I have designed a window using Netbean's visual editor. Now, I have a JTextField, which I want to add using a Scroll bar. How can I do that?
You should not add Scollbar to a TextField.TextField is meant for inputting small entries from the user like name,age,roll number,etc.The best component to input large sized texts ,like comments, from user is JTextArea.So You must add JTextArea instead of JTextField.
After adding JTextArea to the JFrame,you can write few lines of code:-
JScrollPane jsc=new JScrollPane();
jsc.add(jta);
where 'jta' is the name of your JTextArea which your Netbeans have generated for you.
(Now ,when you add text greater than the limit size of text Area ,the scrollbars will appear.
If you want the scrollbars appear permanently,then,the JScrollPane has two properties: horizontalScrollBarPolicy and verticalScrollBarPolicy. Set this two properties to ALWAYS and you will see the Scroll bars always irrespective the size of text in JTextArea.)
Here is the complete code to demonstrate you what you can do:-
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.event.*;
class TextAreaDemo
{
JTextArea jta;
TextAreaDemo()
{
JFrame jfrm=new JFrame("Text Area");
jfrm.setSize(200,300);
jfrm.getContentPane().setLayout(new FlowLayout());
jfrm.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
jta=new JTextArea("Type Here");
//You can use this line to wrap that text when it extends on right side.
//jtxt.setLineWrap(true);
JScrollPane jscrp=new JScrollPane(jta);
jscrp.setPreferredSize(new Dimension(180,100));
jscrp.setVerticalScrollBarPolicy(JScrollPane.VERTICAL_SCROLLBAR_ALWAYS);
jfrm.add(jscrp);
jfrm.setVisible(true);
}
public static void main(String args[])
{
SwingUtilities.invokeLater(new Runnable(){public void run(){new TextAreaDemo();}});
}
}
Use JTextArea and put this into a JScrollPane. If you are using the visual editor it will be done by default (dropping the TextArea into your Window). The JScrollPane has two properties: horizontalScrollBarPolicy and verticalScrollBarPolicy. Set this two properties to ALWAYS and you will see the Scroll bars.
Related
How do I make a JLabel text vertically and horizontally aligned to the center?
I have to make use of setHorizontalTextPosition and setVerticalTextPosition. Can this be achieved by using these 2?
I have tried but the text remains at the top itself.
import java.awt.FlowLayout;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.SwingConstants;
public class label extends JFrame
{
private JLabel label;
public label() //constructor
{
super("Simple GUI");
setLayout(new FlowLayout());
label=new JLabel("Centered JLabel");
label.setHorizontalTextPosition(SwingConstants.CENTER);
label.setVerticalTextPosition(SwingConstants.CENTER);
add(label);
}
}
I have tried but the text remains at the top itself.
You have two problems:
Andrew addressed the first problem. You are using the wrong method.
Next you are using the wrong layout. The FlowLayout only display components on a single line so the component will always be at the top. Don't change the layout manager. The default layout manager for a JFrame is the BorderLayout. When you add a component to the CENTER (which is the default when you don't specify a constraint), the component will be sized to fill the entire frame. Then the "alignment" properties will control the position of the text within the size allocated to the label.
Or a different option is to use a GridBagLayout. Then you don't need to play with alignment options of the component:
setLayout( new GridBagLayout() );
add(label, new GridBagConstraints());
Try both options as both may be effective in different situations.
Read the Swing tutorial on Layout Managers to better understand how each layout manager works.
I'm very sorry to don't know why the setHorizontalTextPosition method and the setVerticalTextPosition method doesn't work.
But, I'll let you know that there're several ways to sort the text in the label by inserting parameters an alignment with String when we create the label.
First of all, camickr's answer is the best answer, Because Swing was designed to be used with layout managers!!
Please remember that the most recommended method is to apply GridBagLayout() to the Layout of JFrame by camickr.
This answer is intended to inform you that
This method is also possible, but not recommended in the normal case
Using this method is not recommended because changing the size of the frame
keeps the components in place, but it could give you a little help
when it is indicated that the size and location of components in the
container are used in a way that can be used in special cases, such as
when they need to be fixed without external impact.
