public class Create_JFrame extends JFrame{
public Create_JFrame(){
//Create a Frame
JFrame Frame = new JFrame("Bla-Bla");
JPanel Panel_1 = new JPanel();
JPanel Panel_2 = new JPanel();
JButton Option_1 = new JButton("Option-1");
//Layout management for Panels
Frame.getContentPane().add(BorderLayout.WEST, Panel_1);
//Add button to Panel
Panel_1.add(Option_1);
//Registering Listeners for all my buttons
Option_1.addActionListener(new ListenerForRadioButton(Panel_2));
//Make the frame visible
Frame.setSize(500, 300);
Frame.setVisible(true);
}//end of Main
}//end of Class
public class ListenerForRadioButton implements ActionListener{
JPanel Panel_2;
JButton browse = new JButton("Browse");
//Constructor, will be used to get parameters from Parent methods
public ListenerForRadioButton(JPanel Panel){
Panel_2 = Panel;
}
//Overridden function, will be used for calling my 'core code' when user clicks on button.
public void actionPerformed(ActionEvent event){
Panel_2.add(browse);
System.out.println("My listener is called");
}//end of method
}//end of class
Problem Statement:
I have 2 JPanel components in a a given JFrame. Panel_1 is having a Option_1 JButton. When user clicks on that I am expecting my code to add a JButton 'browse' in Panel_2 at runtime.
Runtime Output:
System is not adding any JButton in Panel_2. However, I see my debug message in output, indicating that system was successful in identifying user's click action on 'option-1'.
Question:
Why is JPanel not adding any component at Runtime?
Panel_2.add(browse);
Panel_2.revalidate();
adding a 'revalidate' will solve the problem.
There are some reasons. but:
usually it's because of using unsuitable LayoutManager.
sometimes it's because of adding the JPanel to it's root component in worng way. which any operation (add, remove,...) works but is not visible.
you must refresh the view when you make some changes on it, like adding or removing components to/from it.
try to use Panel_2.revalidate() to refresh.
if it doesn't work properly use it with Panel_2.repaint() method.
see Java Swing revalidate() vs repaint()
see Difference between validate(), revalidate() and invalidate() in Swing GUI
using setSize twice for your jframe is another way.
Frame.setSize(498, 300); then Frame.setSize(500, 300);
Related
I've tried a lot of different ways, but I will explain two and what was happening (no error messages or anything, just not showing up like they should or just not showing up at all):
First, I created a JPanel called layout and set it as a BorderLayout. Here is a snippet of how I made it look:
JPanel layout = new JPanel();
layout.setLayout(new BorderLayout());
colorChoice = new JLabel("Choose your color: ");
layout.add(colorChoice, BorderLayout.NORTH);
colorBox = new JComboBox(fireworkColors);
colorBox.addActionListener(this);
layout.add(colorBox, BorderLayout.NORTH);
In this scenario what happens is they don't show up at all. It just continues on with whatever else I added.
So then I just tried setLayout(new BorderLayout()); Here is a snippet of that code:
setLayout(new BorderLayout());
colorChoice = new JLabel("Choose your color: ");
add(colorChoice, BorderLayout.NORTH);
colorBox = new JComboBox(fireworkColors);
colorBox.addActionListener(this);
add(colorBox, BorderLayout.NORTH);
In this scenario they are added, however, the width takes up the entire width of the frame and the textfield (not shown in the snippet) takes up basically everything else.
Here is what I have tried:
setPreferredSize() & setSize()
Is there something else that I am missing? Thank you.
I also should note that this is a separate class and there is no main in this class. I only say this because I've extended JPanel instead of JFrame. I've seen some people extend JFrame and use JFrame, but I haven't tried it yet.
You created a JPanel, but didn't add it to any container. It won't be visible until it is added to something (a JFrame, or another panel that is in a frame somewhere up the hierarhcy)
You added two components to the same position in the BorderLayout. The last one added is the one that will occupy that position.
Update:
You do not need to extend JFrame. I never do, instead I always extend JPanel. This makes my custom components more flexible: they can be added in another panel, or they can be added to a frame.
So, to demonstrate the problem I will make an entire, small, program:
public class BadGui
{
public static void main(String[] argv)
{
final JFrame frame = new JFrame("Hello World");
final JPanel panel = new JPanel();
panel.add(new JLabel("Hello"), BorderLayout.NORTH);
panel.add(new JLabel("World"), BorderLayout.SOUTH);
frame.setVisible(true);
}
}
In this program I created a panel, but did not add it to anything so it never becomes visible.
