Thread: Array of JPanels not showing.

I'm trying to add 5 identical JPanels to a frame. Each panel has 2 radio buttons and a slider bar. The individual panels seem to render okay, but if I add them to the frame, only the last one is shown. It looks like the others were added--you can see a big space for 4 panels--but they seem to be invisible or their individual components are missing.




The panels are in an array, and I added components to them using a for loop.

 
	private void makeControlFrame()
	{
		JFrame controlPanel = new JFrame("Fan spinner control panel.");
		JPanel componentControlPanel[] = new JPanel[5];
 
		ButtonGroup grpDirection = new ButtonGroup();
		JRadioButton jrbClockWise = new JRadioButton("CLOCKWISE");
		JRadioButton jrbCounterClockWise = new JRadioButton("COUNTERCLOCKWISE");
 
		JSlider jslSpeed = new JSlider(JSlider.HORIZONTAL,1,2000,100);
 
		controlPanel.setLayout(new GridLayout(5,1));
 
		grpDirection.add(jrbClockWise);
		grpDirection.add(jrbCounterClockWise);
 
		for(int i = 0; i < 5; i++)
		{
			componentControlPanel[i] = new JPanel();
			componentControlPanel[i].setLayout(new GridLayout (3,1));
			componentControlPanel[i].add(jrbClockWise);
			componentControlPanel[i].add(jrbCounterClockWise);
			componentControlPanel[i].add(jslSpeed);
			controlPanel.add(componentControlPanel[i]);
 
		}	
 
		controlPanel.setVisible(true);
		controlPanel.setLocationRelativeTo(null);
		controlPanel.pack();
 
}

Oh hmm. That's interesting. I didn't realize that. I might have to do a few more arrays then.... or maybe arrays are more trouble than they're worth in this instance. Thanks for the insight copeg.

Okay, got this working. That thing about needing 1 of each swing element for each panel is one of those things that seems super obvious in hindsight. Here's what I ended up with:

 
	//Method makes the control panel frame.
	private void makeControlFrame()
	{
 
		//Primary frame.
		JFrame controlPanel = new JFrame("CONTROL PANEL");
 
		//Five control panels each to hold controls for one fan or star.
		JPanel componentControlPanel[] = new JPanel[5];
 
		//Labels for control panel elements.
		String[] labels = {"North Fan" , "East Fan", "South Fan", "West Fan", "Center Star"};		
 
		controlPanel.setLayout(new GridLayout(5,1));
		controlPanel.addWindowListener(new FrameListener());
 
		//Add elements to sub panels, then add to the control panel frame.
		for(int i = 0; i < 5; i++)
		{
 
			//Create the basic border.
			Border subPanelBorder = BorderFactory.createLineBorder(Color.BLACK);
			//Modify it to add the name of the current element.
			subPanelBorder = BorderFactory.createTitledBorder(subPanelBorder, labels[i]);
 
			//Create GUI elements for this sub panel.
			componentControlPanel[i] = new JPanel();
			//componentControlPanel[i].add(new JLabel(labels[i] +" Direction"));
			grpDirection[i] = new ButtonGroup();
			jslSpeed[i] = new JSlider(JSlider.HORIZONTAL,1,1000,100);
			jrbClockWise[i] = new JRadioButton("Clockwise");
			jrbCounterClockWise[i] = new JRadioButton("Counterclockwise");			
 
			//Set attributes of speed slider bar.
			jslSpeed[i].setMinorTickSpacing(100);
			jslSpeed[i].setPaintTicks(true);
			jslSpeed[i].setPaintLabels(true);
 
			//Group radio buttons.
			grpDirection[i].add(jrbClockWise[i]);
			grpDirection[i].add(jrbCounterClockWise[i]);
 
			//Set layout manager for the sub panel.
			componentControlPanel[i].setLayout(new FlowLayout(FlowLayout.LEFT));
 
			//Another sub panel to group the radio buttons.
			JPanel radioSubPanel = new JPanel();
			radioSubPanel.setLayout(new GridLayout(3,1));
			radioSubPanel.add(new JLabel("Direction"));
			radioSubPanel.add(jrbClockWise[i]);
			radioSubPanel.add(jrbCounterClockWise[i]);
 
			//Another sub panel to group the speed slider and label.
			JPanel sliderSubPanel = new JPanel();
			sliderSubPanel.setLayout(new GridLayout(3,1));
			sliderSubPanel.add(new JLabel("Speed"));
			sliderSubPanel.add(new JLabel("FAST -------------------------------  SLOW"));
			sliderSubPanel.add(jslSpeed[i]);
 
			//Add radio and slider sub panels to control panel.
			componentControlPanel[i].add(sliderSubPanel);
			componentControlPanel[i].add(radioSubPanel);
 
			//Register listeners.
			jslSpeed[i].addChangeListener(new HandleSliders(i));
			jrbClockWise[i].addActionListener(new HandleRadioButtons(i));
			jrbCounterClockWise[i].addActionListener(new HandleRadioButtons(i));
 
			//Set the title border for the control panel.
			componentControlPanel[i].setBorder(subPanelBorder);
 
			//Add this panel to the main frame.
			controlPanel.add(componentControlPanel[i]);
		}	
		//Speed slider bar for the star has different minimum and maximum values.
		jslSpeed[4].setValue(500);
		jslSpeed[4].setMinimum(100);
		jslSpeed[4].setMaximum(2000);
		jslSpeed[4].setMinorTickSpacing(200);
 
		//Set attributes of frame.
		controlPanel.setVisible(true);
		controlPanel.setResizable(false);
		controlPanel.pack();
 
	}