To get a better idea of the problem, I'll simply change the code that you uploaded to me so that it can be executed.
import java.awt.FlowLayout;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.SwingConstants;
import java.awt.Color;
public class StackOver extends JFrame
{
private JLabel label;
public StackOver() //constructor
{
super("Simple GUI");
setLayout(null);
setSize(500,300);
label=new JLabel("Centered JLabel", JLabel.CENTER);
/*
label.setHorizontalTextPosition(SwingConstants.CENTER);
label.setVerticalTextPosition(SwingConstants.CENTER);*/
add(label);
setDefaultCloseOperation(EXIT_ON_CLOSE);
setVisible(true);
}
public static void main(String[] args) {
// TODO Auto-generated method stub
new StackOver();
}
}
Hmm, let's put some color in JLabel's background to find out more.
label.setOpaque(true); //Transparency Settings
label.setBackground(Color.pink); //Specify background color
//to use 'Color' class, We must import java.awt.Color;
the JFrame setting was set to FlowLayout()which makes the location and size of components were fixed, so we couldn't see it working!
So now we're going to go through the next two processes.
1) Changing JFrame's layout to null to use Absolute Layout ("not recommended, just a case")
2) Changing the size and location of the JLabel
after the progress we can see that the text alignment works!
1) Changing JFrame's Layout
the following link: Layout Manager shows that there are so many Layouts outside of FlowLayout.
Swing is designed to use the layout manager, so of course you should use one of the Layout above link.
But, to use an interesting way that fix the location and size of components absolutely We will switch to setLayout(null);!
2) Changing the size and location of the JLabel
We can directly change the size and position of JLabel with setBounds(int startX, int startY, int Width, int Height) method!
import java.awt.FlowLayout;
import java.awt.Rectangle;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.SwingConstants;
import java.awt.Color;
public class StackOver extends JFrame
{
private JLabel label;
public StackOver() //constructor
{
super("Simple GUI");
setLayout(null);
setSize(500,300);
label=new JLabel("Centered JLabel", JLabel.CENTER);
// Since it also sets the size of the JLabel,
//let's use the constructor to set the alignment of the text inside the JLabel.
label.setOpaque(true); //Transparency Settings
label.setBackground(Color.pink); //Specify background color
//to use 'Color' class, We must import java.awt.Color;
Rectangle r = this.getBounds(); //to get Frame Size
label.setBounds(r.x+100, r.y+100, r.width-200, r.height-200);
/*
label.setHorizontalTextPosition(SwingConstants.CENTER);
label.setVerticalTextPosition(SwingConstants.CENTER);*/
add(label);
setDefaultCloseOperation(EXIT_ON_CLOSE);
setVisible(true);
}
public static void main(String[] args) {
// TODO Auto-generated method stub
new StackOver();
}
}
Now we can see the text of JLabel in the middle as intended!
This method can directly fix the size and location of all components (ex buttons), but the location and size of the components are fixed even if the window size of the JFrame changes after the program runs.
so If you really want set components Absolutely by this way, you rather to set JFrame Resizable false by adding below code on JFrame's code
this.setResizable(false);
I hope the answer was helpful to you and have a peaceful day!
I am almost certain this question was asked before here: Java Swing: How to change GUI dynamically , but I seem to just have some fundamental misunderstanding in how it works.
