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Placing components on Jpanel

Can i combine Java layouts in same JPanel. I'm stuck with with placing my components on JPanel. It shoudl be like this: JLabel, JButton, JButton , JLabel and new line and same. I used BorderLayout but it wont go to the next row, keep adding components to same row and I need a new row. Ideal sit combined with cardlayout or some other good solution.
EDIT: Solved with GridLayout (0,4) It will do the job till i learn to use GridBaglayout. Thank you for trying to help me.

Yes you can combine layouts.
Using a JPanel you are able to embed other JPanels:
JPanel back = new JPanel(new BorderLayout());
JPanel rows = new JPabel(new GridLayout(3,3));
back.add(rows, BorderLayout.CENTER);
Without seeing your code though it's difficult to know exactly what you are trying to achieve!

Yes you can combine java layouts.
A common pattern I use is BorderLayout first on a frame. The central component expands out, while the other components shrink in. Inside these panels I might have a Flowlayout to show buttons evenly spaced horizontally on top.
Another common approach for forms is using a Gridbaglayout, then adding all the form elements at gridX and gridY positions. I then later can stretch and teak these cells using other constraints in the Gridbaglayout repetoire.
Can you add a screenshot so that we can see what you want to do?

Adding panel with without layout to the NORTH of BorderLayout

Colleagues.
I'm trying to construct simple GUI in Java, where JFrame has Border Layout. I want to put JScrollPane with JTable to CENTER, and JPanel without layout to NORTH.
The problem is that JPanel doesn't visible. There is simple examle of the problem:
JFrame frame = new JFrame("Test frame");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
JButton button = new JButton("Test button");
button.setBounds(10, 10, 40, 20);
JPanel panelN = new JPanel(null); // layout = null, panelN without layout
panelN.add(button);
frame.add(panelN, BorderLayout.NORTH);
JTable table = new JTable(new DefaultTableModel(4, 4));
JScrollPane scrollPane = new JScrollPane(table);
frame.add(scrollPane, BorderLayout.CENTER);
frame.setSize(400, 400);
frame.setVisible(true);

You have to use a LayoutManager. It's totally discouraged not using layoutManager, but if you want this you have to set panel.setBounds(..) to the panel too.
By default JPanel has FlowLayout so if you put
JPanel panelN = new JPanel(); // FlowLayout used
panelN.add(button);
frame.add(panelN, BorderLayout.NORTH);
So your frame will look like this.
Layout Managers determines the size and position of the components within a container. Although components can provide size and alignment hints, a container's layout manager has the final say on the size and position of the components within the container.
It's strongly recommended cause for example if you have to resizes components or show in differentes resolutions you delegate this work to layout managers

I don't know the expected behavior of a null layout, but without further requirements you might as well just instantiate with the zero-arg constructor:
new JPanel();

If you didn't set any layout to the panel, when adding components the panel don't know where to put the component, so baisicly the component don't show until you set a specific location for components one by one by component.setBounds(x,y,width,hieght) method.
Note that it's not a good practice to remove the layout manager because of the different platformes, suppose that your program working on Window and MacOS and Linux, you'v better to use the layout managers instead.
Take a look at this post also and see #Andrew Thompson's comment on my answer:
Java GUIs might have to work on a number of platforms, on different
screen resolutions & using different PLAFs. As such they are not
conducive to exact placement of components. For a robust GUI, instead
use layout managers, or combinations of them, along with layout
padding & borders for white space, to organize the components.
After all:
If you have a requirement or an assignment telling you you must use absolute layout, then use it, otherwise avoid it.

