Barcode scanner inserting character by character - java

Ive been trying a while and cant work out a way to get the text out of a textbox only after the barcode scanner has finished scanning. I am using Swing Framework and Java. My Code works if the text is pasted (Ctrl + V) into the JTextbox but the barcode scanner just does not work as my methods run for every couple of characters of the barcode in turn.
textField.getDocument().addDocumentListener(new DocumentListener() {
public void changedUpdate(DocumentEvent e) {
// warn();
}
public void removeUpdate(DocumentEvent e) {
// warn();
}
public void insertUpdate(DocumentEvent e) {
warn();
}
public void warn() {
input = textField.getText();
SwingUtilities.invokeLater(doUpdate);
}
});
Where input is a variable which I use
The doUpdate method which gets executed is here
final Runnable doUpdate = new Runnable() {
#Override
public void run() {
System.out.println(input + " Is being processed");
textField.setText("");
System.out.println(input.length());
lblStatus.setIcon(new ImageIcon(Main.class
.getResource("/com/daniel/status2.png")));
// frame.getContentPane().add(lblStatus2, BorderLayout.EAST);
if (input.length() <= 4) {
lblStatus.setIcon(new ImageIcon(Main.class
.getResource("/com/daniel/status3.png")));
return;
}
// TODO START
if (!content.containsKey(input)) {
content.put(input, "1");
} else {
Integer i = Integer.valueOf(content.get(input));
i++;
lblStatus.setIcon(new ImageIcon(Main.class.getResource(i
+ ".png")));
playSound(i + "");
if (i.equals(6)) {
i = 0;
}
content.put(input, String.valueOf(i));
}
System.out.println(content.get(input));
Properties properties = new Properties();
for (Entry<String, String> entry : content.entrySet()) {
properties.put((String) entry.getKey(), entry.getValue());
}
try {
properties.store(new FileOutputStream(path
+ "data.properties"), null);
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
};
All Im asking is how do I run a method with a String from the text box only after the barcode reader has finished

It's been a while since I used a barcode reader, but when I did each scan was a line. That is, each scan was a sequence of characters terminated by the new line character. So, you could test the input and only invoke doUpdate when you detect the new line character. That said, you might need to set a property on the text box to allow the new line character and remove it when detected.

You need someway to inject a delay between each update of the DocumentListener and the time your inspect/use the value from the text field.
A simple solution is to use a Swing Timer with a short delay (you can play around with this to find the threashold which is most useful to you). Each time the DocumentListener is notified, you simply reset the timer (start it again), so that it won't trigger until after the delay you specified has occurred, at which time you can read the text from the field.
public class TestPane extends JPanel {
private Timer updateTimer;
private JTextField field;
private JLabel label;
public TestPane() {
setLayout(new GridBagLayout());
GridBagConstraints gbc = new GridBagConstraints();
gbc.gridwidth = GridBagConstraints.REMAINDER;
updateTimer = new Timer(250, new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
label.setText(field.getText());
}
});
updateTimer.setRepeats(false);
label = new JLabel("...");
field = new JTextField(14);
field.getDocument().addDocumentListener(new DocumentListener() {
#Override
public void insertUpdate(DocumentEvent e) {
processUpdate();
}
#Override
public void removeUpdate(DocumentEvent e) {
processUpdate();
}
#Override
public void changedUpdate(DocumentEvent e) {
processUpdate();
}
});
add(field, gbc);
add(label, gbc);
}
protected void processUpdate() {
updateTimer.restart();
}
}
You could test this using Robot, which can be used to inject key strokes into the event queue with a specified delay, or just run your scanner at it.
See How to use Swing Timers for more details
You should also attach a ActionListener to the field and see if the scanner triggers the ActionListener, which would be a simpler solution over all

Related

AddDocumentListener's variable scope when creating two titles (using TitledBorder) in Java Swing

