Your showProgress method is being executed within the context of the Event Dispatching Thread. The EDT is responsible for, amongst other things, processing paint requests. This means that so long as your for-loop is executing, the EDT can not process any new paint requests (or handle the invokeLater events either) as it is blocking the … Read more
This is the official reference: Swing’s Threading Policy In general Swing is not thread safe. All Swing components and related classes, unless otherwise documented, must be accessed on the event dispatching thread. And the repaint method does not “document otherwise”. To doubly reassure you that you do not need to look any further than an … Read more
It is a known bug as acknowledged by Oracle Bug ID:6924233 The JOptionPane apparently causes another event to be generated with a check box value = false. The recommended fix is to instantiate the JOptionPane using invokeLater. Submitted On 09-MAR-2010 The change is in the BasicButtonListener – Method focusLost() In 1.6.0_18 it is … ButtonModel … Read more
The problem is, your long running task is blocking the Thread that keeps the GUI responsive. What you will need to do is put the long running task on another thread. Some common ways of doing this are using Timers or a SwingWorker. The Java tutorials have lots of information regarding these things in their … Read more
Although the Swing concurrency tutorial already contains some very good samples on how to deal with concurrency in Swing, find below an example which contains a checkbox to prove the UI is still alive has a progress bar, which gets updated from the SwingWorker has a label, which gets updated once the SwingWorker is finished … Read more
Use a Swing Timer for repeating tasks & a SwingWorker for long running tasks. E.G. of both below – it uses a Timer to repeatedly perform a ‘long running’ task (a ping) in a SwingWorker. See Concurrency in Swing for more details on the Event Dispatch Thread and doing long running or repeating tasks in … Read more
As other answers have said, it executes your Runnable on the AWT event-dispatching thread. But why would you want to do that? Because the Swing data structures aren’t thread-safe, so to provide programmers with an easily-achievable way of preventing concurrent access to them, the Swing designers laid down the rule that all code that accesses … Read more
Can anyone tell me why sleeping one thread is stopping my whole execution to better explain your Swing GUI is created on its own special thread separate from that which main() and other code will run in, this is done via creating your Swing components in the SwingUtilities.invokeXXX block (even if you have not done … Read more
Do I have to use each time I need to update the GUI components? No, not if you’re already on the event dispatch thread (EDT) which is always the case when responding to user initiated events such as clicks and selections. (The actionPerformed methods etc, are always called by the EDT.) If you’re not on … Read more
The event dispatch thread is a special thread that is managed by AWT. Basically, it is a thread that runs in an infinite loop, processing events. The java.awt.EventQueue.invokeLater and javax.swing.SwingUtilities.invokeLater methods are a way to provide code that will run on the event queue. Writing a UI framework that is safe in a multithreading environment … Read more