I am working on a GUI project with Swing in Java and the program is generally working fine. However, under each screen, I have a back button that calls the method of the screen before it and goes through the ArrayList containing all of the elements on the current screen and calls setVisible(false) on them. Upon running the program, the back button works correctly if you click it once but if you go back on the screen, and click it again, it takes two clicks for it to correctly work and then four clicks and then eight clicks and so on. I have no idea what is going on or why it is behaving this way as nothing in my code seems to do it. Also, sometimes, the button correctly returns to the previous screen but then keeps the components on the current screen active as if setVisible(false) was never called. The following code represents the general structure of my project. Is there anything that it is doing that is generating this problem?
import java.awt.Color;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.*;
public class MAIN {
static JFrame frame;
static JPanel panel;
public static void main(String [] args) {
mainScreen();
}
public static void mainScreen() {
JButton newScreen = new JButton("Next Screen");
frame = new JFrame();
panel = new JPanel();
panel.setBounds(0,0,1920,1080);
panel.setBackground(Color.cyan);
newScreen.setBounds(50, 500, 100, 500);
newScreen.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
newScreen.setVisible(false);
JButton returnButton = new JButton("return");
returnButton.setBounds(50, 50, 100, 100);
panel.add(returnButton);
returnButton.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
returnButton.setVisible(false);
mainScreen();
}
});
}
});
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
panel.add(newScreen);
frame.add(panel);
frame.setSize(1920,1080);
frame.setLayout(null);
frame.setVisible(true);
}
}
Related
I'm implementing an "in app" search engine with Swing and I want it to behave exactly like Windows 10's search box.
The search box should:
Open above and to the right of the search button, touching the button's edge.
Have the focus when open.
Close (if open) on a press of the search button.
Close (if open) when pressing with the mouse anywhere out of the search box.
It was perfect if JPopUpMenu could have JDialog as it's child but since it can't I need to implement the behaviors from scratch (or do I?).
This is my first time using Swing and I'm having difficulties implementing everything by myself.
I tried looking for examples online but I couldn't find much helpful information.
Is there a workaround to the fact that JPopUpMenu can't host JDialog?
Are there examples of implementing the behaviors I described?
Thanks
===============================Edit============================
Thanks for the comments so far. I've managed to get the behavior I wanted except one issue.
The following code creates a frame with a button:
public static void main(String[] args){
JFrame mainWindow = new JFrame();
mainWindow.setSize(420,420);
mainWindow.setVisible(true);
JFrame popUp = new JFrame();
popUp.setSize(210, 210);
JButton button = new JButton("button");
mainWindow.add(button);
button.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
if(!button.isSelected()){
button.setSelected(true);
popUp.setVisible(true);
}
else{
button.setSelected(false);
popUp.setVisible(false);
}
}
});
popUp.addWindowFocusListener(new WindowAdapter() {
#Override
public void windowLostFocus(WindowEvent e) {
popUp.setVisible(false);
}
});
}
When I click the button, a pop-up window appears and if I click out of the main window the pop up disappear but then when I want to re-open the pop-up I need to press the button twice.
How can I get the button to operate correctly when the pop-up was closed due to lose of focus?
Your "solution" is very brittle. Try moving the main JFrame before left-clicking on the JButton.
Oracle has a helpful tutorial, Creating a GUI With Swing. Skip the Netbeans section. Study the rest of the tutorial.
I created a main JFrame that pops up a JDialog. I put the close JButton on the JDialog. The JDialog is modal, meaning you cannot access the main JFrame while the JDialog is visible.
You can place the JDialog anywhere you wish on the screen. Normally, you have a JDialog appear in the center of the parent JFrame. That's where users expect a dialog to appear. I placed the JDialog towards the upper left, just to show you how it's done.
Here's the complete runnable code.