In the next program I will fix it by adding the panel to the frame.
public class FixedGui
{
public static void main(String[] argv)
{
final JFrame frame = new JFrame("Hello World");
final JPanel panel = new JPanel();
panel.add(new JLabel("Hello"), BorderLayout.NORTH);
panel.add(new JLabel("World"), BorderLayout.SOUTH);
frame.getContentPane().add(panel);
frame.setVisible(true);
}
}
Note that in both of these, when I added something to the panel, I chose different layout parameters (one label I put in 'North' and the other in 'South').
Here is an example of a JPanel with a BorderLayout that adds a JPanel with a button and label to the "North"
public class Frames extends JFrame
{
public Frames()
{
JPanel homePanel = new JPanel(new BorderLayout());
JPanel northContainerPanel = new JPanel(new FlowLayout());
JButton yourBtn = new JButton("I Do Nothing");
JLabel yourLabel = new JLabel("I Say Stuff");
homePanel.add(northContainerPanel, BorderLayout.NORTH);
northContainerPanel.add(yourBtn);
northContainerPanel.add(yourLabel);
add(homePanel);
setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
setLocationRelativeTo(null);
setExtendedState(JFrame.MAXIMIZED_BOTH);
setTitle("Cool Stuff");
pack();
setVisible(true);
}
public static void main(String[] args)
{
SwingUtilities.invokeLater(Frames::new);
}
}
The below suggestion is assuming that your extending JFrame.
Testing
First of all, without seeing everything, theres always a numerous amount of things you can try.
First off, after you load everything, try adding this in (Again, assuming your extending JFrame:
revalidate();
repaint();
I add this into my own Swing projects all the time, as it refreshes and checks to see that everything is on the frame.
If that doesn't work, make sure that all your JComponent's are added to your JPanel, and ONLY your JPanel is on your JFrame. Your JFrame cannot sort everything out; the JPanel does that.
JPanel window = new JPanel();
JButton button = new JButton("Press me");
add(window);
window.add(button); // Notice how it's the JPanel that holds my components.
One thing though, you still add your JMenu's and what-not through your JFrame, not your JPanel.
I am trying to open a GUI from my main GUI by pressing a button. When the button is pressed, this is executed:
WorkloadFactor wf = new WorkloadFactor();
wf.setVisible(true);
This doesn't open the WorkloadFactor GUI. I am confused by this because I have other GUIs that open this way without issue.
WorkloadFactor class works fine when I run it by itself but won't open when it is called by my main GUI. Below is my class without imports and stuff:
public class WorkloadFactor extends JPanel {
public WorkloadFactor() {
setLayout(new BorderLayout());
JTabbedPane tabbedPane = new JTabbedPane();
String[] tabnames = { "Zero", "One", "Two", "Three", "Four" };
for (int i = 0; i < tabnames.length; i++) {
tabbedPane.addTab(tabnames[i], createPane(tabnames[i]));
}
tabbedPane.setSelectedIndex(0);
JButton submit = new JButton("Submit All");
submit.setForeground(Color.RED);
add(tabbedPane, BorderLayout.CENTER);
add(submit, BorderLayout.SOUTH);
}
public JPanel createPane(final String t) {
JPanel contentPane = new JPanel();
contentPane.setBorder(new EmptyBorder(5, 5, 5, 5));
//setContentPane(contentPane); I think this might be it?
contentPane.setLayout(null);
setBounds(100, 100, 531, 347);
//***** all the components I am including then add them like so
//******contentPane.add(checkbox1);
//****** contentpane.add(label1);
return contentPane;
}
public static void main(String[] args) {
JFrame frame = new JFrame("Set Workload Factor Information");
frame.getContentPane().add(new WorkloadFactor());
frame.setBounds(100, 100, 531, 347);
frame.setVisible(true);
frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
}
}
I have tried arranging things in so many ways, putting everything in the constructor and other changes but can't seem to find a reason why instantiating this WorkloadFactor class elsewhere and setting it visible won't work.
Does it have something to do with setContentPane(contentPane) vs contentPane.add(xxxx) and returning it?
Thank you for reading!
WorkloadFactor wf = new WorkloadFactor();
wf.setVisible(true);
To be blunt, this won't display anything. Please understand that WorkloadFactor extends JPanel and like all non-top level components must be placed into a container that is ultimately held by a top-level window in order to be displayed. Look at how you display it in your main method -- you first put it into a JFrame, and then display that JFrame. You must do the same thing if you want to display it on button press -- you need to put it into a JPanel or other container that is held by a JFrame or JDialog, or JOptionPane.
Make sure that you have properly registered the button on your main GUI which opens WorkLoadFactor GUI to an action listener.
