WIP components (as built)

drawing_tools.go

@@ -10,7 +10,7 @@ import (
 	"github.com/egoist/mygo/ui"
 )
 
-// DrawingTool is what clicks on a price chart do. The zero value selects and moves drawings.
+// DrawingTool selects annotation creation or selection behavior.
 type DrawingTool int
 
 const (
@@ -22,7 +22,7 @@ const (
 	ToolText
 )
 
-// DrawingPoint anchors a drawing at a candle time and a price, so it survives panning and new data.
+// DrawingPoint anchors annotations to candle time and price.
 type DrawingPoint struct {
 	Time  time.Time
 	Price float64
@@ -35,7 +35,7 @@ type Drawing struct {
 	Text string
 }
 
-// DrawingTools is the caller-held set of drawings, the current tool and an undo history.
+// DrawingTools holds annotations, the current tool, and undo history.
 type DrawingTools struct {
 	Items []Drawing
 	Tool  DrawingTool
@@ -50,7 +50,7 @@ type DrawingTools struct {
 	moving  bool
 }
 
-// fibLevels are the retracement ratios drawn between a Fibonacci's two points.
+// fibLevels lists Fibonacci retracement ratios.
 var fibLevels = []float64{0, 0.236, 0.382, 0.5, 0.618, 0.786, 1}
 
 // Selected returns the selected drawing's index, or -1.
@@ -63,10 +63,10 @@ func (d *DrawingTools) save() {
 	d.undo = append(d.undo, slices.Clone(d.Items))
 }
 
-// Undo restores the drawings before the last change and reports whether there was one.
+// Undo restores the preceding annotations unless locked.
 func (d *DrawingTools) Undo() bool {
 	n := len(d.undo)
-	if n == 0 {
+	if d.Locked || n == 0 {
 		return false
 	}
 	d.Items, d.undo = d.undo[n-1], d.undo[:n-1]
@@ -103,12 +103,12 @@ func (t DrawingTool) twoPoint() bool {
 	return t == ToolTrendLine || t == ToolFibonacci || t == ToolRectangle
 }
 
-// point turns a plot position into a drawing point on the nearest candle.
+// point maps plot coordinates onto the nearest candle.
 func (d *DrawingTools) point(m *mktCore, g mktGeom, x, y float32) DrawingPoint {
 	return DrawingPoint{Time: m.candles[g.index(m, x)].Time, Price: m.priceAt(g.ys.Invert(y))}
 }
 
-// priceAt turns an axis value back into a price, rounded to the decimals.
+// priceAt resolves an axis value into a rounded price.
 func (m *mktCore) priceAt(v float64) float64 {
 	if m.base != 0 {
 		v = m.base * (1 + v/100)
@@ -123,11 +123,19 @@ func (d *DrawingTools) xy(m *mktCore, g mktGeom, pt DrawingPoint) (float32, floa
 	return g.x(m, i), g.ys.Map(m.val(pt.Price))
 }
 
-// input places, selects, drags, nudges and deletes drawings; it reports taking the pointer.
+// input places, selects, moves, and deletes chart annotations.
 func (d *DrawingTools) input(m *mktCore, plot *ui.Element, g mktGeom, x, y float32, over, held bool, dx, dy float32) bool {
 	if d.Tool < ToolSelect || d.Tool > ToolText {
 		panic(fmt.Sprintf("mujica: unknown DrawingTool %d", d.Tool))
 	}
+	if d.pending != nil && d.pending.Tool != d.Tool {
+		d.pending, d.moving = nil, false
+	}
+	if plot.Shortcut(ui.Alt, ui.KeyEnter) && !d.Locked && len(d.Items) > 0 {
+		d.sel = d.sel%len(d.Items) + 1
+		m.st.alertFocus = -1
+		m.c.Announce(fmt.Sprintf(msg(m.c, "drawing_tools.selected"), d.sel))
+	}
 	if plot.Shortcut(ui.Cmd, ui.KeyZ) {
 		d.Undo()
 	}
@@ -155,22 +163,7 @@ func (d *DrawingTools) input(m *mktCore, plot *ui.Element, g mktGeom, x, y float
 	}
 	if plot.Clicked() && d.Tool != ToolSelect {
 		pt := d.point(m, g, x, y)
-		switch {
-		case d.Tool.twoPoint() && d.pending == nil:
-			d.pending = &Drawing{Tool: d.Tool, A: pt, B: pt}
-		default:
-			item := Drawing{Tool: d.Tool, A: pt, B: pt, Text: d.Text}
-			if d.pending != nil {
-				item.A = d.pending.A
-			}
-			if d.Tool == ToolText && item.Text == "" {
-				item.Text = msg(m.c, "drawing_tools.note")
-			}
-			d.save()
-			d.Items = append(slices.Clone(d.Items), item)
-			d.sel, d.pending, d.Tool = len(d.Items), nil, ToolSelect
-			slog.Debug("mujica: drawing_tools add", "tool", item.Tool)
-		}
+		d.place(m, pt)
 		return true
 	}
 	if d.pending != nil {
@@ -203,7 +196,7 @@ func (d *DrawingTools) input(m *mktCore, plot *ui.Element, g mktGeom, x, y float
 	return true
 }
 
-// nudge moves item i by candles and price, keeping it on the chart's candles.
+// nudge moves annotations by candles and price.
 func (d *DrawingTools) nudge(m *mktCore, i, candles int, price float64) {
 	it := &d.Items[i]
 	move := func(pt *DrawingPoint) {
@@ -214,7 +207,7 @@ func (d *DrawingTools) nudge(m *mktCore, i, candles int, price float64) {
 	move(&it.B)
 }
 
-// hit returns the drawing within 6 DIPs of (x, y), newest first, or -1.
+// hit finds the newest annotation within 6 DIPs.
 func (d *DrawingTools) hit(m *mktCore, g mktGeom, x, y float32) int {
 	for i := len(d.Items) - 1; i >= 0; i-- {
 		it := d.Items[i]
@@ -239,7 +232,7 @@ func (d *DrawingTools) hit(m *mktCore, g mktGeom, x, y float32) int {
 	return -1
 }
 
-// drawingSegmentDist is the distance from (x, y) to the segment a-b.
+// drawingSegmentDist measures distance to a line segment.
 func drawingSegmentDist(x, y, ax, ay, bx, by float32) float64 {
 	vx, vy := float64(bx-ax), float64(by-ay)
 	t := 0.0
@@ -248,3 +241,22 @@ func drawingSegmentDist(x, y, ax, ay, bx, by float32) float64 {
 	}
 	return math.Hypot(float64(x-ax)-t*vx, float64(y-ay)-t*vy)
 }
+
+func (d *DrawingTools) place(m *mktCore, pt DrawingPoint) {
+	if d.Tool.twoPoint() && d.pending == nil {
+		d.pending = &Drawing{Tool: d.Tool, A: pt, B: pt}
+	} else {
+		item := Drawing{Tool: d.Tool, A: pt, B: pt, Text: d.Text}
+		if d.pending != nil {
+			item.A = d.pending.A
+		}
+		if d.Tool == ToolText && item.Text == "" {
+			item.Text = msg(m.c, "drawing_tools.note")
+		}
+		d.save()
+		d.Items = append(slices.Clone(d.Items), item)
+		d.sel, d.pending, d.Tool = len(d.Items), nil, ToolSelect
+		slog.Debug("mujica: drawing_tools add", "tool", item.Tool)
+	}
+	m.c.Invalidate()
+}