totalrowexample.java

tame,扩展了好多SWing组件:JTable

/* (swing1.1beta3) swing#960 */
package tame.examples;

import java.awt.Container;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import java.text.DecimalFormat;
import java.text.ParseException;
import java.util.Vector;

import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JScrollPane;
import javax.swing.JTable;
import javax.swing.event.ChangeEvent;
import javax.swing.table.DefaultTableCellRenderer;
import javax.swing.table.DefaultTableModel;
import javax.swing.table.TableModel;

/**
@author Nobuo Tamemasa
@version 1.0 12/03/98
*/
public class TotalRowExample extends JFrame {
  final private int TOTAL_ROW    = 3;
  final private int TOTAL_COLUMN = 1;

  TotalRowExample() {
    super( "Total Row Example" );

    final DecimalFormat formatter = new DecimalFormat("###,##0.00");
    DefaultTableModel dm = new DefaultTableModel() {
      public void setValueAt(Object value, int row, int col) {
        Vector rowVector = (Vector)dataVector.elementAt(row);
        if (col == TOTAL_COLUMN) {
          Double d = null;
          if (value instanceof Double) {
            d = (Double)value;
          } else {
            try {
              d = new Double(
                ((Number)formatter.parse((String)value)).doubleValue());
            } catch (ParseException ex) {
              d = new Double(0.0);
            }
          }
          rowVector.setElementAt(d, col);
        } else {
          rowVector.setElementAt(value, col);
        }
      }

      public boolean isCellEditable(int row, int col) {
        if (row == TOTAL_ROW) return false;
        return true;
      }

      public Class getColumnClass(int col) {
        if (col == TOTAL_COLUMN) return Number.class;
        return String.class;
      }
    };

    dm.setDataVector(
      new Object[][]{
        {"coffee",new Double(0.0)},
        {"tea"   ,new Double(0.0)},
        {"cocoa" ,new Double(0.0)},
        {"total" ,new Double(0.0)}},
      new Object[]{"Item","Price"});

    JTable table = new JTable( dm ) {
      public void editingStopped(ChangeEvent e) {
        super.editingStopped(e);
        reCalcurate(getModel());
        repaint();
      }
    };

    table.getColumn("Price").setCellRenderer(
             new DecimalRenderer(formatter));

    JScrollPane scroll  = new JScrollPane(table);
    Container content = getContentPane();
    content.add(scroll);
    setSize( 300, 120 );
    setVisible(true);
  }

  private void reCalcurate(TableModel ml) {
    if (ml == null) return;
    double total = 0.0;
    for (int i=0;i<TOTAL_ROW;i++) {
      total += ((Double)ml.getValueAt(i,TOTAL_COLUMN)).doubleValue();
    }
    ml.setValueAt(new Double(total),TOTAL_ROW,TOTAL_COLUMN);
  }

  public static void main(String[] args) {
    TotalRowExample frame = new TotalRowExample();
    frame.addWindowListener( new WindowAdapter() {
      public void windowClosing( WindowEvent e ) {
	System.exit(0);
      }
    });
  }
}

/**
@author Nobuo Tamemasa
@version 1.0 12/03/98
*/
class DecimalRenderer extends DefaultTableCellRenderer {
  DecimalFormat  formatter;

  DecimalRenderer(String pattern) {
    this(new DecimalFormat(pattern));
  }

  DecimalRenderer(DecimalFormat formatter) {
    this.formatter = formatter;
    setHorizontalAlignment(JLabel.RIGHT);
  }

  public void setValue(Object value) {
    setText((value == null) ? ""
      : formatter.format(((Double)value).doubleValue()));
  }
}