CODEWITHSUNDEEP
vaadin
Norman Shelley
Norman Shelley

Reputation: 41

Vaadin: force Button to be visually disabled

I have several TextField's inside a window along with a Button, e.g. aButton. The TextField's, Button, and window all have setImmediate(True).

When a TextField loses focus some validation code is executed and if it fails it calls: aButton.setEnabled(False);

When incorrect data is entered into one TextField and then focus is lost the debugger shows that aButton.setEnabled(False) is called but aButton still looks enabled.

Two possible things can happen from here:

1.) If one modifies data in another TextField and exits that field (loses focus), the validation can be successful or not for that field but the system knows to call aButton.setEnabled(False) as the previous TextField is still invalid. This time though aButton is visually disabled.

2.) If one clicks on aButton which is visually enabled it produces this warning then visually becomes disabled: Warning: Ignoring variable change for disabled component < class 'ui.button.Button'>, caption=OK

Currently using Vaadin 6.7.3

Are there any known work arounds to force aButton to visually become disabled immediately (force the client to update) after manually setting it to be disabled?

Upvotes: 2

Views: 4207

Answers (2)

Balint Bako
Balint Bako

Reputation: 2560

Sadly I have only Vaadin 7 at my disposal right now, but I checked this anyway. It works as you wanted it to work and I have to jump to the conclusion that this should be the same in Vaadin 6.7.3. This part is not really different in Vaadin7... Have you tried this feature in an isolated code (only a textbox and the button)?

VerticalLayout vlTestContent = new VerticalLayout();
final Button butChangeMe = new Button("Enabled");
final TextField tf = new TextField("Blur", "default value");
tf.addBlurListener(new BlurListener() {
    private static final long serialVersionUID = 5544993392287938660L;
    @Override
    public void blur(BlurEvent event) {
        butChangeMe.setCaption("Disabled");
        butChangeMe.setEnabled(false);
    }
});
Button but = new Button("Change button", new ClickListener() {
    private static final long serialVersionUID = -2235317499126190105L;
    @Override
    public void buttonClick(ClickEvent event) {
        butChangeMe.setCaption("Enabled");
        butChangeMe.setEnabled(true);
    }
});
vlTestContent.addComponent(butChangeMe);
vlTestContent.addComponent(tf);
vlTestContent.addComponent(but);

(The second button is just for fun)

Upvotes: 2

David Hofmann
David Hofmann

Reputation: 5775

button.setVisible(false) will always work. You need to be careful to not fire up a another event on the focus lost event that ends up setting the visibility of the button to true.

You can request a repaint of a component or the whole window, but the whole point of the framework is that you will never need to do that, because visually modified components will automatically repaint on each request.

Just to be curious, do you let your request to finish before trying to see if the browser updates? Or you look at your browser right after you pass the setVisible() line in your debugger ?

I think that your point nr 2 happens because you clicked on the button, and what happens in this order is: 1st your focus lost event runs (which probably disables your button), 2nd button click runs and somehow a repaint is requested for that button because a state change happened in the button but a repaint show the warning that it won't do anything with it because it is disabled (was just disable by the focus lost event)

As a side note. I think this UI won't make for a good user experience, it should be the other way arround, if a validation is ok, then show the button (or better, always show the button, but enable/disable instead) But it depends...

Upvotes: 1

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