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

chart/chart_tooltip.go

@@ -0,0 +1,97 @@
+package chart
+
+import (
+	"strings"
+
+	"github.com/egoist/mygo/ui"
+
+	"github.com/ZacharyZhang-NY/MujicaUI/core"
+	"github.com/ZacharyZhang-NY/MujicaUI/internal"
+	"github.com/ZacharyZhang-NY/MujicaUI/theme"
+)
+
+// ChartTooltipLine pairs readout text with an optional marker.
+type ChartTooltipLine struct {
+	Text  string
+	Color ui.Color
+	Shape int
+}
+
+// ChartTooltip shows readouts beside a window point, 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 := core.Tokens(c)
+	u := core.Density(c).Unit()
+	size := core.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()
+	w, h = min(w, max(1, ww-8)), min(h, max(1, wh-8))
+	left, top := core.PlaceOverlay(c, ui.Rect{X: x, Y: y}, w, h, gap)
+	if x+gap+w <= ww-4 {
+		left = max(4, x+gap)
+	} else {
+		left = max(4, min(x-gap-w, ww-4-w))
+	}
+	var tip *ui.Element
+	ui.Overlay(c, func() {
+		tip = ui.Column(c).Absolute().Left(left).Top(top).Size(w, h).Role(ui.RoleNone)
+		core.OverlayStyle(c, tip, core.OverlayEnter(c, tip))
+		tip.Children(func() {
+			inner := max(1, w-2*pad)
+			content := float32(0)
+			for i, l := range lines {
+				width := inner
+				if l.Color.A > 0 {
+					width = max(1, width-14)
+				}
+				_, lh[i] = c.MeasureText(width, ui.Span{Text: l.Text, Size: size, Weight: chartTipWeight(i)})
+				content += lh[i]
+			}
+			ui.Scroll(c).Fill().Padding(pad).Children(func() {
+				ui.Box(c).Width(inner).Height(content).Shrink(0).Draw(func(p *ui.Painter, r ui.Rect) {
+					at := r.Y
+					for i, l := range lines {
+						tx, width := r.X, inner
+						if l.Color.A > 0 {
+							internal.Marker(p, l.Shape, tx+5, at+lh[i]/2, 9, l.Color)
+							tx, width = tx+14, max(1, width-14)
+						}
+						p.RichText(tx, at, width, 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 into tooltip lines.
+func chartTipLines(readout string) []ChartTooltipLine {
+	var out []ChartTooltipLine
+	for _, s := range strings.Split(readout, " · ") {
+		out = append(out, ChartTooltipLine{Text: s})
+	}
+	return out
+}