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Java swing GUI absolute positioning

I know that absolute positioning is not recommended, but I need to show my labels randomly scattered as well as randomly changing their positions.
I have researched how to use setBounds but it doesn't seem to work. The following code shows the labels in a Flow Layout, and when I use setLayout(null) it shows a blank frame.
public class GUI extends JFrame{
device mobiles[];
device station;
JPanel pane= new JPanel();
public GUI()
{
setTitle("communication is Key");
setSize(1000, 1000);
setResizable(false);
setDefaultCloseOperation(EXIT_ON_CLOSE);
pane.setBackground(Color.WHITE);
int x=0; int y=0;
mobiles= new device[10];
for (int i = 0; i < 10; i++) {
x=randInt();
y=randInt();
mobiles[i]= new device(1,x,y);
pane.add(mobiles[i]);
}
x=randInt();
y=randInt();
station = new device(0,x,y);
pane.add(station);
this.add(pane);
}
and this is class "devices" that extends JLabel
public class device extends JLabel{
ImageIcon mob = new ImageIcon("mob.png");
ImageIcon tow = new ImageIcon("tower.png");
public device(int num, int x, int y)
{ if(num==1)
this.setIcon(mob);
else this.setIcon(tow);
this.setBounds(x, y, 3, 7);
}
}
any help in finding out what the problem is, would be be appreciated.

The following code shows the labels in a Flow Layout, and when I use setLayout(null) it shows a blank frame.
The layout manager sets the size and location of the component.
If you don't use the layout manager, then you are responsible for set the size and location of each component.
Typically I would set the size to equal to the components preferred size.
Also, did you display the x/y value that are randomly generated? Maybe the values are larger than the size of the panel.
and when I use setLayout(null) it shows a blank frame.
What layout is set to null? The panel of the frame. Your code doesn't use the above method. Post the code that you use to cause the problem. We don't want to guess what you may or may not be doing.

thanks to #CasparNoree ... the answer suggested was to initialize the Japnel from the start:
JPanel pane = new JPanel(null);

When you set the layout to null you can set the bounds manually with coordinates.
JFrame jf = new JFrame();
JPanel p = new JPanel();
JButton jb = new JButton();
// this is where you make it so setting the bounds actually does something
p.setLayout(null);
jb.setBounds(100,100,100,100);
p.add(jb);
jf.add(p);
jf.setVisible(true);

Why does a JButton under a JPanel still react?

I looked around for my problem, and i couldn't find an answer, so here I go:
I have a JLayeredPane, and in there there are 2 JPanels.
The deepest one ( furthest down ) has JButtons on there.
The second one ( The one on top ) has a partially transparent background color ( although i don't think this should influence it ).
Now when I hover over my JButtons ( which are behind the other JPanel ), they still fire events to the MouseListener I added to them. I don't know why...
Why is this the case? What can I do to make it stop?
Here I add both the panels to the layered pane, and this refers to my class which extends a JFrame.
JLayeredPane layer = this.getLayeredPane();
layer.removeAll();
this.gamePanel = new GamePanel(game);
this.ghostPanel = new GhostPanel();
this.ghostPanel.setOpaque(true);
this.ghostPanel.setVisible(true);
layer.add(this.gamePanel, new Integer(0));
layer.add(this.ghostPanel, new Integer(1));
Here I have some buttons ( with an absolute layout ) added to the lowest panel
this.setLayout(null);
for (int j = 0; j < 5; j++) {
for (int i = 0; i < 5 + j; i++) {
this.add(this.buttons[i][j]);
}
}
for (int j = 1; j < 5; j++) {
for (int i = j; i < 9; i++) {
this.add(this.buttons[i][4 + j]);
}
}
Here this refers to the most bottom JPanel
The purpose of this is a game called gipf, and the layout I went with is absolute because it was very hard to align everything in a hexagonal shape.

Now when I hover over my JButtons ( which are behind the other JPanel ), they still fire events to the MouseListener I added to them
When an event is generated in needs to be passed to a component, so Swing searches from the bottom of the parent/child hierarchy to the top until it finds a component that wants to handle the event.
What can I do to make it stop?
Add a MouseMotionListener to the top panel to intercept events like mouseEntered/mouseExited. This way you will still be able to handle button clicks in the other panel.

Why does the last item added to a panel occupy the whole panel?

I'm adding a quantity of JTextField to a panel, and all of them are added but, the last one added takes the whole panel and seems all other text boxes added on the last one..... here is the code
public JPanel crearCartonFormulario() {
panel = new JPanel();
panel.setLayout(new BorderLayout());
JTextField[] textBoxes = new JTextField[25];
int cont = 0;
int posX = 10;
int posY = 0;
llenarArreglo();
while (cont <= 4) {
for (int i = 0; i <= 4; i++) {
if (cont == 2 && i == 2) {
textBoxes[i] = new JTextField("");
} else {
textBoxes[i] = new JTextField(String.valueOf(numeros[cont][i]));
}
textBoxes[i].setBounds(i + posX, 15 + posY, 40, 40);
textBoxes[i].setEditable(false);
panel.add(textBoxes[i]);
posX += 50;
}
posY += 50;
posX = 10;
cont++;
}
return panel;
}
This is returned at a panel where I keep multiple panels of this one, it works but in this one the last JTextField takes the whole panel space....
The new JFrame that contains the panels created by the method, adopt the last JTextField size and that text box doesn't take the bounds indicated by the method, but all the other text boxes still inside and correctly added.

panel.setLayout(new BorderLayout());
You are using a BorderLayout.
panel.add(textBoxes[i]);
When you use the add() method the default is to add the component to the CENTER of the BorderLayout. However, only a single component can be added to the center so the layout manager will only manage the size/location of the last component added. The rules of the BorderLayout is to make the component take up all the available space.
However, you have also used the setBounds() methods for the other text fields which is causing a problem. You should NOT attempt to use a layout manager and manage the bounds of the components yourself.
The solution is to just use a layout manager and let the layout manager do its job. Read the section from the Swing tutorial on Using Layout Managers for more information and use a more appropriate layout manager.
Update:
its a bingo table
Then maybe you shouldn't even be using JTextFields. Maybe a JTable would be a better component to use. The tutorial also has a section on How to Use Tables.