import javax.swing.*;
import javax.swing.event.*;
import java.awt.*;
import java.awt.event.*;
public class JTest extends JFrame
{
public static void main(String[] args)
{
JTest t = new JTest();
}
Container pane;
public JTest()
{
setSize(500,500);
setTitle("JTest");
setDefaultCloseOperation(EXIT_ON_CLOSE);
pane = getContentPane();
pane.setLayout(new GridLayout(1,2));
JButton old = new JButton("old");
old.addActionListener(new OldButton());
pane.add(old);
JScrollPane scroll = new JScrollPane(new JTextArea(50,20));
pane.add(scroll);
setVisible(true);
}
private class OldButton implements ActionListener
{
public void actionPerformed(ActionEvent e)
{
pane.setLayout(new GridLayout(1,2));
JButton old = new JButton("new");
old.addActionListener(new NewButton());
pane.add(old);
JScrollPane scroll = new JScrollPane(new JTextArea(50,20));
pane.add(scroll);
pane.validate();
}
}
private class NewButton implements ActionListener
{
public void actionPerformed(ActionEvent e)
{
pane.setLayout(new GridLayout(1,2));
JButton old = new JButton("old");
old.addActionListener(new OldButton());
pane.add(old);
JScrollPane scroll = new JScrollPane(new JTextArea(50,20));
pane.add(scroll);
pane.validate();
}
}
}
This code should replace the preexisting layout with a new one anytime the button in the corner is pressed, but instead, it just adds the new layout to the frame. Can someone tell me what I'm doing wrong?
EDIT:
Adding some information. A picture for reference:
I'm making a set of components like this inside the scroll pane. whenever I press the "Make new field" button, I want it to add a "field" (the name of the field followed by a textarea or some such) to the set in that scrollpane. This means changing the layout of the area inside the scrollpane to include the new field.
OK -- so it looks like what you want to do (and please correct me if I'm wrong) is to add a new component to a JPanel that is displayed within a JScrollPane. If so, then you do not want to change or swap layouts, and you certainly don't want to keep adding new JScrollPanes. Instead consider doing:
Create one JScrollPane and add to your GUI. Don't re-add this as you'll only need one.
add a JPanel to the JScrollPane's viewport that uses a layout that allows multiple components to be easily added to it. Perhaps a GridLayout or a BoxLayout, depending on what you need.
Also consider not adding the above JPanel directly to the viewport but rather adding it to another JPanel, one that uses BorderLayout, adding the first JPanel to the BorderLayout-using JPanel's BorderLayout.PAGE_START position, and then add this to the JScrollPane's viewport. This way the first JPanel won't stretch to fill the viewport initially.
Then in your button's ActionListener, add your components to the first JPanel by calling .add(...) on it, and then call revalidate() and repaint() on that first JPanel to layout the newly added components and repaint the JPanel and its contents.
Ok, so it turns out this wasn't a layout problem at all. I had failed to realize that setting a new layout doesn't cause the previous layout's components to disappear, you have to remove them before adding the new components. That's why I was getting duplication.
Thanks for pointing me in the right direction, though.
I'm new to Java programming and I'd like to know how to mess around with buttons, I have created a "Home Screen" and some buttons as well as text, however it's not as advanced as I'd like it to be, I want to know how to create things like image effects, so let's say I hover over a button, I want it to display a glowing animation behind it, or since I don't have that animation, if there's no easy way to create it, just displaying an image behind it is alright, also I don't have anything happening when pressing the button bcs IDK how to do that yet so if you could help with that it'd be awesome!
Here's the code I currently have:
package Menu;
import java.awt.FlowLayout;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import javax.imageio.ImageIO;
import javax.swing.ImageIcon;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JTextField;
public class BackgroundPanel extends JFrame {
private BufferedImage image;
public BackgroundPanel() {
ImageIcon icon = new ImageIcon("image_path.png");
JButton btn = new JButton(icon);
btn.setOpaque(false);
btn.setContentAreaFilled(false);
btn.setBorderPainted(false);
btn.setFocusPainted(false);
try {
image = ImageIO.read(new File("image_path.jpg"));
// Set your Image Here.
this.setContentPane(new JLabel(new ImageIcon(image)));
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
JPanel panel = new JPanel();
panel.add(new JLabel("Username:"));
panel.add(new JTextField("",20));
panel.add(new JLabel("Password:"));
panel.add(new JTextField("",20));
panel.add(btn);
//Adding components to Panel and JFrame
this.add(panel);
// JFrame Properties
this.setSize(1280,720);
this.setLayout(new FlowLayout());
this.setResizable(true);
this.setLocationRelativeTo(null);
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
this.setTitle("Panel");
this.setVisible(true);
}
public static void main(String[] args) {
new BackgroundPanel();
}
}
[...] also I don't have anything happening when pressing the button bcs IDK how to do that yet so if you could help with that it'd be awesome [...]