It is OK to use containers with no layout manager because you actually CAN set container's layout to NULL. And it's a nice idea to position your components with setBounds(). But in this case, you just have to consider your container. What size it need to be? A layout manager would calculate this for you, and if you don't have one, you have to set the size of your panel by yourself, according to components you have added to it.
As pointed by others here, the case it that the border-layout manager of your frame needs the preferred size of your NORTH panel (actually, the preferred height). And you have to set it, or values will be zeros and the container will become invisible. Note that for the CENTER panel this is not needed as it gets all space possible.
I had a problem like yours before and have written a fast function to resize a container according to bounds of a given component. It will be as large as needed to show this component, so dimension (w,h) and position (x,y) are considered. There's an "auto-resize" version that can be used once, after all components are added.
public static void updatePreferredSize(Container cont, Component comp) {
int w = cont.getPreferredSize().width;
int h = cont.getPreferredSize().height;
int W = comp.getBounds().x + comp.getBounds().width;
int H = comp.getBounds().y + comp.getBounds().height;
if (W>w||H>h) cont.setPreferredSize(new Dimension(W>w?W:w, H>h?H:h));
}
public static void autoPreferredSize(Container cont) {
for (Component comp : cont.getComponents())
updatePreferredSize(cont, comp);
}
You can use updatePreferredSize() after adding every component to a panel, or use autoPreferredSize() once, after all addings.
// [...]
panelN.add(button);
updatePreferredSize(panelN, button);
// [...]
// or...
// [...]
autoPreferredSize(panelN);
// [...]
frame.setVisible(true);
This way, if you do not set you north panel height with a fixed value, with help of these functions you can expect your button will be visible according the position you set it with setBounds().

Overlap JPanels with WindowBuilder for eclipse

I am using WindowBuilder Pro for eclipse, and I would like to have two Jpanels that perfectly overlap each other. I would then be able to toggle their visibilty based on the selection of a combox box. When I try and acheive this in the gui builder, the first panel gets displaced by the second panel. And advice please?

It is possible using groupLayout, according to the tutorial .
What you must do is add the components to a mother JPanel , and set that panel to use GroupLayout.
Then add the components to the layout as a ParallelGroup in both the horizontal and vertical spacing. This means they will occupy the same X and Y space. Then disable/enable as needed, hiding the JPanels as well.
I believe the way it would work is so:
JPanel panel1, panel2, panel3;
//initialize panel3, etc
panel1=new JPanel();
panel2 = new JPanel();
panel1.add(new JTextField("Panel1"));
panel2.add(new JTextField("PANEL2"));
groupLayout = new GroupLayout(panel3);
panel3.setLayout(groupLayout);
groupLayout.setHorizontalGroup(
groupLayout.createParallelGroup(GroupLayout.Alignment.LEADING)
.addComponent(panel1)
.addComponent(panel2)
);
groupLayout.setVerticalGroup(
groupLayout.createParallelGroup(GroupLayout.Alignment.LEADING)
.addComponent(panel1)
.addComponent(panel2)
);
panel1.setEnabled(false);
panel1.setVisible(false);
then add a jCheckBox with an ActionPerformed method containing:
if(panel1.isEnabled()) {
panel1.setEnabled(false);
panel1.setVisible(false);
panel2.setEnabled(true);
panel2.setVisible(true);
}else
if(panel2.isEnabled()) {
panel2.setEnabled(false);
panel2.setVisible(false);
panel1.setEnabled(true);
panel1.setVisible(true);
}
That produced the desired behaviour for me. You should be able to switch the JComboBox for the JCheckBox fairly easily.
EDIT: Removed the necessity of having "Jpanel of their own". That should not be the case, and the above method allows you to get the benefits of both GroupLayout and CardLayout.

I would like to have two Jpanels that perfectly overlap each other. I would then be able to toggle their visibilty based on the selection of a combox box
See: How to Use Card Layout for an example that does exactly this.

I would like to have two Jpanels that perfectly overlap each other.
I believe the CardLayout is there exactly for that reason.
Basically, you can nest different panels or 'Cards' using the CardLayout and set the appropriate card to be displayed programmatically (on some event).

