JTree & JButtons - 当鼠标悬停在 Button 上时出现错误的渲染

Question

我对 JTree 和 JButton 有疑问 似乎当进入编辑模式并将鼠标悬停在 TreeCells 上的按钮上时，它会在按钮内渲染树的某些部分。 即使在同一行中从一个按钮拖动到另一个按钮时，它也会将一个按钮呈现在另一个按钮之上。

这里有一个简短的自我解释示例，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 天的时间来完成这个 JTree 定制。但这真的让我很困惑，我怎么能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);
        }
    });
}