JTextField value is not updating after button click

Question

I am new to java swing. I am creating application for patient registration using Swing. There is a button called Clear, that button should clear the input data from the text fields.When button is InputPanel.clear() set the values correctly.But it is not updating. My classes are below.

MainWindow class create and show the GUI.

public class MainWindow extends JFrame implements ActionListener {
private static final long serialVersionUID = 1905122041950251207L;

  transient TableRowSorter<PatientTableModel> sorter;

  private PatientListView patientListViewPanel = new PatientListView();

  private InputPanel inputPanel = new InputPanel();
  private SearchCriteriaPanel searhCriteriaPanel = new SearchCriteriaPanel(this);
    public void createAndShowGUI() {
        ButtonPanel btnPanel = new ButtonPanel(new MainWindow());
        this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        this.setSize(600, 600);

        sorter = new TableRowSorter<>(patientListViewPanel.getTableModel());

        GridBagLayout gbl = new GridBagLayout();
        this.setLayout(gbl);

        GridBagConstraints gcon = new GridBagConstraints();
        gcon.weightx = 1;
        gcon.weighty = 5;
        gcon.fill = GridBagConstraints.BOTH;

        gcon.gridx = 0;
        gcon.gridy = 0;
        gcon.gridwidth = 11;
        gcon.gridheight = 10;
        gbl.setConstraints(inputPanel, gcon);
        this.add(inputPanel);

        gcon.gridx = 4;
        gcon.gridy = 10;
        gcon.gridwidth = 11;
        gcon.gridheight = 5;
        gbl.setConstraints(btnPanel, gcon);
        this.add(btnPanel);

        gcon.gridx = 0;
        gcon.gridy = 22;
        gcon.gridwidth = 11;
        gcon.gridheight = 10;
        gbl.setConstraints(searhCriteriaPanel, gcon);
        this.add(searhCriteriaPanel);

        gcon.gridx = 0;
        gcon.gridy = 33;
        gcon.gridwidth = 11;
        gcon.gridheight = 10;
        gbl.setConstraints(patientListViewPanel, gcon);
        this.add(patientListViewPanel);

        this.setVisible(true);

        inputPanel.getNameText().addKeyListener(new KeyAdapter() {
            @Override
            public void keyReleased(KeyEvent e) {
                super.keyReleased(e);
                if (inputPanel.getNameText().getText().length() > 0)
                    btnPanel.getSaveBtn().setEnabled(true);

            }
        });

        patientListViewPanel.getTable().addMouseListener(new java.awt.event.MouseAdapter() {
            @Override
            public void mouseClicked(java.awt.event.MouseEvent evt) {
                getSelectedData();
            }
        });

    }

    public MainWindow() {
        super("Patient Registration");
    }

    @Override
    public void actionPerformed(ActionEvent e) {
        JButton button = (JButton) e.getSource();
        switch (button.getText()) {
        case "Save":
            patientListViewPanel.getTableModel()
                    .addData(inputPanel.getData(patientListViewPanel.getTable().getRowCount()));
            button.setEnabled(false);
            break;

        case "Clear":
            inputPanel.clear();
            break;

        case "Search":
            SearchCriteria s = new SearchCriteria(searhCriteriaPanel.getSearchNameText().getText(),
                    searhCriteriaPanel.getBirthYearText().getText(), searhCriteriaPanel.getMaleChkBx().isSelected(),
                    searhCriteriaPanel.getFemaleChkBx().isSelected());
            patientListViewPanel.filter(s);
            break;
        default:

        }
    }
}

InputPanel is handle the fields and methods related to input data

public class InputPanel extends JPanel implements PropertyChangeListener {

    /**
     * clear fields in input panel
     */
    public void clear() {

        nameText.setText(" ");
        phnText.setText("0");
        datePickerObj.jDatePicker.getJFormattedTextField().setText("");
        maleBtn.setSelected(true);
        femaleBtn.setSelected(false);
        adrsTxt.setText("");
        statusList.setSelectedIndex(4);

    }

    public InputPanel() {

        // fiels will be set to panel
        addDataChangedListner();
        isDataValid(phnText);
    }

    public void addDataChangedListner() {

        PatientData model = new PatientData();

        model.addPropertyChangeListener(this);
        nameText.getDocument().addDocumentListener(new DataChangedListener(model, "name"));

        phnText.getDocument().addDocumentListener(new DataChangedListener(model, "phnNumber"));
        adrsTxt.getDocument().addDocumentListener(new DataChangedListener(model, "address"));

    }

    @Override
    public void propertyChange(PropertyChangeEvent evt) {

        String property = evt.getPropertyName();
        String newValue = (String) evt.getNewValue();
        switch (property) {
        case "name":
            updatedName = newValue;
            break;
        case "phnNumber":
            updatedPhoneNumber = newValue;
            break;
        case "address":
            updatedAddress = newValue;
            break;
        default:
        }

    }
}

Can someone help me to resolve this?

