I am relatively new to programming, so I am sorry if this question is stupid. I am creating a Java program that involves one JButton inside a JPanel, and the JPanel is in a JFrame. Another button is outside the JPanel but still in the JFrame. I set the layout to a BoxLayout. My problem is that the the panel, which I made black, is taking up the whole JFrame except for where the second button is. How do I make the JPanel so it is only taking up the area right around the first button?
public class alt {
JFrame frame = new JFrame();
JPanel panel = new JPanel();
JButton button1 = new JButton("button 1");
JButton button2 = new JButton("button 2");
public alt(){
frame.setVisible(true);
frame.getContentPane().setLayout(new BoxLayout(frame.getContentPane(), BoxLayout.Y_AXIS));
panel.setBackground(Color.black);
frame.setTitle("test");
frame.setExtendedState(java.awt.Frame.MAXIMIZED_BOTH);
panel.add(button1);
frame.add(panel);
frame.add(button2);
button2.setAlignmentX(Component.CENTER_ALIGNMENT);
}
}
You could make use of a different layout manager, one which gives you more control over deciding how space is allocated and filling is handled, for example, GridBagLayout...
import java.awt.Color;
import java.awt.EventQueue;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
public class SampleLayout {
public static void main(String[] args) {
new SampleLayout();
}
public SampleLayout() {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
}
JPanel panel = new JPanel();
JButton button1 = new JButton("button 1");
JButton button2 = new JButton("button 2");
panel.setBackground(Color.black);
panel.add(button1);
JFrame frame = new JFrame("Testing");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setLayout(new GridBagLayout());
GridBagConstraints gbc = new GridBagConstraints();
gbc.gridwidth = GridBagConstraints.REMAINDER;
frame.add(panel, gbc);
frame.add(button2, gbc);
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
}
Take a look at Laying Out Components Within a Container for more details
The reason why your panel takes up the bulk of the frame's content pane lies
in the way the BoxLayout manager works with the minimum, preferred,
and maximum values of components. It takes the maximum value of a component
into account. And since the maximum value of a JPanel is huge, it takes
all the space available. The solution is to change the maximum value
of a panel. However, this is bad practice. I do not recommend to use
the BoxLayout manager -- it is very weak and leads to poor code.
I recommend to use either the MigLayout manager or the GroupLayout manager.
I provide three solutions: a corrected BoxLayout solution, a MigLayout solution,
and a GroupLayout solution.
BoxLayout solution
We determine the maximum size of the button and change the panel's size
to be a bit larger than the button's.
package com.zetcode;
import java.awt.Color;
import java.awt.Component;
import java.awt.Dimension;
import java.awt.EventQueue;
import javax.swing.BorderFactory;
import javax.swing.Box;
import javax.swing.BoxLayout;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
public class BoxLayoutPanel extends JFrame {
public BoxLayoutPanel() {
initUI();
}
private void initUI() {
JPanel cpane = (JPanel) getContentPane();
cpane.setBorder(BorderFactory.createEmptyBorder(15, 15, 15, 15));
cpane.setLayout(new BoxLayout(cpane,
BoxLayout.Y_AXIS));
JPanel pnl = new JPanel();
JButton btn1 = new JButton("Button 1");
JButton btn2 = new JButton("Button 2");
Dimension dm = btn1.getMaximumSize();
dm.height += 15;
dm.width += 15;
pnl.setMaximumSize(dm);
pnl.setBackground(Color.black);
add(pnl);
add(Box.createVerticalStrut(10));
pnl.add(btn1);
btn2.setAlignmentX(Component.CENTER_ALIGNMENT);
add(btn2);
setTitle("BoxLayout solution");
pack();
setLocationRelativeTo(null);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
public static void main(String[] args) {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
BoxLayoutPanel ex = new BoxLayoutPanel();
ex.setVisible(true);
}
});
}
}
This is not a clean solution. Generally, we should avoid calling the getMaximumSize() and
the setMaximumSize() in the application code -- this is the layout manager's job. Also in three occasions, we use fixed pixel widths: when we define an empty border, a vertical strut, and a maximum panel's size. This code is however not portable.
Pixel widths change when the resolution of the screen changes. This is a
shortcoming of the BoxLayout manager.
