBagConstraints.BOTH, new Insets(0, 0, 0, 0), 0, 0));
                              jHermiteButton.setText("Hermite");
                              jHermiteButton.setFont(new java.awt.Font("Tahoma",0,10));
                              jSPLineButton = new JButton();
                              jPanel2.add(jSPLineButton, new GridBagConstraints(1, 2, 1, 1, 0.0, 0.0, GridBagConstraints.CENTER, GridBagConstraints.BOTH, new Insets(0, 0, 0, 0), 0, 0));
                              jSPLineButton.setText("SP Line");
                              jSPLineButton.setFont(new java.awt.Font("Tahoma",0,10));
                              jLabel1 = new JLabel();
                              jPanel2.add(jLabel1, new GridBagConstraints(0, 3, 1, 1, 0.0, 0.0, GridBagConstraints.CENTER, GridBagConstraints.NONE, new Insets(0, 0, 0, 0), 0, 0));
                              jLabel1.setText("Posicion Mouse");
                              jLabel2 = new JLabel();
                              jPanel2.add(jLabel2, new GridBagConstraints(1, 3, 1, 1, 0.0, 0.0, GridBagConstraints.NORTH, GridBagConstraints.NONE, new Insets(12, 0, 0, 0), 0, 0));
                              jLabel2.setText("X:");
                              jLabel3 = new JLabel();
                              jPanel2.add(jLabel3, new GridBagConstraints(1, 3, 1, 1, 0.0, 0.0, GridBagConstraints.SOUTH, GridBagConstraints.NONE, new Insets(0, 0, 12, 0), 0, 0));
                              jLabel3.setText("Y:");
                              jLabel4 = new JLabel();
                              jPanel2.add(jLabel4, new GridBagConstraints(2, 3, 1, 1, 0.0, 0.0, GridBagConstraints.NORTH, GridBagConstraints.NONE, new Insets(12, 0, 0, 0), 0, 0));
                              jLabel4.setText("-");
                              jLabel5 = new JLabel();
                              jPanel2.add(jLabel5, new GridBagConstraints(2, 3, 1, 1, 0.0, 0.0, GridBagConstraints.SOUTH, GridBagConstraints.NONE, new Insets(0, 0, 12, 0), 0, 0));
                              jLabel5.setText("-");
               this.setSize(600, 400);
                    jMenuBar1 = new JMenuBar();
                    setJMenuBar(jMenuBar1);
                         jMenu3 = new JMenu();
                         jMenuBar1.add(jMenu3);
                         jMenu3.setText("Archivo");
                              jSeparator2 = new JSeparator();
                              jMenu3.add(jSeparator2);
                              exitMenuItem = new JMenuItem();
                              jMenu3.add(exitMenuItem);
                              exitMenuItem.setText("Exit");
                              jResetMenuItem1 = new JMenuItem();
                              jMenu3.add(jResetMenuItem1);
                              jResetMenuItem1.setText("Reset");
                         jMenu4 = new JMenu();
                         jMenuBar1.add(jMenu4);
                         jMenu4.setText("Edit");
                              cutMenuItem = new JMenuItem();
                              jMenu4.add(cutMenuItem);
                              cutMenuItem.setText("Cut");
                              copyMenuItem = new JMenuItem();
                              jMenu4.add(copyMenuItem);
                              copyMenuItem.setText("Copy");
                              pasteMenuItem = new JMenuItem();
                              jMenu4.add(pasteMenuItem);
                              pasteMenuItem.setText("Paste");
                              jSeparator1 = new JSeparator();
                              jMenu4.add(jSeparator1);
                              deleteMenuItem = new JMenuItem();
                              jMenu4.add(deleteMenuItem);
                              deleteMenuItem.setText("Delete");
                         jMenu5 = new JMenu();
                         jMenuBar1.add(jMenu5);
                         jMenu5.setText("Help");
                              helpMenuItem = new JMenuItem();
                              jMenu5.add(helpMenuItem);
                              helpMenuItem.setText("Help");
          } catch (Exception e) {
               e.printStackTrace();
     private void bezierActionPerformed(){
          botonSeleccionado = 1;
