Develop Reference

How to have a JButton that moves as I scroll on the frame?

I have a Panel which I have made scrollable in my frame.
What I need is to add a button that stays fixed in the lower right corner even when I scroll.
I'm new to Java Swing so would appreciate all and any help that I can get.
mainPanel = new SimulationPanel(); //class SimulationPanel extends JPanel
//making mainPanel scrollable
mainPanel.setPreferredSize(new Dimension(((int)(WIDTH*1.2)), HEIGHT));
JScrollPane scrollPane = new JScrollPane(mainPanel);
scrollPane.setViewportView(mainPanel);
// Settings for JFrame
Dimension screenSize = Toolkit.getDefaultToolkit().getScreenSize();
frame = new JFrame("Warehouse Simulator");
frame.setContentPane(scrollPane);
frame.setSize(screenSize.width, screenSize.height);
frame.setResizable(true);
frame.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
frame.setVisible(true);

I would use nested panels with the outer one be with BorderLayout. Then one with FlowLayout and align FlowLayout.RIGHT and the button inside it.
public class Example extends JFrame {
public Example() {
super("");
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setLayout(new BorderLayout());
JTextArea textArea = new JTextArea(10000, 0);
JScrollPane scrollPane = new JScrollPane(textArea);
add(scrollPane, BorderLayout.CENTER);
JButton button = new JButton("button");
JPanel panelWithButton = new JPanel(new FlowLayout(FlowLayout.RIGHT));
panelWithButton.add(button);
add(panelWithButton, BorderLayout.PAGE_END);
setLocationByPlatform(true);
pack();
setSize(600, 600);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(() -> {
new Example().setVisible(true);
});
}
}
Result:

I would go for a BoxLayout. Add another panel (metaPanel) in which your first put your scrollingPanel, and then you add a button. Instead of usgin scrollingPanel as contentPane, you use metaPanel. Example (the example works, but you need to modify it to make the interface look nice):
JPanel mainPanel = new JPanel();
JScrollPane scrollPane = new JScrollPane(mainPanel);
scrollPane.setViewportView(mainPanel);
JPanel metaPanel = new JPanel();
BoxLayout boxlayout = new BoxLayout(metaPanel, BoxLayout.Y_AXIS);
metaPanel.setLayout(boxlayout);
metaPanel.add(scrollPane);
metaPanel.add(new JButton("button"));
// Settings for JFrame
frame = new JFrame("Warehouse Simulator");
frame.setContentPane(metaPanel); // Put metaPanel here
frame.setSize(500, 300);
frame.setResizable(true);
frame.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
frame.setVisible(true);

Align JTextArea in JPanel

I'm currently building GUI with Java Swing.
My current code produces this.
The JTextArea of Product List makes the GUI looks awkward, how can I make the JTextArea looks like this, where it seems to have an extra row:
The GroupLayout code I'm using is:
gr.setVerticalGroup(gr.createSequentialGroup()
.addGroup(gr.createParallelGroup(GroupLayout.Alignment.BASELINE).addComponent(productName).addComponent(productText).addComponent(productList))
.addGroup(gr.createParallelGroup(GroupLayout.Alignment.BASELINE).addComponent(amount).addComponent(amountText).addComponent(prodScroll))
.addGroup(gr.createParallelGroup(GroupLayout.Alignment.BASELINE).addComponent(description).addComponent(desScroll))
.addGroup(gr.createParallelGroup(GroupLayout.Alignment.BASELINE).addComponent(addButton).addComponent(remButton)));
gr.setHorizontalGroup(gr.createSequentialGroup()
.addGroup(gr.createParallelGroup(GroupLayout.Alignment.LEADING).addComponent(productName).addComponent(amount).addComponent(description).addComponent(addButton))
.addGroup(gr.createParallelGroup(GroupLayout.Alignment.CENTER).addComponent(productText).addComponent(amountText).addComponent(desScroll).addComponent(remButton))
.addGroup(gr.createParallelGroup(GroupLayout.Alignment.CENTER).addComponent(productList).addComponent(prodScroll)));

