bigrenderer.java

java swing 开发代码

// BigRenderer.java
// A renderer for numbers that shows an icon in front of big numbers.
//
package	jswing.ch15;

import java.awt.*;
import javax.swing.*;
import javax.swing.table.*;

public class BigRenderer extends DefaultTableCellRenderer {
  double threshold;
  Icon bang = new ImageIcon("bang.gif");

  public BigRenderer(double t) {
    threshold = t;
    setHorizontalAlignment(JLabel.RIGHT);
    setHorizontalTextPosition(SwingConstants.RIGHT);
  }

  public Component getTableCellRendererComponent(JTable table,
    Object value, boolean isSelected, boolean hasFocus, int row, int col)
  {
    // be a little paranoid about where the user tries to use this renderer
    if (value instanceof Number) {  
      if (((Number)value).doubleValue() > threshold) {
        setIcon(bang);
      }
      else {
        setIcon(null);
      }
    }
    else {
      setIcon(null);
    }
    return super.getTableCellRendererComponent(table, value, isSelected,
                     hasFocus, row, col);
  }
}