How to prevent JFrame from being oversized for window when calling pack()?

I have a JFrame that uses the method pack() to minimize the size of the components within the frame. This works well enough, but occasionally, due to something upon startup, I'll have a lot of components and the frame will be gigantic. Technically, the frame won't be bigger than my screen, but essentially it will be the same size.

I also call a method on my JFrame called setLocationByPlatform(true), which places my frame in the platform-relative default location.

However, when calling these 2 together, they end up with part of my frame being off-screen.

Now, there are a million-and-1 ways to work around this. I could full screen my application, which is most likely the real solution here. I could deactivate either or both options. I could set my size and location explicitly. And there's more solutions.

But is there any way to call both pack() and setLocationByPlatform(true) without ending up with my frame partially off-screen? Excluding above solutions of course. I'll accept no as an answer if it can be backed up (maybe docs say these 2 can contradict each other, or something like that). I just want my window to be fully on-screen after calling both of the mentioned methods.

And to be clear, I am A-OK with the actual content on my frame being cut off because the frame is too small. By all means, if the frame is too small to hold all of the content, that is a different problem that I already have solutions that I will later apply. But for now, to demonstrate the point, I am A-OK with an answer that allows content to be cutoff the window, but the full window is fully on-screen.

And not that this needs a code example, but here is one.

import javax.swing.*;

public class SOQ_20231003
{

   public static void main(final String[] args)
   {

      SwingUtilities.invokeLater(SOQ_20231003::new);

   }

   public SOQ_20231003()
   {
   
      final JFrame frame = new JFrame();
      
      frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
   
      final JPanel panel = new JPanel();
   
      for (int i = 0; i < 100; i++)
      {
      
         final JButton button = new JButton();
      
         final String text = 
            """
            <html>
            <p>
            Totam qui nihil qui possimus architecto. Quo quia voluptatem possimus. Aliquid praesentium ab assumenda nisi eligendi eum dolore sed. Sint dolorem eaque est vitae ipsam architecto. Consectetur consequatur ipsum assumenda nostrum debitis ab a nobis. Dignissimos nobis rem aut nihil mollitia rerum. Porro quis neque eos. Dolorum eum sit aperiam cumque velit nulla quidem qui. Velit facilis maiores rerum mollitia. Tempore dolor consequatur quis. Similique minima animi et et repellat quam. Hic dolore voluptatem tempora est et dolor atque dolores. Odio est repellendus fugiat neque ut quas sunt quia. Sunt ea ab qui. Placeat pariatur dolores quis earum exercitationem. Nulla aut id nulla pariatur. Officia architecto sunt ipsum. Quo voluptatibus aut qui voluptates velit accusamus fuga. Beatae et ullam adipisci. Quo ducimus et in quam soluta officia ducimus. Placeat molestiae qui quia ut. Sint dolorem porro amet minus. Labore expedita dolorem omnis eveniet et quis.
            </p>
            </html>
            """
            ;
      
         button.setText(text);
         
         panel.add(button);
      
      }
      
      frame.add(panel);
      
      frame.pack();
      frame.setLocationByPlatform(true);
      
      frame.setVisible(true); //image is cut-off on the right hand side of the screen!
   
   }

}

I guess I am just more surprised that a method as encouraged as pack() or setLocationByPlatform(true) would default to shoving things off-screen. I felt like that is something where they would either have coded it not to do that, or provided another method that would undo that from happening. Maybe a resizeToAvoidClippingScreen method or something.

Solution

After thinking about it, I am pretty sure I have a very good reason why the answer is no. Not a definitive, backed by documentation answer, but one that is logical.

Imagine we did have that method -- resizeToAvoidClippingScreen(). While it would certainly be convenient, in rare occasions, it would actually be DANGEROUS.

Imagine I have a grid of squares where each square has a large gap between all of its neighbors. On small screens, you run the risk of having the squares on the right and the bottom cut off, but in a convincing way that is not obvious to the user that there is a component hidden. Here is a visual example.

Here is our grid.

Now, on a large window, they may look like this.

But on a small window, if we used our magic method and let the content get cutoff by the window instead of letting the window get cut off by the screen, we might end up with this instead.

As you can see, it might be completely non-obvious to the user that content is cut off of the screen.

That is the danger of this method. Introducing this method would end up causing a whole bunch of issues that are hard to find and easy to make.

Now, obviously, if you have content that is so wildly out of bounds that it careens off the screen, then that's on the developer. But, for methods like pack(), they will try their best to fit it in, but will extend the window slightly off screen if needed. If anything, it's a good signifier that your content is a little too big and needs to be broken up.

Gilbert Le Blanc gave some good examples on how to do that above. You can use JScrollPane to add scroll bars when your content gets too big. You can move some of the content into a popup window called a JDialog or JOptionPane. You could use CardLayout, a layout that allows you to cycle through your components one by one (paginate through them) on the same frame.

As is, if your frame has so many components that pack() ends up putting your frame slightly off-screen, consider that to be Swing's gentle hint that there is too much content in your frame at one time, and you need to rework your solution. Understanding that, I'm glad they did it this way. It would be much harder to discover if pack() tried to keep everything on screen so diligently, even in examples where there is just enough space to do so. As is, even when there is just enough space to fit everything, pack() will still shift you slightly off-screen, almost like an intentional hint by Swing that you still need to rework the frame because it has TOO MUCH STUFF IN IT. BREAK IT UP OR BREAK IT OUT.