Question

Can someone please explain to me, why every time I use the FlowLayout Layout manager
my textfields are displayed as slits.

I have bumped my head against this problem for some time now, and I can’t seem to figure
out why it goes wrong.

I get a feeling it is a simple thing that I am overlooking time and time again, so if
someone would please explain this phenomenon to me, I would be forever grateful.

import java.awt.Container;
import java.awt.FlowLayout;

import javax.swing.JFrame;
import javax.swing.JTextField;

public class Console
{   
    public Console()
    {
        makeConsole();
    }

    private void makeConsole()
    {
        JFrame console = new JFrame("ArchiveConsole");
        Container base  = console.getContentPane();
        base.setSize(400, 250);
        console.setSize(base.getSize());
        base.setLayout(new FlowLayout(FlowLayout.CENTER, 5,5));

        JTextField tf = new JTextField();
        tf.setSize(base.getWidth(), 25);
        base.add(tf);

        console.setVisible(true);
    }
}

Answer 1

From the Swing layout manager tutorial

The FlowLayout class puts components in a row, sized at their preferred size. If the horizontal space in the container is too small to put all the components in one row, the FlowLayout class uses multiple rows. If the container is wider than necessary for a row of components, the row is, by default, centered horizontally within the container

So you need to adjust the preferred size of your textfield, preferably by using the setColumns method.

Note that if you want your text field to span the whole width you might want to use another layout then the FlowLayout for the reason quoted above

For example, the following code gives a nice looking JTextField, but I have hardcoded the number of columns

import javax.swing.JFrame;
import javax.swing.JTextField;
import java.awt.Container;
import java.awt.EventQueue;
import java.awt.FlowLayout;

public class TextFieldWithFlowLayout {
  public static void main( String[] args ) {
    EventQueue.invokeLater( new Runnable() {
      @Override
      public void run() {
        JFrame console = new JFrame("ArchiveConsole");
        Container base  = console.getContentPane();
        base.setLayout(new FlowLayout( FlowLayout.CENTER, 5,5));

        JTextField tf = new JTextField();
        tf.setColumns( 20 );
        base.add(tf);
        console.pack();
        console.setVisible(true);
      }
    } );
  }
}