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How to make JScrollPane dynamic adjusting

I am trying to make a dynamic tabs with the option to add new ones in the application and some buttons next to it... To do so I have a main class:
private static void initAndDisplayUI() {
frame = new JFrame(...)
tabbedPane = new TabbedPane();
insertTab(tabbedPane, TabFactory.createTab(), true);
insertNewTabButton(tabbedPane);
...
}
}
Container class:
public class TabbedPane extends JPanel {public TabbedPane() {
this.captions = new TabCaptions();
this.tabs = new ArrayList<Tab>();
this.contentContainer = new JPanel(new BorderLayout());
setLayout(new BorderLayout());
add(captions, BorderLayout.NORTH);
add(contentContainer, BorderLayout.CENTER);
}
...
}
And a TabCaptions:
public class TabCaptions extends JPanel {
private TabCaption selectedTab;
private JComponent tabsPane;
private JScrollPane scrollPane;
private JPanel buttonsPane;
public TabCaptions() {
createUI();
}
private void createUI() {
setLayout(new BoxLayout(this, BoxLayout.X_AXIS));
setBackground(Color.DARK_GRAY);
add(createTabsPane());
add(createButtonsPane());
add(Box.createHorizontalGlue());
}
private JComponent createTabsPane() {
tabsPane = new JPanel();
tabsPane.setOpaque(false);
tabsPane.setLayout(new BoxLayout(tabsPane, BoxLayout.X_AXIS));
scrollPane = new JScrollPane(tabsPane, JScrollPane.VERTICAL_SCROLLBAR_NEVER, JScrollPane.HORIZONTAL_SCROLLBAR_NEVER);
return tabsPane;
}
...
}
As a result I have a region with the tabs and some button next to it. However the app window draws a scrollPane with some weird size... I would like to display this "add new tab" button right next to the tabs that are created, resize it when the new tab is being added BUT with the functionality to display a scrollbar once it hits the maximum window width. I already have the scrolling but how can I make the behaviour of this dynamic position of new page?

I already have the scrolling
Not based on the code you have provided:
scrollPane = new JScrollPane(tabsPane, JScrollPane.VERTICAL_SCROLLBAR_NEVER, JScrollPane.HORIZONTAL_SCROLLBAR_NEVER);
return tabsPane;
You need to add the JScrollPane to the frame, so you need to return the scroll pane from the method:
scrollPane = new JScrollPane(tabsPane, JScrollPane.VERTICAL_SCROLLBAR_NEVER, JScrollPane.HORIZONTAL_SCROLLBAR_NEVER);
//return tabsPane;
return scrollPane;

Why does the JScrollPane not appear around my JTextField?

I'm pretty new to GUI but I'm trying to create a simple version of notepad and would like scroll bars to appear around the text area. However, I'm not sure why it isn't appearing.
public class NutPad extends JPanel {
public static void main(String[] args) {
JFrame frame = new JFrame("NutPad");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.getContentPane().add(new NutPad(), BorderLayout.CENTER);
frame.setSize(500,300);
frame.setVisible(true);
}
private NutPad() {
add(makeTextAreaPanel());
}
private JPanel makeTextAreaPanel() {
JPanel textAreaPanel = new JPanel();
textAreaPanel.setSize(100,100);
JTextArea textArea = new JTextArea(20, 60); //15,43
JScrollPane scrollPane = new JScrollPane(textArea);
textAreaPanel.add(scrollPane,BorderLayout.CENTER);
textAreaPanel.add(textArea);
return textAreaPanel;
}
}
Thanks

If you're going to use the BorderLayout.CENTER constraint, then the container needs to have its layout set to BorderLayout.
Also you don't need textAreaPanel since you can just add the scrollPane straight into your NutPad panel.
private NutPad() {
setLayout(new BorderLayout());
add(makeScrollPane(), BorderLayout.CENTER);
}
private JScrollPane makeScrollPane() {
JTextArea textArea = new JTextArea();
JScrollPane scrollPane = new JScrollPane(textArea);
return scrollPane;
}
Now your text area will fill the frame and the scrollbars will appear when the text takes up more than the available space.
Hope that helps :)

JList not displaying any objects?

