WIP mktchart 1

chart_sync.go

@@ -0,0 +1,107 @@
+package mujica
+
+import (
+	"log/slog"
+	"time"
+
+	"github.com/egoist/mygo/ui"
+
+	"mujicaui/internal"
+	"mujicaui/theme"
+)
+
+// ChartSync links charts by time: the same window, zoom and crosshair. The caller holds it.
+type ChartSync struct {
+	// Count is the linked zoom in candles; zero is the default 120.
+	Count int
+	// End is the newest linked time shown; zero follows each chart's newest candle.
+	End time.Time
+	// Cursor is the crosshair time; zero shows none.
+	Cursor time.Time
+	// Unlinked charts keep their own view and crosshair.
+	Unlinked map[string]bool
+	owner    string
+}
+
+func (s *ChartSync) linked(id string) bool { return !s.Unlinked[id] }
+
+// load puts the linked window into view before a chart builds.
+func (s *ChartSync) load(id string, candles []Candle, view *MarketView) {
+	if !s.linked(id) {
+		return
+	}
+	view.Count, view.End = s.Count, 0
+	if !s.End.IsZero() {
+		if i := marketIndexAt(candles, s.End); i+1 < len(candles) {
+			view.End = max(1, i+1)
+		}
+	}
+}
+
+// store writes a linked chart's window and crosshair back after it builds.
+func (s *ChartSync) store(id string, candles []Candle, view *MarketView, active int) {
+	if !s.linked(id) {
+		return
+	}
+	s.Count = view.Count
+	s.End = time.Time{}
+	if view.End > 0 && view.End <= len(candles) {
+		s.End = candles[view.End-1].Time
+	}
+	switch {
+	case active >= 0:
+		s.Cursor, s.owner = candles[active].Time, id
+	case s.owner == id:
+		s.Cursor, s.owner = time.Time{}, ""
+	}
+}
+
+// cursorIndex is the candle at the linked crosshair, or -1.
+func (s *ChartSync) cursorIndex(id string, candles []Candle) int {
+	if !s.linked(id) || s.Cursor.IsZero() || s.owner == id {
+		return -1
+	}
+	return marketIndexAt(candles, s.Cursor)
+}
+
+// Link builds a toggle that links or unlinks chart id; Changed reports a switch.
+func (s *ChartSync) Link(c *ui.Context, id string) ChoiceResult {
+	if id == "" {
+		panic("mujica: ChartSync.Link needs an id")
+	}
+	k := Tokens(c)
+	on := s.linked(id)
+	pressed := on
+	b := ui.ToggleBase(c, &pressed).MinHeight(theme.MinHitSize).Padding(0, Density(c).Unit()*2).Gap(Density(c).Unit()).
+		Radius(theme.ControlRadius).Label(msg(c, "chart_sync.link"))
+	internal.Ring(b, k.Focus, theme.ControlRadius)
+	changed := b.Changed() && !b.IsDisabled()
+	if changed {
+		if s.Unlinked == nil {
+			s.Unlinked = map[string]bool{}
+		}
+		on = pressed
+		s.Unlinked[id] = !on
+		if s.owner == id {
+			s.Cursor, s.owner = time.Time{}, ""
+		}
+		slog.Debug("mujica: chart_sync link", "chart", id, "linked", on)
+	}
+	fg, bg, word := k.TextMuted, ui.Transparent, msg(c, "chart_sync.unlinked")
+	if on {
+		fg, bg, word = k.AccentText, k.Selection, msg(c, "chart_sync.linked")
+	}
+	if b.Hovered() && !on {
+		bg = k.SurfaceHover
+	}
+	b.Background(bg).TextColor(fg).Border(theme.BorderWidth, fg).Transition(colorFade)
+	b.Children(func() {
+		mark := "circle"
+		if on {
+			mark = "check"
+		}
+		ui.Box(c).Size(14, 14).Draw(func(p *ui.Painter, r ui.Rect) { internal.Mark(p, r, mark, fg) })
+		ui.Text(c, word).FontSize(FontSize(c, theme.CaptionSize)).SingleLine()
+	})
+	return ChoiceResult{b, changed}
+}