Develop Reference

How to Keep JCheckBox Horizontally inside JPanel

I have a JPanel. Inside Panel I have kept one JLabel and three JCheckBox.
I want to keep all the checkBox in one line after JLabel. Here is the sample code and some screenshots.
Output 1
Output 2
When i change to X_AXIS it is coming everything in one line and when i switch to Y_AXIS then it is coming new line means vertically.
But my requirement is all the checkbox should come next line means after JLabel.
JLabel should come in line and all the checkBox should come in one line.
public class CheckBoxWithJLabel {
public static void main(String[] args) {
JFrame f= new JFrame("CheckBox Example");
JPanel panel = new JPanel();
panel.setBounds(40,80,600,200);
JCheckBox chk_Embrodary=new JCheckBox("Embrodary");
JCheckBox chk_Cutting=new JCheckBox("Cutting");
JCheckBox cb_Sewing=new JCheckBox("Sewing");
panel.setLayout(new javax.swing.BoxLayout(panel, javax.swing.BoxLayout.X_AXIS));
JLabel lblHeader=new JLabel("Job Work Process Selection");
panel.add(lblHeader);
panel.add(chk_Embrodary);
panel.add(chk_Cutting);
panel.add(cb_Sewing);
f.add(panel);
f.setSize(600,400);
f.setLayout(null);
f.setVisible(true);
}
}
I want this output like
this
How to solve this problem?

I would highly suggest you to have a look through the Java Swing Tutorial, especially the Laying Out Components Within a Container section, since it seems you lack some basic understanding of how Swing and its Layout Managers are supposed to be used.
Regarding your problem:
Currently, you are using a single BoxLayout, which " puts components in a single row or column". You only want that behavior for your JCheckBoxes though, and not for your JLabel. Keeping this in mind, the solution is to split up your components and to not put all of them in a single JPanel. Doing this will grant you more flexibility in how you design your GUI, since you can use multiple layouts in different nested panels.
You could do something like this (explanation in the code comments):
public static void main(String[] args) {
JFrame f = new JFrame("CheckBox Example");
// add a Y_AXIS boxlayout to the JFrames contentpane
f.getContentPane().setLayout(new BoxLayout(f.getContentPane(), BoxLayout.Y_AXIS));
JCheckBox cbEmbrodary = new JCheckBox("Embrodary");
JCheckBox cbCutting = new JCheckBox("Cutting");
JCheckBox cbSewing = new JCheckBox("Sewing");
// no need to set the bounds, since the layoutmanagers will determine the size
JPanel labelPanel = new JPanel(); // default layout for JPanel is the FlowLayout
JLabel lblHeader = new JLabel("Job Work Process Selection");
labelPanel.add(lblHeader); // JPanel for the label done
// JPanel for the comboboxes with BoxLayout
JPanel cbPanel = new JPanel();
cbPanel.setLayout(new BoxLayout(cbPanel, BoxLayout.X_AXIS));
cbPanel.add(cbEmbrodary);
cbPanel.add(cbCutting);
cbPanel.add(cbSewing);
f.add(labelPanel);
f.add(cbPanel);
// No need to set the size of the JFrame, since the layoutmanagers will
// determine the size after pack()
f.pack();
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
f.setVisible(true);
}
Output:
Sidenotes:
Don't set fixed sizes via setSize() or setBounds() to your components. Swing is designed to be used with appropariate LayoutManagers, and if you do that, calling pack() on the JFrame before setting it visible will layout the components and determine their appropriate size. (Also, don't use null-layout for the same reasons)
If you need the JLabel to not be centered but left aligned, like in your screenshot, then use the following:
FlowLayout layout = (FlowLayout) labelPanel.getLayout();
layout.setAlignment(FlowLayout.LEFT);

