We Keep Coding

How to add JPanel into another JPanel with vertical scrollpane at runtime?

I'm trying to insert a new panel into another panel in runtime everytime I press a button. My problem is the original panel runs out of space and I can't see the new panels I'm adding.
What I've tried so far:
Using scrollpane for vertical scrolling with no success.
Using flowlayout-no luck. Tried disabling horizontal scrolling-keep pushing the new panel to the right (can't get to it because there is no scrolling).
Tried using borderlayout-no luck.
testpanel t = new testpanel();
t.setVisible(true);
this.jPanel15.add(t);
this.jPanel15.validate();
this.jPanel15.repaint();
This code suppose to insert the t panel into jpanel15.
With flowlayout it pushes the t panel downwards just like I want it to but with no vertical scroll.
PS: I'm using netbeans in order to create my GUI.

My problem is the original panel runs out of space and I cant see the new panels i'm adding. Tried using scrollpane for vertical scrolling with no success.
A FlowLayout adds components horizontally, not vertically so you will never see vertical scrollbars. Instead you can try the Wrap Layout.
The basic code to create the scrollpane would be:
JPanel main = new JPanel( new WrapLayout() );
JScrollPane scrollPane = new JScrollPane( main );
frame.add(scrollPane);
Then when you dynamically add components to the main panel you would do:
main.add(...);
main.revalidate();
main.repaint(); // sometimes needed

Use JScrollPane instead of the (outer) JPanel
Or have a BorderLayout for the JPanel, put in a JScrollPane at BorderLayout.CENTER as the only control. The JScrollPane takes a regular JPanel as view.
In any case you will then add the control to the JScrollPane. Suppose your JScrollPane variable is spn, your control to add is ctrl:
// Creation of the JScrollPane: Make the view a panel, having a BoxLayout manager for the Y-axis
JPanel view = new JPanel( );
view.setLayout( new BoxLayout( view, BoxLayout.Y_AXIS ) );
JScrollPane spn = new JScrollPane( view );
// The component you wish to add to the JScrollPane
Component ctrl = ...;
// Set the alignment (there's also RIGHT_ALIGNMENT and CENTER_ALIGNMENT)
ctrl.setAlignmentX( Component.LEFT_ALIGNMENT );
// Adding the component to the JScrollPane
JPanel pnl = (JPanel) spn.getViewport( ).getView( );
pnl.add( ctrl );
pnl.revalidate( );
pnl.repaint( );
spn.revalidate( );

How to improve GUI by changing BoxLayout into a different LayoutManager?

I've a big problem with Swing in Java, I used BoxLayout for this but still it looks bad.
Any suggestions about my usage of layouts, or how to change it to look like in assumptions? (here are assumptions)
Container main = new Container();
Container left = new Container();// here goin buttons
Container right = new Container(); // here goin tabs + more buttons, textfields and other stuff
BoxLayout lewyL = new BoxLayout(left, BoxLayout.Y_AXIS);
left.setLayout(lewyL);
left.add(rastrowa); //radiobutton
left.add(wektorowa);//radiobutton
left.add(apDwuliniowa);//checkbox
left.add(wczytaj);//button
left.add(zapisz);//obutton
left.add(wyczysc);//button
BoxLayout prawyL = new BoxLayout(right, BoxLayout.Y_AXIS);
right.setLayout(prawyL);
right.add(zakladki);// tabs (mostly i use BoxLayout but for last one i need something more "complicated")
EDIT: I almost solve this problem, I need to move all elements to left (how it look like)but I have no idea how ;/ Here is constructor of this class.
JLabel label = new JLabel("O wektor");
JLabel labelA = new JLabel("a:");
JLabel labelB = new JLabel("b:");
JButton wykonaj = new JButton("Wykonaj");
JTextField a = new JTextField(5);
JTextField b = new JTextField(5);
add(label);
add(labelA);
add(a);
add(labelB);
add(b);
add(wykonaj);