You need to add an ActionListener to your button. There are various other ways to detect if the button was pressed, but this one is the (in my opinion) easiest. This is how you do it:
btn.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent event) {
// code you write in here will be executed if the button was pressed
}
});
[...] let's say I hover over a button, I want it to display a glowing animation behind it, or since I don't have that animation, if there's no easy way to create it, just displaying an image behind it is alright [...]
For this, you'll have to deal with JLayeredPanes and MouseListeners. Here is an example that I created "on the run"; the layouting is very dirty and has to be improved. Anyhow, you'll notice that once you hover over the button, a black-bordered box containing LA- -LL! will appear behind the button. That's a JLabel and you can use it to display images and such by using the JLabel.setIcon method.
let's say I hover over a button, I want it to display a glowing animation behind it, or since I don't have that animation, if there's no easy way to create it, just displaying an image behind it is alright
This is not that easy, it requires jumping through a whole bunch of hoops, especially when the button isn't rectangle.
A while I ago a did a prototype of a "validation highlighter" which highlighted invalid fields, it makes use of JXLayer library, but which should be convertible to use the included JLayer library on the core libraries
See How can I change the highlight color of a focused JComboBox for more details
The other possibility we'd be to create a custom JPanel and override its paintComponent method and paint your effect there. You would place your button it and with a combination of a a layout manager and borders you should be able to get the button positioned where you need it.
The problem with this, is it will effect the over layout of your form, as the effect will be considered while the primary form is laid out
I really don't have anything happening when pressing the button bcs IDK how to do that yet so if you could help with that it'd be awesome
I suggest you have a look at How to use buttons and How to write ActionListeners
in this code when the new button is clicked, the Jinternalframe goes behind the button, even if i add anything else like, jlabel, jtextfield, etc, the internalframe opens behind everything. i tried the tofront() and movetofront() functions, but it doesnt seem to work. plz help, thanks.
code:
import java.awt.BorderLayout;
import java.awt.CardLayout;
import javax.swing.JFrame;
import javax.swing.JButton;
import java.awt.Color;
import java.awt.FlowLayout;
import java.awt.GridBagLayout;
import java.awt.GridLayout;
import javax.swing.*;
import java.awt.event.ActionListener;
import java.awt.event.ActionEvent;
public class Messages2 extends JFrame {
JFrame frame;
JButton button1;
public static void main(String[] args) {
Messages2 window = new Messages2();
window.frame.setVisible(true);
}
public Messages2() {
frame = new JFrame();
frame.getContentPane().setBackground(Color.WHITE);
frame.setBounds(100, 100, 220, 220);
frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
//frame.getContentPane().setLayout(new FlowLayout());
JButton btnNew = new JButton("New Message");
btnNew.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent arg0) {
JDesktopPane desktopPane = new JDesktopPane();
JInternalFrame intFrame = new JInternalFrame(
"JInternalFrame demo");
intFrame.setMaximizable(true);
intFrame.setIconifiable(true);
intFrame.setResizable(true);
intFrame.setClosable(true);
intFrame.setDefaultCloseOperation(JInternalFrame.DISPOSE_ON_CLOSE);
intFrame.setSize(320, 240);
// intFrame.pack();
intFrame.setVisible(true);
desktopPane.add(intFrame);
frame.add(desktopPane, BorderLayout.CENTER);
}
});
btnNew.setBounds(1, 35, 145, 31);
frame.getContentPane().add(btnNew);
}
}
when the new button is clicked, the Jinternalframe goes behind the button, even if i add anything else like, jlabel, jtextfield, etc,
Based on the code you posted in you last question (before you deleted it), you are attempting to add all your components directly to the frame. Swing paints components in the reverse order that a component is added. So since the internal frame is added last it is painted first and then all the other components are painted over top of it.
This is not the way you should be working with a JInternalFrame. You need to separate the JDesktopPane/JInternalFrames from your other components and work with each separately.
