根据深度级别更改JTree节点图标

Question

我正在寻找改变我的JTree(Swing)的不同图标

java文档解释了如果节点是否为叶子,如何更改图标,但这不是我正在搜索的内容.

对我来说,如果一个节点是一个叶子,或者我只是想在节点处于三个节点的第一/第二/第三深度级别时更改图标.

Answer 1

作为替代的自定义TreeCellRenderer,可以更换UI默认值collapsedIcon和expandedIcon:

Icon expanded = new TreeIcon(true, Color.red);
Icon collapsed = new TreeIcon(false, Color.blue);
UIManager.put("Tree.collapsedIcon", collapsed);
UIManager.put("Tree.expandedIcon", expanded);

TreeIcon只是Icon界面的一个实现:

class TreeIcon implements Icon {

    private static final int SIZE = 14;
    private boolean expanded;
    private Color color;

    public TreeIcon(boolean expanded, Color color) {
        this.expanded = expanded;
        this.color = color;
    }

    //@Override
    public void paintIcon(Component c, Graphics g, int x, int y) {
        Graphics2D g2d = (Graphics2D) g;
        g2d.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
            RenderingHints.VALUE_ANTIALIAS_ON);
        g2d.setPaint(color);
        if (expanded) {
            g2d.fillOval(x + SIZE / 4, y, SIZE / 2, SIZE);
        } else {
            g2d.fillOval(x, y + SIZE / 4, SIZE, SIZE / 2);
        }
    }

    //@Override
    public int getIconWidth() {
        return SIZE;
    }

    //@Override
    public int getIconHeight() {
        return SIZE;
    }
}

Answer 2

实现自定义TreeCellRenderer- JLabel为组件使用a ,并使用树中存储的Object数据设置其图标.如果对象是原始的(例如String),您可能需要包装对象以存储其深度等.

http://download.oracle.com/javase/7/docs/api/javax/swing/tree/TreeCellRenderer.html http://www.java2s.com/Code/Java/Swing-JFC/TreeCellRenderer.htm