Re: Make a simple 4 row by 4 column scratch pad.

In article
<eb326c81-48d8-4e2c-9420-20b92402c135@d27g2000yqf.googlegroups.com>,
 bH <bherbst65@hotmail.com> wrote:


Yes, I think you need at least a renderer and editor to make it usable:

<http://java.sun.com/docs/books/tutorial/uiswing/components/table.html>

import java.awt.Color;
import java.awt.Component;
import java.awt.EventQueue;
import java.text.DecimalFormat;
import java.util.Arrays;
import javax.swing.DefaultCellEditor;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JTable;
import javax.swing.JTextField;
import javax.swing.table.AbstractTableModel;
import javax.swing.table.DefaultTableCellRenderer;

public class TableGrid extends JPanel {

    private DecimalFormat df = new DecimalFormat("#0.00");
    private JTextField tf = new JTextField();

    public static void main(String[] args) {
        EventQueue.invokeLater(new Runnable() {

            @Override
            public void run() {
                JFrame f = new JFrame("TableGrid");
                f.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
                f.add(new TableGrid());
                f.pack();
                f.setVisible(true);
            }
        });
    }

    public TableGrid() {
        TableModel dataModel = new TableModel();
        JTable table = new JTable(dataModel);
        table.setCellSelectionEnabled(true);
        table.setRowHeight(32);
        table.setDefaultRenderer(Double.class, new DecRenderer(df));
        table.setDefaultEditor(Double.class, new DecEditor(tf, df));
        this.add(table);
    }

    private static class TableModel extends AbstractTableModel {

        private static final int SIZE = 4;
        private Double[][] matrix = new Double[SIZE][SIZE];

        public TableModel() {
            for (Object[] row : matrix) {
                Arrays.fill(row, Double.valueOf(0));
            }
        }

        @Override
        public int getRowCount() {
            return SIZE;
        }

        @Override
        public int getColumnCount() {
            return SIZE;
        }

        @Override
        public Object getValueAt(int row, int col) {
            return matrix[row][col];
        }

        @Override
        public void setValueAt(Object value, int row, int col) {
            matrix[row][col] = (Double) value;
        }

        @Override
        public Class<?> getColumnClass(int col) {
            return Double.class;
        }

        @Override
        public boolean isCellEditable(int row, int col) {
            return true;
        }
    }

    private static class DecRenderer extends DefaultTableCellRenderer {

        DecimalFormat df;

        public DecRenderer(DecimalFormat df) {
            this.df = df;
            this.setHorizontalAlignment(JLabel.CENTER);
            this.setBackground(Color.lightGray);
        }

        @Override
        protected void setValue(Object value) {
            setText((value == null) ? "" : df.format(value));
        }
    }

    private static class DecEditor extends DefaultCellEditor {

        private JTextField tf;
        private DecimalFormat df;

        public DecEditor(JTextField tf, DecimalFormat df) {
            super(tf);
            this.tf = tf;
            this.df = df;
            tf.setHorizontalAlignment(JTextField.CENTER);
        }

        @Override
        public Object getCellEditorValue() {
            try {
                return new Double(tf.getText());
            } catch (NumberFormatException e) {
                return Double.valueOf(0);
            }
        }

        @Override
        public Component getTableCellEditorComponent(JTable table,
            Object value, boolean isSelected, int row, int column) {
            tf.setText((value == null) ? "" : df.format((Double) value));
            if (isSelected) tf.selectAll();
            return tf;
        }
    }
}

--
John B. Matthews
trashgod at gmail dot com
<http://sites.google.com/site/drjohnbmatthews>