Swing之JTree篇：在树节点前增加JCheckBox控件

xuzhenqinandy

斯诺克爱好者网：http://www.kkyule.com

淘宝精品导航:http://www.nitaomei.com
在做Swing开发的时候可能经常会遇到类似的案例，关键还是需要实现TreeCellRenderer接口，重写getTreeCellRendererComponent方法

import java.awt.BorderLayout;import java.awt.Color;import java.awt.Component;import java.awt.Dimension;import java.awt.Graphics;import java.awt.GridLayout;import java.awt.event.ActionEvent;import java.awt.event.ActionListener;import java.awt.event.MouseAdapter;import java.awt.event.MouseEvent;import java.awt.event.WindowAdapter;import java.awt.event.WindowEvent;import java.util.Enumeration;import javax.swing.ButtonGroup;import javax.swing.Icon;import javax.swing.JButton;import javax.swing.JCheckBox;import javax.swing.JFrame;import javax.swing.JLabel;import javax.swing.JPanel;import javax.swing.JRadioButton;import javax.swing.JScrollPane;import javax.swing.JTextArea;import javax.swing.JTree;import javax.swing.UIManager;import javax.swing.border.TitledBorder;import javax.swing.plaf.ColorUIResource;import javax.swing.tree.DefaultMutableTreeNode;import javax.swing.tree.DefaultTreeModel;import javax.swing.tree.TreeCellRenderer;import javax.swing.tree.TreeNode;import javax.swing.tree.TreePath;import javax.swing.tree.TreeSelectionModel;public class CheckNodeTreeExample extends JFrame {  public CheckNodeTreeExample() {    super("CheckNode TreeExample");    String[] strs = {"swing",     // 0         "platf",     // 1         "basic",     // 2         "metal",     // 3         "JTree"};    // 4    CheckNode[] nodes = new CheckNode[strs.length];    for (int i=0;i<strs.length;i++) {      nodes = new CheckNode(strs);    }    nodes[0].add(nodes[1]);    nodes[1].add(nodes[2]);    nodes[1].add(nodes[3]);    nodes[0].add(nodes[4]);    nodes[3].setSelected(true);    JTree tree = new JTree( nodes[0] );    tree.setCellRenderer(new CheckRenderer());    tree.getSelectionModel().setSelectionMode(      TreeSelectionModel.SINGLE_TREE_SELECTION    );    tree.putClientProperty("JTree.lineStyle", "Angled");    tree.addMouseListener(new NodeSelectionListener(tree));    JScrollPane sp = new JScrollPane(tree);    ModePanel mp = new ModePanel(nodes);    JTextArea textArea = new JTextArea(3,10);    JScrollPane textPanel = new JScrollPane(textArea);    JButton button = new JButton("print");    button.addActionListener(      new ButtonActionListener(nodes[0], textArea));    JPanel panel = new JPanel(new BorderLayout());    panel.add(mp,     BorderLayout.CENTER);    panel.add(button, BorderLayout.SOUTH);    getContentPane().add(sp,    BorderLayout.CENTER);    getContentPane().add(panel, BorderLayout.EAST);    getContentPane().add(textPanel, BorderLayout.SOUTH);  }  class NodeSelectionListener extends MouseAdapter {    JTree tree;    NodeSelectionListener(JTree tree) {      this.tree = tree;    }    public void mouseClicked(MouseEvent e) {      int x = e.getX();      int y = e.getY();      int row = tree.getRowForLocation(x, y);      TreePath  path = tree.getPathForRow(row);      //TreePath  path = tree.getSelectionPath();      if (path != null) {        CheckNode node = (CheckNode)path.getLastPathComponent();        boolean isSelected = ! (node.isSelected());        node.setSelected(isSelected);        if (node.getSelectionMode() == CheckNode.DIG_IN_SELECTION) {          if ( isSelected) {            tree.expandPath(path);          } else {            tree.collapsePath(path);          }        }        ((DefaultTreeModel) tree.getModel()).nodeChanged(node);        // I need revalidate if node is root.  but why?        if (row == 0) {          tree.revalidate();          tree.repaint();        }      }    }  }  class ModePanel extends JPanel implements ActionListener {    CheckNode[] nodes;    JRadioButton b_single, b_dig_in;    ModePanel(CheckNode[] nodes) {      this.nodes = nodes;      setLayout(new GridLayout(2, 1));      setBorder(new TitledBorder("Check Mode"));      ButtonGroup group = new ButtonGroup();      add(b_dig_in = new JRadioButton("DIG_IN  "));      add(b_single = new JRadioButton("SINGLE  "));      group.add(b_dig_in);      group.add(b_single);      b_dig_in.addActionListener(this);      b_single.addActionListener(this);      b_dig_in.setSelected(true);    }    public void actionPerformed(ActionEvent e) {      int mode;      if (b_single == e.getSource()) {        mode = CheckNode.SINGLE_SELECTION;      } else {        mode = CheckNode.DIG_IN_SELECTION;      }      for (int i = 0; i < nodes.length; i++) {        nodes.setSelectionMode(mode);      }    }  }  class ButtonActionListener implements ActionListener {    CheckNode root;    JTextArea textArea;    ButtonActionListener(final CheckNode root, final JTextArea textArea) {      this.root = root;      this.textArea = textArea;    }    public void actionPerformed(ActionEvent ev) {      Enumeration e = root.breadthFirstEnumeration();      while (e.hasMoreElements()) {        CheckNode node = (CheckNode) e.nextElement();        if (node.isSelected()) {          TreeNode[] nodes = node.getPath();          textArea.append("\n" + nodes[0].toString());          for (int i = 1; i < nodes.length; i++) {            textArea.append("/" + nodes.toString());          }        }      }    }  }  public static void main(String args[]) {//    try {//        UIManager.setLookAndFeel("com.sun.java.swing.plaf.windows.WindowsLookAndFeel");//    } catch (Exception evt) {}    CheckNodeTreeExample frame = new CheckNodeTreeExample();    frame.addWindowListener(new WindowAdapter() {      public void windowClosing(WindowEvent e) {        System.exit(0);      }    });    frame.setSize(300, 200);    frame.setVisible(true);  }}class CheckRenderer extends JPanel implements TreeCellRenderer {  protected JCheckBox check;  protected TreeLabel label;  public CheckRenderer() {    setLayout(null);    add(check = new JCheckBox());    add(label = new TreeLabel());    check.setBackground(UIManager.getColor("Tree.textBackground"));    label.setForeground(UIManager.getColor("Tree.textForeground"));  }  public Component getTreeCellRendererComponent(JTree tree, Object value,      boolean isSelected, boolean expanded, boolean leaf, int row,      boolean hasFocus) {    String stringValue = tree.convertValueToText(value, isSelected,        expanded, leaf, row, hasFocus);    setEnabled(tree.isEnabled());    check.setSelected(((CheckNode) value).isSelected());    label.setFont(tree.getFont());    label.setText(stringValue);    label.setSelected(isSelected);    label.setFocus(hasFocus);    if (leaf) {      label.setIcon(UIManager.getIcon("Tree.leafIcon"));    } else if (expanded) {      label.setIcon(UIManager.getIcon("Tree.openIcon"));    } else {      label.setIcon(UIManager.getIcon("Tree.closedIcon"));    }    return this;  }  public Dimension getPreferredSize() {    Dimension d_check = check.getPreferredSize();    Dimension d_label = label.getPreferredSize();    return new Dimension(d_check.width + d_label.width,        (d_check.height < d_label.height ? d_label.height            : d_check.height));  }  public void doLayout() {    Dimension d_check = check.getPreferredSize();    Dimension d_label = label.getPreferredSize();    int y_check = 0;    int y_label = 0;    if (d_check.height < d_label.height) {      y_check = (d_label.height - d_check.height) / 2;    } else {      y_label = (d_check.height - d_label.height) / 2;    }    check.setLocation(0, y_check);    check.setBounds(0, y_check, d_check.width, d_check.height);    label.setLocation(d_check.width, y_label);    label.setBounds(d_check.width, y_label, d_label.width, d_label.height);  }  public void setBackground(Color color) {    if (color instanceof ColorUIResource)      color = null;    super.setBackground(color);  }  public class TreeLabel extends JLabel {    boolean isSelected;    boolean hasFocus;    public TreeLabel() {    }    public void setBackground(Color color) {      if (color instanceof ColorUIResource)        color = null;      super.setBackground(color);    }    public void paint(Graphics g) {      String str;      if ((str = getText()) != null) {        if (0 < str.length()) {          if (isSelected) {            g.setColor(UIManager                .getColor("Tree.selectionBackground"));          } else {            g.setColor(UIManager.getColor("Tree.textBackground"));          }          Dimension d = getPreferredSize();          int imageOffset = 0;          Icon currentI = getIcon();          if (currentI != null) {            imageOffset = currentI.getIconWidth()                + Math.max(0, getIconTextGap() - 1);          }          g.fillRect(imageOffset, 0, d.width - 1 - imageOffset,              d.height);          if (hasFocus) {            g.setColor(UIManager                .getColor("Tree.selectionBorderColor"));            g.drawRect(imageOffset, 0, d.width - 1 - imageOffset,                d.height - 1);          }        }      }      super.paint(g);    }    public Dimension getPreferredSize() {      Dimension retDimension = super.getPreferredSize();      if (retDimension != null) {        retDimension = new Dimension(retDimension.width + 3,            retDimension.height);      }      return retDimension;    }    public void setSelected(boolean isSelected) {      this.isSelected = isSelected;    }    public void setFocus(boolean hasFocus) {      this.hasFocus = hasFocus;    }  }}class CheckNode extends DefaultMutableTreeNode {  public final static int SINGLE_SELECTION = 0;  public final static int DIG_IN_SELECTION = 4;  protected int selectionMode;  protected boolean isSelected;  public CheckNode() {    this(null);  }  public CheckNode(Object userObject) {    this(userObject, true, false);  }  public CheckNode(Object userObject, boolean allowsChildren,      boolean isSelected) {    super(userObject, allowsChildren);    this.isSelected = isSelected;    setSelectionMode(DIG_IN_SELECTION);  }  public void setSelectionMode(int mode) {    selectionMode = mode;  }  public int getSelectionMode() {    return selectionMode;  }  public void setSelected(boolean isSelected) {    this.isSelected = isSelected;    if ((selectionMode == DIG_IN_SELECTION) && (children != null)) {      Enumeration e = children.elements();      while (e.hasMoreElements()) {        CheckNode node = (CheckNode) e.nextElement();        node.setSelected(isSelected);      }    }  }  public boolean isSelected() {    return isSelected;  }}