Java Simple Question about working with JPanels

Just a quick question here. I have a program in which I need to create a number of JPanels, which will then each contain some objects (usually JLabels).
There are a few operations that I have to do each time i create a new JPanel, and I'm wondering if the order in which I do them has any bearing, or if there is a standard practice.
The operations I do are the following:
Declare the JPanel: JPanel panel = new JPanel(...)
Declare the JLabel: JLabel laberl = new JLabel...
Add the JPanel to some other content pane: frame.getContentPane().add(panel)
Set the bounds of the JPanel: panel.setBounds(...)
Add the JLabel to the JPanel: panel.add(label)

In general order isn't important as long as you add all the components to the panel and the panel is added to the content pane "before" you make the frame visible.
The standard practice is to use a layout manager, so there would be no need to set the bounds of the panel you added to the content pane.

The order doesn't matter. However, after creating and adding everything, you need to call revalidate() on the panel (or pack() on its parent window) so that the layout manager (I presume you're using one!) arranges the components as they should be.

Have a method createPanel() that returns the panel with all its children added.
Panel p = createPanel();
p.setBounds(...); // if you must
frame.getContentPane().add(p);
And then
Panel createPanel() {
Panel p = new Panel();
Label l = new Label("Heading");
p.add(l);
return p;
}
The order of constructing and adding items isn't important, except that when you add children, you should add them in the order you want them in the panel.

Can you set a permanent size for a JPanel inside of a JFrame?

My current problem is that I have a JFrame with a 2x2 GridLayout. And inside one of the squares, I have a JPanel that is to display a grid. I am having a field day with the java swing library... take a look
Image
Java is automatically expanding each JLabel to fit the screen. I want it to just be those blue squares (water) and the black border and not that gray space. Is there a way I can just set the size of that JPanel permanently so that I don't have to go through changing the size of the JFrame a million times before I get the exact dimension so that the gray space disappears?
I also would like to set the size of those buttons so they are not so huge (BorderLayout is being used for the buttons and TextField)

GridBagLayout is what you really want to use. The GridLayout will force the same size for each component in the layout no matter what size constraints you put on them. GridBagLayout is a lot more powerful and a lot more complicated. Study up on the API page for it. Using GridBagLayout, the components won't fill the whole grid space if you don't want them to and can even stay the size that you ask it to be. To keep a component's size from changing, I would set all three available size constraints:
water.setPreferredSize(new Dimension(20, 20));
water.setMinimumSize(new Dimension(20, 20));
water.setMaximumSize(new Dimension(20, 20));
For your buttons, I would definitely use an inner panel as Bryan mentions. You could use either a GridLayout like he suggests or a FlowLayout if you don't want all the buttons to be the same size. Add all your buttons to that inner panel instead of the main one.

If you want the two checkerboards to stay the same size, then you'll need to have them each contained in their own JPanel. Set each of those parent JPanel's to have a layout type of GridBagLayout. Set the preferedSize for each checkerboard component and then add them to their respective containers. GridBagLayout should by default lay each board out in the center of the parent JPanel. So as the window is resized, the JPanel parent area will get larger or smaller, but the checkerboard components inside will remain the same size.
Alternatively, you could have your blue squares scale to the right size as the window is resized by having each checkboard square be a JPanel with a BorderLayout layout manager and adding the JLabel (with a blue background color) to its BorderLayout.CENTER location.
As for your buttons, try something like this:
JPanel theButtonPanel = new JPanel(new BorderLayout());
JButton button1 = new JButton("Fire");
JButton button2 = new JButton("Pass");
JButton button3 = new JButton("Forfiet");
JPanel innerButtonContainer = new JPanel(new Grid(1, 3, 8, 8));
innerButtonContainer.add(button1);
innerButtonContainer.add(button2);
innerButtonContainer.add(button3);
theButtonPanel.add(innterButtonContainer);
Lastly, consider using a design tool for your Swing user interface. Netbeans has an excellent UI designer built into it. Download Netbeans here.

If you can setResizeable( false ) on the top level frame you can then set your layout manager to null and hard code each location and size via setBounds. This is how I would do it (contingent on resizing of course).

I have had success solving problems like these using TableLayout which is a third party layout manager. You will need to download it and read the tutorial but the key would be to set the justification to CENTER when adding the JButtons to their positions in the layout.