I think the minority of people would choose to use GridBagLayout. However, I dislike it (among with GroupLayout) since it is "hard to use". I use nested panels instead with various Layout Managers. Using only BorderLayout and GridLayout you can achieve something like the following example, which is totally resizable, giving emphasis to "interaction" components (I mean, there is no reason to resize a constant-texted JLabel, right?)
I did not add any comments in purpose, so you can experiment with constants (and layout constraints) and see their reason of existence while having the documentations opened.
Code:
public class NestedLayoutManagersExample extends JFrame {
private static final long serialVersionUID = -7042997375941726246L;
private static final int labelsWidth = 80;
private static final int textFieldColumns = 15;
private static final int spaceBetweenAllComponents = 10;
public NestedLayoutManagersExample() {
super("test");
setDefaultCloseOperation(EXIT_ON_CLOSE);
JPanel contentPane = new JPanel(new GridLayout(1, 2, 50, 50));
contentPane.setBorder(BorderFactory.createEmptyBorder(spaceBetweenAllComponents, spaceBetweenAllComponents,
spaceBetweenAllComponents, spaceBetweenAllComponents));
setContentPane(contentPane);
add(createLeftPanel());
add(createRightPanel());
setLocationByPlatform(true);
pack();
}
private Component createRightPanel() {
JPanel mainPanel = new JPanel(new BorderLayout());
JLabel productListLabel = new JLabel("Product list");
mainPanel.add(productListLabel, BorderLayout.PAGE_START);
JList<String> productList = new JList<>();
DefaultListModel<String> listModel = new DefaultListModel<>();
Arrays.asList("Small Chair", "Big Chair", "Flying Chair").forEach(listModel::addElement);
productList.setModel(listModel);
JScrollPane listScrollPane = new JScrollPane(productList);
mainPanel.add(listScrollPane, BorderLayout.CENTER);
return mainPanel;
}
private Component createLeftPanel() {
JPanel mainPanel = new JPanel(new BorderLayout(spaceBetweenAllComponents, spaceBetweenAllComponents));
JPanel topPanel = new JPanel(new GridLayout(2, 1, spaceBetweenAllComponents, spaceBetweenAllComponents));
topPanel.add(createStraightPanel("Product Name"));
topPanel.add(createStraightPanel("Amount"));
mainPanel.add(topPanel, BorderLayout.PAGE_START);
JPanel centerPanel = new JPanel(new BorderLayout());
JLabel label = new JLabel("<html><p style='width:" + labelsWidth + "px';> Description");
label.setVerticalAlignment(JLabel.TOP);
centerPanel.add(label, BorderLayout.LINE_START);
centerPanel.add(createTextAreaPanel());
mainPanel.add(centerPanel, BorderLayout.CENTER);
return mainPanel;
}
private JPanel createTextAreaPanel() {
JPanel mainPanel = new JPanel(new BorderLayout(spaceBetweenAllComponents, spaceBetweenAllComponents));
JTextArea textArea = new JTextArea(1, textFieldColumns);
JScrollPane textAreaScrollPane = new JScrollPane(textArea);
mainPanel.add(textAreaScrollPane, BorderLayout.CENTER);
JPanel buttonsPanel = new JPanel(new BorderLayout());
JButton addButton = new JButton("Add");
buttonsPanel.add(addButton, BorderLayout.LINE_START);
JButton removeButton = new JButton("Remove");
buttonsPanel.add(removeButton, BorderLayout.LINE_END);
mainPanel.add(buttonsPanel, BorderLayout.PAGE_END);
return mainPanel;
}
private Component createStraightPanel(String labelText) {
JPanel mainPanel = new JPanel(new BorderLayout());
JLabel label = new JLabel("<html><p style='width:" + labelsWidth + "px';>" + labelText);
mainPanel.add(label, BorderLayout.LINE_START);
JTextField textField = new JTextField(textFieldColumns);
mainPanel.add(textField, BorderLayout.CENTER);
return mainPanel;
}
public static void main(String[] args) {
SwingUtilities.invokeLater(() -> new NestedLayoutManagersExample().setVisible(true));
}
}
Preview:

