source: src/main/java/genius/gui/panels/DoublePanel.java

package genius.gui.panels;

import java.awt.BorderLayout;
import java.awt.Dimension;

import javax.swing.JComponent;
import javax.swing.JFormattedTextField;
import javax.swing.JLabel;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.JSpinner;
import javax.swing.JTextField;
import javax.swing.SpinnerNumberModel;
import javax.swing.SwingConstants;
import javax.swing.SwingUtilities;
import javax.swing.event.DocumentEvent;
import javax.swing.event.DocumentListener;

import genius.core.listener.Listener;

/**
 * Shows a single text line input area for a double value.
 */
@SuppressWarnings("serial")
public class DoublePanel extends JPanel 
{
        private final JLabel jlabel;
        private final JTextField textfield;
        DoubleModel model;
        
        public DoublePanel(String label, final DoubleModel model) 
        {
                setLayout(new BorderLayout());
                                
                this.model = model;
                setLayout(new BorderLayout());
                
                this.jlabel = new JLabel(label);
                jlabel.setHorizontalAlignment(SwingConstants.RIGHT);
                add(jlabel, BorderLayout.WEST);
                
                JSpinner jSpinner = new JSpinner(new SpinnerNumberModel((double) model.getValue(), 0.0, 1.0, 0.001));
                jSpinner.setMaximumSize(new Dimension(300, 30));
                JSpinner.NumberEditor numberEditor = new JSpinner.NumberEditor(jSpinner,"0.0000");
                jSpinner.setEditor(numberEditor);
                this.textfield = getTextField(jSpinner);
                this.textfield.setColumns(5);
                
                add(jSpinner, BorderLayout.EAST);
                
                // not working?
                // setMaximumSize(new Dimension(99999999, 30));
                textfield.getDocument().addDocumentListener(new DocumentListener() {

                        @Override
                        public void removeUpdate(DocumentEvent e) {
                                if (!textfield.getText().isEmpty()) 
                                {
                                        model.setText(parseDouble());
                                }
                                // we ignore empty text to avoid reacting on replace procedure
                                // too early
                        }

                        @Override
                        public void insertUpdate(DocumentEvent e) {
                                model.setText(parseDouble());
                        }

                        @Override
                        public void changedUpdate(DocumentEvent e) {
                                model.setText(parseDouble());
                        }
                });

                model.addListener(new Listener<Double>() {
                        @Override
                        public void notifyChange(final Double data) {
                                SwingUtilities.invokeLater(new Runnable() {

                                        @Override
                                        public void run() {
                                                textfield.setText("" + data);
                                                updateEnabledness();
                                        }
                                });
                        }
                });
                
                updateEnabledness();
        }
        
        private void updateEnabledness() 
        {
                boolean enabled = !model.isLocked();
                setEnabled(enabled);
                textfield.setEnabled(enabled);
                jlabel.setEnabled(enabled);
        }
        
        private double parseDouble()
        {
                double d = 0;
                String text = textfield.getText();
                String err = "The value \"" + text + "\" is not a valid number.";
                try {
                        d = Double.parseDouble(text);
                        if (d < 0 || d > 1) {
                                showError(err);
                                return 0;
                        }
                } catch (Exception e) {
                        showError(err);
                        return 0;
                }
                return d;
        }
        
        private void showError(String error) 
        {
                JOptionPane.showMessageDialog(null, error, "Edit error", 0);
        }       
        
        private JFormattedTextField getTextField(JSpinner spinner) {
            JComponent editor = spinner.getEditor();
            if (editor instanceof JSpinner.DefaultEditor) {
                return ((JSpinner.DefaultEditor)editor).getTextField();
            } else {
                System.err.println("Unexpected editor type: "
                                   + spinner.getEditor().getClass()
                                   + " isn't a descendant of DefaultEditor");
                return null;
            }
        }
}