根据深度级别更改JTree节点图标 [英] Change JTree node icons according to the depth level

问题描述

我正在寻找更改我的JTree（Swing）的不同图标

I'm looking for changing the different icons of my JTree (Swing)

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

The java documentation explains how to change icons if a node is a leaf or not, but that's really not what I'm searching.

对我而言，如果一个节点是一个叶子，或者我只是想改变节点的图标处于三者的第一/第二/第三深度水平。

For me it doesn't matter if a node is a leaf or, I just want to change the icons if the node is in the first/2nd/3rd depth level of the three.

推荐答案

作为自定义 TreeCellRenderer ，您可以替换 collapsedIcon 和 expandedIcon 的UI默认值：

As an alternative to a custom TreeCellRenderer, you can replace the UI defaults for collapsedIcon and 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<的实现code>图标界面：

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;
    }
}

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