MigLayout solution
This solution is much cleaner and more portable. MigLayout is a third-party
manager, so we need to download additional libraries.
package com.zetcode;
import java.awt.Color;
import java.awt.EventQueue;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import net.miginfocom.swing.MigLayout;
public class MigLayoutPanel extends JFrame {
public MigLayoutPanel(){
initUI();
setTitle("MigLayout solution");
setLocationRelativeTo(null);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
private void initUI() {
JPanel main = new JPanel(new MigLayout("center"));
JPanel pnl2 = new JPanel();
JButton btn1 = new JButton("Button 1");
JButton btn2 = new JButton("Button 2");
pnl2.setBackground(Color.black);
pnl2.add(btn1);
main.add(pnl2, "wrap");
main.add(btn2, "alignx center");
add(main);
pack();
}
public static void main(String[] args){
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
MigLayoutPanel ex = new MigLayoutPanel();
ex.setVisible(true);
}
});
}
}
GroupLayout solution
GroupLayout is a built-in layout manager. With MigLayout, they are the most
portable and flexible layout managers.
package com.zetcode;
import java.awt.Color;
import java.awt.Container;
import java.awt.EventQueue;
import javax.swing.GroupLayout;
import static javax.swing.GroupLayout.Alignment.CENTER;
import static javax.swing.GroupLayout.DEFAULT_SIZE;
import static javax.swing.GroupLayout.PREFERRED_SIZE;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import static javax.swing.LayoutStyle.ComponentPlacement.RELATED;
public class GroupLayoutPanel extends JFrame {
public GroupLayoutPanel(){
initUI();
setTitle("GroupLayout solution");
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setLocationRelativeTo(null);
}
private void initUI() {
Container pane = getContentPane();
GroupLayout gl = new GroupLayout(pane);
pane.setLayout(gl);
JPanel pnl = new JPanel();
JButton btn1 = new JButton("Button 1");
pnl.add(btn1);
JButton btn2 = new JButton("Button 2");
pnl.setBackground(Color.black);
gl.setAutoCreateGaps(true);
gl.setHorizontalGroup(gl.createSequentialGroup()
.addContainerGap(DEFAULT_SIZE, Integer.MAX_VALUE)
.addGroup(gl.createParallelGroup(CENTER)
.addComponent(pnl, DEFAULT_SIZE, DEFAULT_SIZE,
PREFERRED_SIZE)
.addComponent(btn2))
.addContainerGap(DEFAULT_SIZE, Integer.MAX_VALUE)
);
gl.setVerticalGroup(gl.createSequentialGroup()
.addContainerGap()
.addComponent(pnl, DEFAULT_SIZE, DEFAULT_SIZE,
PREFERRED_SIZE)
.addPreferredGap(RELATED)
.addComponent(btn2)
.addContainerGap()
);
pack();
}
public static void main(String[] args){
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
GroupLayoutPanel ex = new GroupLayoutPanel();
ex.setVisible(true);
}
});
}
}
Related
I'm trying to figure out how to position my buttons in the center right position. I added what Ive done so far and I'll add a drawing of how I want it to be.
I'm trying to understand how to determine the position I want in Swing, can't really understand the advantages of each layout.
My code so far:
package Game;
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Container;
import java.awt.Dimension;
import java.awt.FlowLayout;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.GridLayout;
import java.awt.Image;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.image.BufferedImage;
import javax.swing.ImageIcon;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JToolBar;
import javax.swing.Timer;
public class MainWindow extends JFrame implements ActionListener {
private JButton exit;
private JButton start_Game;
private ImageIcon puzzleBackground;
// private JLabel back_Label;
// private GridBagConstraints grid = new GridBagConstraints();
private JPanel menu;
public MainWindow()
{
super("Welcome");
setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
setSize(450,300);
setLocationRelativeTo(null);
this.setLayout(new FlowLayout(FlowLayout.RIGHT));
menu = new JPanel();
menu.setLayout(new BorderLayout());
//setResizable(false);
//===== Background =====
puzzleBackground = new ImageIcon("MyBackground.jpg");
setContentPane(new JLabel(puzzleBackground));
exit = new JButton("Exit");
menu.add(exit, BorderLayout.CENTER);
exit.addActionListener(this);
start_Game = new JButton("Start to play");
menu.add(start_Game, BorderLayout.SOUTH);
exit.addActionListener(this);
start_Game.addActionListener(this);
//
// back_Label = new JLabel(puzzleBackground);
// back_Label.setLayout(new BorderLayout());
//===== Buttons =====
// back_Label.add(exit,BorderLayout.CENTER);
//
// back_Label.add(start_Game,BorderLayout.EAST);
//
add(menu);
setVisible(true);
}
public static void main(String args[])
{
MainWindow a = new MainWindow();
}
#Override
public void actionPerformed(ActionEvent e) {
if(e.getSource() == exit)
{
System.exit(0);
}
else
{
//open start up window.
