When I dispose and reopen a JFrame, it doesn't show anything - java

I have a fairly simple Java Application I created with JFrames. There is more than one JFrame in my program. I have a menu launching at the beginning of the program. After going through the menu, I have the menu JFrame disposed.
The main JFrame has a menu button that should launch the exact same menu at a later time. However, when you launch the menu from inside of the ActionListener (when you press the menu button), the JFrame doesn't launch properly. None of the components show up and colors are off.
However, when the menu is launched from outside of the ActionListener, the JFrame shows up perfectly. I have tried multiple methods to fix this, but none of them have worked.
My full program code is available by clicking here.
The main class is "LetsMultiply5.java". This class also sets up the ActionListener.
The JFrame causing the problem is "MenuWindow.java".
"LetsMultiply5.java" calls the "Booter.java" class, which then calls the "MenuWindow.java".
"MainWindow.java" is the JFrame that has the "Menu" button.
For proof, "SpeedModer.java" calls the menu window after it has been disposed, and works.
================================EDIT================================
Also, I'd like to let you know that I realize my code is a little bit messy. I am not sure how else to write the code for this program.
I am forced to use Thread.sleep(x); because the Swing timers aren't what I am looking for. The Swing timers activate an ActionListener when the timer goes off. I need a system that will wait a second before continuing on with the code.
I realize that the while (repeater==0) loop with ActionListeners inside of it seems crazy, but that was the only way I could get it to work. If I put a single ActionListener and just had the while loop do no code inside of it, nothing happens when I press the button.
I would, as MadProgrammer mentioned:
Advice: Scrap your current approach and start again.
However, the way that I have my program currently coded is the only way that I know how to get what I need to do done. I read the tutorials, but still don't know how to improve the code in the way that you told me.
I thank everyone for trying to tell me to improve my bad "Java grammar", but as far as I am concerned, I am not going to continue this program for the next 20 years and make my millions off of it.
I have looked at the Swing timers before and I understand the whole new Timer(speed, this); concept, but I don't understand how this would make my code any better.
If anyone would like to show me how to fix my ActionListeners or Thread.sleep(x); lines, please tell me. Thank you.

You're blocking the Event Dispatching Thread with Thread.sleep(3000); - Don't do this, it will prevent the UI from been painted
See Concurrency in Swing for more details about the problem and How to use Swing Timers for a possible solution
You may also want to consider having a look at The Use of Multiple JFrames, Good/Bad Practice? and consider using CardLayout or JTabbedPane
If you need to block the user temporarily (to display a error message or gather important details), consider using a modal JDialog. See How to Make Dialogs for more details

Related

Prevent JOption from blocking child JFrame

Is there a possibility to prevent a JOptionPane dialog from blocking the interaction with the rest of the program, especially child JFrames? In my GUI, I launch a JFrame and want a message dialog to pop up after the child is closed to remind the user of something, but they launch parallel and the reminder blocks the child frame from being used.
Like here:
popupObjMan newPopup1 = new popupObjMan(gatewayAbstract, gatewayAbstractID);
JOptionPane.showInternalMessageDialog(this, "REMINDER: DO REFRESH");
I've tried to set the popup always on top, but this doesn't quite do the job.
I have no problem with them launching parallel (I'd even prefer it), but I could not work my head around it yet.
I just started Java programming ,so sorry in case that'd be something obvious.
A JOptionPane normally need to be modal. It shows something important and waits till the user answers with whatever option you give him (e.g. ok-button, yes/no-buttons, ...)
But there are several ways to reach your target.
(a)
Normally a JOptionPane creates a modal window.
You need a modeless window which does not block other windows.
https://docs.oracle.com/javase/tutorial/uiswing/misc/modality.html
(b)
You can start different threads to work for your different windows. They can have windows which are shown whenever the responsible thread commands them to. This is a bit difficult and can lead to memory-troubles.
(c)
You can write your own message-panels (e.g. notificaton) which are shown when and how long you like.
Bigger projects use different of these ways to achieve their goals.
A JOptionPane is a component, just like a JPanel. As a component it can be added to any other panel.
The JOptionPane API provides static methods to create a show the JOptionPane on a modal JDialog by default. You can't change this behaviour.
However, you can manually add the JOptionPane to a non-modal JDialog that you create. This is extra work as you now need to handle the closing of the dialog and processing the clicked button.
If you really want to do this then read the JOptionPane API. There is a section on Direct Use which demonstrates the basic code needed to add the JOptionPane to a JDialog.

