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Center JLabel in BorderLayout with a button at line end

I have a header on a section of my swing layout, and I want to have text centered horizontally across the whole width of the section, but also have a button on only the right side. It should look like this:
/------Same width------\ /------Same width------\
[------------------------]Text here[----------------[Button]]
I am currently using a BorderLayout, with the text in the center and the button at the line end, but the text is centered not counting the button, as such:
/----Same width----\ /---Same width----\
[--------------------]Text here[-------------------][Button]]

I'm not sure if this is the answer you really want, but you could use a different layout manager, like GridBagLayout
import java.awt.EventQueue;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
public class JavaApplication295 {
public static void main(String[] args) {
new JavaApplication295();
}
public JavaApplication295() {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
ex.printStackTrace();
}
JFrame frame = new JFrame("Testing");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(new TestPane());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
public class TestPane extends JPanel {
public TestPane() {
setLayout(new GridBagLayout());
GridBagConstraints gbc = new GridBagConstraints();
gbc.gridx = 0;
gbc.gridy = 0;
// gbc.fill = GridBagConstraints.HORIZONTAL;
gbc.weightx = 1;
add(new JLabel("Look ma, no hands"), gbc);
gbc.anchor = GridBagConstraints.EAST;
add(new JButton("No Allowance"), gbc);
}
}
}
Now, the problem with this, is both components are actually positioned at the same location, the difference is, the button is anchored to the right position of the cell, this means that when the layout is been calculated, they will overlap....

Here is an approach using the OverlayLayout which was designed to have multiple components painted on the z axis:
import java.awt.*;
import javax.swing.*;
public class SSCCE extends JPanel
{
public SSCCE()
{
JLabel label = new JLabel("I'm a Centered Label");
Box labelBox= Box.createHorizontalBox();
labelBox.add(Box.createHorizontalGlue());
labelBox.add(label);
labelBox.add(Box.createHorizontalGlue());
JButton button = new JButton("Button");
Box buttonBox= Box.createHorizontalBox();
buttonBox.add(Box.createHorizontalGlue());
buttonBox.add(button);
setLayout( new OverlayLayout(this) );
add(buttonBox);
add(labelBox);
}
private static void createAndShowGUI()
{
JFrame frame = new JFrame("SSCCE");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(new SSCCE(), BorderLayout.NORTH);
frame.setLocationByPlatform( true );
frame.pack();
frame.setVisible( true );
}
public static void main(String[] args)
{
EventQueue.invokeLater(new Runnable()
{
public void run()
{
createAndShowGUI();
}
});
}
}
As the width decreases the button will paint over the label.

how to make JButton show a list of JButtons with just few items

Hey Guys my problem is when I place the mouse on a JButton in my JFrame, I want it to show a list of JButtons on its left.
I don't known how to do that really I feel like I'm blocked and I cant make any progress in my project.
I'd would be grateful if you could help me and thanks in advance.

Can you create the list of buttons in a JPanel, add it to your JFrame and then call myPanel.setVisible(false). When you click your button then call myPanel.setVisible(true)?
As for ensuring that myPanel is positioned correctly you will want to use a Layout Manager
Or is there a more complex behaviour you want?