}
}
}
A better way to add a BG image is to use a custom painted JPanel. Then set the layout of the panel and add other panels or components to it. Note that here the buttons are not appearing largely because they are being added to a JLabel.
Here is an alternative that works along the same lines, with the red panel being the panel which custom paints the background image and the menu panel being set to transparent (look for the opaque method).
import java.awt.*;
import java.awt.image.*;
import javax.swing.*;
import javax.swing.border.*;
public class MainWindow extends JFrame {
private JPanel menu;
private JPanel contentPane = new JPanel(new BorderLayout(4,4));
public MainWindow() {
super("Welcome");
setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
//setSize(450, 300); // use pack() instead
setContentPane(contentPane);
contentPane.setBorder(new EmptyBorder(8,8,8,8));
contentPane.setBackground(Color.RED);
contentPane.add(new JLabel(new ImageIcon(
new BufferedImage(400,200,BufferedImage.TYPE_INT_RGB))));
menu = new JPanel(new GridLayout(0,1,10,10));
menu.add(new JButton("Exit"), BorderLayout.CENTER);
menu.add(new JButton("Start to play"), BorderLayout.SOUTH);
JPanel menuCenterPanel = new JPanel(new GridBagLayout());
menuCenterPanel.add(menu);
add(menuCenterPanel, BorderLayout.LINE_END);
pack();
setLocationRelativeTo(null); // do AFTER pack()
setMinimumSize(getSize());
setVisible(true);
}
public static void main(String args[]) {
MainWindow a = new MainWindow();
}
}
So, your basic problem boils down the following lines...
this.setLayout(new BorderLayout());
//...
//===== Background =====
puzzleBackground = new ImageIcon("MyBackground.jpg");
setContentPane(new JLabel(puzzleBackground));
Can you tell me what the layout manager in use actually is now? Wrong. The layout manager is now null, because JLabel doesn't actually have a default layout manager.
So, the "simple" answer would be to move the setLayout call to below the setContentPane call, but this would be a short sighted answer, as JLabel calculates it's preferred based on the icon and text properties only, not it's contents of child components.
A better solution would be to do something demonstrated in How to set a background picture in JPanel (see the second example)
This means that if the image is smaller then the required space, the components will disappear off the screen.
I went through and cleaned up the code slightly, only with the intention of getting the layout to work
import java.awt.BorderLayout;
import java.awt.Dimension;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.ImageIcon;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
public class MainWindow extends JFrame implements ActionListener {
private JButton exit;
private JButton start_Game;
private JPanel menu;
public MainWindow() {
super("Welcome");
setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
setLocationRelativeTo(null);
this.setLayout(new BorderLayout());
menu = new JPanel();
menu.setLayout(new GridBagLayout());
exit = new JButton("Exit");
exit.addActionListener(this);
start_Game = new JButton("Start to play");
exit.addActionListener(this);
start_Game.addActionListener(this);
GridBagConstraints gbc = new GridBagConstraints();
gbc.weightx = 1;
gbc.fill = gbc.HORIZONTAL;
gbc.gridwidth = GridBagConstraints.REMAINDER;
menu.add(exit, gbc);
menu.add(start_Game, gbc);
// This is just a filler, it can be removed, but it helps prove the point
add(new JPanel() {
#Override
public Dimension getPreferredSize() {
return new Dimension(200, 200);
}
});
add(menu, BorderLayout.EAST);
pack();
setVisible(true);
}
public static void main(String args[]) {
MainWindow a = new MainWindow();
}
#Override
public void actionPerformed(ActionEvent e) {
if (e.getSource() == exit) {
System.exit(0);
} else {
//open start up window.
}
}
}
I'd also like to point out that extending directly from JFrame is also short sighted, it's locking you into a single use container and you're not actually adding any new functionality to the class.
Example of better structure...
