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);

Swing JScrollPane resizing to fit the viewport panel

I tried a lot of layout managers but none could solve my problem:
I want the items in a scrollPane to keep their size (preferred or minimum) and not being resized (reduced) to fit the viewport Panel. Since if it is a JTextArea, and if the text area has blank space and it is bigger then the viewport, it would reduce it so the blank text area won't be shown. I want the blank text area to be shown for appearance issues.
Im stacking one item after another using BoxLayout, and it seems to me that for text areas the setMinimum method fails.
If the text area has blank space, then the scrollbar of the ScrollPane won't appear, instead it only appears it there are no blank space left.
Any solution?
JScrollPane materialPane = new FScrollPane();
this.materialPaneView = new TPanel();
this.materialPaneView.setMinimumSize(new Dimension((int)(WIDTH*0.95), (int)(HEIGHT/2)));
this.materialPaneView.setLayout(new BoxLayout(this.materialPaneView, BoxLayout.Y_AXIS));
materialPane.setViewportView(materialPaneView);
materialPane.setMinimumSize(new Dimension((int)(WIDTH*0.95), (int)(HEIGHT/2)));
for(Material mat: this.unit.getMaterial()){
this.addMaterial(mat);
}
centerPanel.add(sectionPane);
centerPanel.add(exercisePane);
centerPanel.add(materialPane);
this.add(upperPanel, BorderLayout.NORTH);
this.add(centerPanel, BorderLayout.CENTER);
public void addMaterial(Material mat){
JTextField matName = new JTextField(30);
JPanel fieldButtonPanel = new TPanel();
fieldButtonPanel.setLayout(new GridLayout(1,2));
JPanel fieldPanel = new TPanel(new FlowLayout(FlowLayout.LEFT));
JPanel deleteMatButtonPanel = new TPanel(new FlowLayout(FlowLayout.RIGHT));
matName.setText(mat.getName());
matName.setMaximumSize(new Dimension(FFont.def.getSize()*20, 30));
fieldPanel.add(matName);
JButton deleteMat = new JButton("Delete Material");
deleteMatButtonPanel.add(deleteMat);
fieldButtonPanel.add(fieldPanel);
fieldButtonPanel.add(deleteMatButtonPanel);
fieldButtonPanel.setAlignmentX(LEFT_ALIGNMENT);
JTextArea matText = new FTextArea(mat.getDesc(), (int)(WIDTH*0.95), (int)(HEIGHT/3.4));
matText.setMinimumSize(new Dimension((int)(WIDTH*0.95), (int)(HEIGHT/3.5)));
/*matText.setMaximumSize(new Dimension((int)(WIDTH*0.95), (int)(HEIGHT/3.4)));*/
matText.setText(mat.getDesc());
matText.setAlignmentX(LEFT_ALIGNMENT);
this.materialPaneView.add(fieldButtonPanel);
this.materialPaneView.add(matText);
matName.addActionListener(new ActionListener(){
#Override
public void actionPerformed(ActionEvent e) {
mat.setName(matName.getText());
}
});
HEIGHT and WIDTH are constants, and TPanel FScrollPane are my predefined transparent panels. The BoxLayout panel is the viewport of a scrollPane, and still, it would resize the text areas.

I am not sure i get what you are asking for so please tell me if i totally missed the point...
As far as i know the Viewport size is controlled by the component inside the JScrollPane and the JScrollPane size wont change no matter what happens to the viewport.
You either want to:
A) Resize the JScrollPane to the same size as it's content.
I would implement listeners to look for the content size change and resize the ScrollPane accordingly but you need to pay attention to resize the whole Hierarchy too.
B) You want to resize the viewport so that it fits in the JScrollPane? Y'know without scrollbars.
I had this problem and fixed it by using a ScrollablePanel component. Check this answer, follow the link to download the .class and use it to use a JPanel that resizes to fit the ScrollPane.
Those arent very detailed answers but i will need more information about what you are trying to do before expanding on it. And your code isnt complete, always share a code that we can CTRL+C/V and readily verify the problem in our end.