          ((pizarra) jPanel1).setTipoFigura(botonSeleccionado);
          ((pizarra) jPanel1).pintarGrafico();
//class graphUtils
package func;
import java.awt.Image;
import java.awt.Point;
import java.awt.image.BufferedImage;
public class graphUtils {
     public static void dibujarPixel(BufferedImage img, int x, int y, int color){
          img.setRGB(x, y, color);
     public static void dibujarLinea(BufferedImage img, int x0, int y0, int x1, int y1, int color){
        int dx = x1 - x0;
        int dy = y1 - y0;
        if (Math.abs(dx) > Math.abs(dy)) {          // Pendiente m < 1
            float m = (float) dy / (float) dx;
            float b = y0 - m*x0;
            if(dx < 0) dx = -1; else dx = 1;
            while (x0 != x1) {
                x0 += dx;
                dibujarPixel(img, x0, Math.round(m*x0 + b), color);
        } else
        if (dy != 0) {                              // Pendiente m >= 1
            float m = (float) dx / (float) dy;
            float b = x0 - m*y0;
            if(dy < 0) dy = -1; else dy = 1;
            while (y0 != y1) {
                y0 += dy;
                dibujarPixel(img, Math.round(m*y0 + b), y0, color);
     public static void dibujarBezier(BufferedImage img, Point puntos, int color){
//class pizarra
package gui;
import javax.swing.*;
import sun.awt.VerticalBagLayout;
import sun.security.krb5.internal.bh;
import java.awt.Color;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Image;
import java.awt.Point;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import java.awt.image.BufferedImage;
import java.util.ArrayList;
import func.graphUtils;
* esta clase pizarra extiende la clase JPanel y se agregan las funciones de pintado
* y rellenado que se muestra en pantalla dentro del panel que se crea con esta clase
* @author victorg
public class pizarra extends JPanel implements MouseListener{
     private int tipoFigura;
     BufferedImage bufferImagen;
     Image img;
     Graphics img_gc;
     private Color colorRelleno, colorLinea;
     private Point puntosBezier[] = new Point[3];
     public pizarra(){
          super();
          addMouseListener(this);
          //this.setBackground(Color.BLUE);
          colorLinea = Color.BLUE;
     public void setTipoFigura(int seleccion){
          // se setea para ver si es bezier, hermite, SP line
          tipoFigura = seleccion;
     public void setTipoRelleno(int seleccion){
     public void setColorRelleno(Color relleno){
          colorRelleno = relleno;
     public void setColorLinea(Color linea){
          colorLinea = linea;
     public void setBufferedImage(BufferedImage bufimg){
          bufferImagen = bufimg;
     public void pintarGrafico(){
          Graphics g = this.getGraphics();
          g.setColor(colorLinea);
          //accion ejecutada cuando se selecciona para graficar un poligono
          if(tipoFigura == 1){// bezier
               if(bufferImagen == null){
                    //mantiene guardada la imagen cuando la pantalla pasa a segundo plano
                    bufferImagen = new BufferedImage(getWidth(), getHeight(), BufferedImage.TYPE_INT_RGB);
                    this.setBackground(Color.WHITE);
                    bufferImagen = (BufferedImage)createImage(getWidth(), getHeight());
                    //bufferImagen = this.createImage(getWidth(), getHeight());
               //g.drawImage(bufferImagen,0,0,this);
               graphUtils.dibujarLinea(bufferImagen,10, 10, 50, 50, colorLinea.getRGB());
               g.drawImage(bufferImagen,0,0,this);
     protected void paintComponent(Graphics g) { // llamado al repintar
          //setBackground(colorFondo);
          super.paintComponent(g);
//          Graphics2D g2 = (Graphics2D)g;
//          g2.drawImage(bufferImagen, 0,0, this);
//          g2.dispose();
     public void mouseClicked(MouseEvent arg0) {
     public void mousePressed(MouseEvent arg0) {
          // TODO Auto-generated method stub
     public void mouseReleased(MouseEvent arg0) {
          // TODO Auto-generated method stub
     public void mouseEntered(MouseEvent arg0) {
          // TODO Auto-generated method stub
     public void mouseExited(MouseEvent arg0) {
          // TODO Auto-generated method stub
}

