Pagination

Pagination

Pagination renders a list of ViewItem values into an ordered region of slots. It belongs to one ViewContents session.

Basic setup

Layout layout = Layout.of(
    "#########",
    "#ppppppp#",
    "#ppppppp#",
    "#ppppppp#",
    "<###b###>");

View view = VGui.chest(5)
    .layout(
        "#########",
        "#ppppppp#",
        "#ppppppp#",
        "#ppppppp#",
        "<###b###>")
    .map('#', filler)
    .map('<', ViewItem.pagePrevious(previousArrow))
    .map('>', ViewItem.pageNext(nextArrow))
    .map('b', ViewItem.backButton(backItem))
    .onOpen(contents -> contents.pagination()
        .slots(layout, 'p')
        .items(entries))
    .build();

The p character stays unmapped in the view layout. slots(layout, 'p') extracts its indexes in reading order.

Configure slots directly

contents.pagination().slots(10, 11, 12, 13, 14, 15, 16);

Every slot is validated against the top inventory and duplicate indexes are rejected. The array is copied. Setting slots resets the page to zero and renders.

Set items

pagination.items(List.copyOf(items));

The list is copied. Replacing the list clamps the current page to the new valid range and renders immediately.

Queries

• page() returns the zero-based page.
• pageCount() returns at least one, even with no items or slots.
• itemsPerPage() returns the number of region slots.
• isFirst() and isLast() describe the current position.

Navigation

• open(page) clamps to the valid range.
• next() and previous() stay at the edge when necessary.
• first() and last() jump directly.
• render() redraws the current page.

Every navigation method re-renders the region in one batch.

Empty slots on the last page

Pagination clears region slots that do not have an item for the current page. This prevents leftover items from a fuller previous page.

Dynamic controls

The built-in previous and next buttons always remain clickable. If you want disabled edge buttons, update them after navigation:

ViewItem next = ViewItem.clickable(nextArrow, click -> {
    Pagination pagination = click.contents().pagination();
    pagination.next();
    renderControls(click.contents(), pagination);
});

renderControls can display a disabled item when isLast() is true and change the title to show the page number.

Updating data

Call items(newItems) after filters or live data change. The helper keeps its configured region, clamps the page, and re-renders.

For mutable external collections, always pass a snapshot. The pagination helper intentionally copies the list so concurrent mutations cannot change rendering halfway through.

Common mistakes

• Mapping the region character to a filler, which fills the slots before pagination but is harmless because pagination replaces them.
• Using a layout with dimensions different from the view.
• Creating a new layout whose region does not match the builder layout.
• Assuming pageCount() can be zero.
• Manually calling refresh() after page navigation. Pagination already batches and refreshes.