我终于得到了我想要的垂直堆叠组件的行为，这些组件具有随时间变化的首选高度。但我需要使用 MigLayout。
有没有办法在没有 MigLayout 的情况下做到这一点？（这是一个图书馆，我不想强制依赖，除非我必须）
这是我正在寻找的行为（我的测试程序实现了）：
在垂直顺序中，有一个调整大小按钮、“空白空间”（嗯，一个标记为这样的 JLabel）、一个红色矩形和一个绿色正方形。调整大小按钮具有固定高度。红色方块的大小是随机的，可以在任意时间改变。绿色方块设置其首选高度以匹配其宽度，我想扩大其宽度以填充容器。空白空间水平和垂直扩展以填充容器中的剩余空间。
什么可以代替 MigLayout？
import java.awt.Color;
import java.awt.Dimension;
import java.awt.FlowLayout;
import java.awt.FontMetrics;
import java.awt.Graphics;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.ComponentAdapter;
import java.awt.event.ComponentEvent;
import java.util.Random;
import javax.swing.BorderFactory;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import net.miginfocom.swing.MigLayout;
public class AutoResizeDemo extends JPanel
{
static private class ResizingPanel extends JPanel
{
final private Color color;
private Dimension dpref = new Dimension(100,100);
@Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
int w = getWidth();
int h = getHeight();
g.setColor(this.color);
g.fillRect(0, 0, w, h);
g.setColor(Color.BLACK);
g.drawRect(0, 0, w-1, h-1);
String s = this.dpref.width+"x"+this.dpref.height;
FontMetrics fm = g.getFontMetrics();
g.drawString(s, 0, fm.getHeight());
}
public ResizingPanel(Color color, boolean isSquare)
{
this.color = color;
if (isSquare)
{
addComponentListener(new ComponentAdapter() {
@Override public void componentResized(ComponentEvent e) {
doResize(getWidth(), getWidth());
}
});
}
}
@Override public Dimension getPreferredSize() {
return this.dpref;
}
public void doResize(int w, int h)
{
this.dpref = new Dimension(w, h);
revalidate();
}
}
public AutoResizeDemo()
{
super(new MigLayout("","[grow]",""));
setPreferredSize(new Dimension(200, 800));
final ResizingPanel resizingPanelRandom = new ResizingPanel(Color.RED, false);
ResizingPanel resizingPanelSquare = new ResizingPanel(Color.GREEN, true);
JPanel buttonPanel = new JPanel(new FlowLayout());
final Random rand = new Random();
addButton(buttonPanel, "resize",new Runnable() {
@Override public void run() {
resizingPanelRandom.doResize(
rand.nextInt(100)+100,
rand.nextInt(100)+100
);
}
});
add(buttonPanel, "wrap");
JLabel spaceLabel = new JLabel("empty space");
spaceLabel.setBorder(BorderFactory.createLineBorder(Color.BLACK));
add(spaceLabel, "push, grow, wrap");
add(resizingPanelRandom, "wrap");
add(resizingPanelSquare,"pushx, growx, wrap");
}
private void addButton(JPanel panel, String title, final Runnable r) {
JButton button = new JButton(title);
button.addActionListener(new ActionListener() {
@Override public void actionPerformed(ActionEvent e) {
r.run();
}
});
panel.add(button);
}
public static void main(String[] args) {
JFrame frame = new JFrame(AutoResizeDemo.class.getSimpleName());
frame.setContentPane(new AutoResizeDemo());
frame.pack();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setVisible(true);
}
}