1) Swing related questions should be posted in the Swing forum.
Custom painting should be done in the paintComponent(..) method. You created a "pintarGraphico" method to do the custom painting, but that method is only execute once. When Java determines that the panel needs to be repainted, the paintComponent() method is executed which simply does a super.paintComponent(), which in turn simply paints the background of the panel overwriting you custom painting.

Help with JLabel

Hello all. I am fairly new to Java and having a problem setting the text in a JLabel. I am trying to create a calculator program and when the user clicks a button I want that number to appear in a JLabel at the top. I used output.setText("7"); but when I compiled it said <identifier> expected. I will paste the full code below and would appreciate any help. Also, is there a getText function with JLabel, because I need to get what is currently in the output field and concatenate it with the number pressed.
Thanks in advance for your help,
Jeremy
* Write a description of class calculator here.
* @author (Jeremy Kruer)
* @version (11/19/02)
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class calculator extends JFrame
private JButton one, two, three, four, five, six, seven, eight, nine, zero, dec, eq, plus, minus, mult, div;
private JLabel output;
private Container container;
//set up GUI
public calculator()
//Create Title
super("Calculator");
//Set size and make visible
setSize( 400, 400 );
setVisible( true );
container = getContentPane();
container.setLayout( new FlowLayout() );
//set up output
output = new JLabel();
container.add( output );
//set up seven and register its event handler
seven = new JButton( " 7 " );
seven.addActionListener(
//anonymouse inner class
new ActionListener()
//add a seven to the output diplay when clicked
output.setText( "7" );
}//end anonymouse inner class
); //end call to addActionListener
container.add( seven );
//set up eight
eight = new JButton( " 8 " );
container.add( eight );
//set up nine
nine = new JButton( " 9 " );
container.add( nine );
//set up div
div = new JButton( " / " );
container.add( div );
//set up four
four = new JButton( " 4 " );
container.add( four );
//set up five
five = new JButton( " 5 " );
container.add( five );
//set up six
six = new JButton( " 6 " );
container.add( six );
//set up mult
mult = new JButton( " * " );
container.add( mult );
//set up one
one = new JButton( " 1 " );
container.add( one );
//set up two
two = new JButton( " 2 " );
container.add( two );
//set up three
three = new JButton( " 3 " );
container.add( three );
//set up minus
minus = new JButton( " - " );
container.add( minus );
//set up zero
zero = new JButton( " 0 " );
container.add( zero );
//set up dec
dec = new JButton( " . " );
container.add( dec );
//set up eq
eq = new JButton( " = " );
container.add( eq );
//set up plus
plus = new JButton( " +" );
container.add( plus );
//Set size and make visible
setSize( 220, 250 );
setVisible( true );
//execute application
public static void main( String args[] )
calculator application = new calculator();
application.setDefaultCloseOperation( JFrame.EXIT_ON_CLOSE );
}