Hello I am trying to display one String ("Character Count: ") and one dynamic character count on the bottom of JTextArea.
When I run this code below, there is a panel that opens up without characterCountTitle. Only when I start typing, characterCountTitle displays and the number is correctly dynamic.
My goal is to show characterCountTitle (string + character count) as soon as the panel is open to users.
private void initComponents() {
this.notePanel.getNoteDocument().addDocumentListener(new DocumentListener() {
TitledBorder characterCountTitle;
Border emptyBorder;
public void insertUpdate(DocumentEvent e) {
displayEditInfo(e);
}
public void removeUpdate(DocumentEvent e) {
displayEditInfo(e);
}
public void changedUpdate(DocumentEvent e) {
displayEditInfo(e);
}
private void displayEditInfo(DocumentEvent e) {
Document document = e.getDocument();
emptyBorder = BorderFactory.createEmptyBorder();
//displays a string of "Character Count: " and another string of dynamic character count
characterCountTitle = BorderFactory.createTitledBorder(emptyBorder, "Character Count: " + document.getLength());
characterCountTitle.setTitlePosition(TitledBorder.BOTTOM);
panel.setBorder(characterCountTitle);
}
});
this.panel.add(notePanel, BorderLayout.CENTER);
this.panel.add(navigation.buildPanel(), BorderLayout.SOUTH);
}
Due to this issue, I was trying to create two titles; one for string(outside of addDocumentListener) and one for character count (inside displayEditInfo method), but it messes up the variable scope.
I'd greatly appreciate your input!
You may simply create and add your border outside of the DocumentListener, and just change the title text on document events :
private void initComponents() {
Border emptyBorder = BorderFactory.createEmptyBorder();
final TitledBorder characterCountTitle = BorderFactory.createTitledBorder(emptyBorder, "Character Count:");
characterCountTitle.setTitlePosition(TitledBorder.BOTTOM);
panel.setBorder(characterCountTitle);
this.notePanel.getNoteDocument().addDocumentListener(new DocumentListener() {
public void insertUpdate(DocumentEvent e) {
displayEditInfo(e);
}
public void removeUpdate(DocumentEvent e) {
displayEditInfo(e);
}
public void changedUpdate(DocumentEvent e) {
displayEditInfo(e);
}
private void displayEditInfo(DocumentEvent e) {
Document document = e.getDocument();
//displays a string and dynamic character count
characterCountTitle.setTitle("Character Count: " + document.getLength());
panel.repaint();
}
});
this.panel.add(notePanel, BorderLayout.CENTER);
this.panel.add(navigation.buildPanel(), BorderLayout.SOUTH);
}

Wait for TextField input, before continuing with the code

I have a Graphical User Interface that has a TextField, my code looks as following:
int port = 0;
try{
port = Integer.parseInt(frame.textfieldInput.getText());
}
catch(NumberFormatException npe)
{
System.out.println("Error! parse exception");
}
System.out.println("The Port is " + port); //is 0
I have to assign the value '0' to port, because otherwise the code wont compile, because the variable wouldn't be initialized.
Because the TextField is empty at the beginning of the Program, getText() wont get a value, which is why port stays '0'.
Is there any way to wait for the input before the code continues?
Found a solution, this is how I solved it:
I created a global variable outside of my ActionListener:
public String value = "";
public void createInput() {
buttonInput.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
value = textfieldInput.getText();
}
});
}
named 'value'.
in my public static void main(String[] args) I declared the following:
while(frame.value.equalsIgnoreCase(""))
{
try
{
System.out.println("waiting...");
Thread.sleep(1000);
}
catch(InterruptedException ie)
{
System.out.println("interrupted");
}
}
I just have to clear the variable 'value' everytime I used it, so it is empty again for future uses.
I tis not the best way to solve it, but it worked for me.
Below code may give you some idea to more efficient way to get value on focus lost.
JFrame frame = new JFrame();
frame.setSize(50, 50);
TextField field = new TextField();
field.addFocusListener(new FocusListener() {
#Override
public void focusLost(FocusEvent e) {
// continue from here
System.out.println(field.getText());
}
#Override
public void focusGained(FocusEvent e) {
// TODO Auto-generated method stub
}
});
frame.getContentPane().add(field);
frame.setVisible(true);

Restrict Input of JTextField to Double Numbers?

