Java Swing Jtree или Jlist с пользовательскими элементами

Question

Может кто-нибудь объяснить мне, пожалуйста, как я могу создать расширяемый список с пользовательскими элементами в Java Swing Desktop App? Я немного новичок в Swing Desktop (обычно я работаю на Android), и я не вижу хороших компонентов, которые могли бы помочь мне создать такой список с изображениями и текстом, как на изображении. Я думал использовать JTree, но я не уверен, что могу настроить его достаточно, чтобы получить результат, который мне нужен.

Answer 1

Здесь используется возможная реализация настраиваемым TreeCellRenderer, Tree.closedIcon и Tree.openIcon:

import java.awt.*; 
import java.awt.geom.*; 
import javax.swing.*; 
import javax.swing.plaf.*; 
import javax.swing.plaf.basic.*; 
import javax.swing.tree.*; 

public class CustomItemTreeTest { 
    public JComponent makeUI() { 
    IconUIResource emptyIcon = new IconUIResource(new Icon() { 
     @Override public void paintIcon(Component c, Graphics g, int x, int y) {} 
     @Override public int getIconWidth() { 
     return 0; 
     } 
     @Override public int getIconHeight() { 
     return 0; 
     } 
    }); 
    UIManager.put("Tree.expandedIcon", emptyIcon); 
    UIManager.put("Tree.collapsedIcon", emptyIcon); 
    //UIManager.put("Tree.closedIcon", emptyIcon); 
    //UIManager.put("Tree.openIcon",  emptyIcon); 
    UIManager.put("Tree.paintLines", Boolean.FALSE); 

    UIDefaults d = new UIDefaults(); 
    d.put("Tree:TreeCell[Enabled+Selected].backgroundPainter", new Painter<JComponent>() { 
     @Override public void paint(Graphics2D g, JComponent c, int w, int h) { 
     g.setPaint(Color.GREEN.darker()); 
     g.fillRect(0, 0, w, h); 
     } 
    }); 

    JTree tree = new JTree(makeModel()); 
    tree.setCellRenderer(new TestTreeCellRenderer()); 
    //tree.setRowHeight(0); 
    tree.setRootVisible(false); 
    tree.setShowsRootHandles(false); 
    tree.setBackground(Color.WHITE); 
    tree.putClientProperty("Nimbus.Overrides", d); 
    tree.putClientProperty("Nimbus.Overrides.InheritDefaults", false); 

    return new JScrollPane(tree); 
    } 

    private static TreeModel makeModel() { 
    Dimension d64 = new Dimension(64, 64); 
    Dimension d32 = new Dimension(32, 32); 
    Dimension d24 = new Dimension(24, 24); 
    DefaultMutableTreeNode root = new DefaultMutableTreeNode("Root"); 
    DefaultMutableTreeNode set1 = new DefaultMutableTreeNode(
     new TestNode("SubCategory 1", Color.ORANGE, d64, false)); 
    set1.add(new DefaultMutableTreeNode(
     new TestNode("SubSubCategory 1", Color.ORANGE, d32, true))); 
    set1.add(new DefaultMutableTreeNode(
     new TestNode("SubSubCategory 2", Color.CYAN.darker(), d32, true))); 
    set1.add(new DefaultMutableTreeNode(
     new TestNode("SubSubCategory 3", Color.GREEN, d32, true))); 
    DefaultMutableTreeNode set2 = new DefaultMutableTreeNode(
     new TestNode("SubCategory 2", Color.GREEN.darker().darker(), d64, false)); 
    DefaultMutableTreeNode set3 = new DefaultMutableTreeNode(
     new TestNode("SubSubCategory 5", Color.GREEN, d32, false)); 
    set3.add(new DefaultMutableTreeNode(
     new TestNode("SubSubSubCategory 1", Color.BLUE, d24, true))); 
    set3.add(new DefaultMutableTreeNode(
     new TestNode("SubSubSubCategory 2", Color.GREEN, d24, true))); 
    set3.add(new DefaultMutableTreeNode(
     new TestNode("SubSubSubCategory 3", Color.ORANGE.darker(), d24, true))); 
    set2.add(new DefaultMutableTreeNode(
     new TestNode("SubSubCategory 4", Color.ORANGE.darker().darker(), d32, true))); 
    set2.add(set3); 
    set2.add(new DefaultMutableTreeNode(
     new TestNode("SubSubCategory 6", Color.ORANGE, d32, true))); 
    root.add(set1); 
    root.add(set2); 
    return new DefaultTreeModel(root); 
    } 