Adding a Tabbed Pane to a Panel using Layout managers

I am simply trying to add a tabbed pane with 5 tabs onto a panel, although only the final tab (tab e) is being shown.
I am obviously doing something fundamentally wrong here, I have tried changing the layout manager of the Panel the tabbed pane is being added to but I don't think this is the problem. Any adivce would be helpful thanks!
Main Class Code:
public static void main(String[] args) {
JFrame frame = new JFrame("Data Structures Program");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setSize(600, 600);
GraphicPanel G = new GraphicPanel();
frame.add(G.getPanel());
frame.setVisible(true);
}
Graphics Class
public class GraphicPanel {
public JPanel topPanel;
public GraphicPanel() {
JPanel Panel = new JPanel();
Panel.setLayout(new GridLayout(1, 1));
JTabbedPane tabbedPane = new JTabbedPane();
tabbedPane.addTab("a", Panel);
tabbedPane.addTab("b", Panel);
tabbedPane.addTab("c", Panel);
tabbedPane.addTab("d", Panel );
tabbedPane.addTab("e", Panel );
topPanel = new JPanel();
topPanel.setLayout(new GridLayout(1, 1));
topPanel.add(tabbedPane);
}
public JPanel getPanel(){
return topPanel;
}
}

you must creates new instance of JPanel if you want to show in JTabbedPane
try this code:
JTabbedPane tabbedPane = new JTabbedPane();
tabbedPane.addTab("a", new Panel());
tabbedPane.addTab("b", new Panel());
tabbedPane.addTab("c", new Panel());
tabbedPane.addTab("d", new Panel());
tabbedPane.addTab("e", new Panel());

How to resize a JPanel

I am trying to resize the JPanels but there is a space under it . Here is a link to show :
And this is the code :
import java.awt.*;
import javax.swing.*;
public class Ex1 extends JFrame{
private JTextArea textarea = new JTextArea ();
private JTextField field = new JTextField ();``
private JButton buton = new JButton ("Trimite");
public Ex1(){
JPanel panel = new JPanel (new BorderLayout(2,2));
JPanel panel1 = new JPanel (new BorderLayout(2,2));
JPanel panel2 = new JPanel (new BorderLayout(2,2));
JLabel label1 = new JLabel ("Mesaje");
JLabel label2 = new JLabel ("Scrieti un mesaj");
panel1.setPreferredSize(new Dimension(350,100));
panel2.setPreferredSize(new Dimension(350,25));
panel1.add(label1, BorderLayout.NORTH);
panel1.add(textarea, BorderLayout.CENTER);
panel2.add(label2, BorderLayout.WEST);
panel2.add(field, BorderLayout.CENTER);
panel2.add(buton, BorderLayout.EAST);
setLayout(new GridLayout(2,1,1,1));
panel.add(panel1, BorderLayout.NORTH);
panel.add(panel2, BorderLayout.CENTER);
add(panel);
}
public static void main(String[] args) {
JFrame frame = new Ex1();
frame.pack();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
}