Add JButton to JScrollPame

I have the following code taken from GeeksforGeeks that displays the contents of a 2-d array in JTable using JScrollPane:
public class JTableExamples {
// frame
JFrame f;
// Table
JTable j;
// Constructor
JTableExamples()
{
// Frame initiallization
f = new JFrame();
// Frame Title
f.setTitle("JTable Example");
// Data to be displayed in the JTable
String[][] data = {
{ "Kundan Kumar Jha", "4031", "CSE" },
{ "Anand Jha", "6014", "IT" }
};
// Column Names
String[] columnNames = { "Name", "Roll Number", "Department" };
// Initializing the JTable
j = new JTable(data, columnNames);
j.setBounds(30, 40, 200, 300);
// adding it to JScrollPane
JScrollPane sp = new JScrollPane(j);
f.add(sp);
// Frame Size
f.setSize(500, 200);
// Frame Visible = true
f.setVisible(true);
}
What I am trying to do is add a simple Component (like JButton) underneath the table but it does not seem to work. I tried modifying the code by adding the JButton to JPanel and adding JPanel to the frame:
JButton button = new JButton("Back");
JPanel panel = new JPanel();
panel.add(button);
f.add(sp);
f.add(panel);
But this simply deletes the entire table and replaces it with a single button. I also tried adding the button to JPanel and adding that JPanel to JScrollPane:
JButton button = new JButton("Back");
JPanel panel = new JPanel();
panel.add(button);
sp.add(panel);
f.add(sp);
But this did not seem to change anything. I also tried to tinker with preferred and maximum size of JScrollPanel to no avail - it always occupies the entire screen and prevents JButton from appearing on the screen.
Not shooting for design here, just functionality: have a JButton appear underneath my JTable. Any suggestions will be greatly appreciated. Thank you in advance!

The default layout manager of a JFrame is the BorderLayout.
f.add(sp);
f.add(panel);
When you don't specify a constraint for the BorderLayout the CENTER is assumed. You can only have a single component added to the CENTER.
Instead your code should be:
f.add(sp, BorderLayout.CENTER);
f.add(panel, BorderLayout.PAGE_END);
Note the default layout manager for a JPanel is the FlowLayout. So the button will be horizontally centered in the panel.
Also, instead of using a JPanel, try adding the button directly to the PAGE_END of the frame to see the difference.
Read the section from the Swing tutorial on Using Layout Manager for more information and examples for using each of the different layout managers to understand the differences of the above suggestions.
Edit:
Is there a way to decrease the height of the table
If you know you have a small table then you can use:
table.setPreferredScrollableViewportSize(table.getPreferredSize());
This will make the scroll pane the size of the table.
Then you use:
//f.setSize(500, 200);
f.pack();
Now all components will be displayed at their preferred size.

Why does my JButton appear the full size of the JFrame?

I am a newbie, I have a question. I am trying to use Eclipse to write a Java windows application, in which I will have a main window, which will contain several things, like a dashboard sort of thing, and it will have buttons, for example to add a record to a database, and this button when pressed, will open a new relevant window on top.
I tried to start, I wrote this code in Java, and for some reason, the button is in the size of the frame...full screen ! How do I fix it ?
Can you suggest me better ideas for a design than what I specified ?
Thank you
public class MainClass {
public static void main(String[] args) {
// TODO Auto-generated method stub
JFrame jfrm = new JFrame("Frame1");
Dimension screenSize = Toolkit.getDefaultToolkit().getScreenSize();
jfrm.setSize(screenSize.width, screenSize.height);
jfrm.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
JLabel jlab = new JLabel("Hello");
jfrm.add(jlab);
JButton button = new JButton("Button");
button.setSize(new Dimension(50, 50));
button.setLocation(500, 350);
jfrm.getContentPane().add(button);
jfrm.setVisible(true);
}

Add a layout to the JFrame first. For example FlowLayout:
jfrm.setLayout(new FlowLayout());

"I tried to start, I wrote this code in Java, and for some reason, the button is in the size of the frame...full screen ! How do I fix it ?"
The reason the button stretches is because JFrame has a default BorderLayout that does not respect the preferred sizes of child components.
The solution is to set the Layout Manager to layout that does respect preferred sizes. The image blow from this example shows the most common Layout Managers and show visually which one respect the preferred size of child components.
Also, the BorderLayout is also the reason your JLabel does not show. By default, every component that is added to a BorderLayout without a position specified e.g. BorderLayout.SOUTH, will automatically be placed in the BorderLayout.CENTER position. Each position may only have one component. So when you add the JLabel it goes to the CENTER, but when you add the JButton, it also goes the CENTER, kicking out the JLabel.
If you've never encountered Layout Managers, this is probably all confusing to you. You should take the time to go over How to Layout Components Within a Container

