WIP charts2 frame parts

chart_tooltip.go

@@ -0,0 +1,83 @@
+package mujica
+
+import (
+	"strings"
+
+	"github.com/egoist/mygo/ui"
+
+	"mujicaui/internal"
+	"mujicaui/theme"
+)
+
+// ChartTooltipLine is one row of a tooltip; a zero Color shows no marker.
+type ChartTooltipLine struct {
+	Text  string
+	Color ui.Color
+	Shape int
+}
+
+// ChartTooltip floats painted lines beside window point (x, y), avoiding edges.
+func ChartTooltip(c *ui.Context, x, y float32, lines []ChartTooltipLine) *ui.Element {
+	if len(lines) == 0 {
+		panic("mujica: ChartTooltip needs a line")
+	}
+	k := Tokens(c)
+	u := Density(c).Unit()
+	size := FontSize(c, theme.CaptionSize)
+	pad, gap := u*2, float32(12)
+	w, h := float32(0), pad*2
+	lh := make([]float32, len(lines))
+	for i, l := range lines {
+		tw, th := c.MeasureText(0, ui.Span{Text: l.Text, Size: size, Weight: chartTipWeight(i)})
+		if l.Color.A > 0 {
+			tw += 14
+		}
+		w, lh[i] = max(w, tw), th
+		h += th
+	}
+	w += pad * 2
+	ww, wh := c.Size()
+	left, top := x+gap, y+gap
+	if left+w > ww-4 {
+		left = x - gap - w
+	}
+	if top+h > wh-4 {
+		top = y - gap - h
+	}
+	left, top = max(4, left), max(4, top)
+	var tip *ui.Element
+	ui.Overlay(c, func() {
+		tip = ui.Box(c).Absolute().Left(left).Top(top).Size(w, h).PassThrough().Role(ui.RoleNone)
+		overlayStyle(c, tip, 1)
+		tip.Draw(func(p *ui.Painter, r ui.Rect) {
+			at := r.Y + pad
+			for i, l := range lines {
+				tx := r.X + pad
+				if l.Color.A > 0 {
+					internal.Marker(p, l.Shape, tx+5, at+lh[i]/2, 9, l.Color)
+					tx += 14
+				}
+				p.RichText(tx, at, 0, ui.Span{Text: l.Text, Size: size, Weight: chartTipWeight(i), Color: k.Text})
+				at += lh[i]
+			}
+		})
+	})
+	return tip
+}
+
+// chartTipWeight sets the first line, the heading, in semibold.
+func chartTipWeight(i int) int {
+	if i == 0 {
+		return 600
+	}
+	return 400
+}
+
+// chartTipLines splits a readout at " · " into a heading and rows.
+func chartTipLines(readout string) []ChartTooltipLine {
+	var out []ChartTooltipLine
+	for _, s := range strings.Split(readout, " · ") {
+		out = append(out, ChartTooltipLine{Text: s})
+	}
+	return out
+}