A basic option would be to use a MouseListener and a CardLayout. The MouseListener would be used to determine when the mouse cursor enters/exists a given component and the CardLayout would be used to display the appropriate sub component for each "menu" element.
I have to say, JButton would be me last choice for the "menu" item, in most cases, a JLabel would be preferred or even perhaps using a JMenu, which can can have sub menus, which can be displayed automatically might be a better choice, or even a JComboBox....
import java.awt.BorderLayout;
import java.awt.CardLayout;
import java.awt.EventQueue;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
public class ShowStuff {
public static void main(String[] args) {
new ShowStuff();
}
public ShowStuff() {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
ex.printStackTrace();
}
MenuPane menu = new MenuPane();
menu.addMenu("Fruit", new FruitPane());
menu.addMenu("Meat", new MeatPane());
menu.addMenu("Dairy", new DairyPane());
JFrame frame = new JFrame("Testing");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(menu);
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
public class MenuPane extends JPanel {
private JPanel subMenu;
private JPanel menu;
private CardLayout cardLayout;
private MouseListener mouseHandler;
public MenuPane() {
setLayout(new BorderLayout());
cardLayout = new CardLayout();
subMenu = new JPanel(cardLayout);
menu = new JPanel(new GridBagLayout());
add(subMenu);
add(menu, BorderLayout.WEST);
subMenu.add(new JPanel(), "BLANK");
mouseHandler = new MouseAdapter() {
#Override
public void mouseEntered(MouseEvent e) {
if (e.getSource() instanceof JButton) {
JButton btn = (JButton) e.getSource();
cardLayout.show(subMenu, btn.getText());
}
}
#Override
public void mouseExited(MouseEvent e) {
cardLayout.show(subMenu, "BLANK");
}
};
}
public void addMenu(String name, JPanel subMenuPane) {
JButton button = new JButton(name);
GridBagConstraints gbc = new GridBagConstraints();
gbc.gridwidth = GridBagConstraints.REMAINDER;
menu.add(button, gbc);
subMenu.add(subMenuPane, name);
button.addMouseListener(mouseHandler);
}
}
public abstract class ButtonPane extends JPanel {
private int gridy = 0;
public ButtonPane() {
setLayout(new GridBagLayout());
}
protected void addButton(String name) {
JButton btn = new JButton(name);
GridBagConstraints gbc = new GridBagConstraints();
gbc.gridx = 0;
gbc.gridy = gridy++;
gbc.fill = GridBagConstraints.HORIZONTAL;
add(btn, gbc);
}
}
public class FruitPane extends ButtonPane {
public FruitPane() {
addButton("Banana");
addButton("Grapes");
addButton("Apples");
addButton("Tomatoes");
}
}
public class MeatPane extends ButtonPane {
public MeatPane() {
addButton("Lamb");
addButton("Beef");
addButton("Pork");
addButton("Mince");
}
}
public class DairyPane extends ButtonPane {
public DairyPane() {
addButton("Milk");
addButton("Cream");
addButton("Cheese");
addButton("Yoghurt");
}
}
}

Java GUI layout cannot quite get it right

I tried a bunch of different layouts but none are giving me the desired effect.
I want something like this:
+-----------------------------+
Centered Text
+-------+
|Button |
+-------+
+-----------------------------+
In html it might look like this:
<p align="center">Some text</p>
<input type="button" value="Press"/>
The trouble I am having is with certain layouts (BorderLayout) it likes to resize the button to fit. Other layouts (Boxlayout and GroupLayout) will do something like this:
+-----------------------------+
Centered Text
+-------+
|Button |
+-------+
+-----------------------------+
Even when I have the JLabel aligned to CENTER and the Button aligned to LEFT.
Much appreciation to my helpers.

There are a number layouts that would be able to achieve this, in fact, you might even be able to use BorderLayout and FlowLayout together to do this, but this example simply uses GridBagLayout
import java.awt.BorderLayout;
import java.awt.EventQueue;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
public class ExampleLayout {
public static void main(String[] args) {
new ExampleLayout();
}
public ExampleLayout() {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
}
JFrame frame = new JFrame("Testing");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setLayout(new BorderLayout());
frame.add(new TestPane());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
public class TestPane extends JPanel {
public TestPane() {
setLayout(new GridBagLayout());
GridBagConstraints gbc = new GridBagConstraints();
gbc.gridx = 0;
gbc.gridy = 0;
gbc.fill = GridBagConstraints.HORIZONTAL;
gbc.gridwidth = GridBagConstraints.REMAINDER;
gbc.weightx = 1;
JLabel center = new JLabel("Centered Text");
center.setHorizontalAlignment(JLabel.CENTER);
add(center, gbc);
gbc.gridy++;
gbc.fill = GridBagConstraints.NONE;
gbc.gridwidth = 1;
gbc.weightx = 0;
gbc.anchor = GridBagConstraints.WEST;
JButton button = new JButton("Button");
add(button, gbc);
}
}
}
Take a look at Laying Out Components Within a Container for more examples and details