You need to use some form of layoutmanager, you can use this information: http://docs.oracle.com/javase/tutorial/uiswing/layout/visual.html

You must use Layout manager.
Use this code..
public static void main(String[] args)
{
JFrame jfrm = new JFrame("Frame1");
Dimension screenSize = Toolkit.getDefaultToolkit().getScreenSize();
jfrm.setSize(screenSize.width, screenSize.height);
jfrm.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
JLabel jlab = new JLabel("Hello");
jfrm.add(jlab);
JButton button = new JButton("Button");
button.setSize(new Dimension(50, 50));
button.setLocation(500, 350);
jfrm.add(button);
jfrm.setVisible(true);
jfrm.setLayout(new FlowLayout());
jfrm.pack();
you forgot to add pack(). so use this code to get Jlabel and JButtion side by side.
Thanks...

How to layout multiple panels on a jFrame? (java)

I am in the process of making my own java socket game. My game is painting alright to the full screen (where it says "paint graphics here", but im painting to the whole jframe at the moment). I want to add a textbox with a scroll bar for displaying only text, not taking any input and another textbox to take text inputs from the user and then a button to send the text, for chat purposes. But onto my question, how do I even start to lay this out? I understand I need a layout, but can someone help me on this? Here is my code at the moment (this code only sets up painting to the whole screen at the moment, need to divide the screen up now like I have in the picture above):
public class Setup extends JFrame implements Runnable{
JPanel panel;
JFrame window;
public Setup(Starter start, JFrame window){
window.setSize(600,500);
window.setLocationRelativeTo(null);
window.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
window.setResizable(false);
panel = new Display(start);
this.window = window;
}
public void run(){
window.getContentPane().add(panel);
window.setBackground(Color.BLACK);
window.setVisible(true);
}
}
"new Display(start)" - this extends jpanel, its basically where I paint everything graphics wise.
In addition, I've seen people add in different panels but I cant have them be the same size. Like in the picture, the "paint graphics here" panel is the biggest one, and so on.

