Add navigation components 131-150; pixel Pad, Finish, Park, Since

navigation/toc.go

@@ -0,0 +1,67 @@
+package navigation
+
+import (
+	"log/slog"
+
+	"github.com/egoist/mygo/ui"
+
+	"git.zacharyzhang.com/ZacharyZhang-NY/8bitMyGoUI/pixel"
+)
+
+var pointer = pixel.MustSprite(`
+	#..
+	##.
+	###
+	##.
+	#..
+`)
+
+type TocItem struct {
+	Title string
+	// Level indents sub-sections; zero is the top.
+	Level int
+}
+
+type TableOfContentsOptions struct {
+	// Width is in dots; zero means 160.
+	Width    int
+	Disabled bool
+}
+
+type TableOfContentsResult struct {
+	Element *ui.Element
+	Changed bool
+}
+
+// TableOfContents lists sections; ▶ marks the current one.
+func TableOfContents(c *ui.Context, text string, items []TocItem, current *int, o TableOfContentsOptions) TableOfContentsResult {
+	k := pixel.K(c)
+	w := pixel.Or("TableOfContents Width", o.Width, 160)
+	res := TableOfContentsResult{}
+	res.Element = ui.RadioGroup(c, func() {
+		for i, it := range items {
+			shell, base, st := pixel.Shell(c, func() *ui.Element {
+				return ui.RadioBase(c, current, i).Label(it.Title).Disabled(o.Disabled)
+			})
+			if base.Changed() {
+				res.Changed = true
+			}
+			shell.Size(k.D(w), k.D(pixel.LineHeight)).Draw(func(p *ui.Painter, r ui.Rect) {
+				g := k.Canvas(p, r)
+				x, ink := 8+it.Level*10, pixel.Faint
+				if i == *current {
+					g.Sprite(x-6, 5, pointer, 0, pixel.Accent, 1)
+					ink = pixel.Accent
+				} else if st.Hover {
+					ink = pixel.Ink
+				}
+				g.Text(x, 0, it.Title, ink, 1)
+				g.Finish(st)
+			})
+		}
+	}).Gap(0).Label(text)
+	if res.Changed {
+		slog.Debug("8bit: toc", "label", text, "section", items[*current].Title)
+	}
+	return res
+}