In java , i am trying to make simple currency converter, but for that i need a text field which can restrict input to numbers only and more importantly double numbers. I tried using JFormatedTextField but it only format the input after you have done your input and click elsewhere but i need to restrict TextField to consume() each invalid character while doing input.
Possible Attempts:
Using JFormatedTextField:
JFormatedTextField textField = new JFormatedTextField(new DoubleFormat());
textField.setBounds(190, 49, 146, 33);
frame.getContentPane().add(textField);
textField.setColumns(10);
Using KeyTyped Event:
char c = arg0.getKeyChar();
if(!(Character.isDigit(c) || c == KeyEvent.VK_BACK_SPACE || c== KeyEvent.VK_DELETE)){
arg0.consume();
}
Using KeyTyped Event with regex:
if(!((textField.getText().toString+arg0.getKeyChar()).matches("[0-9]*(.[0-9]*)?"))){
arg0.consume();
}
Second and third attempt were close but then second attempt failed on point values and third attempt always read first character on textField no matter what it is, So any suggestions ? i am not very fond of JAVA GUI so kindly be patient.
If you know how many places before and after decimal point you want, you can also use MaskFormatter. For example:
JFormattedTextField field = new JFormattedTextField(getMaskFormatter("######.##"));
(...)
private MaskFormatter getMaskFormatter(String format) {
MaskFormatter mask = null;
try {
mask = new MaskFormatter(format);
mask.setPlaceholderCharacter('0');
}catch (ParseException ex) {
ex.printStackTrace();
}
return mask;
}
However it will chenge a look of JTextField, so it will be always visible 000000.00 in it.
EDIT
Another way, not too elegant, but in my opinion working. Try with DecumentListener, maybe it will suit your needs:
field = new JFormattedTextField();
field.getDocument().addDocumentListener(new DocumentListener() {
#Override
public void insertUpdate(DocumentEvent e) {
Runnable format = new Runnable() {
#Override
public void run() {
String text = field.getText();
if(!text.matches("\\d*(\\.\\d{0,2})?")){
field.setText(text.substring(0,text.length()-1));
}
}
};
SwingUtilities.invokeLater(format);
}
#Override
public void removeUpdate(DocumentEvent e) {
}
#Override
public void changedUpdate(DocumentEvent e) {
}
});
I used regex: \\d*(\\.\\d{0,2})? because two decimal places is enough for currency.
You would need to use a DocumentFilter. Read the section from the Swing tutorial on Implementing a DocumentFilter for an example to get you started.
Your implementation will be more complex because you will need to take the text already in the Document and then insert the new text in the appropriate location in the String and then invoke Double.parseDouble(...) on the String to make sure it is a valid double value.
If the validation succeeds then you continue with the insertion otherwise you can generate beep.
You can add a key listener to the text field and implement the keyReleased() method to determine if they value in the text field is a double after every key stroke by the user.
public class CurrencyJTF extends JFrame {
JButton jButton = new JButton("Unfocus");
final JFormattedTextField textField = new JFormattedTextField(new DecimalFormat());
double lastDouble = 0.0;
public CurrencyJTF() throws HeadlessException {
textField.setColumns(20);
textField.setText(lastDouble + "");
this.setLayout(new FlowLayout());
this.add(textField);
this.add(jButton);
textField.addKeyListener(new KeyAdapter() {
#Override
public void keyReleased(KeyEvent e) {
handleKeyReleased();
}
});
}
private void handleKeyReleased() {
String text = textField.getText();
if (text.isEmpty()) return;
try {
lastDouble = Double.parseDouble(text);
} catch (NumberFormatException ex) {
textField.setText(lastDouble + ""); // or set to other values you want
}
}
public static void main(String[] args) {
JFrame frame = new CurrencyJTF();
frame.setVisible(true);
frame.pack();
}
}
You can write your own KeyListener something like that:
public class DoubleNumbersKeyListener implements KeyListener {
final HashSet<Character> valid_keys = new HashSet<>();
final ArrayList<Character> sequence = new ArrayList<>();
public DoubleNumbersKeyListener() {
valid_keys.add('.');
valid_keys.add('0');
valid_keys.add('1');
valid_keys.add('2');
valid_keys.add('3');
valid_keys.add('4');
valid_keys.add('5');
valid_keys.add('6');
valid_keys.add('7');
valid_keys.add('8');
valid_keys.add('9');
valid_keys.add((char) KeyEvent.VK_BACK_SPACE);
valid_keys.add((char) KeyEvent.VK_DELETE);
}
#Override
public void keyTyped(KeyEvent event) {
char c = event.getKeyChar();
if (!valid_keys.contains(c)) {
event.consume();
} else {
if (c == KeyEvent.VK_DELETE || c == KeyEvent.VK_BACK_SPACE) {
if (!sequence.isEmpty()) {
char last = sequence.remove(sequence.size() - 1);
if (last == '.') {
valid_keys.add(last);
}
}
} else {
sequence.add(c);
if (c == '.') {
valid_keys.remove(c);
}
}
}
}
#Override
public void keyPressed(KeyEvent e) {
}
#Override
public void keyReleased(KeyEvent e) {
}
}

