Adding a vertical scroll bar to a JTextArea - java

I'm making a simple GUI that has a JTextArea that I can paste a string in. When the string gets too long the JTextArea fills up and I can see the words going below the set bounds I have for the text area. I would like to add a vertical scroll bar to this text area.
public class GUI implements ActionListener {
private static JTextArea fileContents;
public static void main(String[] args) {
JFrame frame = new JFrame();
JPanel panel = new JPanel();
frame.setSize(700, 500);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(panel);
panel.setLayout(null);
fileContents = new JTextArea();
fileContents.setBounds(175, 75, 275, 275);
panel.add(fileContents);
JScrollPane sp = new JScrollPane();
sp.add(fileContents, JScrollPane.VERTICAL_SCROLLBAR_ALWAYS);
panel.add(sp);
I get an error when I have this setup.
Exception in thread "main" java.lang.IllegalArgumentException: illegal component position
at java.desktop/java.awt.Container.addImpl(Container.java:1111)
at java.desktop/java.awt.Container.add(Container.java:489)
at harness.GUI.main(HarnessGUI.java:60)

This code works:
JFrame frame = new JFrame();
JPanel panel = new JPanel();
frame.setSize(700, 500);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(panel);
frame.setVisible(true);
panel.setLayout(null);
fileContents = new JTextArea();
JScrollPane sp = new JScrollPane(fileContents);
sp.setBounds(175, 75, 300, 300);
panel.add(sp);
Your had 2 problems:
If fileContents added to sp that added to panel, tou needn't add fileContents to panel.
When using JScrollPane, you should add Components only with the constractor JScrollPane(Component view) and not with the add() method.

Related

Java Swing GUI JLabel Not Showing

I am trying to write a Title for the main menu of my program, by using a JLabel, but it doesn't seem to appear on my screen.
import javax.swing.*;
public class GUI {
public GUI() {
JFrame frame = new JFrame();
JPanel panel = new JPanel();
panel.setBorder(BorderFactory.createEmptyBorder(30,30,10,30));
panel.setLayout(new GridLayout());
frame.add(panel, BorderLayout.CENTER);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setTitle("Title");
frame.pack();
frame.setSize(854,560);
frame.setVisible(true);
JLabel title = new JLabel();
title.setText("Title");
//title.setSize();
title.setVisible(true);
}
public static void main(String[] args) {
new GUI();
}
}
What am I doing wrong and how could I change the position of the Text if I manage to make it visible?
And I also want to add a button to go to the next page so if you could tell me how to do that too that would be great.
I would quickly and untested say that you are adding the label after you set the frame visible.
Do it before. Else you would have to revalidate and repaint the frame
As I can see in your code you are not adding title in panel. As a quick solution put panel.add(title); after title.setVisible(true); line in your code, it will display the label.
JFrame frame = new JFrame();
JPanel panel = new JPanel();
panel.setBorder(BorderFactory.createEmptyBorder(30,30,10,30));
panel.setLayout(new GridLayout());
frame.add(panel, BorderLayout.CENTER);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setTitle("Title");
frame.pack();
frame.setSize(854,560);
frame.setVisible(true);
JLabel title = new JLabel();
title.setText("Title");
//title.setSize();
title.setVisible(true);
panel.add(title); //<---- this one line will diaplay label in GUI

Trying to add ScrollPane in Jpanel with null layout inside BorderLayout

I am trying to add a scrollbar in jpanel with null layout.
I want to create a form. This should should display few buttons at the bottom at all times.Any content inside form should maintain it's size and ratio even if the parent container is resized.
Here is what I've come with. I have a panel with borderlayout and added buttons at the south of border. Then created another jpanel to contain form that is added at the center of parent jpanel. Since I want form to maintain it's ratio I went with null layout for inner panel. But I want it to display scrollbar when content is not fully visible. enter image description here
Now adding inner jpanel into scrollpane and adding scrollpanel into parent panel (.add(scrollpane, BorderLayout.CENTER)) doesn't give desired format.
Is there any thing that I can do to get desired format?
Here is code Sample:
public static void main(String[] args) {
JFrame jFrame = new JFrame();
jFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
jFrame.setSize(new Dimension(1000, 700));
Container c = jFrame.getContentPane();
c.setLayout(new BorderLayout());
bottomPanel(c);
centerPanel(c); //scrollbar should go in this panel
jFrame.setVisible(true);
}
private static void centerPanel(Container c) {
JPanel centerPanel = new JPanel();
centerPanel.setLayout(null);
JButton button = new JButton("This jObject should not resize when window resizes and also should maintain relative position.");
button.setBounds(new Rectangle(10, 10, 600, 50));
JButton button1 = new JButton("Just like it works in this code. Just Add ScrollPane to centerPanel That is in green backround");
button1.setBounds(new Rectangle(10, 70, 600, 50));
JButton button2 = new JButton("For clearity");
button2.setBounds(new Rectangle(10, 130, 600, 50));
centerPanel.add(button);
centerPanel.add(button1);
centerPanel.add(button2);
centerPanel.setBackground(Color.GREEN);
c.add(centerPanel, BorderLayout.CENTER);
}
private static void bottomPanel(Container c) {
JPanel bottomPanel = new JPanel(); //Buttons that goes at the bottom of screen will go in here
JPanel bottomInnerPanel = new JPanel();
bottomInnerPanel.setLayout(new BorderLayout());
bottomPanel.setLayout(new GridLayout());
bottomInnerPanel.add(new JButton("Add"), BorderLayout.WEST);
bottomInnerPanel.add(new JButton("Search"), BorderLayout.EAST);
bottomPanel.add(bottomInnerPanel);
bottomPanel.setBorder(BorderFactory.createLineBorder(Color.BLACK));
c.add(bottomPanel, BorderLayout.SOUTH);
}

Why does the JScrollPane not appear around my JTextField?