Java: Close Specific JFrame Window

I hope everyone is doing well.
I've built a hangman game with a swing gui and everything works well enough, HOWEVER I am trying to make a popup show up by constructing a new JFrame object when the user wins or loses with a "you lose" message or what have you. No problem, but I want a specific window to close when activating the button listener on the popup, or when the 'x' is clicked. Assume my program has 3 windows up, and I only want to close 2 of them with one click.
I tried stuff in the area of
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
But that specific one closes all the windows. If you want to see more specific sample code, I would happy to provide it, but it didn't seem necessary for this question.
Either way, I can't figure out how to do this. Is this possible using Swing?
Thank you so much in advance. You guys are always so helpful.

Unable to modify or edit JFrame fields after clicking on a button

I have a JFrame with three text fields, two combo boxes and two Jbuttons. The coding is written in Java. One button is to start the execution of the automation script and another button is to abort the execution.
But after clicking on Start Execution button, I am unable to click on the second button and unable to edit other fields like text fields, combo boxes in the JFrame also.
As this is my project related I cannot post my code here. I apologise for that. I hope you can understand the logic or concept behind my problem. I have done a lot of search in internet but still no progress.
Please help me with this. I am using action listener behind the two Jbuttons.
The Event Dispaching Thread (EDT) should only and only do graphic related work. Any other work should be done in another thread (see SwingWorker).
Every event generated by swing, will run in the EDT, this includes actionPerformed()
That is happen because of the code implement you in the first button is continuously running , use java thread to do that stuff in the first button code. then that will be works fine.

How to make "pages" in a java program

I have a question.
I just started with Java and may have some small basic things. Now I wonder how a kind of pages (sections) in a program makes.
I do not mean some kind of tabbed panel, or if you click on a button that a text is visible.
I mean that for example all over the screen a separate part of the program looks. As the main menu of a game.
There is nothing else than the main menu visible at that time. If you for example a button from that menu click. The game is loading.
(I'm using the building of a standard game as an example)
If you for example the main menu click on another button (eg "Settings")
Then wort settings "page" is visible, and there is nothing else that the program is really doing.
I do not know how this type of navigation is called. But almost every program does have something.
How can I do this too? What should I do for example, as a new file, import the classes of a particular page, or something?
You seem to be searching for CardLayout. As shown here.
I think you should look for "state machines", which is a way for structuring your code, and implement your menu changing swing components (like JPanel, for example) in a JFrame. If I understand what you want, I think this can be an option.
There is no short answer, but based on your question, you need to read alot. I would suggest the swing tutorial It explains use of Panels, Frames, Layout managers and other containers.
You can also use the Matisse builder in netbeans (relevant plugin in eclipse)

Adding MouseListener breaks Keylistener

When I remove all of the MouseListener components and run the applet I have to click on it to give it focus, then the KeyListener works perfectly. To solve this I added an "opening page" where you have to click on start before the game runs. This would give the applet focus and not start until the player was ready at the same time. I add in the MouseListener and it works great, but now the KeyListener does not register at all. I can not find out why, but I imagine it has something to do with focus again. Anyone know what should be done here?
Code can be found here: http://pastebin.com/LDxtk878
Thanks!
Without examining all 322 lines of your code, you might look at the article How to Write a Key Listener with attention to the section following "Note: To fire keyboard events, a component must have the keyboard focus."
Also, consider extending JApplet, as an alternative.

Categories