java - JTree 和 JButtons - 鼠标悬停在 Button 上时渲染错误

Question

我在使用 JTree 和 JButton 时遇到问题似乎当进入编辑模式并将鼠标悬停在 TreeCell 上的按钮上时，它会在按钮内渲染树的某些部分。即使从一个按钮拖动到同一行中的另一个按钮，它也会将一个按钮呈现在另一个按钮之上。

这是一个简短的 self 解释示例，您可以复制粘贴以了解我的意思。

import java.awt.Color;
import java.awt.Component;
import java.awt.Dimension;
import java.awt.FlowLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.MouseEvent;
import java.awt.event.MouseMotionListener;
import java.util.EventObject;

import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTree;
import javax.swing.UIManager;
import javax.swing.tree.DefaultMutableTreeNode;
import javax.swing.tree.DefaultTreeCellEditor;
import javax.swing.tree.DefaultTreeCellRenderer;


public class MyProblemWithTree {

    public static void main(String...args) {
        JFrame frame = new JFrame("Panel");
        JScrollPane scroll = new JScrollPane();

        DefaultMutableTreeNode node = new DefaultMutableTreeNode("Root");

        DefaultMutableTreeNode nodeChild = new DefaultMutableTreeNode("childcaretaker1");
        nodeChild.add(new DefaultMutableTreeNode("child1"));
        nodeChild.add(new DefaultMutableTreeNode("child2"));

        node.add(nodeChild);


        final JTree tree = new JTree(node);

        tree.setCellRenderer(new MyTreeCellRenderer());
        tree.setEditable(true);
        tree.setCellEditor(new MyTreeCellEditor(tree));

        tree.addMouseMotionListener(new MouseMotionListener() {

            @Override
            public void mouseMoved(MouseEvent e) {
                // TODO Auto-generated method stub
                if (tree.getRowForLocation(e.getX(), e.getY()) != -1)
                {
                    tree.startEditingAtPath(tree.getPathForLocation(e.getX(), e.getY()));
                } 
            }

            @Override
            public void mouseDragged(MouseEvent arg0) {
                // TODO Auto-generated method stub

            }
        });

        scroll.setViewportView(tree);
        frame.add(scroll);
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.pack();
        frame.setVisible(true);
    }
}
class MyTreeCellEditor extends DefaultTreeCellEditor {

    JPanel      leafPanel;
    JLabel      colorIcon;
    PlayButton  play; 
    PauseButton pause;
    JLabel      name; 

    public MyTreeCellEditor(JTree tree) {
        super(tree, (MyTreeCellRenderer)tree.getCellRenderer());
        leafPanel   = new JPanel(new FlowLayout());
        colorIcon   = new JLabel(UIManager.getIcon("OptionPane.informationIcon"));
        play        = new PlayButton();
        pause       = new PauseButton();
        name        = new JLabel();

        play.addActionListener(new ActionListener() {

            @Override
            public void actionPerformed(ActionEvent arg0) {
                // TODO Auto-generated method stub
                System.out.println("Playbutton klickt");
            }
        });

        leafPanel.add(colorIcon);
        leafPanel.add(name);
        leafPanel.add(pause);
        leafPanel.add(play);
    }


    @Override
    public Component getTreeCellEditorComponent(JTree tree, Object value,
            boolean selected, boolean expanded, boolean leaf, int row) {

        name.setText((String)((DefaultMutableTreeNode)value).getUserObject());
        pause.setVisible(!leaf);
        return leafPanel;
    }

    @Override
    public boolean isCellEditable(EventObject arg0) {
        return true;
    }
}
class MyTreeCellRenderer extends DefaultTreeCellRenderer {
    private static final long serialVersionUID = 3691823996133806942L;

    JPanel leafPanel;
    JLabel colorIcon;
    PlayButton play; 
    PauseButton pause;
    JLabel name; 

    DefaultTreeCellRenderer defaultRenderer = new DefaultTreeCellRenderer();

    Color backgroundSelectionColor; 
    Color backgroundNonSelectionColor;


    public MyTreeCellRenderer() {
        leafPanel = new JPanel(new FlowLayout());
        colorIcon = new JLabel(UIManager.getIcon("OptionPane.informationIcon"));
        play = new PlayButton();
        pause = new PauseButton();
        name = new JLabel();

        leafPanel.add(colorIcon);
        leafPanel.add(name);
        leafPanel.add(pause);
        leafPanel.add(play);

        backgroundSelectionColor = new Color(200,200,255,50);
        backgroundNonSelectionColor = new Color(0,0,0,0);
    }

    @Override
    public Component getTreeCellRendererComponent(JTree tree, Object value, boolean selected, boolean expanded, boolean leaf, int row, boolean hasFocus) {
        name.setText((String)((DefaultMutableTreeNode) value).getUserObject());
        if (selected) {
            leafPanel.setBackground(backgroundSelectionColor);
        } else {
            leafPanel.setBackground(backgroundNonSelectionColor);                       
        }
        leafPanel.setEnabled(tree.isEnabled());
        pause.setVisible(!leaf);
        return leafPanel;
    }
}

class PlayButton extends JButton{
    private static final long serialVersionUID = 550654173835539853L;

    Dimension size = new Dimension(140,28);

    public PlayButton() {
        setIcon(UIManager.getIcon("OptionPane.informationIcon"));
        setPressedIcon(UIManager.getIcon("OptionPane.errorIcon"));
        setBackground(new Color(0,0,0,0));
        setBorderPainted(false);
        setPreferredSize(size);
        setMaximumSize(size);
        setMinimumSize(size);
    }
}
class PauseButton extends JButton{
    private static final long serialVersionUID = -5877843953696256070L;

    Dimension size = new Dimension(140,28);

    public PauseButton() {
        setIcon(UIManager.getIcon("OptionPane.warningIcon"));
        setPressedIcon(UIManager.getIcon("OptionPane.questionIcon"));
        setBackground(new Color(0,0,0,0));
        setBorderPainted(false);
        setPreferredSize(size);
        setMaximumSize(size);
        setMinimumSize(size);
    }
}

即使我删除了这部分。我必须单击一个单元格才能进入编辑模式，我仍然可以通过用鼠标离开单元格并返回来获得效果。

        public void mouseMoved(MouseEvent e) {
            // TODO Auto-generated method stub
            if (tree.getRowForLocation(e.getX(), e.getY()) != -1)
            {
                tree.startEditingAtPath(tree.getPathForLocation(e.getX(), e.getY()));
            } 
        }

我已经花了 4 天时间进行 JTree 定制。但这真的让我很困惑，我如何通过输入按钮来停止渲染。

Answer 1

我不知道如何解决这个问题，但使用 invokeLater 和 setRowHeight() 会有所帮助。

public static void main(String... args) {
    EventQueue.invokeLater(new Runnable() {

        @Override
        public void run() {
            JFrame frame = new JFrame("Panel");
            ...
            tree.setRowHeight(icon.getIconHeight());
            ...
            frame.setVisible(true);
        }
    });
}