    public static void main(String... args) { 
    EventQueue.invokeLater(() -> { 
     try { 
     for (UIManager.LookAndFeelInfo laf: UIManager.getInstalledLookAndFeels()) { 
      if ("Nimbus".equals(laf.getName())) { 
      UIManager.setLookAndFeel(laf.getClassName()); 
      } 
     } 
     } catch (Exception ex) { 
     ex.printStackTrace(); 
     } 
     JFrame f = new JFrame(); 
     f.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE); 
     f.getContentPane().add(new CustomItemTreeTest().makeUI()); 
     f.setSize(320, 512); 
     f.setLocationRelativeTo(null); 
     f.setVisible(true); 
    }); 
    } 
} 

class TestTreeCellRenderer extends DefaultTreeCellRenderer { 
    @Override public Component getTreeCellRendererComponent(
     JTree tree, Object value, boolean selected, boolean expanded, 
     boolean leaf, int row, boolean hasFocus) { 
    JLabel l = (JLabel) super.getTreeCellRendererComponent(
     tree, value, selected, expanded, leaf, row, hasFocus); 
    if (value instanceof DefaultMutableTreeNode) { 
     DefaultMutableTreeNode node = (DefaultMutableTreeNode) value; 
     Object uo = node.getUserObject(); 
     if (uo instanceof TestNode) { 
     TestNode i = (TestNode) uo; 
     l.setForeground(Color.BLACK); 
     l.setIcon(new TestNode(i.title, i.color, i.dim, leaf, expanded)); 

     int indent = 0; 
     TreeNode parent = node.getParent(); 
     while (parent instanceof DefaultMutableTreeNode) { 
      DefaultMutableTreeNode pn = (DefaultMutableTreeNode) parent; 
      if (pn.getUserObject() instanceof TestNode) { 
      TestNode pi = (TestNode) pn.getUserObject(); 
      indent += pi.dim.width/2; 
      } 
      parent = pn.getParent(); 
     } 
     l.setBorder(BorderFactory.createEmptyBorder(2, indent, 2, 5)); 
     } 
    } 
    return l; 
    } 
} 

class TestNode implements Icon { 
    public final String title; 
    public final Color color; 
    public final Dimension dim; 
    private final boolean expanded; 
    private final boolean leaf; 
    private static int GAP = 4; 
    //public TestNode(String title, ImageIcon img, Dimension dim) { 
    public TestNode(String title, Color color, Dimension dim, boolean leaf) { 
    this(title, color, dim, leaf, false); 
    } 
    public TestNode(String title, Color color, Dimension dim, 
        boolean leaf, boolean expanded) { 
    this.title = title; 
    this.color = color; 
    this.dim = dim; 
    this.expanded = expanded; 
    this.leaf = leaf; 
    } 
    @Override public void paintIcon(Component c, Graphics g, int x, int y) { 
    g.setColor(color); 
    g.fillRect(x + GAP, y + GAP, dim.width - GAP - GAP, dim.height - GAP - GAP); 
    if (dim.width < 64) { 
     Graphics2D g2 = (Graphics2D) g.create(); 
     g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, 
          RenderingHints.VALUE_ANTIALIAS_ON); 
     int w6 = dim.width/12; 
     int w3 = dim.width/6; 
     g2.setColor(Color.WHITE); 
     g2.setStroke(new BasicStroke(w6)); 
     Point pt = new Point(x + dim.width/2, y + dim.height/2); 
     Path2D path = new Path2D.Double(); 
     path.moveTo(pt.x - w6, pt.y - w3); 
     path.lineTo(pt.x + w6, pt.y); 
     path.lineTo(pt.x - w6, pt.y + w3); 
     int numquadrants; 
     if (leaf) { 
     numquadrants = 0; 
     } else if (expanded) { 
     numquadrants = 3; 
     } else { 
     numquadrants = 1; 
     } 
     AffineTransform at = AffineTransform.getQuadrantRotateInstance(
      numquadrants, pt.x, pt.y); 
     g2.draw(at.createTransformedShape(path)); 
     g2.dispose(); 
    } 
    } 
    @Override public int getIconWidth() { 
    return dim.width; 
    } 
    @Override public int getIconHeight() { 
    return dim.height; 
    } 
    @Override public String toString() { 
    return title; 
    } 
}