Implement a "result counter"

Question

I have a search/query register screen and when I do the query, for example, from all countries, a label "arrow" how many countries found, (eg 19 countries found).

However, if within these results I type a letter to correspond to a country, for example, letter "B" for Brazil, and have only Brazil, it does not update the amount of results to 1.

I’m getting the amount of results with the method getRouwCount, because each row set in the table is equivalent to a different result.

Here is a very basic example, more that already illustrates the problem.

package teste;

import javax.swing.JButton;
import javax.swing.JComponent;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JTable;
import javax.swing.JTextField;
import javax.swing.RowFilter;
import javax.swing.event.DocumentEvent;
import javax.swing.event.DocumentListener;
import javax.swing.table.DefaultTableModel;
import javax.swing.table.TableModel;
import javax.swing.table.TableRowSorter;

public class Teste extends JFrame {

    private String[] colunas
            = {"Country", "Capital", "Population in Millions", "Democracy"};

    private Object[][] dados = {
        {"USA", "Washington DC", 280, true},
        {"Canada", "Ottawa", 32, true},
        {"United Kingdom", "London", 60, true},
        {"Germany", "Berlin", 83, true},
        {"France", "Paris", 60, true},
        {"Norway", "Oslo", 4.5, true},
        {"India", "New Delhi", 1046, true}
    };

    private DefaultTableModel model = new DefaultTableModel(dados, colunas);
    private JTable tabela = new JTable(model);

    private TableRowSorter<TableModel> rowSorter = new TableRowSorter<>(tabela.getModel());

    private JTextField barraPesquisa = new JTextField();
    private JButton botao = new JButton("OK");

    private JPanel painel = new JPanel();
    private JLabel label = new JLabel();

    public Teste() {
        add(x());
        setSize(600, 400);
        setLocationRelativeTo(null);
        setVisible(true);
        setDefaultCloseOperation(EXIT_ON_CLOSE);
    }

    public JComponent x() {
        JPanel painelX = new JPanel();
        painelX.setLayout(null);

        painelX.add(barraPesquisa);
        barraPesquisa.setBounds(20, 10, 270, 27);
        painelX.add(botao);
        botao.setBounds(300, 10, 65, 27);

        barraPesquisa.getDocument().addDocumentListener(new DocumentListener() {
            @Override
            public void insertUpdate(DocumentEvent e) {
                String text = barraPesquisa.getText();

                //model.setRowCount(0); // limpar as linhas
                label.setText(model.getRowCount() + " resultados encontrados");
                if (text.trim().length() == 0) {
                    rowSorter.setRowFilter(null);
                } else {
                    rowSorter.setRowFilter(RowFilter.regexFilter("(?i)" + text));
                    model.getRowCount();

                }
            }

            @Override
            public void removeUpdate(DocumentEvent e) {
                String text = barraPesquisa.getText();
                label.setText(model.getRowCount() + " resultados encontrados");
                if (text.trim().length() == 0) {
                    rowSorter.setRowFilter(null);
                } else {
                    rowSorter.setRowFilter(RowFilter.regexFilter("(?i)" + text));
                }
            }

            @Override
            public void changedUpdate(DocumentEvent e) {

            }
        });

        tabela.setRowSorter(rowSorter);

        painelX.add(tabela);
        tabela.setBounds(5, 100, 500, 150);

        painelX.add(label);
        label.setBounds(10, 250, 150, 30);
        label.setText(model.getRowCount() + " resultados encontrados!");

        painelX.setBounds(1, 1, 600, 400);
        return painelX;
    }

    public static void main(String[] args) {
        Teste t = new Teste();
    }
}

Answer 1

The problem is because you are counting the number of your lines TableModel, when in fact should count the number of lines that were filtered from the search by your RowSorter, after all, when doing a search, nothing is changed in the Tablemodel, and yes, in the RowSorter.

Another important detail, you should count the number of lines after the search has been done, that is, after applying the filter through the setRowFilter(), and not before.

See the corrected code below:

import javax.swing.JButton;
import javax.swing.JComponent;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JTable;
import javax.swing.JTextField;
import javax.swing.RowFilter;
import javax.swing.event.DocumentEvent;
import javax.swing.event.DocumentListener;
import javax.swing.table.DefaultTableModel;
import javax.swing.table.TableModel;
import javax.swing.table.TableRowSorter;

public class Teste extends JFrame {

    private String[] colunas
            = {"Country", "Capital", "Population in Millions", "Democracy"};

    private Object[][] dados = {
        {"USA", "Washington DC", 280, true},
        {"Canada", "Ottawa", 32, true},
        {"United Kingdom", "London", 60, true},
        {"Germany", "Berlin", 83, true},
        {"France", "Paris", 60, true},
        {"Norway", "Oslo", 4.5, true},
        {"India", "New Delhi", 1046, true}
    };

    private DefaultTableModel model = new DefaultTableModel(dados, colunas);
    private JTable tabela = new JTable(model);

    private TableRowSorter<TableModel> rowSorter = new TableRowSorter<>(tabela.getModel());

    private JTextField barraPesquisa = new JTextField();
    private JButton botao = new JButton("OK");

    private JPanel painel = new JPanel();
    private JLabel label = new JLabel();

    public Teste() {
        add(x());
        setSize(600, 400);
        setLocationRelativeTo(null);
        setVisible(true);
        setDefaultCloseOperation(EXIT_ON_CLOSE);
    }

    public JComponent x() {
        JPanel painelX = new JPanel();
        painelX.setLayout(null);

        painelX.add(barraPesquisa);
        barraPesquisa.setBounds(20, 10, 270, 27);
        painelX.add(botao);
        botao.setBounds(300, 10, 65, 27);

        barraPesquisa.getDocument().addDocumentListener(new DocumentListener() {
            @Override
            public void insertUpdate(DocumentEvent e) {
                String text = barraPesquisa.getText();

                //model.setRowCount(0); // limpar as linhas

                if (text.trim().length() == 0) {
                    rowSorter.setRowFilter(null);
                } else {
                    rowSorter.setRowFilter(RowFilter.regexFilter("(?i)" + text));
                    model.getRowCount();
                }
                label.setText(rowSorter.getViewRowCount() + " resultados encontrados");
            }

            @Override
            public void removeUpdate(DocumentEvent e) {
                String text = barraPesquisa.getText();
                if (text.trim().length() == 0) {
                    rowSorter.setRowFilter(null);
                } else {
                    rowSorter.setRowFilter(RowFilter.regexFilter("(?i)" + text));
                }
                label.setText(rowSorter.getViewRowCount() + " resultados encontrados");
            }

            @Override
            public void changedUpdate(DocumentEvent e) {

            }
        });

        tabela.setRowSorter(rowSorter);

        painelX.add(tabela);
        tabela.setBounds(5, 100, 500, 150);

        painelX.add(label);
        label.setBounds(10, 250, 150, 30);
        label.setText(model.getRowCount() + " resultados encontrados!");

        painelX.setBounds(1, 1, 600, 400);
        return painelX;
    }

    public static void main(String[] args) {
        Teste t = new Teste();
    }
}

Working: