java - GUI freezes during for-loop once the button is clicked

Question

In more details, I have a loop that takes in mathematical operations and a switch case in which it translates those operations in order to apply addition or subtraction.. etc.

The loop (int i) is the number of operations it reads. The condition is also a part of the operations entered, it's also inside the switch case. So whenever the user enters that condition, and the number (for instance j) that the loop should repeat, the program should take in j and equalizes it with i but it freezes. I want it to branch to that part of the loop where the user defines to get the condition right.

the GUI freezes once the user hits a JButton so that operations written in TextArea are to be calculated.

Answer 1

the GUI freezes once the user hits a JButton

Code invoked in a listener executes on the Event Dispatch Thread (EDT). The EDT is responsible for handling events and painting the GUI. So if you execute long running tasks when you click on the button you will cause the GUI to freeze until the task finishes executing.

You need to execute the long running task on a separate Thread. One way to do this is to use a Swing Worker. Read the section from the Swing tutorial on Concurrency for more information about the EDT and SwingWorker.