Why aren't my components wrapping?

[Luigi Plinge]

I understand that FlowLayout is the default layout manager for JPanels.

So why isn't my text area wrapping in this window?

Thanks for any suggestions...

import java.awt.BorderLayout;
import java.awt.Color;
import javax.swing.*;

public class LayoutExperiment {

    public static void main(String[] args) {
        new LayoutExperiment().buildGui();
    }
    void buildGui(){
        try {
            UIManager.setLookAndFeel("com.sun.java.swing.plaf.nimbus.NimbusLookAndFeel");
        } catch (Exception e) {System.out.println("Could not set look and feel");
        }


        JFrame frame = new JFrame();
        JPanel panel = new JPanel();

        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setSize(500, 500);

        panel.setBackground(Color.DARK_GRAY);
        panel.setLayout(new BoxLayout(panel, BoxLayout.Y_AXIS));
        frame.add(BorderLayout.EAST, panel);

        JButton button1 = new JButton("Click me");
        JButton button2 = new JButton("Me too");
        panel.add(button1);
        panel.add(button2);

        JPanel leftPanel = new JPanel();
        frame.add(BorderLayout.WEST, leftPanel);

        JLabel label = new JLabel("Type here");
        JTextField field = new JTextField(20);
        leftPanel.add(label);
        leftPanel.add(field);
        field.setText("This is my text");
        field.selectAll();
        field.requestFocus();

        JTextArea area = new JTextArea(10, 20);
        area.setLineWrap(true);
        JScrollPane scrollPane = new JScrollPane(ScrollPaneConstants.VERTICAL_SCROLLBAR_ALWAYS,
                ScrollPaneConstants.HORIZONTAL_SCROLLBAR_NEVER);
        scrollPane.setViewportView(area);
        leftPanel.add(scrollPane);
        area.setText("This is just a test");
        
        frame.setVisible(true);
    }
}

[Ernest Friedman-Hill]

Because the WEST component of a JPanel is allowed to be as wide as it requires. The JPanel says it wants to be wide enough to contain all its contents, and the BorderLayout says "OK".

As to why when the window is first created, the TextArea paints over the buttons: that seems like a bug. But in any case, if you expand the window, you'll see what's going on.

If you want the JTextArea to be below the other components, you should arrange that manually by using a different LayoutManager.

[Luigi Plinge]

Thanks. I've set the left panel's position to CENTER and it looks a bit more as expected.

But I want the components to be left-alligned. I've tried

        JPanel leftPanel = new JPanel();
        frame.add(BorderLayout.CENTER, leftPanel);
        leftPanel.setAlignmentY(JPanel.LEFT_ALIGNMENT);

but the components are still centered within leftPanel. Any suggestions? (BTW I also tried setAlignmentX and that had no effect either.)

[Luigi Plinge]

Never mind, I worked it out:

        JPanel leftPanel = new JPanel();
        FlowLayout flowLayout = new FlowLayout(FlowLayout.LEFT);
        leftPanel.setLayout(flowLayout);