The JPanel is actually only a container where you can put different elements in it (even other JPanels). So in your case I would suggest one big JPanel as some sort of main container for your window. That main panel you assign a Layout that suits your needs ( here is an introduction to the layouts).
After you set the layout to your main panel you can add the paint panel and the other JPanels you want (like those with the text in it..).
JPanel mainPanel = new JPanel();
mainPanel.setLayout(new BoxLayout(mainPanel, BoxLayout.Y_AXIS));
JPanel paintPanel = new JPanel();
JPanel textPanel = new JPanel();
mainPanel.add(paintPanel);
mainPanel.add(textPanel);
This is just an example that sorts all sub panels vertically (Y-Axis). So if you want some other stuff at the bottom of your mainPanel (maybe some icons or buttons) that should be organized with another layout (like a horizontal layout), just create again a new JPanel as a container for all the other stuff and set setLayout(new BoxLayout(mainPanel, BoxLayout.X_AXIS).
As you will find out, the layouts are quite rigid and it may be difficult to find the best layout for your panels. So don't give up, read the introduction (the link above) and look at the pictures – this is how I do it :)
Or you can just use NetBeans to write your program. There you have a pretty easy visual editor (drag and drop) to create all sorts of Windows and Frames. (only understanding the code afterwards is ... tricky sometimes.)
EDIT
Since there are some many people interested in this question, I wanted to provide a complete example of how to layout a JFrame to make it look like OP wants it to.
The class is called MyFrame and extends swings JFrame
public class MyFrame extends javax.swing.JFrame{
// these are the components we need.
private final JSplitPane splitPane; // split the window in top and bottom
private final JPanel topPanel; // container panel for the top
private final JPanel bottomPanel; // container panel for the bottom
private final JScrollPane scrollPane; // makes the text scrollable
private final JTextArea textArea; // the text
private final JPanel inputPanel; // under the text a container for all the input elements
private final JTextField textField; // a textField for the text the user inputs
private final JButton button; // and a "send" button
public MyFrame(){
// first, lets create the containers:
// the splitPane devides the window in two components (here: top and bottom)
// users can then move the devider and decide how much of the top component
// and how much of the bottom component they want to see.
splitPane = new JSplitPane();
topPanel = new JPanel(); // our top component
bottomPanel = new JPanel(); // our bottom component
// in our bottom panel we want the text area and the input components
scrollPane = new JScrollPane(); // this scrollPane is used to make the text area scrollable
textArea = new JTextArea(); // this text area will be put inside the scrollPane
// the input components will be put in a separate panel
inputPanel = new JPanel();
textField = new JTextField(); // first the input field where the user can type his text
button = new JButton("send"); // and a button at the right, to send the text
// now lets define the default size of our window and its layout:
setPreferredSize(new Dimension(400, 400)); // let's open the window with a default size of 400x400 pixels
// the contentPane is the container that holds all our components
getContentPane().setLayout(new GridLayout()); // the default GridLayout is like a grid with 1 column and 1 row,
// we only add one element to the window itself
getContentPane().add(splitPane); // due to the GridLayout, our splitPane will now fill the whole window
// let's configure our splitPane:
splitPane.setOrientation(JSplitPane.VERTICAL_SPLIT); // we want it to split the window verticaly
splitPane.setDividerLocation(200); // the initial position of the divider is 200 (our window is 400 pixels high)
splitPane.setTopComponent(topPanel); // at the top we want our "topPanel"
splitPane.setBottomComponent(bottomPanel); // and at the bottom we want our "bottomPanel"
// our topPanel doesn't need anymore for this example. Whatever you want it to contain, you can add it here
bottomPanel.setLayout(new BoxLayout(bottomPanel, BoxLayout.Y_AXIS)); // BoxLayout.Y_AXIS will arrange the content vertically
bottomPanel.add(scrollPane); // first we add the scrollPane to the bottomPanel, so it is at the top
scrollPane.setViewportView(textArea); // the scrollPane should make the textArea scrollable, so we define the viewport
bottomPanel.add(inputPanel); // then we add the inputPanel to the bottomPanel, so it under the scrollPane / textArea
// let's set the maximum size of the inputPanel, so it doesn't get too big when the user resizes the window
inputPanel.setMaximumSize(new Dimension(Integer.MAX_VALUE, 75)); // we set the max height to 75 and the max width to (almost) unlimited
inputPanel.setLayout(new BoxLayout(inputPanel, BoxLayout.X_AXIS)); // X_Axis will arrange the content horizontally
inputPanel.add(textField); // left will be the textField
inputPanel.add(button); // and right the "send" button
pack(); // calling pack() at the end, will ensure that every layout and size we just defined gets applied before the stuff becomes visible
}
public static void main(String args[]){
EventQueue.invokeLater(new Runnable(){
#Override
public void run(){
new MyFrame().setVisible(true);
}
});
}
}
Please be aware that this is only an example and there are multiple approaches to layout a window. It all depends on your needs and if you want the content to be resizable / responsive. Another really good approach would be the GridBagLayout which can handle quite complex layouting, but which is also quite complex to learn.

You'll want to use a number of layout managers to help you achieve the basic results you want.
Check out A Visual Guide to Layout Managers for a comparision.
You could use a GridBagLayout but that's one of the most complex (and powerful) layout managers available in the JDK.
You could use a series of compound layout managers instead.
I'd place the graphics component and text area on a single JPanel, using a BorderLayout, with the graphics component in the CENTER and the text area in the SOUTH position.
I'd place the text field and button on a separate JPanel using a GridBagLayout (because it's the simplest I can think of to achieve the over result you want)
I'd place these two panels onto a third, master, panel, using a BorderLayout, with the first panel in the CENTER and the second at the SOUTH position.
But that's me

How to represent a Board Panel in Java for a game?