The following is a simple example of a possibly better structure. It's missing the concept of a "controller", which controls stuff and "model" which maintains the state information which is used by the UI to display "stuff", but gives a starting point
import java.awt.BorderLayout;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
public class Main {
public static void main(String args[]) {
new Main();
}
public Main() {
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("Welcome");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(new MainPane());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
public class MainPane extends JPanel {
public MainPane() {
setLayout(new BorderLayout());
// This is just a filler, it can be removed, but it helps prove the point
add(new JPanel() {
#Override
public Dimension getPreferredSize() {
return new Dimension(200, 200);
}
});
add(new MenuPane(), BorderLayout.EAST);
}
}
public class MenuPane extends JPanel {
private JButton exit;
private JButton start_Game;
private JPanel menu;
public MenuPane() {
menu = new JPanel();
menu.setLayout(new GridBagLayout());
ActionHandler actionHandler = new ActionHandler();
exit = new JButton("Exit");
exit.addActionListener(actionHandler);
start_Game = new JButton("Start to play");
start_Game.addActionListener(actionHandler);
GridBagConstraints gbc = new GridBagConstraints();
gbc.weightx = 1;
gbc.fill = gbc.HORIZONTAL;
gbc.gridwidth = GridBagConstraints.REMAINDER;
menu.add(exit, gbc);
menu.add(start_Game, gbc);
}
public class ActionHandler implements ActionListener {
#Override
public void actionPerformed(ActionEvent e) {
if (e.getSource() == exit) {
System.exit(0);
} else {
//open start up window.
// This should be used to notifiy a controller class
// that some new action needs to take place, the controller
// is then responsible for making it happen
}
}
}
}
}
Doing UI in Java is not advised, but ignoring that.
You get (calculate) the height and width of the screen. Then start drawing buttons depending on that. Drawing a button on screens 50% of pixel value width and 50% of pixel value of height will center the button.
Simply crate buttons with variable location that is calculated from main screen px size and place them where ever you want.
So I'm trying to get the button on the bottom right and the text field taking up the bottom left but it keeps switching around for some reason. I think its borderLayout being stupid. I'm a noob at Java btw. Here's my code:
package textchat;
import java.awt.BorderLayout;
import java.awt.Dimension;
import java.awt.Toolkit;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import javax.swing.*;
public class window extends JFrame{
public static void main(String[] args)
{
new window();
}
public window()
{
//Window Config
//JFrame frame = new JFrame();
Toolkit tk = Toolkit.getDefaultToolkit();
Dimension dm = tk.getScreenSize();
this.setSize(400,400);
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
this.setTitle("CALI V1");
this.setExtendedState(this.getExtendedState() | JFrame.MAXIMIZED_BOTH);
//this.setLayout(null);
int Width = this.getWidth();
//Panel(s)
JPanel Panel = new JPanel();
Panel.setLayout(new BorderLayout());
JPanel PanelSouth = new JPanel();
JPanel PanelEast = new JPanel();
JPanel PanelWest = new JPanel();
//button
JButton btn = new JButton("SEND");
//Text Area
JTextArea txt = new JTextArea(100 , 100);
txt.setText("TEXT IS HERE");
//Text Field
JTextField fld = new JTextField("Type Here",15);
//Adding to the panel
Panel.add(txt);
PanelSouth.add(PanelEast, BorderLayout.EAST);
PanelSouth.add(PanelWest, BorderLayout.WEST);
PanelEast.add(btn);
PanelWest.add(fld);
//adding to frame
this.add(Panel);
this.add(PanelSouth , BorderLayout.SOUTH);
this.setVisible(true);
}
}
While using BorderLayout in such a way kind of works, you should
not use it in such a way. Besides, your example has several issues.
For instance, you did not start the application on the EDT (Event Dispatch Tread).
