Scroll and Grid

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Scroll views and grids make it easy to build inventories, lists, menus, and card layouts. This guide shows the correct patterns for both, including layout, IDs, and scroll bars.

Follow the UI fundamentals: start from screen rects, use cut for layout, and always use defer for push/pop pairs.

Scroll Views

Use scroll views for content that can exceed the available space. The scroll bar must be outside the scroll view content area.

draw_scrollable_list :: proc(items: []string) {
    rect := UI.get_safe_screen_rect()->inset(50);

    // Reserve space for the scroll bar first
    scroll_bar_area := rect->cut_right(8)->inset(2);

    settings: Scroll_View_Settings;
    settings.vertical = true;
    settings.horizontal = false;
    settings.clip_padding = {10, 10, 10, 10};

    sv := UI.push_scroll_view(rect, "my_scroll_view", settings); {
        defer UI.pop_scroll_view();

        content := sv.content_rect;
        ts := UI.default_text_settings();
        ts.size = 24;

        for i: 0..items.count-1 {
            item_rect := content->cut_top(40);
            UI.text(item_rect, ts, items[i]);
        }
    }

    scroll_bar_rect := sv->compute_scroll_bar_rect(scroll_bar_area);

    UI.quad(scroll_bar_area, core_globals.white_sprite, {0.025, 0.025, 0.025, 1});
    UI.quad(scroll_bar_rect, core_globals.white_sprite, {0.1, 0.1, 0.1, 1});
}

Important: If the scroll bar is inside the scroll view content, it will break the bounds and scrolling behavior. Always cut the scroll bar area out first.

Grid Layout

Use Grid_Layout for equally-sized elements like inventory slots or icon grids. Grids start at the top-left, advance to the right, then wrap to the next row.

draw_inventory_grid :: proc(items: []Item) {
    rect := UI.get_safe_screen_rect()->inset(40);

    bs := UI.default_button_settings();
    ts := UI.default_text_settings();

    // 4 columns x 6 rows based on element count, 8px padding
    grid := UI.make_grid_layout(rect, 4, 6, .ELEMENT_COUNT, 8);

    for i: 0..items.count-1 {
        UI.push_id("slot_%", {i});
        defer UI.pop_id();

        slot_rect := grid->next();
        if UI.button(slot_rect, bs, ts, items[i].name).clicked {
            select_item(i);
        }
    }
}

If you prefer fixed-size tiles, use .ELEMENT_SIZE instead of .ELEMENT_COUNT:

grid := UI.make_grid_layout(rect, 100, 100, .ELEMENT_SIZE, 8);

The next() method updates grid state:

slot_rect := grid->next();
grid.index; // 0, 1, 2, ...
grid.cur_x; // column
grid.cur_y; // row

Scrollable Grids

Grid_Layout automatically expands scroll views when used inside one. This pattern is ideal for large inventories:

draw_scrollable_grid :: proc(items: []Item) {
    rect := UI.get_safe_screen_rect()->inset(50);
    scroll_bar_area := rect->cut_right(8)->inset(2);

    settings: Scroll_View_Settings;
    settings.vertical = true;
    settings.horizontal = false;
    settings.clip_padding = {10, 10, 10, 10};

    sv := UI.push_scroll_view(rect, "inventory_scroll", settings); {
        defer UI.pop_scroll_view();

        grid := UI.make_grid_layout(sv.content_rect, 4, 6, .ELEMENT_COUNT, 8);
        bs := UI.default_button_settings();
        ts := UI.default_text_settings();

        for i: 0..items.count-1 {
            UI.push_id("slot_%", {i});
            defer UI.pop_id();

            slot_rect := grid->next();
            if UI.button(slot_rect, bs, ts, items[i].name).clicked {
                select_item(i);
            }
        }
    }

    scroll_bar_rect := sv->compute_scroll_bar_rect(scroll_bar_area);
    UI.quad(scroll_bar_area, core_globals.white_sprite, {0.025, 0.025, 0.025, 1});
    UI.quad(scroll_bar_rect, core_globals.white_sprite, {0.1, 0.1, 0.1, 1});
}

Best Practices

• Use UI.push_id() for repeated elements inside lists or grids.

• Cut the scroll bar area before creating a scroll view.

• Start from UI.get_safe_screen_rect() and derive all layout.

• Keep hover-only interactions to a minimum (mobile-first).