Although MadProgrammer and Costis Aivalis already answered your question, here is also an answer with MigLayout:
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;
import net.miginfocom.swing.MigLayout;
public class MigLayoutDemo {
JFrame frame = new JFrame();
JPanel panel = new JPanel();
JLabel label = new JLabel("Centered text");
JButton button = new JButton("Button");
public MigLayoutDemo() {
panel.setLayout(new MigLayout());
label.setHorizontalAlignment(JLabel.CENTER);
panel.add(label, "wrap, pushx, growx");
panel.add(button);
frame.add(panel);
frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
frame.pack();
frame.setVisible(true);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(MigLayoutDemo::new);
}
}
Same effect, but this approach is less verbose unlike in case of GridBagLayout and I personally think that MigLayout is easier to use.

FlowLayout(int align) allows you to define justification. The default is CENTER. If you just left justify the FlowLayout of the panel that contains your button it works without having to use GridBagLayout manually. NetBeans provide an excellent GridBagLayout customizer, but you do not want to touch the code it generates automatically.
import javax.swing.*;
import java.awt.*;
public class MyLooks extends JFrame {
public MyLooks() {
setDefaultCloseOperation(EXIT_ON_CLOSE);
p = new JPanel(new GridLayout(2, 1));
p1 = new JPanel();
p2 = new JPanel(new FlowLayout(FlowLayout.LEFT));
myLabel = new JLabel("this is a label");
myButton = new JButton("press");
p1.add(myLabel);
p2.add(myButton);
p.add(p1);
p.add(p2);
setContentPane(p);
pack();
}
public static void main(String[] args) {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
new MyLooks().setVisible(true);
}
});
}
private JLabel myLabel;
private JButton myButton;
private JPanel p, p1, p2;
}

Writing at the bottom of JTextArea

I have a JScrollPane and a JTextArea (editable) with 10 rows. I want the first user input to appear at the bottom of the JTextArea and the most recent input should push the previous input upward. To achieve this I use textArea.setMargin(new Insets(x,0,0,0)); and everything works as it should - except that my second input will toggle the JScrollPane.
How can I start at the bottom of the JTextArea and only enable scrolling when the entire original viewport is filled?

Basically, you could add the JTextText onto a JPanel with another JPanel which acts a filler, causing the JTextArea to occupy the smallest space it actually needs.
I did this by using GridBagLayout to force the fill to occupy the most of space it could...
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.EventQueue;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTextArea;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
public class TestTextArea {
public static void main(String[] args) {
new TestTextArea();
}
public TestTextArea() {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
}
JFrame frame = new JFrame("Testing");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setLayout(new BorderLayout());
frame.add(new JScrollPane(new TestPane()));
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
public class TestPane extends JPanel {
private JTextArea ta;
public TestPane() {
setLayout(new GridBagLayout());
GridBagConstraints gbc = new GridBagConstraints();
gbc.gridx = 0;
gbc.gridy = 0;
gbc.weightx = 1;
gbc.weighty = 1;
gbc.fill = GridBagConstraints.BOTH;
JPanel filler = new JPanel();
filler.setBackground(Color.WHITE);
add(filler, gbc);
gbc.gridy = 1;
gbc.weighty = 0;
ta = new JTextArea(1, 20);
add(ta, gbc);
}
}
}

To achieve this I use textArea.setMargin(new Insets(x,0,0,0)); and everything works as it should - except that my second input will toggle the JScrollPane.
Well I would guess that you would need to reset the margin every time you add text to the text area to take into account the new preferred size of the text area in relation to the size of the scroll pane.
You should be able to add a DocumentListener to the text area and make your adjustment whenever text is added to the Document.