Here is a working example that creates your inteded layout. It uses the powerful GroupLayout manager.
package com.zetcode;
import java.awt.Container;
import java.awt.EventQueue;
import javax.swing.GroupLayout;
import javax.swing.JButton;
import javax.swing.JComponent;
import javax.swing.JFrame;
import javax.swing.JTextArea;
import javax.swing.JTextField;
public class TextChatEx extends JFrame {
public TextChatEx() {
initUI();
}
private void initUI() {
JTextArea area = new JTextArea(15, 15);
JTextField field = new JTextField(15);
JButton sendButton = new JButton("Send");
createLayout(area, field, sendButton);
setTitle("Text chat");
setLocationRelativeTo(null);
setDefaultCloseOperation(EXIT_ON_CLOSE);
}
private void createLayout(JComponent... arg) {
Container pane = getContentPane();
GroupLayout gl = new GroupLayout(pane);
pane.setLayout(gl);
gl.setAutoCreateContainerGaps(true);
gl.setAutoCreateGaps(true);
gl.setHorizontalGroup(gl.createParallelGroup()
.addComponent(arg[0])
.addGroup(gl.createSequentialGroup()
.addComponent(arg[1])
.addComponent(arg[2]))
);
gl.setVerticalGroup(gl.createSequentialGroup()
.addComponent(arg[0])
.addGroup(gl.createParallelGroup(GroupLayout.Alignment.BASELINE)
.addComponent(arg[1])
.addComponent(arg[2]))
);
pack();
}
public static void main(String[] args) {
EventQueue.invokeLater(() -> {
TextChatEx ex = new TextChatEx();
ex.setVisible(true);
});
}
}
GroupLayout is a powerful layout manager; with this manager, you don't have to create a bunch of panels to create some basic layout.
public TextChatEx() {
initUI();
}
The GUI creation is delegated to the initUI() method. Rather than placing all the code into the constructor, we use a specialized method.
EventQueue.invokeLater(() -> {
TextChatEx ex = new TextChatEx();
ex.setVisible(true);
});
Each Swing application should be placed on the EDT. Failing to do this can lead to hard to find bugs in the future.
I have a question on my GUI. after I ran my codes. my GUI will display like the picture shown below
But when I enlarged it to full screen. it will become like this.
How do I keep in the center and just like the size in picture one only when enlarged to full screen?
import java.awt.BorderLayout;
import java.awt.GridLayout;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JTextField;
import javax.swing.SwingUtilities;
public class GuiTest {
JFrame frame = new JFrame("Gui Test");
JPanel panel = new JPanel(new GridLayout(4,0));
JPanel panelTwo = new JPanel(new BorderLayout());
JLabel labelOne = new JLabel("Text One:");
JLabel labelTwo = new JLabel("Text Two:");
JTextField textFieldOne = new JTextField(15);
JTextField textFieldTwo = new JTextField(15);
JTextField textFieldThree = new JTextField(15);
public GuiTest() {
panel.add(labelOne);
panel.add(textFieldOne);
panel.add(labelTwo);
panel.add(textFieldTwo);
panelTwo.add(panel, BorderLayout.CENTER);
frame.add(panelTwo);
frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
frame.pack();
frame.getPreferredSize();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
//frame.setResizable(false);
}
public static void main(String[]args) {
SwingUtilities.invokeLater(new Runnable() {
#Override
public void run() {
new GuiTest();
}
});
}
}
Yet another GridLayout confusion!
It is stretching its children and there is nothing that we can do about it.
GridLayout is a very simple manager with very limited practical
usage. Skip it and skip BorderLayout as well. The only thing that
you need to know about BorderLayout is that it is the default manager
of the frame's content pane.
Layout management is a complex thing -- there not shortcuts. One has to
put some effort to learn it. The good news is that there are some very capable
layout managers. I recommend the following two:
MigLayout
GroupLayout
JGoodies' FormLayout is a good option too. These managers are doing
it properly. Study them carefully and choose your favourite.
I provide two solutions, one with MigLayout, one with GroupLayout.
MigLayout solution
MigLayout is a third-party layout manager for which we need to dowload
a single jar file.
package com.zetcode;
import java.awt.EventQueue;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JTextField;
import net.miginfocom.swing.MigLayout;
public class MigLayoutEx extends JFrame {
public MigLayoutEx() {
initUI();
}
private void initUI() {
JPanel pnl = new JPanel(new MigLayout("ins dialog, center, "
+ "center, wrap"));
pnl.add(new JLabel("Text one"));
pnl.add(new JTextField(15));
pnl.add(new JLabel("Text two"));
pnl.add(new JTextField(15));
add(pnl);
pack();
setTitle("MigLayout example");
setLocationRelativeTo(null);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
public static void main(String[] args) {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
MigLayoutEx ex = new MigLayoutEx();
ex.setVisible(true);
}
});
}
}
GroupLayout solution
GroupLayout is a built-in layout manager.
