JLabel not appearing until frame is moved out of the screen and back again

Question

I have the following fragment of code, where a JLabel is not displayed unless I move the JFrame out of the screen and back in again. I tried to change the layout from null to BorderLayout or FloatLayout without much luck so far. Any ideas?

public class StartPage extends Main{

// Global variables
private JPasswordField passField = new JPasswordField();
private String infoLabel =  "<html>Bla, bla some text</html>";

// CONSTRUCTOR
public StartPage() {
    frame.setSize(1400, 1000);
    frame.setLocationRelativeTo(null); 
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    frame.setVisible(true);
    frame.setResizable(false);
    startPage.setBounds(0, 0, 1400, 1000);  
    startPage.setLayout(null);
    frame.getContentPane().add(startPage);

    // TITLE LABEL
    JLabel lblTitle = new JLabel("My Title");
    lblTitle.setForeground(Color.RED);
    lblTitle.setHorizontalAlignment(SwingConstants.CENTER);
    lblTitle.setFont(new Font("Arial Black", Font.BOLD, 30));
    lblTitle.setBounds(190, 150, 1000, 85);
    startPage.add(lblTitle);

    // TEXT LABEL       
    JLabel areaText = new JLabel(infoLabel, SwingConstants.CENTER); 
    areaText.setVerticalAlignment(SwingConstants.CENTER);
    areaText.setBounds(315, 220, 750, 300);
    areaText.setFont(new Font("Arial Black", Font.PLAIN, 15));  
    areaText.setVisible(true);
    startPage.add(areaText);

Don't call `setVisible(true)` on the JFrame until after all components are added. Else they won't show up reliably. Also avoid absolute positioning unless you like difficult debugging sessions. — Hovercraft Full Of Eels, Oct 03 '17 at 21:30

score 2 · Answer 1 · answered Oct 03 '17 at 21:30

This line:
```
frame.setVisible(true);
```
Should be the last one in your program, it should be called after you've added all your components to it.
Another thing that is wrong with your code is this:
```
startPage.setLayout(null);
```
Calling setLayout null will break your GUI, it might seem easy for complex GUIs but here's a good example of what happens when you run it in another machine with different resolution, OS, PLAF, etc. Use one or a combination of layout managers.

score 0 · Answer 2 · answered Oct 03 '17 at 21:26

0

You have two solutions, call frame.invalidate() after finishing layout or call setVisible(true) after finishing layout;

answered Oct 03 '17 at 21:26

Marcos Vasconcelos

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I am already calling `startPage.setVisible(true)` at the end, just forgot to add it to the piece of code above. Or are you referring to the whole frame, as startPage is just a panel? – Vlad Balanescu Oct 03 '17 at 21:29
You have to call frame.setVisible not the other fields. The JFrame is the window. – Marcos Vasconcelos Oct 03 '17 at 21:31
else you need to call frame.invalidate() in the end of the method – Marcos Vasconcelos Oct 03 '17 at 21:32
Thanks. The problem was that I validated the JFrame before adding all components. Right answer is a call to `frame.setVisible(true)` at the very end of my constructor – Vlad Balanescu Oct 03 '17 at 21:33
And that's EXACTLY what I meant to -.- – Marcos Vasconcelos Oct 04 '17 at 14:37

JLabel not appearing until frame is moved out of the screen and back again

2 Answers2