I've been trying to figure out how to use JList and I cant seem to get it to display an object into my GUI.
there's a class called Drawing that I'm trying to add to the JList and it just doesnt seem to show..
Any help would be greatly appreciated
here's my code:
public class DrawingDisplayer extends JPanel implements ActionListener, ListSelectionListener {
JLabel title;
JButton draw,pause,clear,
open,close,
lines,background;
JSlider speedSlider;
JProgressBar progress;
Drawing drawing;
JFileChooser chooser;
JList fileList;
DefaultListModel listModel;
JPanel drawPanel;
JScrollPane scrollPane;
public DrawingDisplayer(){
title = new JLabel("The Drawing Displayer");
title.setHorizontalAlignment(JLabel.CENTER);
title.setFont(new Font("Serif", Font.BOLD, 24));
draw = new JButton("Draw");
pause = new JButton("Pause");
clear = new JButton("Clear");
speedSlider = new JSlider();
progress = new JProgressBar();
open = new JButton("Open Drawing");
close = new JButton("Close Drawing");
listModel = new DefaultListModel();
fileList = new JList(listModel);
fileList.setSelectionMode(ListSelectionModel.SINGLE_SELECTION);
fileList.addListSelectionListener(this);
fileList.setVisibleRowCount(10);
scrollPane = new JScrollPane(fileList);
scrollPane.setPreferredSize(new Dimension(200,250));
lines = new JButton("Lines");
background = new JButton("Background");
setLayout(new BorderLayout());
//Draw Panel
drawPanel = new JPanel();
drawPanel.setBorder(BorderFactory.createTitledBorder("Drawing Area"));
//Drawing Speed
JPanel drawSpeed = new JPanel();
drawSpeed.setPreferredSize(new Dimension(300,200));
drawSpeed.setBorder(BorderFactory.createTitledBorder("Drawing Speed"));
drawSpeed.add(draw);
drawSpeed.add(pause);
drawSpeed.add(clear);
drawSpeed.add(speedSlider);
drawSpeed.add(progress);
//File Options
JPanel fileOptions = new JPanel();
fileOptions.setPreferredSize(new Dimension(300,350));
fileOptions.setBorder(BorderFactory.createTitledBorder("File Options"));
open.addActionListener(this);
close.addActionListener(this);
fileOptions.add(open);
fileOptions.add(close);
fileOptions.add(fileList);
fileOptions.add(scrollPane);
//Colour Options.
JPanel colourOptions = new JPanel();
colourOptions.setPreferredSize(new Dimension(300,200));
colourOptions.setBorder(BorderFactory.createTitledBorder("Colour Options"));
colourOptions.add(lines);
colourOptions.add(background);
//Control Panel
JPanel controlPanel = new JPanel();
controlPanel.setPreferredSize(new Dimension(325,200));
controlPanel.add(drawSpeed);
controlPanel.add(fileOptions);
controlPanel.add(colourOptions);
chooser = new JFileChooser(".");
add(title, BorderLayout.NORTH);
add(controlPanel,BorderLayout.WEST);
add(drawPanel,BorderLayout.CENTER);
}
public void actionPerformed(ActionEvent e) {
if(e.getSource() == open){
chooser = new JFileChooser(".");
if(chooser.showOpenDialog(null) == chooser.APPROVE_OPTION){
drawing = new Drawing(chooser.getSelectedFile());
fileList.add(drawing);
listModel.addElement("test");
}
}
else if (e.getSource() == close){
}
}
public void valueChanged(ListSelectionEvent e) {
}
public static void main(String[] args){
DrawingDisplayer panel = new DrawingDisplayer();
JFrame frame = new JFrame("drawing");
frame.getContentPane().add(panel);
frame.pack();
frame.setVisible(true);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
}

To understand the problem you're having you need to understand that a component can only reside within a single container (it can only have a single parent).
If you try and add the component to another container, it is removed from the first before been added to the second.
So, in your code you do...
fileList = new JList(listModel);
//...
// Add fileList as the view for the scrollpane...
scrollPane = new JScrollPane(fileList);
scrollPane.setPreferredSize(new Dimension(200, 250));
//...
// Remove fileList from the scrollpane and add it to fileOptions...
fileOptions.add(fileList);
fileOptions.add(scrollPane);
...So, basically, you've started out well, but ended up removing the fileList from the scrollPane and adding it to the fileOptions instead, then added the (now empty) scrollPane to the fileOptions as well...
Remove fileOptions.add(fileList); and it should work as you expect it...
You might also want to take a look at Should I avoid the use of set(Preferred|Maximum|Minimum)Size methods in Java Swing?.
You can control the size of the JScrollPane by using things like setVisibleRowCount and appropriate cell renderers ...

The default rendering of an object added to the ListModel is to simple display the toString() of the object.
If you are adding a custom object, then you need to provide a custom renderer. Read the section from the Swing tutorial on How to Use Lists, especially the section on Writing a Custom Cell Renderer for more information on this concept.

error displaying JList in JPanel

Below is the code in which I create the JPanel
public class ListBranchesInterface extends JPanel {
private Library theLibrary; // reference to back end
private ArrayList<LibraryBranch> branches;
private DefaultListModel dlm;
private JList list;
private JScrollPane scroll;
public ListBranchesInterface(Library theLibrary) {
this.theLibrary = theLibrary;
branches = new ArrayList<LibraryBranch>();
branches.addAll(theLibrary.getLibraryBranches());
System.out.println(branches.size());
Iterator<LibraryBranch> iter = branches.iterator();
dlm = new DefaultListModel();
while (iter.hasNext()) {
dlm.addElement(iter.next().toString());
System.out.println("Added");
}
list = new JList(dlm); // create a JList from the default list model
scroll = new JScrollPane(list); // add a scroll pane to the JList
add(scroll);
setSize(400, 400);
setVisible(true);
}
}
when I add the panel to the JFrame nothing is displayed. (The error is not in adding it to the JFrame because I am adding other panels and they work properly.) What is the error?

JScrollPane not resizing when added to JPanel

I cant get the scrollPane to resize correctly when added to the scrollPanel. I want the scrollPane to scale to the size of the scrollPanel. Any tips?
public class MTabbedPane_HomePanel extends JPanel {
private JPanel scrollPanel;
private JScrollPane scrollPane;
public MTabbedPane_HomePanel()
{
init();
makePanel();
}
private void init() {
scrollPanel = new JPanel();
scrollPane = new JScrollPane(scrollPanel, JScrollPane.VERTICAL_SCROLLBAR_ALWAYS, JScrollPane.HORIZONTAL_SCROLLBAR_NEVER);
}
private void makePanel() {
IAppWidgetFactory.makeIAppScrollPane(scrollPane);
setLayout(new BorderLayout());
scrollPane.setBorder(null);
add(scrollPane, BorderLayout.CENTER);
}
}

your code is correct, maybe
try to disable UIDelegate from IAppWidgetFactory.makeIAppScrollPane(), if remains unchanged
then
check how you added (if is used LayoutManager) for MTabbedPane_HomePanel to the parent

Call setPreferredSIze() for the panel.