Find an element by CSS selector in GWT

Use GwtQuery, is updated to GWT 2.4: http://code.google.com/p/gwtquery/

Selector examples :

//select an element having id equals to 'container'
GQuery myElement = $("#container");
//select all elements having 'article' as css class
GQuery allArticles = $(".article");
/select all cells of tables
GQuery allCells = $("table > tr > td");
//find the ul elements being inside a element with class 'article' itself inside a element with id 'container'
GQuery articleUls = $("#container .article ul");

http://code.google.com/p/gwtquery/wiki/GettingStarted

There's the DOM class, that provides many wrapper methods for accessing the DOM tree. There's no function that takes a CSS selector jQuery style that I'm aware of - GWT just encourages/enforces accessing DOM elements through Widgets (and such), not directly - though I understand that in your case such "low-level" approach might be needed. The only way I see pulling that off through pure Java GWT methods is via lots and lots of (probably horrible) chaining/invocations of the DOM class. It'd be easier if all you had to do was access some id - for that there's RootPanel.get(id) (and DOM.getElementById(id), they differ in what type of objects they return).

However, like you already suggested, JSNI might offer a better solution - try returning, for example, $wnd.$("#someId .className a") from JSNI as an Element - actually, you can return anything as anything from JSNI, GWT will just crap up the second you try to use, say an int as a DOM element or something.

PS: while the GQuery project does seem dead/inactive, it might be worth checking how they wrapped the jQuery calls (such as $) so that they could be used seemingly in GWT.