There's nothing wrong with the way it looks (in my opinion), but if you want it to look a little better, why don't you convert the left panel (which is 6x1) into a 3x2 panel, with the checkboxes/radiobuttons on the left, and buttons on the right? Sounds like a job for GridLayout - one of my favorite classes...
JPanel leftPanel = new JPanel(new GridLayout(3,2));
leftPanel.add(rastrowa); //radiobutton
leftPanel.add(wczytaj); //button
leftPanel.add(wektorowa); //radiobutton
leftPanel.add(zapisz); //obutton
leftPanel.add(apDwuliniowa); //checkbox
leftPanel.add(wyczysc); //button
Note that the 3,2 defines the number of rows,columns. When adding panels, they are added to the grid from left-to-right, and top-to-bottom. GridLayout also auto-sizes the components, so all the buttons etc will be the same width and height, making it look more consistent.
The GridLayout documentation might be useful, and the Visual Guide to Layout Managers is a great place to see other layout managers that might work better for your different situations. I personally find BorderLayout and GridLayout to be the most useful, and cover about 95% of the situations I ever need for my GUIs.

when adding 2+ buttons to east layout, only 1 shows

When adding 2+ buttons to east layout, only 1 shows. I am trying to test a layout that uses tabbed panes. For some reason when I try to add multiple buttons to the east region, it only shows 1 button. It just so happens the button displayed is the last one added to the east region, the rest are ignored. I am thinking maybe they are just hidden underneath the last button.
public void createPage1()
{
{
panel1 = new JPanel();
panel1.setLayout( new BorderLayout() );
panel1.add( new JButton( "North" ), BorderLayout.EAST );
panel1.add( new JButton( "South" ), BorderLayout.EAST );
panel1.add( new JButton( "East" ), BorderLayout.EAST );
panel1.add( new JButton( "West" ), BorderLayout.EAST );
panel1.add( new JButton( "Center" ), BorderLayout.EAST );
}
}

I dont know, how you want your UI to look like, but try it this way:
public void createPage1() {
//This will be the main panel.
//We are going to put several buttons only in the "EAST" part of it.
panel1 = new JPanel();
panel1.setLayout( new BorderLayout() );
//We create a sub-panel. Notice, that we don't use any layout-manager,
//Because we want it to use the default FlowLayout
JPanel subPanel = new JPanel();
subPanel.add( new JButton( "1" ));
subPanel.add( new JButton( "2" ));
subPanel.add( new JButton( "3" ));
//Now we simply add it to your main panel.
panel1.add(subPanel, BorderLayout.EAST);
}

BorderLayout only allows one component per section. If you want to keep BorderLayout, but have 2+ buttons, I suggest first putting each of those buttons into a JPanel and then putting that JPanel into the east slot.
However, there are probably much better layout choices for you. You also mention tabs, which there is already JTabbedPane for.
Check out the different LayoutManagers, and try to figure out which one is right for you.

1. The default layout for JFrame is BorderLayout, and it has East, West , North , South, and Center area, out of which Center is the default if positioning is not mentioned.
2. Now each section/area can hold only one widget (ie. swing component).
3. You will have this done in much better way by using Group Layout, which was developed by NetBeans team in 2005, use Windows Builder Pro, now free from google.
4. But if you still want to go with the BorderLayout, i will suggest you to use JPanel on the content pane of the JFrame to add Buttons in the manner you want......

Placing JTextFields in a JFrame of a Java GUI

I have:
public class BaseStationFrame1 extends JFrame
{
JButton activateButton;
JButton deactivateButton;
BaseStation bs;
JTextField networkIdField;
JTextField portField;
public BaseStationFrame1(BaseStation _bs){
bs = _bs;
setTitle("Base Station");
setSize(600,500);
setLocation(100,200);
setVisible(true);
activateButton = new JButton("Activate");
deactivateButton = new JButton("Deactivate");
Container content = this.getContentPane();
content.setBackground(Color.white);
content.setLayout(new FlowLayout());
content.add(activateButton);
content.add(deactivateButton);
networkIdField = new JTextField("networkId : "+ bs.getNetworkId());
networkIdField.setEditable(false);
content.add(networkIdField);
portField = new JTextField("portId : "+ bs.getPort());
portField.setEditable(false);
content.add(portField);}
}
My problem is that i don't want the two TextFields to appear on the right of Activate and Deactivate buttons but below them. How can i fix that?