Enable Jbutton only if Validation is True

What is the best way to validate swing application's input fields such as text fields, comboboxes, etc and let the user to press Save button only if everything is ok. Assume that Search function also in the same interface. So searching for record will also fill up input fields. But Save button should remain disable in that case.
initComponents();
btnSave.setEnabled(false);
txt1.getDocument().addDocumentListener(new DocumentListener() {
#Override
public void changedUpdate(DocumentEvent e) {
}
#Override
public void removeUpdate(DocumentEvent e) {
validate(txt1.getText(),e);
}
#Override
public void insertUpdate(DocumentEvent e) {
validate(txt1.getText(),e);
}
public void validate(String enteredText,DocumentEvent e) {
String currText = "";
try {
Document doc = (Document) e.getDocument();
currText = doc.getText(0, doc.getLength());
} catch (BadLocationException e1) {
}
if(enteredText.equals(currText)){
//if validated successfully
btnSave.setEnabled(false);
}else{
btnSave.setEnabled(true);
}
}
});
did you try like this?
final JTextField textField = new JTextField();
final JButton submitBtn = new JButton();
submitBtn.setEnabled(true);
textField.getDocument().addDocumentListener(new DocumentListener() {
public void changedUpdate(DocumentEvent e) {
validate(e);
}
public void removeUpdate(DocumentEvent e) {
validate(e);
}
public void insertUpdate(DocumentEvent e) {
validate(e);
}
public void validate(String enteredText) {
String currText = "";
try {
Document doc = (Document)e.getDocument();
currText = doc.getText(0, doc.getLength());
} catch (BadLocationException e1) {
e1.printStackTrace();
}
//validation of currText here
//if validated successfully
submitBtn.setEnabled(true);
//else
submitBtn.setEnabled(false);
}
});
Condition the enabled property of your Save button using setEnabled() in two places:
In your implementation of shouldYieldFocus() in an InputVerifier attached to each relevant component. The tutorial and some examples are cited here.
In your component's normal listener.
Create a method to check if all the inputs are completed or/and all the validations are passed and finally return a boolean.
public boolean validate(...){
//some stuff
if(validated){
return true;
}else{
return false;
}
}
then you can use it like.
button.setEnabled(validate(...));

searching a Jtable for a value in a textfield [duplicate]

I have a JTable (DefaultTableModel) and a JTextField. I'd like to filter the JTable with the regex I put into the text field. When I start the program, all entries are shown, but when I enter text into the text field, no rows are displayed even though it should find the text within a row.
private void createFilter() {
_sorter = new TableRowSorter<DefaultTableModel>(new DefaultTableModel());
JPanel filterPanel = new JPanel();
filterPanel.setLayout(new BorderLayout());
JLabel filterLabel = new JLabel("Filter:");
filterPanel.add(filterLabel, BorderLayout.WEST);
_inputField = new JTextField();
_inputField.setColumns(40);
filterPanel.add(_inputField, BorderLayout.CENTER);
_inputField.getDocument().addDocumentListener(new DocumentListener() {
public void insertUpdate(DocumentEvent de) {
newFilter();
}
public void removeUpdate(DocumentEvent de) {
newFilter();
}
public void changedUpdate(DocumentEvent de) {
newFilter();
}
});
JButton clearButton = new JButton("X");
clearButton.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
_inputField.setText("");
}
});
filterPanel.add(clearButton, BorderLayout.EAST);
_mainFrame.add(filterPanel, BorderLayout.SOUTH);
}
private void newFilter() {
RowFilter<DefaultTableModel, Object> rowFilter = null;
try {
rowFilter = RowFilter.regexFilter(_inputField.getText());
}
catch(java.util.regex.PatternSyntaxException ex) {
return;
}
_sorter.setRowFilter(rowFilter);
_table.setRowSorter(_sorter);
}
My debugger shows me, that rowFilter is initialized, so it can't be because of a wrong RegEx. Also newFilter() is called at every keystroke.
Thanks in advance. I'd be happy to provide more information if needed.
Sincerely,
Michael
It seems that the JTable and the TableRowSorter each have a different table model. The TableRowSorter should be constructed with the table model of the JTable.
At first it's easier to print stack trace on this block instead of debugging to be able to know if there was an error during initializing RowFilter.
catch(java.util.regex.PatternSyntaxException ex) {
ex.printStackTrace();
return;
}
I cannot find anything wrong with the code, it seems like problem is on the regular expression. So if you could test the regex typed into the JTextField against one of the row you expect to show to see if it matches or not:
Javascript Regular Expression Validator
JTable tutorial contains example for JTable Filtering and Sorting, another examples here,
for Case Insensitive you have to set
TableRowSorter<TableModel>#setRowFilter(
RowFilter.regexFilter("(?i)" + myTextField.getText()));
EDIT:
basic workaround:
final TableRowSorter<TableModel> sorter = new TableRowSorter<TableModel>(tableFxModel);
myTable.setRowSorter(sorter);
filterFxText.getDocument().addDocumentListener(new DocumentListener() {
private void searchFieldChangedUpdate(DocumentEvent evt) {
String text = filterFxText.getText();
if (text.length() == 0) {
sorter.setRowFilter(null);
} else {
try {
sorter.setRowFilter(RowFilter.regexFilter("(?i)" + text));
} catch (PatternSyntaxException pse) {
JOptionPane.showMessageDialog(null, "Bad regex pattern",
"Bad regex pattern", JOptionPane.ERROR_MESSAGE);
}
}
}
#Override
public void insertUpdate(DocumentEvent evt) {
searchFieldChangedUpdate(evt);
}
#Override
public void removeUpdate(DocumentEvent evt) {
searchFieldChangedUpdate(evt);
}
#Override
public void changedUpdate(DocumentEvent evt) {
searchFieldChangedUpdate(evt);
}
});

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