Question

Is UIObject#setVisible(false) functionally different from Widget#removeFromParent?

Besides, Is DialogBox#hide just a wapper call to UIObject#setVisible(false)?

Any practical examples?

Answer 1

UIObject#setVisible sets the CSS ‘display’ attribute on the element. If you have an HTMLPanel and call setVisible(false) on it, it will result in this

< div style=”display:none”>My HTML Panel !< /div>

Whereas removeFromParent will remove the element from the DOM of your page. Again, if you had an HTMLPanel attached to the body of your page and called removeFromParent() on it, you would go from

< body>
    <div >My HTML Panel !</div>
</body>

to

< body> < /body>

So once you’ve remove a widget from it’s parent, you will have to reattach it if you want to display it again.

As for your second question, I haven’t looked at the code for DialogBox#hide but I would say that it probably calls setVisible(false) at some point, among other things.