You are setting a layout for a frame to GridLayout in which all components are given equal size. You have two rows, add(panel) adds the panel to the first row of the grid. The second row is left empty. See How to Use GridLayout.
Comment out setLayout(new GridLayout(2,1,1,1)); and the extra space should go away. When you comment this line the layout of frame's content pane will be BorderLayout. The default layout of the JFrame is BorderLayout. So add(panel); will add the panel to the center of the frame's content pane. As a result the panel should occupy all the available space.
As a side note, avoid setPreferredSize(), usually it is not necessary, see Should I avoid the use of set(Preferred|Maximum|Minimum)Size methods in Java Swing for details.
You can specify the number of rows and columns for a text area and wrap it in the scroll pane, ie:
textArea = new JTextArea(5, 20);
JScrollPane scrollPane = new JScrollPane(textArea);
For more details see How to Use Text Areas
EDIT: example of getPreferredSize()
import java.awt.BorderLayout;
import java.awt.Dimension;
import javax.swing.*;
public class Ex1 extends JPanel{
private JTextArea textarea = new JTextArea ();
private JTextField field = new JTextField ();
private JButton buton = new JButton ("Trimite");
public Ex1() {
setLayout(new BorderLayout());
JPanel panel1 = new JPanel (new BorderLayout(2,2));
JPanel panel2 = new JPanel (new BorderLayout(2,2));
JLabel label1 = new JLabel ("Mesaje");
JLabel label2 = new JLabel ("Scrieti un mesaj");
panel1.add(label1, BorderLayout.NORTH);
panel1.add(new JScrollPane(textarea), BorderLayout.CENTER);
panel2.add(label2, BorderLayout.WEST);
panel2.add(field, BorderLayout.CENTER);
panel2.add(buton, BorderLayout.EAST);
add(panel1, BorderLayout.CENTER);
add(panel2, BorderLayout.SOUTH);
}
#Override
public Dimension getPreferredSize() {
return new Dimension(350, 300);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
JFrame frame = new JFrame("Test");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setLocationByPlatform(true);
Ex1 panel = new Ex1();
frame.add(panel);
frame.pack();
frame.setVisible(true);
}
});
}
}

You need to resize the JFrame not the JPanel. Try:
this.setPreferredSize(new Dimension(350, 25);// in Ex1
Or in your main method:
frame.setPreferredSize(new Dimension(350, 25);

Scrollpane for JPanel?

I want to add Scrollpane to JPanel which is in turn called by another jpanel?
public class test {
JFrame jframe;
JPanel jpanel;
JScrollPane js= null;
public void createFrame()
{
jframe=new JFrame("Thick client Wallboard");
Dimension dim = Toolkit.getDefaultToolkit().getScreenSize();
jframe.setSize(dim.width,dim.height);
jframe.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
jframe.setUndecorated(true);
jframe.setResizable(false);
jframe.setLocation(0, 0);
getJContentPane();
jframe.setContentPane(jpanel);
jframe.setVisible(true);
}
public void getJContentPane()
{
jpanel = new JPanel();
jpanel.setBackground(new Color(0x505050));
jpanel.setLayout(null);
jpanel.setFont(new Font("verdana",Font.BOLD,12));
jpanel.setBorder(new LineBorder(Color.BLACK,2));
getpanel();
jpanel.add(js);
jpanel.setBackground(Color.LIGHT_GRAY);
jpanel.setVisible(true);
}
public void getpanel()
{
JPanel mainPanel=new JPanel();
mainPanel.setBounds(50,50,920,650);
mainPanel.setBackground(Color.WHITE);
mainPanel.setLayout(new BoxLayout(mainPanel, BoxLayout.PAGE_AXIS));
for(int i = 0; i < 30; i++) {
mainPanel.add(new JButton("Button " + i));
}
js=new JScrollPane(mainPanel);
}
public static void main(String[] args) {
test t=new test();
t.createFrame();
}
}
I have done like this but it is not working...

You can do it:
public static void main(String[] args) {
Frame frame = new JFrame();
JPanel panel = new JPanel();
panel.setLayout(new BoxLayout(panel, BoxLayout.PAGE_AXIS));
for(int i = 0; i < 20; i++) {
panel.add(new JButton("Button " + i));
}
//Creating JScrollPane with JPanel
JScrollPane scrollPane = new JScrollPane(panel);
JPanel otherPanel = new JPanel();
otherPanel.setLayout(new BorderLayout());
//Adding scrollPane to panel
otherPanel.add(scrollPane);
frame.add(otherPanel);
frame.setSize(200,200);
frame.setVisible(true);
}
Also check :
http://www.coderanch.com/t/342486/GUI/java/Adding-ScrollPane-JPanel

JScrollPane is, like all JComponent derivatives, a decorator, and you can decorate any component with it.
You can put any component in the scroll pane.
JScrollPane pane = new JScrollPane(component);
and just add the scrollpane instead of the wrapped component.