Answer 1

The basic functionality that you are having difficulty with is demonstrated in the following mre: ⁽¹⁾

import java.awt.BorderLayout;
import java.awt.event.KeyAdapter;
import java.awt.event.KeyEvent;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JTextField;

public class MainWindow extends JFrame{

  private InputPanel inputPanel;
  private  JButton saveBtn;

    public void createAndShowGUI() {

        inputPanel = new InputPanel();
        saveBtn = new JButton("Save");
        saveBtn.setEnabled(false);
        add(saveBtn, BorderLayout.SOUTH);

        JButton clearButton = new JButton("Clear");
        clearButton.addActionListener(e->clearInput());
        add(clearButton, BorderLayout.CENTER);

        add(inputPanel, BorderLayout.NORTH);

        inputPanel.getNameText().addKeyListener(new KeyAdapter() {
            @Override
            public void keyReleased(KeyEvent e) {
                super.keyReleased(e);
                if (inputPanel.getNameText().getText().length() > 0) {
                    saveBtn.setEnabled(true);
                }
            }
        });

        this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        this.pack();
        this.setVisible(true);
    }

    private void clearInput(){
        inputPanel.clear();
        saveBtn.setEnabled(false);
    }

    public MainWindow() {
        createAndShowGUI();
    }

    public static void main(String[] args) {
        new MainWindow();
    }
}

class InputPanel extends JPanel {

    JTextField nameText;

    /**
     * clear fields in input panel
     */
    public void clear() {
        nameText.setText(""); //use "" and not " " so text length = 0
    }

    public InputPanel() {
        nameText = new JTextField(5);
        add(nameText);
    }

    public JTextField getNameText() {
        return nameText;
    }
}

However, a better approach is to use the model to implement the change of data :

public class MainWindow extends JFrame implements PropertyChangeListener{

    private InputPanel inputPanel;
    private  JButton saveBtn;
    private final PatientData model;

    public void createAndShowGUI() {

        inputPanel = new InputPanel(model);
        saveBtn = new JButton("Save");
        saveBtn.setEnabled(false);
        add(saveBtn, BorderLayout.SOUTH);

        JButton clearButton = new JButton("Clear");
        clearButton.addActionListener(e->clearInput());
        add(clearButton, BorderLayout.CENTER);

        add(inputPanel, BorderLayout.NORTH);

        this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        this.pack();
        this.setVisible(true);
    }

    private void clearInput(){
        inputPanel.clear();
    }

    public MainWindow() {
        model = new PatientData();
        model.setPropertyChangeListener(this);
        createAndShowGUI();
    }

    @Override
    public void propertyChange(PropertyChangeEvent evt) {
        updateGui();
    }

    private void updateGui() {
        if(model.getName().trim().isEmpty()){
            saveBtn.setEnabled(false);
        }else{
            saveBtn.setEnabled(true);
        }
    }

    public static void main(String[] args) {
        new MainWindow();
    }
}

class InputPanel extends JPanel implements DocumentListener{

    private final JTextField nameText;
    private final PatientData model;

    /**
     * clear fields in input panel
     */
    public void clear() {
        nameText.setText(""); //use "" and not " " so text length = 0
        updateModel();
    }

    public InputPanel(PatientData model) {
        this.model = model;
        nameText = new JTextField("",5);
        nameText.getDocument().addDocumentListener(this);
        add(nameText);
    }

    @Override
    public void changedUpdate(DocumentEvent e) {
        updateModel();
    }
    @Override
    public void removeUpdate(DocumentEvent e) {
        updateModel();
    }
    @Override
    public void insertUpdate(DocumentEvent e) {
        updateModel();
    }

    private void updateModel() {
        model.setName(nameText.getText());
    }
}

class PatientData{

    private String name ="";
    private PropertyChangeListener listener;

    public String getName() {
        return name;
    }

    public void setPropertyChangeListener(PropertyChangeListener listener) {
        this.listener = listener;
    }

    public void setName(String name) {
        String oldName = this.name;
        this.name = name;

        if(listener != null) {
            listener.propertyChange(new PropertyChangeEvent(this,"name", oldName, name));
        }
    }
}

(Test is online here)

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⁽¹⁾ Always consider an mre when posting a question or answer.