Why is Only the Top Component of My JFrame Displaying?

Troubleshooting a GUI Rendering Issue

You've encountered a problem where only the topmost component of your JFrame is displaying. To understand why, let's analyze the BorderLayout of your JFrame.

The BorderLayout divides the frame into five regions: North, South, East, West, and Center. By default, components added to the BorderLayout without specifying constraints appear in the Center region. However, the Center region can only display a single component.

To resolve this issue, you should explicitly specify the locations of your components within the JFrame using appropriate constraints. For an immediate fix, consider the following changes:

<br>f.add(top, BorderLayout.PAGE_START);<br>f.add(mid);<br>f.add(bot, BorderLayout.PAGE_END);<br>

This will place the top panel at the top, the middle panel at the center, and the bottom panel at the bottom, allowing all components to be visible.

Additional Considerations for Optimization

Beyond addressing the GUI rendering issue, you can also make the following optimizations to your code:

1. Replace f.setSize(500, 500); with pack(); immediately before setVisible(true);. This will ensure that the frame's size is calculated to fit its contents.


2. Change f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); to f.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);. This will dispose of the frame, releasing its resources, without terminating the entire application.


3. Remove unnecessary calls to setVisible(true); for components added to a top-level container (like the JFrame).


4. Eliminate the extension of the JFrame class (public class EncDecExample extends JFrame). Instead, simply use public class EncDecExample.

These changes will enhance the performance and efficiency of your GUI.

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