import java.awt.BorderLayout;
import java.awt.FlowLayout;
import java.awt.Point;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.BorderFactory;
import javax.swing.JButton;
import javax.swing.JDialog;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;
public class PopupExample {
public static void main(String[] args) {
SwingUtilities.invokeLater(() -> new PopupExample().createAndShowGUI());
}
private JFrame mainWindow;
public void createAndShowGUI() {
mainWindow = new JFrame("Main Window");
mainWindow.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
mainWindow.add(createMainPanel(), BorderLayout.CENTER);
mainWindow.pack();
mainWindow.setLocationByPlatform(true);
mainWindow.setVisible(true);
}
private JPanel createMainPanel() {
JPanel panel = new JPanel(new FlowLayout());
panel.setBorder(BorderFactory.createEmptyBorder(200, 200, 200, 200));
JButton button = new JButton("button");
panel.add(button);
button.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
createAndShowDialog(mainWindow);
}
});
return panel;
}
private void createAndShowDialog(JFrame frame) {
JDialog dialog = new JDialog(frame, "Dialog", true);
dialog.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
dialog.add(createDialogPanel(dialog), BorderLayout.CENTER);
dialog.pack();
// Here's where you set the location of the JDialog relative
// to the main JFrame
Point origin = frame.getLocation();
dialog.setLocation(new Point(origin.x + 30, origin.y + 30));
dialog.setVisible(true);
}
private JPanel createDialogPanel(JDialog dialog) {
JPanel panel = new JPanel(new FlowLayout());
panel.setBorder(BorderFactory.createEmptyBorder(100, 100, 100, 100));
JButton button = new JButton("Close");
panel.add(button);
button.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
dialog.dispose();
}
});
return panel;
}
}
I'm making a program that has a popup menu with two buttons, one of which should close the popup menu, but I have no idea how to do that and googling hasn't gone too well.
I've tried using popup.hide() but then the menu wouldn't come back, despite doing so when I tried just moving the popup. It also required me to put a SuppressWarning in that case and it took a few seconds for it to close at all. Is there any better way of doing it?
I'm not sure what kind of code is relevant, but here's the relevant buttons and their roles in this(I skipped all the creating the GUI parts that didn't seem relevant, everything looks good and I know that the buttons are working):
package test;
import javax.swing.*;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
interface CustomButton {
JButton create();
void react(JPopupMenu popup, JFrame frame);
}
class ErrandsButton implements CustomButton {
private JButton errands = new JButton("Errands");
public JButton create() {
return errands;
}
public void react(JPopupMenu popup, JFrame frame) {
errands.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
popup.show(frame, 120, 65);
}
});
}
}
class Test {
static JFrame frame = new JFrame("List");
static CustomButton errands = new ErrandsButton();
static JButton cancelTask = new JButton("Cancel");
static JPopupMenu popup = new JPopupMenu();
static void cancelTask() {
cancelTask.addActionListener(new ActionListener() {
#SuppressWarnings("deprecation")
public void actionPerformed(ActionEvent e) {
popup.hide();
}
});
}
public static void main(String args[]) {
createInterface();
cancelTask();
errands.react(popup, frame);
}
static void createInterface() {
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setSize(500, 500);
JPanel popup1 = new JPanel();
JPanel button = new JPanel();
popup1.add(cancelTask);
popup.add(popup1);
frame.add(popup);
button.add(errands.create());
frame.getContentPane().add(BorderLayout.CENTER, button);
frame.setVisible(true);
}
}
Use popup.setVisible(true) and popup.setVisible(false).
frame.add(popup); is the problem. Do not add a JPopupMenu to a Container. Instead, use setComponentPopupMenu.
Alternatively, you could do the work yourself by adding a MouseListener whose mousePressed, mouseReleased and mouseClicked methods call isPopupTrigger and show. (It is vital that you do this in all three of those methods—different platforms have different conditions for showing popup menus.)
But really, using setComponentPopupMenu is easier.
Hi I am new to programming and trying to figure things out as I go. Thanks in advance for the help.
I am trying to make a button in one class that when pressed, the other class knows.
Here is the first class that contains the testWindow method that I want to call in my other class.
import javax.swing.*;
import java.awt.event.*;
public class TestWindow {
public static void testWindow() {
JFrame frame = new JFrame("test");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
JLabel text = new JLabel("this is a test!",SwingConstants.CENTER);
text.setBounds(0,30,300,50);
JButton button = new JButton("Start");
button.setBounds(100,100,100,40);
frame.add(text);
frame.add(button);
frame.setSize(300,200);
frame.setLayout(null);
frame.setLocationRelativeTo(null);
frame.setVisible(true);
button.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
//I don't know what to put here
}
});
}
}
And here is the second class where I want to use my testWindow method.
public class MainTest extends TestWindow {
public static void main(String[] arg){
testWindow();
//other stuff that happens when "start" is pressed
}
}
When I run the MainTest class, the testWindow appears as it should. But when the "start" button is pressed, I want to close that frame then do other actions in the main method. How would I go about that?
When I run the MainTest class, the testWindow appears as it should. But when the "start" button is pressed, I want to close that frame then do other actions in the main method. How would I go about that?