Since you have not included code from your main GUI I can't confirm this is the issue. However it is a commonly overlooked issue.
Heres some suggestions from the Java documentation tutorials:
"Problem: I'm trying to handle certain events from a component, but the component isn't generating the events it should.
First, make sure you registered the right kind of listener to detect the events. See whether another kind of listener might detect the kind of events you need.
Make sure you registered the listener on the right object.
Did you implement the event handler correctly? For example, if you extended an adapter class, then make sure you used the right method signature. Make sure each event-handling method is public void, that the name spelled right and that the argument is of the right type."
source: Solving Common Event-Handling Problems
Make a JFrame and add a JButton in it than add action listener in button and add this code in it like this:
This code makes a frame with a button and when button is pressed new window is opened.
public class Example extends JFrame {
public Example() {
super("Title");
setLayout(new FlowLayout());
JButton b = new JButton("Open new Frame");
b.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent arg0) {
newWindow nw = new newWindow();
}
});
add(b);
}
}
newWindow Code:
public class newWindow extends JFrame {
newWindow() {
super("title");
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setSize(400,400);
setVisible(true);
}
}
I'm writing a simple java game and I'm facing this problem:
My different layouts are in different JPanels (1 JPanel for the welcoming page, where I have to press 'start game' and another one with the actuall functionallity)
I start the game from a JFrame
import javax.swing.JFrame;
public class RType extends JFrame {
public RType() {
add(new Welcome());//first panel
add(new Board());//panel with the game
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setSize(100, 100);
setResizable(false);
setVisible(true);
}
public static void main(String[] args) {
new RType();
}
}
obviuosly, this launches the second panel right after the first, and I cant see the first one.
I've tried some stuff, trying to invoke the second panel in the main method, when the first panel is clicked that way:
RType rt=new RType();
rt.add(new Board()); //in this case add(new Board()); is removed from constructor
but it's doing nothing.
how can I solve it?
As #nachokk has said, you should be using a CardLayout instead. It lets you do things like tabs in a browser, but you don't need to make the tabs visible for your game if you don't want to. You make your welcome "card" visible at first, then when the user clicks you switch to the Board "card".
I don't recommend to add directly to the JFrame components, instead use another container as JPanel . JFrame default layout is BorderLayout, when you add in the way you are adding it always put in the center.
Make something like this:
JFrame frame = new JFrame();
JPanel mainPanel = new JPanel();
mainPanel.setLayout(new CardLayout());
mainPanel.add(new Welcome(), "Welcome");
mainPanel.add(new Board(),"Board");
frame.add(mainPanel);
Here is a tutorial How to use CardLayout
on first panel of welcome add a button, and apply actionperformed like
JButton myButton = new JButton("Add Component ");
myButton.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
frame.remove(welcome);
frame.add(Board, BorderLayout.CENTER);
frame.revalidate();
frame.repaint();
}
});
By default, both panels will fill up the entire Frame's area. To fix this, you will need to use another layout, such as a GridLayout to structure the areas in which the panels will take up the Frame's area.
You can also go with no layout to hard code the pixel values of where you want the panels to fit in your frame.
EDIT: Based on what you're looking to do, the CardLayout is probably what you'll want to use for your Frame's layout.
I need to write a simple tennis game.
To move between different windows(panel with main menu, panel with game, panel with settings) I decided to use inner classes extends JPanel and replace it when some events like start new game occurs.
but the problem is - it doesn't see my inner class. I mean I add it to JFrame
mainframe.add(new MainMenuPanel());
but there is nothing on the screen when I run program. What's the problem?
import java.awt.*;
import javax.swing.*;
import java.awt.event.*;
public class MainFrame{
JFrame mainframe;
public static void main(String[] args){
new MainFrame();
}
public MainFrame() {
mainframe = new JFrame();
mainframe.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
mainframe.setSize(300, 400);
mainframe.setTitle("X-Tennis v0.1");
mainframe.add(new MainMenuPanel());
mainframe.getContentPane().setLayout(new GridLayout());
mainframe.getContentPane().setBackground(Color.WHITE);
mainframe.setVisible(true);
}
public class MainMenuPanel extends JPanel {
JPanel mainmenupanel;
JLabel label1;
JButton btnNewGame,btnJoinGame;
ImageIcon iconNewGame,iconJoinGame;
public MainMenuPanel(){
mainmenupanel = new JPanel();
label1 = new JLabel("X-TENNIS");
label1.setFont(new Font("Comic Sans MS",Font.ITALIC,20));
label1.setForeground(Color.BLUE);
btnNewGame = new JButton("New Game", iconNewGame);
btnNewGame.setFocusPainted(false);
btnNewGame.addActionListener(
new ActionListener() {
public void actionPerformed(ActionEvent e){
JOptionPane.showMessageDialog(mainframe, "New game");
//delete current panel and add another to mainframe
}
}
);
btnNewGame.setPreferredSize(new Dimension(140,30));
btnJoinGame = new JButton("Join game",iconJoinGame);
mainmenupanel.add(label1);
mainmenupanel.add(btnNewGame);
}
}
}
There is no need for mainmenupanel within the MainMenuPanel class as MainMenuPanel is a JPanel itself
Simple add all the components in MainMenuPanel directly to itself
You create a new JPanel, mainmenupanel, inside MainMenuPanel but never add that to the container itself. You could do
add(mainmenupanel);
If you intend for this JPanel to occupy the full area of the parent, then you can simply add your components directly to your instance of MainMenuPanel as indicated by #Mad
First you should add your component to the ContentPane. In Swing, all the non-menu components displayed by the JFrame should be in the ContentPane.
