How would I use GWT to create an infinite scroll panel?

Question

By infinite scrolling, I mean I initially load a few child widgets, and as the user scrolls down lazily load more to fill it out.

Any ideas appreciated.

(ideally would like something for GWT 1.6 and 1.5)

Answer 1

Try something like this:

public static class InfiniteScrollPanel implements ScrollHandler {
    String text = "Lorem ipsum dolor sit amet, consectetuer...";
    ScrollPanel panel = new ScrollPanel(new HTML(text));
    int height = 200;
    int width = 200;

    public InfiniteScrollPanel() {
        panel.setHeight(height);
        panel.setWidth(width);
        panel.addScrollHandler(this);  
    }
    public void onScroll(ScrollEvent event) {
        if (panel.getScrollPosition == height) {
            panel.add(new HTML(text));
        }
    }
}

What this code does: it creates a ScrollPanel and adds a ScrollHandler to it. In the ScrollHandler the scrollheight gets compared to the height of the panel and it then adds another child to the panel.

I haven't tested it because I'm writing this on a netbook and don't have an IDE on it.