I wanna fix a 2D board for a game. I've already fixed other panels for the Gui and everything goes well. But the panel for the board cant be printed on the window. I'm a bit confused about it as i think i've followed the same ideas as for the others panels i need.
Here's what i've done:
EDIT:
what I'm trying to do is fix a board panel for the game according to the dimensions of the it,hold every square in an array in order to use it after wherever it;s needed. I draw each little square of it with the method draw and put it back to the panel. So, each square on the board is a panel. This is the idea. But as u can see. There are troubles/errors on it.
EDIT: code updated.
just found a part of the problem. i thought first that i had set background to squared, but i didnt. with this one it appears on the panel a wide black "column". Unfortunately,still none squares. :(
One More EDIT:
Also,i realized that draw method is never called. when i put the draw method in the following method i can see the squares but they remain small. I redefine them with setSize but still no change.
How can I use paint method to edit the panels properly???? As it is now it can't. Even it can't return an object(eg panel) as it's polymorphic void!
/**
*Method used to construct the square in the area of the
*gui's grid. In this stage a GUISquare array is being constructed,
* used in the whole game as
*a mean of changing a square graphical state.
*#param squares is the squares array from whom the gui grid will be
*constructed.
*#see getSquare about the correspondance beetween a squareModel and
* a GUISquare.
*/
private void initBoardPanel(SquareModel[][] squares){
BoardPanel.setLayout(new GridLayout(height ,width )); //set layout
SquareRenderer[][] Squares;
JPanel[][] grid;
Squares=new GUISquare[height][width()];
grid=new JPanel[height()][width()];
for (int i=0; i<height(); i++){
for (int j=0; j<width() ; j++){
SquareRenderer kou=new SquareRenderer(i,j);
kou.setSquare(myGame.getSquares()[i][j]);
//NOTE: THE FOLLOWING DRAW METHOD CANT BE CALLED!!!?
if (myGame.getSquares()[i][j] instanceof SimpleSq ){
kou .paintPanel(i,j,"");}
else if (myGame.getSquares()[i][j] instanceof ActionSq )
{ kou .paintPanel(i,j);
}
//JUST BECAUSE DRAW CANT BE CALLED I PUT ITS CODE HERE:
//JUST TO CHECK:
JPanel panel = new JPanel();
panel.setLayout(new BorderLayout());
JLabel label1 = new JLabel("Move To "+myGame.getSquares()[i][j].getGoTo());
JLabel label2 = new JLabel(""+myGame.getSquares()[i][j].getSquare());
panel.setBackground(Color.ORANGE);
panel.add(label2, BorderLayout.NORTH);
panel.add(label1, BorderLayout.CENTER);
panel.setSize(250,250);
///////// <--until here ---paint method<---
kou.add(panel);
kou.setVisible(true);
kou.setBackground(Color.BLACK);
Squares[i][j]= kou;
BoardPanel.add(kou);
BoardPanel.setVisible(true);
BoardPanel.setBackground(Color.WHITE);
}
}
this.add(BoardPanel,BorderLayout.WEST);
// this.pack(); //sets appropriate size for frame
this.setVisible(true); //makes frame visible
}
IMPLEMENTED BY SQUARERENDERER:
/**
* Transformer for Snake/Ladder
* <br>This method is used to display a square on the screen.
*/
public void paintPanel(int i,int j) {
JPanel panel = new JPanel();
panel.setLayout(new BorderLayout());
JLabel label1 = new JLabel("Move To"+myGame.getSquares()[i][j].getGoTo());
JLabel label2 = new JLabel(""+myGame.getSquares()[i][j].getSquare());
JSeparator CellSeparator = new JSeparator(orientation);
panel.add(CellSeparator);
panel.setForeground(Color.ORANGE);
panel.add(label2, BorderLayout.NORTH);
panel.add(label1, BorderLayout.CENTER);
}

I see a couple things that are problematic:
When using a layout manager, you should avoid calling setSize. Most layout managers will simply override it. You should use setPreferredSize, setMinimumSize, and setMaximumSize instead, which provide hints to the layout manager.
It doesn't look like the draw method of SquareRenderer ever adds the panel you create to anything. You should either add panel to the SquareRenderer in the last line of draw or (better) add the sub-components directly to the SquareRenderer instead.