Your problem is here:
panel.setLayout(new BorderLayout());
You set the layout to BorderLayout and yet add components to the JPanel as if it were a GridLayout. Understand that when you add components to a BorderLayout-using container in a default way, the components get added in the BorderLayout.CENTER position which fills this position, covering anything added prevsiously.
Perhaps you wish to use a GridLayout instead? You will want to read the layout manager tutorial for more.

This is because you are using BorderLayout and BorderLaout Always requires a parameter like BorderLayout.CENTER, BorderLayout.WEST, BorderLayout.EAST, BorderLayout.NORTH and BorderLayout.SOUTH.
So basically BorderLayout only has 5 position where a component can go. And if you do not specify where when adding a component it defaults to BorderLayout.CENTER. And as there can only be one component at a time in the BorderLayout.CENTER position it only really adds the last one. So I'd suggest an other layout manager like GridLayout( if you want all the components to be equally sized).
I hope this helps :).
P.S. If you want me to give some explination on GridLayout just ask.

mixing gridlayout and borderlayout

I was tired but before quitting just stuck in the nearly-last 3 lines in the code snippet below to make a "refresh" button on my tictactoe panel, hoping to get away with it but expecting errors, since it mixes layout managers on a single container.
But it WORKED.
ButtonPanel.setLayout(new GridLayout(3, 3));
guiFrame.add(ButtonPanel);
for (int i = 0; i < 3; i++) {
for (int j = 0; j < 3; j++) {
button[i][j] = addButton(ButtonPanel, i, j);
}
}
JButton refreshbutton = new JButton("Refresh");
guiFrame.add(refreshbutton, BorderLayout.SOUTH); // ... border layout worked. Hm.
refreshbutton.addActionListener(this);
guiFrame.setVisible(true); }
Should I be surprised? (Keep in mind my newbieness.)
(BOY, did I learn/stumble onto a buncha stuff in writing this silly game's program!!!--for instance, using setActionCommand to "label" each button internally [as 11,12,13,21,...33] so the ONE actionPerformed method could use getActionCommand to correctly label [with X or O] whatever button was pushed by whoever's turn it was.)

guiFrame.add(refreshbutton, BorderLayout.SOUTH); // ... border layout worked. Hm.
Just because you used BorderLayout.SOUTH does not make a panel a BorderLayout. Your code worked because the default layout manager for the content pane of a JFrame (JDialog) is a BorderLayout. So you are just taking advantage of the default layout.
since it mixes layout managers on a single container.
Yes, this is a common practice. In fact it is almost impossible to create a reasonably complex GUI if you don't use different layout managers on different panels that you add to a GUI.

JScrollPane not scrolling when a JPanel is added

I was hoping someone would be able to help. This seems like it should be a simple problem but for the life of me I can't work it out.
Problem: I am creating a JPanel that is made up of panels containing 5 labels each with ImageIcons. [sounds confusing]
I am then adding this panel to a JScrollPane. But when it is displayed the images are showing and correctly placed but I am unable to scroll down to see the panels that are off the screen.
here is a screenshot: http://img841.imageshack.us/img841/36/screenshot20120510at160.png
Here is the snippet of code I am using to populate the panels and add the JScrollPane.
private void setSeriesViewContainer(){
container = new BackgroundPanel(backGround, BackgroundPanel.TILED);
//container.setPreferredSize(new Dimension(650,500));
container.setLayout(new BoxLayout(container, BoxLayout.PAGE_AXIS));
FlowLayout flowLayout = new FlowLayout();
JPanel[] jp = new BackgroundPanel[10];
for (int i = 0; i < jp.length; i++) {
jp[i] = new BackgroundPanel(backGround, BackgroundPanel.TILED);
jp[i].setLayout(flowLayout);
for (int j = 0; j < 10; j++) {
jp[i].add(new JLabel(new ImageIcon(getClass().getResource("/placeHolder.png"))));
}
}
for (int i = 0; i < jp.length; i++) {
container.add(jp[i]);
}
public void init(){
seriesViewContainer = new javax.swing.JScrollPane(container);
seriesViewContainer.setBorder(null);
seriesViewContainer.setHorizontalScrollBarPolicy(javax.swing.ScrollPaneConstants.HORIZONTAL_SCROLLBAR_ALWAYS);
seriesViewContainer.setVerticalScrollBarPolicy(javax.swing.ScrollPaneConstants.VERTICAL_SCROLLBAR_ALWAYS);
seriesViewContainer.setPreferredSize(new java.awt.Dimension(700, 300));}
I have searched around for the solution but have not come up with one as yet.

container.setPreferredSize(new Dimension(x,y)); the dimensions of container should be larger than the dimensions of the scrollpane.
from what I've read setPreferredSize() is not a good thing to use though. The problem is probably the LayoutManager for container or jp.
same problem here: Java Swing: JScrollPane not working

Have you tried to call revalidate() to the JScrollPane and/or container after each add ?