mainframe.getContentPane().add(new MainMenuPanel());
Edit: I was wrong about the content pane, see #MadProgrammer comment.
Then you have to add the JPanel that you create in MainMenuPanel to the MainMenuPanel instance itself.
add(mainmenupanel);
But you should probably get rid of that intermediary container itself and add your labels to the MainMenuPanel instance itself:
add(label1);
add(btnNewGame);
mainmenupanel.add(label1);
mainmenupanel.add(btnNewGame);
try this :
super.add(label1);
super.add(btnNewGame);
I'm trying to open a window that has both an image and buttons in it. But I can't seem to figure out how to add the button. The image displays great and the menu works fine, but no matter where I add the button (into the JLabel, JPanel, or JFrame), it doesn't ever show...
Main:
public static void main(String[] args) {
GUI myGUI = new GUI();
myGUI.show();
}
GUI class: openImage is called when using the menu. The image then displays, but no button.
private JFrame myFrame;
private JPanel myPanel;
private JLabel myLabel;
public GUI()
{
myFrame = new JFrame();
initializePanel();
}
public void show()
{
myFrame.setSize(600,600);
myFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
myFrame.addMouseListener(this);
setupMenu(myFrame);
myFrame.setVisible(true);
}
private void initializePanel()
{
myPanel = new JPanel();
myPanel.setPreferredSize(new Dimension(500,500));
//myPanel.setLayout(new BorderLayout());
}
private void openImage(String fileName)
{
try {
myImage = ImageIO.read(new File(fileName));
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
myLabel = getJLabel();
JButton button = new JButton("ButtonClick");
button.addActionListener(this);
myFrame.setContentPane(myLabel);
myPanel.add(button);
myFrame.getContentPane().add(myPanel);
myFrame.pack();
myFrame.setSize(600,600);
}
private void setupMenu(JFrame window) {
JMenuBar menubar = new JMenuBar();
JMenu file = new JMenu("File");
JMenuItem open = new JMenuItem("Open");
open.addActionListener(this);
file.add(open);
menubar.add(file);
window.setJMenuBar(menubar);
}
Your main issue is your setting the contentPane to be a JLabel -- don't do this! The contentPane needs to be opaque, needs to be built to be easily used as a Container and in your case, really should be a JPanel. JLabel I believe uses a null layout so it's no surprise that your code shows no button. If you want to show a background image, make have myPanel constructed from an anonymous class that extends JPanel, override the paintComponent method in this class (calling super.paintComonent first in the method), and draw the image in this method. Then you can add components to the contentPane which will now use a FlowLayout (the default for a JPanel) and it will be opaque by default.
Also, if your goal is to swap items displayed in your GUI, use a CardLayout to do the swapping for you as this layout makes swapping components a breeze.
really don't know, depends of method(s) how you are added picture to the JLabel, JPanel, or JFrame, but maybe for simle Container that contains a few, only one-two JComponents is there crazy idea, without side effects, with idea to display picture and to add there JButton:
JLabel is very similair JComponent to the JPanel, and is by default translucent and very simple implements Icon/ImageIcon, then you'll only to call myLabel.setIcon(myPicture)
to the all of JComponents you are/could be able to add another JComponent by using some of LayoutManager (Box, Flow, GridBagLayout)
You tried to set the label as the content pane and then tried to add the panel to that image which doesn't make sanse at all.
Change it so you add the label to the panel and have the panel as content pane:
Like this:
You have this line which is the problem. It doesn't make much sense:
myFrame.setContentPane(myLabel);
Try instead:
myFrame.getContentPane().add(myLabel);