I don't think that using margins and insets is the way to go because you are using layout adjustments to achieve text (content) functionality. This should be controlled by the Document object, which is what JTextArea makes its calls to regarding its content.
If you are calling append internally, then override it in a new class extending JTextArea:
public class Test {
static MyTextArea ta = new MyTextArea();
static int x = 0;
public static void main(String[] args) {
ta.setRows(10);
ta.setText("\n\n\n\n\n\n\n\n\n");
ta.setCaretPosition(ta.getDocument().getLength());
JButton append = new JButton("Append");
append.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
ta.append("\n" + x);
x++;
}
});
JFrame frame= new JFrame();
frame.setContentPane(new JPanel(new BorderLayout()));
frame.getContentPane().add(new JScrollPane(ta), BorderLayout.CENTER);
frame.getContentPane().add(append, BorderLayout.LINE_START);
frame.pack();
frame.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
static class MyTextArea extends JTextArea {
#Override
public void append(String str) {
super.append(str);
try {
if (getDocument().getText(0, 1).equals("\n"))
getDocument().remove(0, 1);
} catch (BadLocationException e) {
e.printStackTrace();
}
}
}
}
If you are editing it manually, add a DocumentListener:
public class Test {
public static void main(String[] args) {
JTextArea ta = new JTextArea();
ta.setRows(10);
ta.setText("\n\n\n\n\n\n\n\n\n");
ta.setCaretPosition(ta.getDocument().getLength());
ta.getDocument().addDocumentListener(new MyDocListener());
JFrame frame= new JFrame();
frame.setContentPane(new JPanel(new BorderLayout()));
frame.getContentPane().add(new JScrollPane(ta), BorderLayout.CENTER);
frame.pack();
frame.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
static class MyDocListener implements DocumentListener {
#Override
public void insertUpdate(DocumentEvent e) {
final DocumentEvent de = e;
Runnable pushUp = new Runnable() {
#Override
public void run() {
String t = null;
try {
t = de.getDocument().getText(de.getOffset(), de.getLength());
if (t.equals("\n") && de.getDocument().getText(0, 1).equals("\n"))
ta.getDocument().remove(0, 1);
} catch (BadLocationException e1) {
e1.printStackTrace();
}
}
};
SwingUtilities.invokeLater(pushUp);
}
#Override
public void removeUpdate(DocumentEvent e) {}
#Override
public void changedUpdate(DocumentEvent e) {}
}
}
Note that all you need from the code are the inner classes, the rest is just so you can see it working. I also don't have information regarding the initial state of the text area. Here I just set the number of rows to 10 and the text to 10 empty lines. I'm also not sure what you're allowed to do in the text area. This solution assumes that you can't jump lines and each time you insert a line it's not blank and it follows the previous line.

Set layout with JPanels

I haven't really worked with Swing at all in Java. I'm experimenting with it. I want to make a set layout that the size can't be changed. I've seen alot of things suggesting to use Layout managers to add multiple JPanels into a JFrame.
However, all the tutorials I've seen involving layout managers say it allows for the user to resize the screen. The layout I want has a rectangle going along the left hand side, a thin rectangle going along the bottom, and a third rectangle taking up the rest of the space. I attempting it using an Absolute layout but it just doesn't want to work for me.
import java.awt.Color;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;
public class Test extends JFrame {
public Test() {
JPanel rect1 = new JPanel();
rect1.setBounds(101, 650, 900, 50);
rect1.setBackground(Color.RED);
getContentPane().add(rect1);
JPanel rect2 = new JPanel();
rect2.setBounds(0, 650, 100, 1000);
rect2.setBackground(Color.BLUE);
getContentPane().add(rect2);
JPanel rect3 = new JPanel();
rect3.setBounds(101, 700, 900, 950);
rect3.setBackground(Color.GREEN);
getContentPane().add(rect3);
setTitle("TEST");
setSize(1000, 700);
setLocationRelativeTo(null);
setDefaultCloseOperation(EXIT_ON_CLOSE);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
#Override
public void run() {
Test ex = new Test();
ex.setVisible(true);
}
});
}
}
Can someone help me properly make three Jpanels in a Jframe in this layout (all with different colors)?

