Split into category packages; module github.com/ZacharyZhang-NY/MujicaUI

input/qr_code.go

@@ -0,0 +1,80 @@
+package input
+
+import (
+	"cmp"
+	"log/slog"
+	"math"
+
+	"github.com/egoist/mygo/ui"
+
+	"github.com/ZacharyZhang-NY/MujicaUI/core"
+	"github.com/ZacharyZhang-NY/MujicaUI/theme"
+)
+
+// QRCodeOptions configure a QRCode.
+type QRCodeOptions struct {
+	Level QRLevel
+	// Size is the side in DIPs with the quiet zone; zero is 160.
+	Size float32
+	// Label names the code for assistive technology; empty uses "QR code".
+	Label string
+}
+
+// qrCodeCache keeps the last encoding so it runs only when the text or level changes.
+type qrCodeCache struct {
+	text  string
+	level QRLevel
+	m     QRMatrix
+	err   error
+	done  bool
+}
+
+// QRCode draws text as a QR code, encoded offline; too long a text shows an error.
+func QRCode(c *ui.Context, text string, opts QRCodeOptions) *ui.Element {
+	_ = opts.Level.String()
+	if !(opts.Size >= 0) || math.IsInf(float64(opts.Size), 1) {
+		panic("mujica: QRCode Size must be finite and >= 0")
+	}
+	size := opts.Size
+	if size == 0 {
+		size = 160
+	}
+	k := core.Tokens(c)
+	e := ui.Box(c).Size(size, size).Shrink(0).Role(ui.RoleImage).Label(cmp.Or(opts.Label, core.Msg(c, "qr_code.label")))
+	cache := ui.Local(e, "qr_code", func() qrCodeCache { return qrCodeCache{} })
+	if !cache.done || cache.text != text || cache.level != opts.Level {
+		m, err := EncodeQR([]byte(text), opts.Level)
+		*cache = qrCodeCache{text: text, level: opts.Level, m: m, err: err, done: true}
+		slog.Debug("mujica: qr_code encoded", "version", m.Version, "level", opts.Level, "err", err)
+	}
+	if cache.err != nil {
+		e.Center().Padding(core.Density(c).Unit()*2).Background(k.Surface).Border(theme.BorderWidth, k.Danger).Radius(theme.CardRadius).
+			Description(cache.err.Error())
+		e.Children(func() {
+			ui.Text(c, core.Msg(c, "qr_code.too_long")).TextColor(k.Danger).FontSize(core.FontSize(c, theme.CaptionSize)).TextAlign(ui.Center)
+		})
+		return e
+	}
+	m := cache.m
+	// Scanners need dark modules on a light field, in either theme.
+	light, dark := theme.Light().Surface, theme.Light().Text
+	e.Draw(func(p *ui.Painter, r ui.Rect) {
+		n := m.Size() + 8
+		s := p.Scale()
+		mod := float32(math.Floor(float64(r.W*s)/float64(n))) / s
+		if mod <= 0 {
+			return
+		}
+		ox := float32(math.Round(float64((r.X+(r.W-mod*float32(n))/2)*s))) / s
+		oy := float32(math.Round(float64((r.Y+(r.H-mod*float32(n))/2)*s))) / s
+		p.Fill(r, light, theme.ControlRadius)
+		for y, row := range m.Modules {
+			for x, on := range row {
+				if on {
+					p.Fill(ui.Rect{X: ox + float32(x+4)*mod, Y: oy + float32(y+4)*mod, W: mod, H: mod}, dark, 0)
+				}
+			}
+		}
+	})
+	return e
+}