checklistexample.java

自制java的swing组件

package zb.swing;

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.border.*;
import javax.swing.plaf.metal.*;

import zb.swing.renderer.*;

/**
 * @version 1.0 04/24/99
 */
public class CheckListExample
    extends JFrame {

  public CheckListExample() {
    super("CheckList Example");
    String[] strs = {
        "swing", "home", "basic", "metal", "JList"};

    final JList list = new JList(createData(strs));

    // set "home" icon
    Icon icon = MetalIconFactory.getFileChooserHomeFolderIcon();
    ( (CheckableItem) list.getModel().getElementAt(1)).setIcon(icon);

    list.setCellRenderer(new CheckListRenderer());
    list.setSelectionMode(ListSelectionModel.SINGLE_SELECTION);
    list.setBorder(new EmptyBorder(0, 4, 0, 0));
    list.addMouseListener(new MouseAdapter() {
      public void mouseClicked(MouseEvent e) {
        int index = list.locationToIndex(e.getPoint());
        CheckableItem item = (CheckableItem) list.getModel().getElementAt(index);
        item.setSelected(!item.isSelected());
        Rectangle rect = list.getCellBounds(index, index);
        list.repaint(rect);
      }
    });
    JScrollPane sp = new JScrollPane(list);

    final JTextArea textArea = new JTextArea(3, 10);
    JScrollPane textPanel = new JScrollPane(textArea);
    JButton printButton = new JButton("print");
    printButton.addActionListener(new ActionListener() {
      public void actionPerformed(ActionEvent e) {
        ListModel model = list.getModel();
        int n = model.getSize();
        for (int i = 0; i < n; i++) {
          CheckableItem item = (CheckableItem) model.getElementAt(i);
          if (item.isSelected()) {
            textArea.append(item.toString());
            textArea.append(System.getProperty("line.separator"));
          }
        }
      }
    });
    JButton clearButton = new JButton("clear");
    clearButton.addActionListener(new ActionListener() {
      public void actionPerformed(ActionEvent e) {
        textArea.setText("");
      }
    });
    JPanel panel = new JPanel(new GridLayout(2, 1));
    panel.add(printButton);
    panel.add(clearButton);

    getContentPane().add(sp, BorderLayout.CENTER);
    getContentPane().add(panel, BorderLayout.EAST);
    getContentPane().add(textPanel, BorderLayout.SOUTH);
  }

  private CheckableItem[] createData(String[] strs) {
    int n = strs.length;
    CheckableItem[] items = new CheckableItem[n];
    for (int i = 0; i < n; i++) {
      items[i] = new CheckableItem(strs[i]);
    }
    return items;
  }

  class CheckableItem {
    private String str;
    private boolean isSelected;
    private Icon icon;

    public CheckableItem(String str) {
      this.str = str;
      isSelected = false;
    }

    public void setSelected(boolean b) {
      isSelected = b;
    }

    public boolean isSelected() {
      return isSelected;
    }

    public String toString() {
      return str;
    }

    public void setIcon(Icon icon) {
      this.icon = icon;
    }

    public Icon getIcon() {
      return icon;
    }
  }

  class CheckListRenderer
      extends CheckRenderer
      implements ListCellRenderer {
    Icon commonIcon;

    public CheckListRenderer() {
      check.setBackground(UIManager.getColor("List.textBackground"));
      label.setForeground(UIManager.getColor("List.textForeground"));
      commonIcon = UIManager.getIcon("Tree.leafIcon");
    }

    public Component getListCellRendererComponent(JList list, Object value,
                                                  int index, boolean isSelected,
                                                  boolean hasFocus) {
      setEnabled(list.isEnabled());
      check.setSelected( ( (CheckableItem) value).isSelected());
      label.setFont(list.getFont());
      label.setText(value.toString());
      label.setSelected(isSelected);
      label.setFocus(hasFocus);


      Icon icon = ( (CheckableItem) value).getIcon();
      if (icon == null) {
        icon = commonIcon;
      }
      label.setIcon(icon);
      return this;
    }
  }

  public static void main(String args[]) {
    CheckListExample frame = new CheckListExample();
    frame.addWindowListener(new WindowAdapter() {
      public void windowClosing(WindowEvent e) {
        System.exit(0);
      }
    });
    frame.setSize(300, 200);
    frame.setVisible(true);
  }
}