TreeLineselection

Gewöhnlich wenn ein Knoten selektiert ist, hebt JTree nur den Text hervor:

Hier wird eine Möglichkeit gezeigt, die ganze selektierte Zeile in einem JTree hervorzuheben:

import javax.swing.*;

public class LineTreeDemo extends JFrame {

    final private JTree tree;

    public LineTreeDemo() {
        super("Tree Lineselection");
        setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
        setSize(400, 300);
        setLocationRelativeTo(null);
        tree = new LineTree();
        add(new JScrollPane(tree));
    }

    public static void main(final String args[]) throws Exception {
        new LineTreeDemo().setVisible(true);
    }
}

/*
 * LineTree.java
 *
 * Normally, when a node is selected, the tree marks only the text.
 * This shows one way to mark the whole selected line in a JTree.
 */
 
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.event.*;
import javax.swing.tree.*;
 
 
public class LineTree extends JTree {
 
    final private Color SELECTION_COLOR = new Color(180, 210, 230, 90);
    private Rectangle selectedRowBounds;
    private boolean expand;//allows the MouseListener to detect "handles" action (->no row selection)
 
    public LineTree() {
        //Set the selection mode:
        selectionModel.setSelectionMode(TreeSelectionModel.SINGLE_TREE_SELECTION);
        //Adapt the default selection colors:
        DefaultTreeCellRenderer renderer = (DefaultTreeCellRenderer) getCellRenderer();
        renderer.setTextSelectionColor(Color.BLACK);
        renderer.setBorderSelectionColor(Color.WHITE);
        renderer.setBackgroundSelectionColor(Color.WHITE);
        //Add the TreeSelectionListener:
        selectionModel.addTreeSelectionListener(new TreeSelectionListener() {
 
            @Override
            public void valueChanged(final TreeSelectionEvent e) {
                paintSelectionRect();
            }
        });
        //Add the TreeExpansionListener:
        addTreeExpansionListener(new TreeExpansionListener() {
 
            @Override
            public void treeCollapsed(final TreeExpansionEvent event) {
                paintSelectionRect();
                expand = true;
            }
 
            @Override
            public void treeExpanded(final TreeExpansionEvent event) {
                paintSelectionRect();
                expand = true;
            }
        });
        //Add MouseListener if you want to listen to whole line width:
        addMouseListener(new MouseAdapter() {
 
            @Override
            public void mousePressed(final MouseEvent e) {
                if (!expand) {
                    int row = getClosestRowForLocation(e.getX(), e.getY());
                    if (e.getClickCount() == 2) {
                        if (isCollapsed(row)) {
                            expandRow(row);
                        } else {
                            collapseRow(row);
                        }
                    } else {
                        setSelectionRow(row);
                    }
                }
                expand = false;
            }
        });
 
    }
    //This method is called in valueChanged, treeCollapsed and treeExpanded
    //to paint the selection rectangle:
 
    private void paintSelectionRect() {
        //Get selected row bounds:
        int[] rows = getSelectionRows();
        if (rows == null) {
            return;
        }
        selectedRowBounds = getRowBounds(rows[0]);
        //Repaint the JTree:
        repaint();
    }
 
    //Override paintComponent of JTree:
    @Override
    public void paintComponent(final Graphics g) {
        super.paintComponent(g);
        if (selectedRowBounds == null) {
            return;
        }
        //Set selection Color:
        g.setColor(SELECTION_COLOR);
        //Draw selection rectangle using the width of JTree:
        g.fillRect(0, (int) selectedRowBounds.getY(), getWidth(), (int) selectedRowBounds.getHeight());
    }
}