Why Isn't My JPanel's paintComponent() Method Being Called After repaint()?

Program Not Invoking paintComponent() Method of Extended JPanel Class

The provided code contains an extension of JPanel called DrawPanelRemoteControl, which overrides the paintComponent() method for custom image rendering. However, it's observed that despite numerous executions of imagePanel.repaint(), the program never enters the paintComponent() method.

Possible Cause:

The issue may not lie directly with the DrawPanelRemoteControl class or its paintComponent() method. However, it's essential to consider the repaint process and its dependencies.

Repaint Process:

When calling repaint(), the program requests the system to trigger a repaint event for the component at the next available opportunity. This event places the component in a repaint queue. After all other pending events are processed, the system will initiate the repaint process.

Dependencies:

The repaint process can be affected by various factors, including:

• The component's visibility: If the DrawPanelRemoteControl is not visible, it will not be included in the repainting process.
• The event loop: If the event loop is blocked or occupied, the repaint event may not be processed in a timely manner.
• Other UI operations: Ongoing user interactions or system tasks can take precedence over repaint events.

Suggested Solution:

To ensure that the paintComponent() method is invoked, consider the following steps:

• Verify the visibility of the DrawPanelRemoteControl instance.
• Check for any UI operations or system tasks that may be blocking the event loop.
• Use a debugger to observe the repaint process and identify potential bottlenecks.

Alternative Implementation:

Additionally, consider using a more direct approach to update the component's display. Instead of relying on repaint(), you could explicitly call the paintImmediately() method on the DrawPanelRemoteControl instance. This forces the component to repaint immediately, bypassing the repaint queue.

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