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/statcompare.go

@@ -0,0 +1,58 @@
+package data
+
+import (
+	"fmt"
+	"strconv"
+
+	"github.com/egoist/mygo/ui"
+
+	"git.zacharyzhang.com/ZacharyZhang-NY/8bitMyGoUI/pixel"
+)
+
+// Change is a stat before and after.
+type Change struct {
+	Label    string
+	Old, New int
+}
+
+type StatCompareOptions struct{}
+
+// StatCompare lists stats old → new with ▲▼ deltas.
+func StatCompare(c *ui.Context, changes []Change, o StatCompareOptions) *ui.Element {
+	k := pixel.K(c)
+	lw, ow, nw, dw := 0, 0, 0, 0
+	deltas := make([]string, len(changes))
+	for i, ch := range changes {
+		switch d := ch.New - ch.Old; {
+		case d > 0:
+			deltas[i] = "▲" + strconv.Itoa(d)
+		case d < 0:
+			deltas[i] = "▼" + strconv.Itoa(-d)
+		}
+		lw = max(lw, pixel.Measure(ch.Label))
+		ow = max(ow, pixel.Measure(strconv.Itoa(ch.Old)))
+		nw = max(nw, pixel.Measure(strconv.Itoa(ch.New)))
+		dw = max(dw, pixel.Measure(deltas[i]))
+	}
+	arrow := lw + 8 + ow + 4
+	newAt := arrow + pixel.Measure("→") + 4
+	deltaAt := newAt + nw + 6
+	return ui.Column(c).Children(func() {
+		for i, ch := range changes {
+			delta, ink := deltas[i], pixel.Good
+			if ch.New < ch.Old {
+				ink = pixel.Bad
+			}
+			ui.Box(c).Size(k.D(deltaAt+dw), k.D(pixel.LineHeight)).Role(ui.RoleText).
+				Label(fmt.Sprintf("%s %d → %d %s", ch.Label, ch.Old, ch.New, delta)).Draw(func(p *ui.Painter, r ui.Rect) {
+				g := k.Canvas(p, r)
+				old, now := strconv.Itoa(ch.Old), strconv.Itoa(ch.New)
+				g.Text(0, 0, ch.Label, pixel.Faint, 1)
+				g.Text(arrow-4-pixel.Measure(old), 0, old, pixel.Ink, 1)
+				g.Text(arrow, 0, "→", pixel.Faint, 1)
+				g.Text(newAt+nw-pixel.Measure(now), 0, now, pixel.Ink, 1)
+				g.Text(deltaAt, 0, delta, ink, 1)
+			})
+		}
+	})
+}