wip markets

asset_allocation_chart.go

@@ -0,0 +1,113 @@
+package mujica
+
+import (
+	"fmt"
+	"math"
+
+	"github.com/egoist/mygo/ui"
+
+	"mujicaui/icons"
+	"mujicaui/internal"
+	"mujicaui/theme"
+)
+
+// AllocationItem is an asset class's value and target weight in percent.
+type AllocationItem struct {
+	Name   string
+	Value  float64
+	Target float64
+}
+
+// AssetAllocationChartOptions configure an AssetAllocationChart.
+type AssetAllocationChartOptions struct {
+	Frame ChartFrame
+	// Tolerance is the drift in points that warns; zero means 5.
+	Tolerance float64
+	Format    func(v float64) string
+}
+
+// AssetAllocationChart shows holdings as a donut and lists each weight against its target.
+func AssetAllocationChart(c *ui.Context, items []AllocationItem, opts AssetAllocationChartOptions) ChartResult {
+	if opts.Tolerance < 0 {
+		panic("mujica: AssetAllocationChart Tolerance is negative")
+	}
+	tol := opts.Tolerance
+	if tol == 0 {
+		tol = 5
+	}
+	total, targets := 0.0, 0.0
+	for _, it := range items {
+		if it.Name == "" || it.Value < 0 || it.Target < 0 || math.IsNaN(it.Value) || math.IsNaN(it.Target) {
+			panic("mujica: AllocationItem needs a Name and values ≥ 0")
+		}
+		total += it.Value
+		targets += it.Target
+	}
+	if len(items) > 0 && math.Abs(targets-100) > 0.01 && targets != 0 {
+		panic(fmt.Sprintf("mujica: AllocationItem targets sum to %v, not 100", targets))
+	}
+	k := Tokens(c)
+	u := Density(c).Unit()
+	pal := internal.Palette(k)
+	var res ChartResult
+	row := ui.Row(c).Gap(u * 6).AlignItems(ui.Start).Wrap()
+	row.Children(func() {
+		slices := make([]ChartSlice, len(items))
+		for i, it := range items {
+			slices[i] = ChartSlice{Label: it.Name, Value: it.Value}
+		}
+		frame := opts.Frame
+		if frame.Height == 0 {
+			frame.Height = 220
+		}
+		ui.Column(c).Width(frame.Height + 40).Children(func() {
+			res = PieChart(c, slices, PieChartOptions{Frame: frame, Donut: true, Format: opts.Format})
+		})
+		if total == 0 {
+			return
+		}
+		size := FontSize(c, theme.CaptionSize)
+		g := ui.Grid(c).ColumnTracks(ui.FitContent(), ui.FitContent(), ui.FitContent(), ui.FitContent()).GapX(u * 4).GapY(u * 2).
+			Role(ui.RoleTable).Label(frame.Label)
+		g.Children(func() {
+			for _, h := range []string{"asset_allocation_chart.asset", "asset_allocation_chart.weight", "asset_allocation_chart.target", "asset_allocation_chart.drift"} {
+				ui.Text(c, msg(c, h)).FontSize(size).TextColor(k.TextMuted).Role(ui.RoleColumnHeader)
+			}
+			for i, it := range items {
+				w := it.Value / total * 100
+				drift := w - it.Target
+				ui.Row(c).Key(it.Name).Gap(u * 2).AlignItems(ui.Center).Children(func() {
+					ui.Box(c).Size(12, 12).Draw(func(p *ui.Painter, r ui.Rect) { internal.Marker(p, i, r.X+6, r.Y+6, 10, pal[i%len(pal)]) })
+					ui.Text(c, it.Name).SingleLine()
+				})
+				ui.Text(c, fmt.Sprintf("%.1f%%", w)).FontFeatures("tnum").JustifySelf(ui.End)
+				ui.Text(c, fmt.Sprintf("%.1f%%", it.Target)).FontFeatures("tnum").TextColor(k.TextMuted).JustifySelf(ui.End)
+				allocationDrift(c, drift, tol)
+			}
+		})
+	})
+	res.Element = row
+	return res
+}
+
+// allocationDrift shows the drift in points; beyond tolerance it warns with an icon and a word.
+func allocationDrift(c *ui.Context, drift, tol float64) {
+	k := Tokens(c)
+	text := statisticSigned(drift, 1) + " pt"
+	over := math.Abs(drift) > tol
+	ink := k.TextMuted
+	if over {
+		ink = k.Warning
+	}
+	ui.Row(c).Gap(4).AlignItems(ui.Center).JustifySelf(ui.End).TextColor(ink).Children(func() {
+		if over {
+			ui.Icon(c, icons.Must("triangle-alert")).Size(12, 12)
+			word := "asset_allocation_chart.over"
+			if drift < 0 {
+				word = "asset_allocation_chart.under"
+			}
+			ui.Text(c, msg(c, word)).FontSize(FontSize(c, theme.CaptionSize))
+		}
+		ui.Text(c, text).FontFeatures("tnum")
+	})
+}