swing的tree

最新推荐文章于 2024-03-30 20:13:01 发布

dssd3

最新推荐文章于 2024-03-30 20:13:01 发布

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CC 4.0 BY-SA版权

文章标签： swing tree string null jcomponent import

本文链接：https://blog.youkuaiyun.com/dssd3/article/details/6165669

本文介绍了一个使用 Java Swing 实现的自定义树形组件示例，该组件基于 JButton 扩展，并集成了 JTree 的功能。文章展示了如何通过监听事件实现下拉树形菜单效果，以及如何自定义单元格渲染器来改变树节点的表现形式。

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代码copy自网上

import java.awt.Component;
import java.awt.Container;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Insets;
import java.awt.Point;
import java.awt.Rectangle;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.FocusAdapter;
import java.awt.event.FocusEvent;
import javax.swing.JButton;
import javax.swing.JComponent;
import javax.swing.JFrame;
import javax.swing.JOptionPane;
import javax.swing.JScrollPane;
import javax.swing.JTree;
import javax.swing.Popup;
import javax.swing.PopupFactory;
import javax.swing.SwingConstants;
import javax.swing.SwingUtilities;
import javax.swing.UIManager;
import javax.swing.event.TreeSelectionEvent;
import javax.swing.event.TreeSelectionListener;
import javax.swing.plaf.basic.BasicGraphicsUtils;
import javax.swing.plaf.metal.MetalComboBoxIcon;
import javax.swing.tree.DefaultMutableTreeNode;
import javax.swing.tree.DefaultTreeCellRenderer;
import javax.swing.tree.TreeCellRenderer;
import javax.swing.tree.TreePath;

public class Test extends JButton {

/**
*
*/
private static final long serialVersionUID = 1L;
private JTree tree;//
private JScrollPane js;
private Popup pop;
private boolean ispopshow;//
private int gap;//
private String curveName;//选择的曲线名字

public Test(JTree jtree) {
super(" ", new MetalComboBoxIcon());
this.setPreferredSize(new Dimension(200, 10));
gap = this.getIconTextGap();// 返回此按钮中显示的文本与图标之间的间隔量
ispopshow = false;
setMargin(new Insets(1, 2, 1, 2));
this.tree = jtree;
tree.setEditable(false);
tree.getSelectionModel().setSelectionMode(1);// 设置选择模型 1表示一次只能选择一个路径
setTableCellRender(new DefaultTreeCellRenderer());
tree.setOpaque(false);// 组件不透明的就设置为true
js = new JScrollPane(tree);
this.setPreferredSize(new Dimension(js.getPreferredSize().width,
    getPreferredSize().height));
this.setText(jtree.getPathForRow(0).toString());
updateUI();
tree.addTreeSelectionListener(new TreeSelectionListener() {
   public void valueChanged(TreeSelectionEvent treeselectionevent) {
    if (isLeafNode()) {
     String coboBoxContent=getLastSelectedPathComponent().toString();
     setText(coboBoxContent);
     curveName=coboBoxContent;
     setCurveName(curveName);
    } else {
     TreePath treePath = (TreePath) tree.getSelectionPath();
     if (treePath != null) {
      DefaultMutableTreeNode node = (DefaultMutableTreeNode) treePath
        .getLastPathComponent();
      JOptionPane.showMessageDialog(null, "请选择"
        + node.toString() + "的子节点", "alert",
        JOptionPane.INFORMATION_MESSAGE);
     }
    }
    if (!ispopshow)
     pophide();
   }
});
addActionListener(new ActionListener() {
   public void actionPerformed(ActionEvent actionevent) {
    if (!ispopshow) {
     pupshow();
    } else {
     pophide();
    }
   }
});

addFocusListener(new FocusAdapter() {
   public void focusLost(FocusEvent focusevent) {
    if (focusevent.getOppositeComponent() != tree)
     pophide();
    else
     requestFocus();
   }
});
}

public boolean isLeafNode() {
boolean isLeafNode = false;
TreePath treePath = (TreePath) tree.getSelectionPath();
if (treePath != null) {
   DefaultMutableTreeNode node = (DefaultMutableTreeNode) treePath
     .getLastPathComponent();
   if (node.getChildCount() == 0) {
    isLeafNode = true;
   }
}
return isLeafNode;
}

private void pupshow() {
if (pop == null) {
   Point point = new Point(0, getHeight());
   SwingUtilities.convertPointToScreen(point, this);
   int y = tree.getPreferredScrollableViewportSize().height;
   y = y > 220 ? 220 : y;
   js.setPreferredSize(new Dimension(getWidth(), y));
   pop = PopupFactory.getSharedInstance().getPopup(this, js, point.x,
     point.y);
   pop.show();
}
}

private void pophide() {
if (pop != null) {
pop.hide();
pop = null;
}
}

public void setTableCellRender(TreeCellRenderer treecellrenderer) {
tree.setCellRenderer(treecellrenderer);
((JComponent) treecellrenderer).setOpaque(false);
if (treecellrenderer instanceof DefaultTreeCellRenderer) {
   ((DefaultTreeCellRenderer) treecellrenderer)
     .setTextNonSelectionColor(UIManager
       .getColor("ComboBox.foreground"));
   ((DefaultTreeCellRenderer) treecellrenderer)
     .setBackgroundNonSelectionColor(UIManager
       .getColor("ComboBox.background"));
}
}

public Object getLastSelectedPathComponent() {
return tree.getLastSelectedPathComponent();// 返回当前选择的第一个节点中的最后一个路径组件。
}

protected void paintComponent(Graphics g) {
super.paintComponent(g);
if (getLastSelectedPathComponent() != null) {
   Component component = tree.getCellRenderer()
     .getTreeCellRendererComponent(
       tree,
       getLastSelectedPathComponent(),
       false,
       tree.isExpanded(tree.getSelectionPath()),
       tree.getModel().isLeaf(
         getLastSelectedPathComponent()),
       tree.getRowForPath(tree.getSelectionPath()), false);
   component.paint(g);
}
}

public void setBounds(Rectangle rectangle) {
setBounds(rectangle.x, rectangle.y, rectangle.width, rectangle.height);
}

public void setBounds(int rx, int ry, int rw, int rh) {
super.setBounds(rx, ry, rw, rh);
Dimension dimension = BasicGraphicsUtils.getPreferredButtonSize(this,
    gap);
if (rw > dimension.width)
   setIconTextGap((rw - dimension.width) + gap);
else
   setIconTextGap(gap);
}

public void updateUI() {
super.updateUI();
setHorizontalTextPosition(SwingConstants.LEFT);
setText(getText());
}

// test
public static void main(String[] args) {
JFrame frame = new JFrame();
JTree tree = new JTree();
Test tc = new Test(tree);
tc.setPreferredSize(new Dimension(200, 40));
Container cc = frame.getContentPane();
cc.add(tc);
frame.setSize(200, 60);
frame.setVisible(true);
frame.setDefaultCloseOperation(3);
}

public String getCurveName() {
return curveName;
}

public void setCurveName(String curveName) {
this.curveName = curveName;
}

}