I played with the lauout a bit and added the actionListener:
you will see what you click on !!
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.border.*;
public class calcu extends JFrame implements ActionListener
     private JButton one, two, three, four, five, six, seven, eight, nine, zero, dec, eq, plus, minus, mult, div;
     private JLabel   output;
public calcu()
     super("Calculator");
     JPanel container = new JPanel();
     container.setLayout(new FlowLayout(FlowLayout.LEFT));
     output = new JLabel("");
     output.setBorder(new MatteBorder(2,2,2,2,Color.gray));
     output.setPreferredSize(new Dimension(1,26));
     getContentPane().setBackground(Color.white);
     getContentPane().add("North",output);
     getContentPane().add("Center",container);
//set up seven and register its event handler
     seven = new JButton(" 7 ");
     container.add(seven);
     seven.addActionListener(this);
//set up eight
     eight = new JButton(" 8 ");
     container.add(eight);
     eight.addActionListener(this);
//set up nine
     nine = new JButton( " 9 " );
     container.add( nine );
     nine.addActionListener(this);
//set up div
     div = new JButton( " / " );
     container.add( div );
     div.addActionListener(this);
//set up four
     four = new JButton( " 4 " );
     container.add( four );
     four.addActionListener(this);
//set up five
     five = new JButton( " 5 " );
     container.add( five );
     five.addActionListener(this);
//set up six
     six = new JButton( " 6 " );
     container.add( six );
     six.addActionListener(this);
//set up mult
     mult = new JButton( " * " );
     container.add( mult );
     mult.addActionListener(this);
//set up one
     one = new JButton( " 1 " );
     container.add( one );
     one.addActionListener(this);
//set up two
     two = new JButton( " 2 " );
     container.add( two );
     two.addActionListener(this);
//set up three
     three = new JButton( " 3 " );
     container.add( three );
     three.addActionListener(this);
//set up minus
     minus = new JButton( " - " );
     container.add( minus );
     minus.addActionListener(this);
//set up zero
     zero = new JButton( " 0 " );
     container.add( zero );
     zero.addActionListener(this);
//set up dec
     dec = new JButton( " . " );
     container.add( dec );
     dec.addActionListener(this);
//set up eq
     eq = new JButton( " = " );
     container.add( eq );
     eq.addActionListener(this);
//set up plus
     plus = new JButton( " +" );
     container.add( plus );
     plus.addActionListener(this);
//Set size and make visible
     setSize(220,250);
     setResizable(false);
     setVisible( true );
public void actionPerformed(ActionEvent ae)
     JButton but = (JButton)ae.getSource();
     output.setText(but.getText());
//execute application
public static void main( String args[] )
     calcu application = new calcu();
     application.setDefaultCloseOperation( JFrame.EXIT_ON_CLOSE );
} Noah

Having probelm with JLabel and setText

I posted a message in Java Programming but I think it will be more appropriate here. I am trying to create a calculator so I want my JLabel(output) to display the number of the button that is clicked on. I used output.setText("7") but I get an error when compiling saying <identifier> expected. Any advice would be great. Also, is there a getText method in JLabel? I need to concatenate the current contents of JLabel and the value of the button pushed. For example:
output.setText( output.getText() + "7" );
Anyways, here is my code. I tried to make it indent so it is easier to read but it doesn't show up once I post it.
Thanks for you help.
* Write a description of class calculator here.
* @author (Jeremy Kruer)
* @version (11/19/02)
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class calculator extends JFrame
private JButton one, two, three, four, five, six, seven, eight, nine, zero, dec, eq, plus, minus, mult, div;
private JLabel output;
private Container container;
//set up GUI
public calculator()
//Create Title
super("Calculator");
//Set size and make visible
setSize( 400, 400 );
setVisible( true );
container = getContentPane();
container.setLayout( new FlowLayout() );
//set up output
output = new JLabel();
container.add( output );
//set up seven and register its event handler
seven = new JButton( " 7 " );
seven.addActionListener(
//anonymouse inner class
new ActionListener()
//add a seven to the output diplay when clicked
output.setText( "7" );
}//end anonymouse inner class
); //end call to addActionListener
container.add( seven );
//set up eight
eight = new JButton( " 8 " );
container.add( eight );
//set up nine
nine = new JButton( " 9 " );
container.add( nine );
//set up div
div = new JButton( " / " );
container.add( div );
//set up four
four = new JButton( " 4 " );
container.add( four );
//set up five
five = new JButton( " 5 " );
container.add( five );
//set up six
six = new JButton( " 6 " );
container.add( six );
//set up mult
mult = new JButton( " * " );
container.add( mult );
//set up one
one = new JButton( " 1 " );
container.add( one );
//set up two
two = new JButton( " 2 " );
container.add( two );
//set up three
three = new JButton( " 3 " );
container.add( three );
//set up minus
minus = new JButton( " - " );
container.add( minus );
//set up zero
zero = new JButton( " 0 " );
container.add( zero );
//set up dec
dec = new JButton( " . " );
container.add( dec );
//set up eq
eq = new JButton( " = " );
container.add( eq );
//set up plus
plus = new JButton( " +" );
container.add( plus );
//Set size and make visible
setSize( 220, 250 );
setVisible( true );
//execute application
public static void main( String args[] )
calculator application = new calculator();
application.setDefaultCloseOperation( JFrame.EXIT_ON_CLOSE );

