Java first GUI, two classes

Question

I'm trying to program my first GUI-class in Java, using the Window Builder. Ok, the GUI is ready but has no functions yet (it contains 10 checkboxes (yes, they are all neccessary) and 2 buttons and a JTextField, so nothing special). So I just drag'n'dropped the checkboxes and button into the window, I haven't coded anything yet.

I have two classes: GUI.java -> only for the layout Main.java -> should get 'inputs' from GUI.java

Now the user should check or uncheck the checkboxes and then finally press a button.

But how do I 'read out' if a checkbox is checked or not - I have two classes?

I have to add that I'm a beginner to Java and especially to GUI-programming, but I just want to learn it. I would be happy to receive some help but NOT the complete code.

Answer 1

Basically you instantiate an object of your GUI from the Main.java. Then you have access to this GUI (assumed you have setter/getter-methods or the Components in the GUI are public). In the GUI constructor you call all builder methods, so when you then call new GUI() from Main.java, you got a) the GUI running and b) access to it from Main.java

For your specific question about the checkboxes, you can call

nameOfCheckbox.isSelected()

which returns a boolean wheter the checkbox is checked or not.

Viceversa: since your Main.java has (or should have) static methods (like the main-method), you can then simply call Main.anyMethodName() from GUI.java (assuming this anyMethod is static) and pass data from the "visual area" to the "logic area" (it is recommended to seperate this two componentes as good as possible).