树的可见区域的获取和滚动条监听

来源：互联网发布：天谕捏脸数据编辑：程序博客网时间：2024/06/05 15:27
1.树的前序，中序，后序遍历
2.树所在面板的滚动条监听
3.树的可见区域的获取
package treeTest;import java.awt.BorderLayout;import java.awt.GridLayout;import java.awt.Rectangle;import java.awt.event.ActionEvent;import java.awt.event.ActionListener;import java.awt.event.AdjustmentEvent;import java.awt.event.AdjustmentListener;import java.util.Enumeration;import javax.swing.JButton;import javax.swing.JFrame;import javax.swing.JPanel;import javax.swing.JScrollBar;import javax.swing.JScrollPane;import javax.swing.JTree;import javax.swing.tree.DefaultMutableTreeNode;import javax.swing.tree.DefaultTreeModel;import javax.swing.tree.TreePath;public class Treetest extends JFrame {    private DefaultMutableTreeNode root; // 定义根节点.    JTree tree;    // 主方法.    public static void main(String[] args) {        // 实例化本类.        Treetest frame = new Treetest();        frame.setVisible(true);    }    // 构造方法.    public Treetest() {        super(); // 继承父类.        setTitle("遍历节点方法"); // 设置窗口标题.        setBounds(100, 100, 300, 300); // 设置绝对位置.        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); // 设置窗口关闭方法.        root = new DefaultMutableTreeNode("ROOT"); // 设置根节点名.        DefaultMutableTreeNode noteA = new DefaultMutableTreeNode("FirstA"); // 定义及设置第一个子节点.        root.add(noteA); // 将第一节点添加到树根上.        // 给noteA增加两个子节点.        noteA.add(new DefaultMutableTreeNode("SecondAA"));        noteA.add(new DefaultMutableTreeNode("SecondAB"));        DefaultMutableTreeNode noteB = new DefaultMutableTreeNode("FirstB");// 定义及设置第二个子节点.        root.add(noteB);        DefaultMutableTreeNode noteC = new DefaultMutableTreeNode("FirstC");// 定义及设置第三个子节点.        root.add(noteC);        noteC.add(new DefaultMutableTreeNode("SecondCA"));// 为noteC增加子节点.        DefaultMutableTreeNode noteSecondCB = new DefaultMutableTreeNode(                "SecondCB");// 为noteC增加子节点.        noteC.add(noteSecondCB);// 将noteSecondCB添加到noteC子节点下.        // 给noteSecondCB增加子节点.        noteSecondCB.add(new DefaultMutableTreeNode("SecondCBA"));        noteSecondCB.add(new DefaultMutableTreeNode("SecondCBB"));        // 给noteC增加SecondCC子节点.        noteC.add(new DefaultMutableTreeNode("SecondCC"));        DefaultMutableTreeNode noteD = new DefaultMutableTreeNode("FirstD");// 定义及设置第三个子节点.        root.add(noteD);        DefaultMutableTreeNode noteE = new DefaultMutableTreeNode("FirstE");// 定义及设置第三个子节点.        root.add(noteE);        DefaultMutableTreeNode noteF = new DefaultMutableTreeNode("FirstF");// 定义及设置第三个子节点.        root.add(noteF);        DefaultMutableTreeNode noteG = new DefaultMutableTreeNode("FirstG");// 定义及设置第三个子节点.        root.add(noteG);        DefaultMutableTreeNode noteH = new DefaultMutableTreeNode("FirstH");// 定义及设置第三个子节点.        root.add(noteH);        DefaultMutableTreeNode noteI = new DefaultMutableTreeNode("FirstI");// 定义及设置第三个子节点.        root.add(noteI);        tree = new JTree(root);// 根据根节点创建树.        JScrollPane jscrcoll = new JScrollPane(tree);        getContentPane().add(jscrcoll, BorderLayout.CENTER);        JScrollBar jscrollBar = jscrcoll.getVerticalScrollBar();        //监听滚动条        jscrollBar.addAdjustmentListener(new AdjustmentListener() {            @Override            public void adjustmentValueChanged(AdjustmentEvent e) {                // 用户一直拖动时，返回true，用户停止拖动时，返回false                if(e.getValueIsAdjusting()){                    return;                }            }        });        createOperationPanel();    }    private void createOperationPanel() {        // 开始操作节点.        // 定义Panel.        final JPanel panel = new JPanel();        panel.setLayout(new GridLayout(0, 1)); // 设置panel为网格布局.        getContentPane().add(panel, BorderLayout.EAST); // 将panel放置到窗口右边.        final JButton button_01 = new JButton("按前序遍历节点"); // 定义及设置第一个按钮.        button_01.addActionListener(new ButtonActionListener("按前序遍历节点"));        panel.add(button_01); // 将按钮放置到panel里.        final JButton button_02 = new JButton("按后序遍历节点"); // 定义及设置第二个按钮.        button_02.addActionListener(new ButtonActionListener("按后序遍历节点"));        panel.add(button_02); // 将按钮放置到panel里.        final JButton button_03 = new JButton("以广度遍历节点"); // 定义及设置第三个按钮.        button_03.addActionListener(new ButtonActionListener("以广度遍历节点"));        panel.add(button_03); // 将按钮放置到panel里.        final JButton button_04 = new JButton("以深度遍历节点"); // 定义及设置第四个按钮.        button_04.addActionListener(new ButtonActionListener("以深度遍历节点"));        panel.add(button_04); // 将按钮放置到panel里.        final JButton button_05 = new JButton("遍历直属子节点"); // 定义及设置第五个按钮.        button_05.addActionListener(new ButtonActionListener("遍历直属子节点"));        panel.add(button_05); // 将按钮放置到panel里.    }    // 定义按钮点击事件.    private class ButtonActionListener implements ActionListener {        private String mode;// 定义mode变量.        // 构造方法.        public ButtonActionListener(String mode) {            this.mode = mode;        }        // 定义激活方法.        public void actionPerformed(ActionEvent e) {            // 声明节点枚举对象.            Enumeration<?> enumeration;            if (mode.equals("按前序遍历节点")) {                // 按前序遍历根节点.                enumeration = root.preorderEnumeration();            } else if (mode.equals("按后序遍历节点")) {                enumeration = root.postorderEnumeration();            } else if (mode.equals("以广度遍历节点")) {                enumeration = root.breadthFirstEnumeration();            } else if (mode.equals("以深度遍历节点")) {                enumeration = root.depthFirstEnumeration();            } else {                enumeration = root.children();// 遍历该节点的所有子节点.            }            printTreeVisibleRect();            // 知道了遍历方式，开始遍历.            while (enumeration.hasMoreElements()) { // 遍历枚举对象.            // 先定义一个节点变量.                DefaultMutableTreeNode node;                node = (DefaultMutableTreeNode) enumeration.nextElement();// 将节点名称给node.                // 根据级别输出占位符.                for (int l = 0; l < node.getLevel(); l++) {                    System.out.print("---");                }                System.out.println(node.getUserObject());// 输入节点标签.                treeIsVisible(node);            }            System.out.println();            System.out.println();        }        /**         * 打印树的可见区域，当用户改变对话框的大小时，树的可见区域发生变化         */        private void printTreeVisibleRect() {            Rectangle rect = tree.getVisibleRect();            System.out.println("x"+rect.x + "y"+rect.y +"width"+rect.width +"height"+rect.height );        }        /**         * 判断节点是否可见         * @param node         */        private void treeIsVisible(DefaultMutableTreeNode node) {            DefaultTreeModel treeModel = (DefaultTreeModel)tree.getModel();            TreePath nodePath = new TreePath(treeModel.getPathToRoot(node));            System.out.println(nodePath);            if(tree.isVisible(nodePath)){                System.out.println("可见");            } else{                System.out.println("不可见");            }        }    }}
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