You're desiring the functionality of a modal dialog, a window that halts program flow until it has been dealt with. And in this situation you shouldn't be using a JFrame which does not allow for this type of modality, but rather a Swing modal dialog such as a JOptionPane or a JDialog that you create, make modal, and display. Then the GUI program flow halt until the dialog window is no longer visible.
If you do this, all the button's action listener has to do is to close the dialog window that holds it, that's it.
Side note: You're misusing inheritance here, as your MainTest class should most definitely not extend from the TestWindow class. While it may not matter in this simple code, it can and will cause problems in future code.
e.g.,
import javax.swing.*;
import java.awt.BorderLayout;
import java.awt.Dialog.ModalityType;
import java.awt.event.*;
public class TestWindow {
public static void testWindow() {
// JFrame frame = new JFrame("test");
final JDialog frame = new JDialog((JFrame) null, "Test", ModalityType.APPLICATION_MODAL);
frame.setDefaultCloseOperation(JDialog.DISPOSE_ON_CLOSE);
// frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
JLabel text = new JLabel("this is a test!", SwingConstants.CENTER);
// text.setBounds(0, 30, 300, 50);
JButton button = new JButton("Start");
// button.setBounds(100, 100, 100, 40);
button.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
frame.dispose();
}
});
int eb = 15;
JPanel panel = new JPanel(new BorderLayout(eb, eb));
panel.setBorder(BorderFactory.createEmptyBorder(eb, eb, eb, eb));
panel.add(text, BorderLayout.PAGE_START);
panel.add(button, BorderLayout.CENTER);
frame.add(panel);
frame.pack();
// frame.setSize(300, 200);
// frame.setLayout(null);
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
}
and
import javax.swing.SwingUtilities;
public class TestTestWindow {
public static void main(String[] args) {
SwingUtilities.invokeLater(() -> {
TestWindow.testWindow();
System.out.println("Called after test window no longer visible");
});
}
}
I'm learning Java and Swing, but my JButton doesn't work.
import javax.swing.JFrame;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.*;
public class Programma {
public static void main(String[] args) {
// TODO Auto-generated method stub
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
}
catch (Exception e){
e.printStackTrace();
}
JFrame frame = new JFrame("DIG");
JPanel panel = new JPanel();
JButton button = new JButton("Click Me");
frame.setSize(400, 400);
frame.setVisible(true);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
button.setBounds(100, 100, 130, 35);
panel.add(button);
frame.add(panel);
button.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
// TODO Auto-generated method stub
JLabel label = new JLabel("Hello World");
label.setVisible(true);
panel.add(label);
}
});
}
}
The frame and button are visible, nut when I click it, the label doesn't appear. How can I fix this?
Do I write this before the other component like JPanel, JButton, etc., or do I write this at the end of code:
frame.setVisible(true);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
What is the difference ?
By the way, button.setBounds(100, 100, 130, 35) doesn't work, either.
I see some issues in your code:
button.setBounds(100, 100, 130, 35); that line will be ignored and you shouldn't be manually be determining the position of the components. See Null layout is evil and Why is it frowned upon to use a null layout in swing? altough you're not using null layout, there is explained why you shouldn't be manually determining the positions of the components.
You're running everything in your program in the main method, that will be hard to maintain later.
You're calling frame.setVisible(true) before you've added all your elements to it, that will cause you random issues.
You're not running your program on the Event Dispatch Thread (EDT), you can solve this by starting your program with the following code, which places it in the EDT. It's recommended as Swing is not thread safe.
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
#Override
public void run() {
//Your constructor here
}
});
}
You're setting the size of the JFrame with setSize(...), instead call frame.pack() and override the getPreferredSize() method of the JPanel.
After all the above has been said, you need to call revalidate() and repaint() on your ActionListener so your program paints its new state.
This program follows all the above recommendations and produces the following outputs (before clicking and after clicking the button 3 times), I on purpose to not make the images so large, made the GUI shorter (200 x 200 instead of 400 x 400)
import java.awt.BorderLayout;
import java.awt.Dimension;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.BoxLayout;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;
public class Programma {
private JFrame frame;
private JPanel panel;
private JButton button;
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
#Override
public void run() {
new Programma().createAndShowGui();
}
});
}
public void createAndShowGui() {
frame = new JFrame("DIG");
panel = new JPanel() {
#Override
public Dimension getPreferredSize() {
return new Dimension(400, 400);
}
};
button = new JButton("Click Me");
panel.add(button);
button.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
JLabel label = new JLabel("Hello World");
panel.add(label);
panel.revalidate();
panel.repaint();
}
});
frame.add(panel);
frame.pack();
frame.setVisible(true);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
}
Do i write this before the other componente like JPanel,JButton... or do i write this at the end of code ?
frame.setVisible(true);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
What is the difference ?