Specify your layout manager, like this:
content.setLayout(new GridLayout(2,2));
That would use the Grid Layout Manager to establish a grid with 2 columns and 2 rows, that your components would then be placed in.
The layout manager you are currently using, FlowLayout, only adds contents onto the end of the current row. it will wrap around once it reaches the constrained edge of the pane, though.
You should also check the other layout managers here
You could alternatively use GridBagLayout , but you will have to specify a GridBagConstraints object you then add alongside the individual elements, like so:
content.add(networkIdField, gridConstraints);
see more on that in the linked tutorial.

can I suggest that you use a Null Layout for the parent component?
setLayout(null);
then use a setBounds(xPos,yPos, Width, Height);
to position the components on the panel etc?
Doing this will prevent Java's UI Manager to manage the components to the Frame, Panel etc.
That seems to be the easiest and less painful way.
Regards

Please help me understanding BoxLayout alignment issues

I'm trying to create a very simple window using Java Layouts. I have got three elements to arrange: a button, a progress bar and a label. The button has to be vertically centered, the progress bar has to take full width, and the label has to be left aligned.
Here's some code (just assume pane is the content pane of a JFrame, and button, progressBar and label have been created before):
BoxLayout layout = new BoxLayout(pane, BoxLayout.Y_AXIS);
pane.setLayout(layout);
button.setAlignmentX(Component.CENTER_ALIGNMENT);
pane.add(button);
progressBar.setAlignmentX(Component.CENTER_ALIGNMENT);
pane.add(progressBar);
label.setAlignmentX(Component.LEFT_ALIGNMENT);
pane.add(label);
When I test the application I see everything misaligned and screwed up: the button and the label are randomly indented, and if I resize the window the indentation amount changes in a strange way.
The progress bar looks good (full width).
I just don't understand what's happening. Can you give me a clue?

BoxLayout cannot handle different alignments: see http://download.oracle.com/javase/tutorial/uiswing/layout/box.html
quoting from that article: "In general, all the components controlled by a top-to-bottom BoxLayout object should have the same X alignment. Similarly, all the components controlled by a left-to-right Boxlayout should generally have the same Y alignment."

Sometimes you need to get a little creative and use nested panels. But I like this approach better then trying to learn and memorize all the constraints required when using other layout managers (GridBagLayout, GroupLayout) there where designed to be used by IDE's that generate code for you.
import java.awt.*;
import javax.swing.*;
public class BoxLayoutVertical extends JFrame
{
public BoxLayoutVertical()
{
Box box = Box.createVerticalBox();
JButton button = new JButton("A button");
button.setAlignmentX(Component.CENTER_ALIGNMENT);
box.add(button);
JProgressBar progressBar = new JProgressBar(0, 100);
progressBar.setAlignmentX(Component.CENTER_ALIGNMENT);
box.add(progressBar);
JPanel panel = new JPanel( new BorderLayout() );
JLabel label = new JLabel("A label");
label.setAlignmentX(Component.LEFT_ALIGNMENT);
panel.add(label);
box.add(panel);
add(box, BorderLayout.NORTH);
}
public static void main(String[] args)
{
BoxLayoutVertical frame = new BoxLayoutVertical();
frame.setDefaultCloseOperation( EXIT_ON_CLOSE );
frame.setSize(300, 200);
frame.setLocationRelativeTo( null );
frame.setVisible(true);
}
}

To complement my comment to the original question, here is a snippet that uses DesignGridLayout:
JButton button = new JButton("Button");
JProgressBar progressBar = new JProgressBar();
JLabel label = new JLabel("Label");
// The interesting stuff is in the next 4 lines
DesignGridLayout layout = new DesignGridLayout(getContentPane());
layout.row().center().add(button).withOwnRowWidth();
layout.row().center().fill().add(progressBar);
layout.row().left().add(label);
pack();
It does exactly what wou describe in your question and doesn't require any specific call of any of the components.

Maybe your code is just a snippet, but I'm missing a call to pack().
Coding swing layout by hand can be very frustrating with the standard Layout managers. I use MiG Layout for that purpose. It is straight forward and you have a nice layout with just a few lines of code. If you're not forced to use BoxLayout I would suggest you give it a try.

Don't use BoxLayout. It works only for very simple cases.
For your case, I would recommend either GridBagLayout or (my favorite) GroupLayout.
For GroupLayout, I created a subclass (LayoutHelper) with some utility methods and useful constructors, which makes writing the Layout much easier.
Of course, usually I align all components in a group the same way, so it is not as short in your case as it would be in the simple case.
LayoutHelper h = new LayoutHelper(pane);
h.setVerticalGroup
( h.sequential( button, progressBar, label));
h.setHorizontalGroup
( ((ParallelGroup)h.parallel())
.addComponent(button, Alignment.CENTER)
.addComponent(progressBar)
.addComponent(label, Alignment.TRAILING));
Here is a screenshot:
For a simple "everything aligned the same way", the horizontal group would look like this:
h.setHorizontalGroup
( h.parallel (button, progressBar, label));
(optionally with a first argument indicating the alignment).