Read the section from the Swing tutorial on How to Use Internal Frames for basic information and examples.
the internal frame is added to a JDesktopPane which is added to the frame.
Don't use a null layout for your other components. Swing was designed to be used with layout managers. These components should be added to a panel and then the panel added to the frame.
The panel and the desktop pane must be added to different areas of the frame. For example:
frame.add(panel, BorderLayout.NORTH);
frame.add(desktopPane, BorderLayout.CENTER);
You're not using JInternalFrame correctly. It should only be placed within a JDesktopPane, something you're not doing and that I suggest that you start doing. Please check the appropriate tutorial on this.
Your button and your JInternalFrame now fill the field since you're using the JFrame's default BorderLayout. Suggestion:
First and foremost, explain fully just what exact effect/user experience you're trying to achieve. Are you sure that a JInternalFrame is your best choice here?
Learn about and use the layout managers to their best advantage.
If you're going to use a JInternalFrame, then while it's OK to add the JInternalFrame in your ActionListener, you're usually going to want to add the JDesktopPane to the GUI on GUI creation, not in the ActionListener.
I am a beginner into Java and OOPS in general. Am studyin Head First Java to start, and studying GUI and Swing concepts in it.
The below code is just for understanding purposes.
On running the code, The frame window is displayed with Button, and when I expand it I can see Radio Button too.
Issues-
Button works till the window size is not more than the button size . As soon as I increase the window size even slightly more than button's dimensions, then the button is displayed only when cursor is on it.
I am changing window size using mouse.
Also even if I set Frame size to be more than button. say frame.setSize(800,800); then the button covers whole contentPane. and still behaves same way on resizing.
And the button responds to clicking on mouse, irrespective of where I click in the contentPane. It should respond only when i click directly on the button.
Please inform me why it is behaving this way.
And if possible,corrections in code or additions to correct this.
import java.awt.Color;
import javax.swing.*;
import java.awt.event.*;
public class Test1 implements ActionListener {
JFrame frame = new JFrame("Frame");
JButton button = new JButton("Button!");
JRadioButton radio = new JRadioButton("VideoKilledTheRadioStar!",true);
int j=0;
public static void main(String[] args) {
Test1 t = new Test1();
t.method1();
}
public void method1()
{
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
button.setSize(100,100);
button.setBackground(Color.ORANGE);
frame.add(button);
frame.setSize(100,100);
frame.setVisible(true);
button.addActionListener(this);
frame.getContentPane().add(radio);
radio.addActionListener(this);
}
public void actionPerformed(ActionEvent e)
{j++;
button.setText("clicked .. " + j);
if(button.getBackground()==Color.ORANGE)
button.setBackground(Color.BLUE);
else
button.setBackground(Color.ORANGE);
}
}
P.S I did not know which segment of code is important or more relevant to this question, so I have put complete code.
You are trying to add the JButton button and JRadioButton objects in the default layout(BorderLayout) of the JFrame.
Whenevery you add a component to JFrame having BorderLayout the components goes in the Middle Section and BorderLayout center section has tendency to occupy the complete space, so to position elements properly you will need to specify the location as well as set the PreferredSize of the component.
frame.add(radio, BorderLayout.SOUTH);
component.setPreferredSize(Dimension);
You are adding the JButton button and the JRadioButton both in the BorderLayout.CENTER location so only one is being displayed. Components at this location will be sized in the X and Y axis.
The JButton only displays when the cursor is over it due to the fact that it has its own MouseListener used for painting.
Also, the statements
frame.add(myComponent);
and
frame.getContentPane().add(myComponent);
both add the component to the frame's ContentPane & are equivalent but the first is chosen for convenience.
Note that components cannot co-exist in the same position in a BorderLayout. You could place the button at the BorderLayout.SOUTH position (& add directly to the frame):
frame.add(radio, BorderLayout.SOUTH);
BorderLayout disregards any preferred sizes for components so you would have to use a different layout manager such as BoxLayout to maintain a fixed size JButton.
See more about Layout Managers