package com.zetcode;
import java.awt.Container;
import java.awt.EventQueue;
import javax.swing.GroupLayout;
import static javax.swing.GroupLayout.Alignment.LEADING;
import static javax.swing.GroupLayout.DEFAULT_SIZE;
import static javax.swing.GroupLayout.PREFERRED_SIZE;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JTextField;
public class GroupLayoutEx extends JFrame {
public GroupLayoutEx() {
initUI();
}
private void initUI() {
Container pane = getContentPane();
GroupLayout gl = new GroupLayout(pane);
pane.setLayout(gl);
JLabel lbl1 = new JLabel("Text one");
JLabel lbl2 = new JLabel("Text two");
JTextField field1 = new JTextField(15);
JTextField field2 = new JTextField(15);
gl.setAutoCreateGaps(true);
gl.setAutoCreateContainerGaps(true);
gl.setHorizontalGroup(gl.createSequentialGroup()
.addGap(5, 50, Short.MAX_VALUE)
.addGroup(gl.createParallelGroup(LEADING)
.addComponent(lbl1)
.addComponent(field1, DEFAULT_SIZE, DEFAULT_SIZE,
PREFERRED_SIZE)
.addComponent(lbl2)
.addComponent(field2, DEFAULT_SIZE, DEFAULT_SIZE,
PREFERRED_SIZE))
.addGap(5, 50, Short.MAX_VALUE)
);
gl.setVerticalGroup(gl.createSequentialGroup()
.addGap(5, 50, Short.MAX_VALUE)
.addGroup(gl.createSequentialGroup()
.addComponent(lbl1)
.addComponent(field1, DEFAULT_SIZE, DEFAULT_SIZE,
PREFERRED_SIZE)
.addComponent(lbl2)
.addComponent(field2, DEFAULT_SIZE, DEFAULT_SIZE,
PREFERRED_SIZE))
.addGap(5, 50, Short.MAX_VALUE)
);
pack();
setTitle("GroupLayout example");
setLocationRelativeTo(null);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
public static void main(String[] args) {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
GroupLayoutEx ex = new GroupLayoutEx();
ex.setVisible(true);
}
});
}
}
When I set the outpanel into a BoxLayout then the panel disappears. However the scrollbar shows that indicates my panel in ArrayList are in the right position.
I am totally new to Java so I'll appreciate any comments.
import java.awt.Color;
import java.awt.Dimension;
import java.awt.FlowLayout;
import java.util.*;
import javax.swing.*;
public class gui extends JFrame{
int ctr=0, top=5;
public List<JPanel> o_panels = new ArrayList<JPanel>(); //Your List
public gui(){
super("MCC");
setLayout(null);
//Output panel for the results
JPanel outpanel = new JPanel();
outpanel.setBackground(Color.blue);
outpanel.setVisible(true);
outpanel.setLayout(new BoxLayout(outpanel, BoxLayout.PAGE_AXIS));
//Scroll pane
JScrollPane scrollPane = new JScrollPane(outpanel,
JScrollPane.VERTICAL_SCROLLBAR_ALWAYS,
JScrollPane.HORIZONTAL_SCROLLBAR_AS_NEEDED);
scrollPane.setBounds(0,0,780,400);
add(scrollPane);
//result panel
//creating and adding panels in to the array list
while(ctr<=4){
JPanel label1 = new JPanel();
label1.setPreferredSize(new Dimension(600,100));
o_panels.add(label1);
outpanel.add(o_panels.get(ctr));
ctr++;
}
}
public void runGui(){
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
this.setSize(800,600);
this.setVisible(true);
this.setResizable(false);
//i call this on the other class
}
}
There is, not much, wrong with your code, the problem is, you've not established any means by which you can see what you've been adding
Have a look at this...
while (ctr <= 4) {
JPanel label1 = new JPanel();
label1.setPreferredSize(new Dimension(600, 100));
o_panels.add(label1);
outpanel.add(o_panels.get(ctr));
ctr++;
}
All the panels are the same color and you've added nothing to them, so how could you possible know if they were been added or layout correctly...