// not tested but try it ...
1. put an empty string into the JLabel
declare
String labString = "";
(and declare the JLabel too)
2. initialise label - init() {
myLabel = new JLabel(labString)
3. activate
actionPerformed(ActionEvent evt) {
if (evt.getSource()==button#7) {
labString = getActionCommand();
myLabel.setText(labString);
validate();
Something like that anyway - it should work + if you 'play' with it, you can probably make it a bit more efficiently than the methods I've outlined here.

Help with Mathscipt and for loop

I have a code in Mathscript/matlab and I need to output the array out. One option is my first code,the other option is using a for loop, but I am only getting the last ouput out. I need to get the whole output out.
Any help.
Thanks
Solved!
Go to Solution.
Attachments:
Help with Mathscript_for loop.vi ‏115 KB
Help with Mathscript_for loop2.vi ‏84 KB

Here's how it should look like.
Message Edited by altenbach on 10-30-2008 05:12 PM
LabVIEW Champion . Do more with less code and in less time .
Attachments:
MathscriptInFOR.png ‏15 KB

Help with encapsulation and a specific case of design

Hello all. I have been playing with Java (my first real language and first OOP language) for a couple months now. Right now I am trying to write my first real application, but I want to design it right and I am smashing my head against the wall with my data structure, specifically with encapsulation.
I go into detail about my app below, but it gets long so for those who don't want to read that far, let me just put these two questions up front:
1) How do principles of encapsulation change when members are complex objects rather than primitives? If the member objects themselves have only primitive members and show good encapsulation, does it make sense to pass a reference to them? Or does good encapsulation demand that I deep-clone all the way to the bottom of my data structure and pass only cloned objects through my top level accessors? Does the analysis change when the structure gets three or four levels deep? Don't DOM structures built of walkable nodes violate basic principles of encapsulation?
2) "Encapsulation" is sometimes used to mean no public members, othertimes to mean no public members AND no setter methods. The reasons for the first are obvious, but why go to the extreme of the latter? More importantly HOW do you go to the extreme of the latter? Would an "updatePrices" method that updates encapsulated member prices based on calculations, taking a single argument of say the time of year be considered a "setter" method that violates the stricter vision of encapsulation?
Even help with just those two questions would be great. For the masochistic, on to my app... The present code is at
http://www.immortalcoil.org/drake/Code.zip
The most basic form of the application is statistics driven flash card software for Japanese Kanji (Chinese characters). For those who do not know, these are ideographic characters that represent concepts rather than sounds. There are a few thousand. In abstract terms, my data structure needs to represent the following.
- There are a bunch of kanji.
   Each kanji is defined by:
   - a single character (the kanji itself); and
   - multiple readings which fall into two categories of "on" and "kun".
      Each reading is defined by:
      - A string of hiragana or katakana (Japanese phoenetic characters); and
      - Statistics that I keep to represent knowledge of that reading/kanji pair.Ideally the structure should be extensible. Later I might want to add statistics associated with the character itself rather than individual readings, for example. Right now I am thinking of building a data structure like so:
- A Vector that holds:
   - custom KanjiEntry objects that each hold
      - a kanji in a primitive char value; and
      - two (on, kun) arrays or Vectors of custom Reading objects that hold
         - the reading in a String; and
         - statistics of some sort, probably in primitive valuesFirst of all, is this approach sensible in the rough outlines?
Now, I need to be able to do the obvious things... save to and load from file, generate tables and views, and edit values. The quesiton of editting values raises the questions I identified above as (1) and (2). Say I want to pull up a reading, quiz the user on it, and update its statistics based on whether the user got it right or wrong. I could do all this through the KanjiEntry object with a setter method that takes a zillion arguments like:
theKanjiEntry.setStatistic(
"on",   // which set of readings
2,      // which element in that array or Vector
"score", // which statistic
98);      // the valueOr I could pass a clone of the Reading object out, work with that, then tell the KanjiEntry to replace the original with my modified clone.
