TextArea sizing question

Question

hi,
i have a TextArea. when i try to set its size it does not work before the window is shown.
after the window is shown there is no problem with the setSize.
any idea why?
import java.awt.*;
import java.awt.event.*;
public class Components extends CloseableFrame
     TextArea textArea = null;
     public static void main(String[] args)
          Components f = new Components();
          f.setBounds(100, 100, 340, 300);
          f.setVisible(true);
     public Components()
          super("Components");
          setLayout(new java.awt.FlowLayout(
               java.awt.FlowLayout.CENTER, 20, 10));
          textArea = new TextArea("my text", 20, 40, TextArea.SCROLLBARS_VERTICAL_ONLY);
          textArea.setForeground(Color.red);
          add(textArea);
          textArea.setSize(10, 10); // <<=== NOW WORKING !!!!!!
          Button btn = new Button("button");
          add(btn);
          btn.addActionListener(
               new ActionListener() {
                    double sizeFactor = 0.5;
                    public void actionPerformed(ActionEvent e) {
                         Dimension size = textArea.getSize();
                         size.width = (int) (size.width * sizeFactor);
                         size.height = (int) (size.height * sizeFactor);
                         textArea.setSize(size); // <== WORKING !!!
                         if (sizeFactor == 0.5)
                              sizeFactor = 2;
                         else
                              sizeFactor = 0.5;
}

Answer 1

When you call setSize or pack the layout manager collects the preferred sizes of the components and lays them out. Until then it doesn't have the information available to give you.