Add data components 151-175; clear MyGo row highlights

Lists, tables, trees, grids, inventories and records in data/.
Outline and GridView build on ui.List: ui.Outline strokes its arrows
and ui.GridView spaces and tints items. The pixel theme keeps MyGo's
row highlights clear so scrolled rows stay on whole dots; off lists
take a veil against the wheel. Adds Canvas.Silhouette, SwitchOptions
Label and exports Rarity.Slot.

data/pager.go

@@ -0,0 +1,65 @@
+package data
+
+import (
+	"fmt"
+	"log/slog"
+	"slices"
+	"strconv"
+
+	"github.com/egoist/mygo/ui"
+
+	"git.zacharyzhang.com/ZacharyZhang-NY/8bitMyGoUI/icon"
+	"git.zacharyzhang.com/ZacharyZhang-NY/8bitMyGoUI/input"
+	"git.zacharyzhang.com/ZacharyZhang-NY/8bitMyGoUI/pixel"
+)
+
+type PagerOptions struct {
+	// Sizes offered; nil means 10, 20 and 50.
+	Sizes    []int
+	Disabled bool
+}
+
+type PagerResult struct {
+	Element *ui.Element
+	Changed bool
+}
+
+// Pager pages through total items: "1–20 OF 312".
+func Pager(c *ui.Context, text string, total int, page, size *int, o PagerOptions) PagerResult {
+	k := pixel.K(c)
+	sizes := o.Sizes
+	if sizes == nil {
+		sizes = []int{10, 20, 50}
+	}
+	at := slices.Index(sizes, *size)
+	if total < 0 || *page < 0 || at < 0 || slices.Min(sizes) < 1 {
+		panic(fmt.Sprintf("data: Pager page %d, size %d of %v, total %d", *page, *size, sizes, total))
+	}
+	old, oldSize := *page, *size
+	last := func() int { return max(0, (total-1) / *size) }
+	*page = min(*page, last())
+	row := ui.Row(c).Gap(k.D(6)).AlignItems(ui.Center).Role(ui.RoleGroup).Label(text)
+	row.Children(func() {
+		pixel.Text(c, k.Msg("per_page"), pixel.TextOptions{Slot: pixel.Faint})
+		labels := make([]string, len(sizes))
+		for i, s := range sizes {
+			labels[i] = strconv.Itoa(s)
+		}
+		if input.Segmented(c, k.Msg("per_page"), labels, &at, input.SegmentedOptions{Disabled: o.Disabled}).Changed {
+			*size, *page = sizes[at], 0
+		}
+		from, to := min(*page**size+1, total), min((*page+1)**size, total)
+		pixel.Text(c, fmt.Sprintf(k.Msg("range"), from, to, total), pixel.TextOptions{})
+		if input.IconButton(c, icon.ChevronLeft, k.Msg("prev"), input.IconButtonOptions{Disabled: o.Disabled || *page == 0}).Clicked {
+			*page--
+		}
+		if input.IconButton(c, icon.ChevronRight, k.Msg("next"), input.IconButtonOptions{Disabled: o.Disabled || *page >= last()}).Clicked {
+			*page++
+		}
+	})
+	res := PagerResult{Element: row, Changed: *page != old || *size != oldSize}
+	if res.Changed {
+		slog.Debug("8bit: pager", "label", text, "page", *page, "size", *size)
+	}
+	return res
+}