My instincts balk at the first approach, and a little at the second. Doesn't it make more sense to work with a reference to the Reading object? Or is that bad encapsulation?
A second point. When running flash cards, I do not care about the subtlties of the structure, like whether a reading is an on or a kun (although this is important when browsing a table representing the entire structure). All I really care about is kanij/reading pairings. And I should be able to quickly poll the Reading objects to see which ones need quizzing the most, based on their statistics. I was thinking of making a nice neat Hashtable with the keys being the kanji characters in Strings (not the KanjiEntry objects) and the values being the Reading objects. The result would be two indeces to the Reading objects... the basic structure and my ad hoc hashtable for runninq quizzes. Then I would just make sure that they stay in sync in terms of the higher level structure (like if a whole new KanjiEntry got added). Is this bad form, or even downright dangerous?
Apart from good form, the other consideration bouncing around in my head is that if I get all crazy with deep cloning and filling the bottom level guys with instance methods then this puppy is going to get bloated or lag when there are several thousand kanji in memory at once.
Any help would be appreciated.
Drake

Usually by better design. Move methods that use the
getters inside the class that actually has the data....
As a basic rule of thumb:
The one who has the data is the one using it. If
another class needs that data, wonder what for and
consider moving that operation away from that class.
Or move from pull to push: instead of A getting
something from B, have B give it to A as a method
call argument.Thanks for the response. I think I see what you are saying.. in my case it is something like this.
Solution 1 (disfavored):
public class kanjiDrill{ // a chunk of Swing GUI or something
     public void runDrill(Vector kanjiEntries){
          KanjiEntry currentKanjiEntry = kanjiEntries.elementAt(0); // except really I will pick one randomly
          char theKanji = currentKanjiEntry.getKanji();
          String theReading = currentKanjiEntry.getReading();
          // build and show a flashcard based on theKanji and theReading
          // use a setter to change currentKanji's data based on whether the user answers correctly;
}Solution 2 (favored):
public class kanjiDrill{ // a chunk of Swing GUI or something
     public void runDrill(Vector kanjiEntries){
          KanjiEntry currentKanjiEntry = kanjiEntries.elementAt(0); // except really I will pick one randomly
          currentKanji.buildAndShowFlashcard(); // method includes updating stats
}I can definitely see the advantages to this, but two potential reasons to think hard about it occur to me right away. First, if this process is carried out to a sufficient extreme the objects that hold my data end up sucking in all the functionality of my program and my objects stop resembling natural concepts.
In your shopping example, say you want to generate price tags for the items. The price tags can be generated with ONLY the raw price, because we do not want the VAT on them. They are simple GIF graphics that have the price printed on a an irregular polygon. Should all that graphics generating code really go into the item objects, or should we just get the price out of the object with a simple getter method and then make the tags?
My second concern is that the more instance methods I put into my bottom level data objects the bigger they get, and I intend to have thousands of these things in memory. Is there a balance to strike at some point?
It's not really a setter. Outsiders are not setting
the items price - it's rather updating its own price
given an argument. This is exactly how it should be,
see my above point. A breach of encapsulation would
be: another object gets the item price, re-calculates
it using a date it knows, and sets the price again.
You can see yourself that pushing the date into the
item's method is much beter than breaching
encapsulation and getting and setting the price.So the point is not "don't allow access to the members" (which after all you are still doing, albeit less directly) so much as "make sure that any functionality implicated in working with the members is handled within the object," right? Take your shopping example. Say we live in a country where there is no VAT and the app will never be used internationally. Then we would resort to a simple setter/getter scheme, right? Or is the answer that if the object really is pure data are almost so, then it should be turned into a standard java.util collection instead of a custom class?
Thanks for the help.
Drake

