CODEWITHSUNDEEP
buttonvaadinbackground-processvaadin7
adhg
adhg

Reputation: 10863

Vaadin button setEnabled(false) doesn't enable

Vaadin newbie: When a user presses a button, I like to disable it so he knows that he clicked it and there's some work going on in the background. When the (long) task is completed, I'd like to enable the button.

For this, I'm using 2 threads (background and work) but for some reason the button doesn't enabled at the end of the task.

In other words, once clicked it goes to enabled(false) and never coming back. Why? and how can I fix it? 

        button.addClickListener(new ClickListener() 
    {
        public void buttonClick(ClickEvent event) 
        {
            Thread background = new Thread(new Runnable(){

                @Override
                public void run()
                {
                    Thread work = new Thread(new Runnable(){

                        @Override
                        public void run()
                        {
                            button.setEnabled(false);
                            try
                            {
                                Thread.sleep(2000); //long work here!
                            } catch (InterruptedException e)
                            { 
                                e.printStackTrace();
                            }

                            button.setEnabled(true); //doesn't enable at the end of the long work!
                        }});

                    work.start();
                    try
                    {
                        work.join();
                    } catch (InterruptedException e)
                    { 
                        e.printStackTrace();
                    }
                }});

            background.start();   
        }
    });

Upvotes: 1

Views: 1518

Answers (1)

Artur Signell
Artur Signell

Reputation: 1812

Maybe the best approach would be to use Button.setDisableOnClick(true) for the button and do the processing directly in the event handler without a background thread. This will show the standard loading indicator to the user until processing is done.

Otherwise you need to enable server push (@Push) and remember to use UI.access() in the background thread before updating the UI. See https://vaadin.com/book/-/page/advanced.push.html

Upvotes: 3

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