Altough I answered this on the recommendations, the difference is that if you call setVisible before adding all your elements to the frame, then you'll find yourself with some random issues where the components are not all visible until you pass your mouse over them (or where they should be). frame.pack() and setVisible should be the last ones to be called in your program, and frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); can be at the start or the end, it doesn't affects, but I prefer to have it at the end too.
button.setBounds(100, 100, 130, 35); doesn't work too.
Well, that's because of you're using a layout manager (and that's the right way to do your GUIs) instead of a null-layout (which you shouldn't be using anyway) (See point #1).
Edit
What is the difference between frame.setSize(); and frame.setpack() ?
If you read the docs for pack():
Causes this Window to be sized to fit the preferred size and layouts of its subcomponents. The resulting width and height of the window are automatically enlarged if either of dimensions is less than the minimum size as specified by the previous call to the setMinimumSize method.
So, it will calculate the minimum size for your JFrame where all the elements are visible and in their preferred size while setSize will only set the window size, but if you place a JScrollBar inside it for example this will reduce the window size, because of that, that's why you should override the getPreferredSize(...) method of your container, so it will calculate its preferred size including the width of the JScrollBar or some other elements that could modify its size. See Should I avoid the use of setPreferred|Maximum|MinimumSize in Swing? (the general consensus says yes)
When you add components dynamically to panel, you need to repain it.
Do this
panel.revalidate();
after
panel.add(label);
So far all i have managed to get is the JButton to close the first JFrame (frame) but the other will not open.
Frame class code
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.*;
public class Frame {
public static void main(String[] args) {
// Frame - Labelled BrickFall
final JFrame frame = new JFrame();
frame.setSize(1290, 730);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setTitle("BrickFall");
frame.setLayout(null);
frame.setLocationRelativeTo(null);
// Start Button
JButton Start = new JButton("Start");
Start.setBounds(100, 300, 1080, 50);
frame.add(Start);
// Exit Button
JButton Exit = new JButton("Exit");
Exit.setBounds(369, 375, 540, 50);
frame.add(Exit);
// Closes when Exit Clicked
Exit.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
System.exit(0);
}
});
//New Frame opens when Start Clicked
Start.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
frame.setVisible(false);
}
});
// Background Image
JLabel background = new JLabel("");
background.setBounds(0, 0, 1280, 720);
background.setIcon(new ImageIcon(Frame.class.getResource("/resources/images/Title.png")));
frame.getContentPane().setLayout(null);
frame.getContentPane().add(background);
frame.setVisible(true);
}
protected static void dispose() {
// TODO Auto-generated method stub
}
}
On the (frame) action listener i have left out the second line to open the other JFrame as my attempts wont work
Game class code
import javax.swing.ImageIcon;
import javax.swing.JFrame;
import javax.swing.JLabel;
public class game {
public static void main(String[] args) {
// Frame - Labelled BrickFall
JFrame game = new JFrame();
game.setSize(1290, 730);
game.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
game.setTitle("BrickFall");
game.setLayout(null);
game.setLocationRelativeTo(null);
// Background Image
JLabel GameBackground = new JLabel("");
GameBackground.setBounds(0, 0, 1280, 720);
GameBackground.setIcon(new ImageIcon(Frame.class.getResource("/resources/images/Fill In.png"))); //Change Picture When Required
game.getContentPane().setLayout(null);
game.getContentPane().add(GameBackground);
game.setVisible(true);
}
}
If anyone has any suggestions on how I can sort this I will be very thankful.
You're disposing the JFrame and setting its default close operation to JFrame.EXIT_ON_CLOSE which closes the JVM, shutting down your entire program.
Solution 1: Make your JFrame invisible via setVisible(false)
or if you do use dispose(), make sure that you set its default close operation to anything but what you're currently doing: frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); as this also closes the JVM.
Solution 2: better yet, make the closing window a JDialog.
Solution 3: Even better, don't spit different windows at the user, but rather swap views by swapping JPanels with a CardLayout. For details, please check out the CardLayout Tutorial.
Suggestion: don't use null layouts like you're doing, but rather learn to use the different layout managers.
Suggestion: get out of the main method. Don't make your classes nothing but large static main methods, basically 1970's procedural programming. Learn to use and then create OOP-compliant classes with constructors, non-static fields, non-static methods, with states and behaviors, and have these classes interact in a pleasing and useful fashion.