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

navigation/tabs.go

@@ -0,0 +1,125 @@
+// Package navigation moves the player between screens and places.
+package navigation
+
+import (
+	"log/slog"
+
+	"github.com/egoist/mygo/ui"
+
+	"git.zacharyzhang.com/ZacharyZhang-NY/8bitMyGoUI/pixel"
+)
+
+type TabsOptions struct {
+	Disabled bool
+}
+
+type TabsResult struct {
+	Element *ui.Element
+	Changed bool
+}
+
+// Tabs are folder tabs; the chosen one joins its panel.
+func Tabs(c *ui.Context, text string, labels []string, selected *int, o TabsOptions, panel func()) TabsResult {
+	return tabs(c, text, labels, selected, false, o, panel)
+}
+
+// VerticalTabs are tabs down the panel's left edge.
+func VerticalTabs(c *ui.Context, text string, labels []string, selected *int, o TabsOptions, panel func()) TabsResult {
+	return tabs(c, text, labels, selected, true, o, panel)
+}
+
+// tabs lays tabs beside a panel; side means left.
+func tabs(c *ui.Context, text string, labels []string, selected *int, side bool, o TabsOptions, panel func()) TabsResult {
+	k := pixel.K(c)
+	th := pixel.LineHeight + 6
+	tw := 0
+	for _, l := range labels {
+		tw = max(tw, pixel.Measure(l)+12)
+	}
+	// size is tab i's extent along the strip.
+	size := func(i int) int {
+		if side {
+			return th
+		}
+		return pixel.Measure(labels[i]) + 12
+	}
+	outer := ui.Column(c)
+	if side {
+		outer = ui.Row(c).FillWidth().AlignItems(ui.Stretch)
+	}
+	res := TabsResult{Element: outer}
+	outer.Children(func() {
+		p := ui.TabsBase(c, selected, len(labels))
+		if side {
+			p.List.Column().Width(k.D(tw))
+		}
+		p.List.Label(text).Children(func() {
+			for i, l := range labels {
+				shell, _, st := pixel.Shell(c, func() *ui.Element { return p.Tab(i).Label(l).Disabled(o.Disabled) })
+				w, h := size(i), th
+				if side {
+					w = tw
+				}
+				shell.Size(k.D(w), k.D(h)).Draw(func(p *ui.Painter, r ui.Rect) {
+					folder(k.Canvas(p, r), l, i == *selected, side, st)
+				})
+			}
+		})
+		res.Changed = p.List.Changed()
+		at := 0
+		for i := range *selected {
+			at += size(i)
+		}
+		body := ui.Column(c).Padding(k.D(8)).Gap(k.D(4))
+		if side {
+			body.Grow(1)
+		}
+		body.Draw(func(p *ui.Painter, r ui.Rect) {
+			g := k.Canvas(p, r)
+			if g.W < 3 || g.H < 3 {
+				return
+			}
+			g.Frame(0, 0, g.W, g.H, pixel.Raised, pixel.Face)
+			// The chosen tab opens into the panel.
+			if side {
+				g.Rect(0, at+1, 2, th-2, pixel.Face)
+			} else {
+				g.Rect(at+1, 0, size(*selected)-2, 2, pixel.Face)
+			}
+		}).Children(panel)
+	})
+	if res.Changed {
+		slog.Debug("8bit: tabs", "label", text, "selected", *selected)
+	}
+	return res
+}
+
+// folder draws a tab: the chosen one stands taller, open-ended.
+func folder(g pixel.Canvas, l string, on, side bool, st pixel.State) {
+	fill, ink, in := pixel.Shade, pixel.Faint, 2
+	if on {
+		fill, ink, in = pixel.Face, pixel.Ink, 0
+	} else if st.Hover {
+		fill = pixel.Lit
+	}
+	if side {
+		g.VLine(in, 1, g.H-2, pixel.Edge)
+		g.HLine(in+1, 0, g.W-in-1, pixel.Edge)
+		g.HLine(in+1, g.H-1, g.W-in-1, pixel.Edge)
+		g.Rect(in+1, 1, g.W-in-1, g.H-2, fill)
+		g.Text(in+6, 3, l, ink, 1)
+		if !on {
+			g.VLine(g.W-1, 0, g.H, pixel.Edge)
+		}
+	} else {
+		g.HLine(1, in, g.W-2, pixel.Edge)
+		g.VLine(0, in+1, g.H-in-1, pixel.Edge)
+		g.VLine(g.W-1, in+1, g.H-in-1, pixel.Edge)
+		g.Rect(1, in+1, g.W-2, g.H-in-1, fill)
+		g.Text(6, in+3, l, ink, 1)
+		if !on {
+			g.HLine(0, g.H-1, g.W, pixel.Edge)
+		}
+	}
+	g.Finish(st)
+}