You might be able to achieve the same thing using a BorderLayout as the bases or even a GridBagLayout.
The main piece you are missing is the fact that layout managers use (or can use depending on the layout manager) the component's preferred/minimum/maximum size
Basically, what you would do is define a custom component (extending from something like JPanel) and override it's getPreferredSize method and return the required value you need. Depending on the layout manager, you may also need to override the getMaximumSize and getMinimumSize methods as well.
For example...
Basically, this shows the "default" size and what happens when the screen is resized...
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
public class FixedSizeLayout {
public static void main(String[] args) {
new FixedSizeLayout();
}
public FixedSizeLayout() {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
}
JFrame frame = new JFrame("Testing");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setLayout(new BorderLayout());
frame.add(new TestPane());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
public class TestPane extends JPanel {
public TestPane() {
setLayout(new GridBagLayout());
GridBagConstraints gbc = new GridBagConstraints();
gbc.gridx = 0;
gbc.gridy = 0;
add(new ContentPane(), gbc);
gbc.gridx++;
add(new LeftPane(), gbc);
gbc.gridwidth = 2;
gbc.gridx = 0;
gbc.gridy = 1;
add(new BottomPane(), gbc);
}
#Override
public Dimension getPreferredSize() {
return new Dimension(200, 200);
}
}
public class ContentPane extends JPanel {
public ContentPane() {
setBackground(Color.GREEN);
}
#Override
public Dimension getPreferredSize() {
return new Dimension(150, 150);
}
#Override
public Dimension getMinimumSize() {
return getPreferredSize();
}
#Override
public Dimension getMaximumSize() {
return getPreferredSize();
}
}
public class BottomPane extends JPanel {
public BottomPane() {
setBackground(Color.RED);
}
#Override
public Dimension getPreferredSize() {
return new Dimension(200, 50);
}
#Override
public Dimension getMinimumSize() {
return getPreferredSize();
}
#Override
public Dimension getMaximumSize() {
return getPreferredSize();
}
}
public class LeftPane extends JPanel {
public LeftPane() {
setBackground(Color.BLUE);
}
#Override
public Dimension getPreferredSize() {
return new Dimension(50, 150);
}
#Override
public Dimension getMinimumSize() {
return getPreferredSize();
}
#Override
public Dimension getMaximumSize() {
return getPreferredSize();
}
}
}
Now, if you prefer, you can make the screen non-resizable, but I for one won't like you. I prefer to use the power of the layout managers and allow users to make decisions about how they want to view the content ... where I can ... but that's just me (I don't like non-resizable windows except in the case of some dialogs)

You can use setResizable(). Please refer to below code fragment.
setResizable(false); // this will not allow resizing
setLocationRelativeTo(null);
setDefaultCloseOperation(EXIT_ON_CLOSE);

AbsoluteLayout is no go. Don't do that. You are probably looking for BorderLayout. Check the tutorial: How to Use BorderLayout for details. If you don't want your JFrame to be able to re-size use frame.setResizable(false); on it.

Just use simple BorderLayout and it will resize automatically:
JPanel panel = new JPanel(new BorderLayout());
panel.add(greenPanel, BorderLayout.CENTER);
panel.add(redPanel, BorderLayout.SOUTH);
panel.add(bluePanel, BorderLayout.EAST);

You can use MigLayout and replace BorderLayout.CENTER by "dock center":
JPanel panel = new JPanel(new MigLayout(" insets 0"));
panel.add(greenPanel, "dock center");
panel.add(redPanel, "dock south");
panel.add(bluePanel, "dock east");
Read more about MigLayout here: http://www.miglayout.com/QuickStart.pdf