Adding a text area to a tabbed pane in java

I have two files that I need to display in a program. I need to use JTabbedPane and each file should be displayed in its own tab. I can make the text appear in the tab, but the scroll bar won't appear, so I can't see all of the information in the file. How do I add the scroll bar to the text area?
I made one method that creates a panel with the text in it (this is for one file). Then, I made another method that has JTabbedPane and I added the panel to a tab.
Panel method:
private void makeTextPanel() throws IOException
{
textPanel = new JPanel();
textArea = new JTextArea();
textArea.setEditable(false);
//width: 770 height: 1000
textAreaDimensions = new Dimension(TEXT_AREA_WIDTH, TEXT_AREA_HEIGHT);
textArea.setPreferredSize(textAreaDimensions);
BufferedReader inputFile = new BufferedReader(new FileReader(FILE_ONE));
String lineOfText = inputFile.readLine();
while(lineOfText != null)
{
textArea.append("\n" + lineOfText);
lineOfText = inputFile.readLine();
}
// Add a scroll bar
scrollPane = new JScrollPane(textArea);
// Add the text area and scroll bar to the panel
textPanel.add(textArea);
textPanel.add(scrollPane);
}
Tabbed pane method:
private void makeTabbedPane() throws IOException
{
frame = new JFrame("Project");
tabbedPane = new JTabbedPane();
frame.add(tabbedPane, BorderLayout.PAGE_START);
// add panel to the tab
makeTextPanel();
tabbedPane.addTab("Tab 1", textPanel);
// dimensions
frameDimensions = new Dimension(FRAME_WIDTH, FRAME_HEIGHT);
frame.setPreferredSize(frameDimensions);
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
To reiterate:
How do I make the scroll bar visible?
I set the height of the text area to 1000. Will the scroll bar be able to scroll through everything? If not, how do I set the height of the text area to fit everything in the file?

The component you want scroll bars for should always a child of the JScrollPane. Adding the textArea and then the scrollPane to that tabbedPane probably isn't doing what you think it is. Make sure that textArea is the child of scrollPane, and add just the scrollPane to the tabbedPane, ensuring you've specified a layout that dictates how the scrollPane is to take up the space you want within tabbedPane.
The scrollpane will automatically add scrollbars only when it decides the textArea is bigger than it can render in the space it's been given.
Question 1) The JScrollPane methods setVerticalScrollBarPolicy() and setHorizontalScrollBarPolicy() will allow you to force the scrollbars to be always visible.
Question 2) The "preferred" height of the textArea is what your scrollPane will use to determine the scrollbar behaviour (see this example). It's all taken care of for you. If not, you'd be forced yourself to consider font rendering height, how much text you put in the textArea etc.
Generally speaking, just throwing a JTextArea into a JScrollPane will see the desired behaviour you're seeking without you having to do anything "special" with JTextArea size.

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

Scrolling issue (Java-JFrame-JScrollBar)

INTRO:
I created a java application using JFrame. I have a JMenuBar at the top and under that I'd like to display rows of text.
PURPOSE:
When I have 50 rows and only 20 are displayable at once, I'd like to be able to scroll down and back up again.
PROBLEM:
Of course, my theory doesn't wanna work as it should. My problem is that I don't know how to add a vertical scroll properly.
QUESTION:
How should I change this code to reach my goal?
public void display(){
Container content = this.window.getContentPane();
content.setLayout(new BorderLayout());
Border border = LineBorder.createGrayLineBorder();
//this is just a sample
for(int i = 0;i<50;i++){
JLabel lab = new JLabel("lonyaladek");
lab.setSize(570, 20);
lab.setBorder(border);
lab.setLocation(10, 20+(i*25));
content.add(lab);
}
//scroll
JScrollBar sb = new JScrollBar(JScrollBar.VERTICAL, 0, 0, 0, 0);
content.add(sb);
}

First you need to start with a layout manager that allows you to add multiple components to the container. Maybe a GridLayout is the best place to start.
Then you add this container to the scrollPane and then you add the scrollpane to the window.
So the basic code would be:
JPanel panel = new JPanel( new GridLayout(0, 1) );
panel.add(...);
panel.add(...);
JScrollPane scrollPane = new JScrollPane( panel );
window.add(scrollPane, BorderLayout.CENTER);
I suggest you read the section from the Swing tutorial on How to Use Scroll Panes for more info.