I simple added label1.setBorder(new LineBorder(Color.RED)); and got this result...
import java.awt.Color;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.util.ArrayList;
import java.util.List;
import javax.swing.BoxLayout;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
import javax.swing.border.LineBorder;
public class Test extends JFrame {
public static void main(String[] args) {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
}
Test test = new Test();
test.runGui();
}
});
}
int ctr = 0, top = 5;
public List<JPanel> o_panels = new ArrayList<JPanel>(); //Your List
public Test() {
super("MCC");
//Output panel for the results
JPanel outpanel = new JPanel();
outpanel.setBackground(Color.blue);
outpanel.setVisible(true);
outpanel.setLayout(new BoxLayout(outpanel, BoxLayout.PAGE_AXIS));
//Scroll pane
JScrollPane scrollPane = new JScrollPane(outpanel,
JScrollPane.VERTICAL_SCROLLBAR_ALWAYS,
JScrollPane.HORIZONTAL_SCROLLBAR_AS_NEEDED);
scrollPane.setBounds(0, 0, 780, 400);
add(scrollPane);
//result panel
//creating and adding panels in to the array list
while (ctr <= 4) {
JPanel label1 = new JPanel();
label1.setPreferredSize(new Dimension(600, 100));
label1.setBorder(new LineBorder(Color.RED));
o_panels.add(label1);
outpanel.add(o_panels.get(ctr));
ctr++;
}
}
public void runGui() {
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
pack();
this.setVisible(true);
// this.setResizable(false);
setLocationRelativeTo(null);
}
}
Also have a look at Should I avoid the use of set(Preferred|Maximum|Minimum)Size methods in Java Swing?
And you really should avoid using null layouts, pixel perfect layouts are an illusion within modern ui design. There are too many factors which affect the individual size of components, none of which you can control. Swing was designed to work with layout managers at the core, discarding these will lead to no end of issues and problems that you will spend more and more time trying to rectify
Hello I would like to make this TextArea stick to the windows size whene I resize it by mouse, the same way as lower buttons does. This is the code it is perfectly working no bugs, please have a glance at it.
import java.awt.BorderLayout;
import java.awt.Component;
import java.awt.Container;
import java.awt.Dimension;
import java.awt.FlowLayout;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.GridLayout;
import java.awt.LayoutManager;
import javax.swing.BoxLayout;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JTextArea;
import javax.swing.JTextField;
import javax.swing.SwingUtilities;
public class Rozklady extends JFrame {
public Rozklady() {
super();
}
public void createGUI(){
setPreferredSize(new Dimension(400,150));
JPanel jp = new JPanel();
// jp.setLayout(new BoxLayout(jp, BoxLayout.Y_AXIS));
jp.setLayout(new GridLayout(0,1));
JPanel gora = new JPanel();
JPanel dol = new JPanel();
pack();
JTextArea jt1 = new JTextArea("JF1");
gora.add(jt1);
jt1.setPreferredSize(new Dimension(getWidth(),getHeight()/2));
dol.setLayout(new BorderLayout());
JPanel lewo = new JPanel();
JPanel prawo = new JPanel();
JPanel srodek = new JPanel();
dol.add(lewo, BorderLayout.EAST);
dol.add(prawo,BorderLayout.WEST);
dol.add(srodek, BorderLayout.CENTER);
lewo.setLayout(new GridLayout(2,2));
prawo.setLayout(new GridLayout(2,2));
srodek.setLayout(new GridLayout(0,1));
for(int i = 0; i < 4; i++){
lewo.add(new JButton(i+""));
prawo.add(new JButton(i+""));
if(i < 3){
srodek.add(new JTextField("JF"+i));
}
}
jp.add(gora);
jp.add(dol);
add(jp);
setVisible(true);
pack();
setDefaultCloseOperation(EXIT_ON_CLOSE);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable()
{
public void run()
{
new Rozklady().createGUI();
}
});
}
}
Use BorderLayout for you gora panel. Put text area to the center:
gora.setLayout(new BorderLayout());
gora.add(jt1, BorderLayout.CENTER);
// declare a GridLayout in constructor, one component will 'fill the container'
JPanel gora = new JPanel(new GridLayout());
JPanel dol = new JPanel();
// this should be called after all components are added! BNI
pack();
JTextArea jt1 = new JTextArea("JF1");
// be sure to use a scroll pane for multi-line text components
gora.add(new JScrollPane(jt1));
// ..
Stretching a single component to fill the available space can be achieved various was. Two common ways are using either BorderLayout as mentioned by AlexR or GridLayout. See this answer for sample code. I prefer GridLayout because it is shorter (less typing). ;)