public class StickyHeaderContainer

A scrollable container that pins the most recently scrolled-past section header to the top of its viewport, in the style of the iOS contacts list or sectioned material lists. As the next section’s header rises into the pinned slot the previous header is replaced through a configurable scroll-driven transition: a directional slide where the rising header pushes the pinned one up and out, or a cover where the rising header progressively slides on top of the pinned one. The outgoing header can optionally fade out alongside either transition via setHeaderFadeOut(boolean). Transitions are driven by scroll position so the visual stays in sync with the user’s gesture and there is no time-based animation that lags behind a slow drag or skips ahead on a fling.

Sections are added with addSection(header, content). The header is a real component that participates in the scroll: when it is the active section’s header it is moved into a pinned overlay slot at the top of the container, and a same-sized invisible placeholder is left behind in the scroll content so nothing jumps. Because the pinned header is the same instance, action listeners and child components remain interactive while it is pinned.

StickyHeaderContainer sticky = new StickyHeaderContainer();
sticky.setTransitionStyle(StickyHeaderContainer.TRANSITION_SLIDE);
for (char c = 'A'; c <= 'Z'; c++) {
    Label header = new Label("" + c, "StickyHeader");
    Container items = new Container(BoxLayout.y());
    for (int i = 0; i < 5; i++) {
        items.add(new Label(c + " entry " + i));
    }
    sticky.addSection(header, items);
}
form.add(BorderLayout.CENTER, sticky);