Can anyone help with iPlayer and Sky Mobile?

Ok, I'm so close to giving up with this useless phone. There are 3 apps on my N97 which give me a constant headache.
BBC iPlayer
Sky Mobile*
YouTube
*I should point out that I only use Sky Mobile to set recordings on my Sky+. I do not use it for, nor have any desire to use it for actually watching Mobile TV.
All of these apps work absolutely fine over my home WiFi network. It's when I try to use them over 3G (my Vodafone Live! connection) that I start running in to trouble.
All 3 give me connection problems, errors, and simply refuse to load half the time when on 3G. I got so annoyed I just did a hard reset the other week, and magically all three started working again. However, now 2 of them are failing me again. YouTube (touch wood) is working fine at the moment, but iPlayer and Sky Mobile just aren't.
iPlayer sometimes works. But sometimes I get script errors (unable to load content), and sometimes it says something about checking my connection settings. I wouldn't mind but it's not actually possible to access any options for the iPlayer. Even in application settings there are no options you're able to set.
Sky Mobile simply flat out refuses to work ever on 3G. But it did after I did a hard reset for a couple of weeks, now it just stopped working! It wont even load. It just gives the error message 'Unable to connect to network - please check connection settings" or something along those lines.
I've tried so many different things. Tried setting my internet connections to 'always ask', tried setting it to default to Vodafone Live! all the time, tried setting my video streaming settings to WAP, all sorts. Every combination I can think of.
I just can't wait to get rid of this phone. I've put so many people off buying one. They see it and think it's all swish and cool, and I just say 'Don't. You'll regret it'. I can't wait for my contract to be up so I can upgrade to an iPhone now Vodafone have got them.
Can anyone help with these problems? Thanks in advance, but I don't hold out much hope...

About iPlayer.
Have a chat with Vodaphone. Streaming iPlayer over 3G IS allowed on Vodaphone contract, unlike my O2 contract. As long as your contract allows it, and you have the correct AP address, it should be fine. Vodaphone should be able to give you the setting.
Mine only works over Wlan.
FWIW, "... streaming over 3G is not currently available on iPhone handsets on any mobile network".
p.s. Just to be clear. You say "Tried setting my internet connections to 'always ask', tried setting it to default to Vodafone Live!".
iPlayer uses the Nokia browser "Web". So that's where you should make the setting "Ask when needed". It should then offer you the choice of whatever you've set in Destinations> Internet> then select whatever you've chosen as your GPRS connection.(as advised, or sent to you by Vodaphone).

Help with exporting and image size or boundaries?

I am trying to slide the cat into the scene a little at a time foir an animation project I am working on. However, when I export the image the back ground of the image expands with a checkered back ground( showing here in white) and shows the whole cat.
How do I just show a little of the cat on the image at a time when exporting. I am trying to give the impression that the cat is walking into the room. I do not want to have to cut the cat up.
I would be thankful for any suggestions.

Provide the name of the program you are using so a Moderator may move this message to the correct program forum
This Cloud forum is not about help with program problems... a program would be Photoshop or Lighroom or Muse or ???

Help with JLabels and JTextFields

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