I'm pretty new to GUI but I'm trying to create a simple version of notepad and would like scroll bars to appear around the text area. However, I'm not sure why it isn't appearing.
public class NutPad extends JPanel {
public static void main(String[] args) {
JFrame frame = new JFrame("NutPad");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.getContentPane().add(new NutPad(), BorderLayout.CENTER);
frame.setSize(500,300);
frame.setVisible(true);
}
private NutPad() {
add(makeTextAreaPanel());
}
private JPanel makeTextAreaPanel() {
JPanel textAreaPanel = new JPanel();
textAreaPanel.setSize(100,100);
JTextArea textArea = new JTextArea(20, 60); //15,43
JScrollPane scrollPane = new JScrollPane(textArea);
textAreaPanel.add(scrollPane,BorderLayout.CENTER);
textAreaPanel.add(textArea);
return textAreaPanel;
}
}
Thanks
If you're going to use the BorderLayout.CENTER constraint, then the container needs to have its layout set to BorderLayout.
Also you don't need textAreaPanel since you can just add the scrollPane straight into your NutPad panel.
private NutPad() {
setLayout(new BorderLayout());
add(makeScrollPane(), BorderLayout.CENTER);
}
private JScrollPane makeScrollPane() {
JTextArea textArea = new JTextArea();
JScrollPane scrollPane = new JScrollPane(textArea);
return scrollPane;
}
Now your text area will fill the frame and the scrollbars will appear when the text takes up more than the available space.
Hope that helps :)

Why doesn't my scrollpane have scrollbars?

For some reason I can't get my scrollpane to be displayed within an applet.
public void init() {
JFrame frame = new JFrame();
JPanel panel = new JPanel();
JScrollPane scrPane = new JScrollPane(panel);
scrPane.setHorizontalScrollBarPolicy(JScrollPane.HORIZONTAL_SCROLLBAR_ALWAYS);
scrPane.setVerticalScrollBarPolicy(JScrollPane.VERTICAL_SCROLLBAR_ALWAYS);
scrPane.setLayout(new ScrollPaneLayout());
frame.getContentPane().add(scrPane);
this.setVisible(true);
}
You never display the JFrame that you create!
This:
frame.getContentPane().add(scrPane):
this.setVisible(true); // this != frame
is not working because you create a JFrame and then ignore it.
You shouldn't have an applet display a JFrame anyway. If you need to show a separate window, consider showing a JDialog. Better still, why not simply put the JScrollPane in the applet itself?
e.g.,
public void init() {
//JFrame frame = new JFrame();
JPanel panel = new JPanel();
JScrollPane scrPane = new JScrollPane(panel);
scrPane.setHorizontalScrollBarPolicy(JScrollPane.HORIZONTAL_SCROLLBAR_ALWAYS);
scrPane.setVerticalScrollBarPolicy(JScrollPane.VERTICAL_SCROLLBAR_ALWAYS);
// scrPane.setLayout(new ScrollPaneLayout());
// frame.getContentPane().add(scrPane);
getContentPane().add(scrPane);
// this.setVisible(true);
}

JScrollPane In JFrame with two panels

I want to add a scroll bar to my JTextArea but it just won't show up. I have read a lot of stuff on forums but all in vain. Any suggestions are highly appreciated.
Thanks in advance. Below is my code.
JPanel pan, pan2;
JTextArea text = new JTextArea();
JTextField fname = new JTextField(18);
JLabel filename = new JLabel("Filename");
JButton view = new JButton("View");
public FileReading() {
setLayout(new BorderLayout());
pan = new JPanel();
pan2 = new JPanel();
JScrollPane scroll = new JScrollPane(text);
//scroll.setBounds(400,400,400,400);
scroll.setVerticalScrollBarPolicy(ScrollPaneConstants.VERTICAL_SCROLLBAR_ALWAYS);
text.setEditable(false);
scroll.setViewportView(text);
pan2.add(scroll);
//scrollpane.setViewportView(text);
pan2.setLayout(new BorderLayout());
//pan2.add(scrollpane);
pan.setLayout(new FlowLayout());
pan.add(filename, FlowLayout.LEFT);
pan.add(fname, FlowLayout.CENTER);
pan.add(view, FlowLayout.RIGHT);
view.addActionListener(this);
fname.addActionListener(this);
pan2.add(text, BorderLayout.CENTER);
pan2.add(pan, BorderLayout.SOUTH);
//BorderLayout.EAST
//add(pan, BorderLayout.SOUTH);
add(pan2);//, BorderLayout.CENTER
setVisible(true);
}
public static void main(String args[]) {
FileReading frame = new FileReading();
frame.setTitle("Enter The Full Path to the File");
frame.setVisible(true);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setBounds(400,400,400,400);
//frame.setSize(400,400);
}
You need to add scroll (JScrollPane) to the pan2 not to the text (JTextArea)
try this
pan2.add(scroll, BorderLayout.CENTER);
in place of pan2.add(text, BorderLayout.CENTER);
EDIT
JTextArea gets added automatically when we add JScrollPane into the panel, as you have added text (JTextArea) inside JScrollPane
here -> JScrollPane scroll = new JScrollPane(text);
Can try this
add(scroll);//, BorderLayout.CENTER
add(pan, BorderLayout.SOUTH);
instead of
add(pan2);//, BorderLayout.CENTER
This way we are directly adding the scrollpane to main frame and putting other things below

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