feat!: rewrote the GUI and model for better testability

The Model was getting unmaintanable mess. This is an attempt to refactor/rewrite the Model so that data of certain type is exposed in standardized way, offering certain standard manipulations for that data type, and on the GUI side, certain standard widgets to tied to that data.

This rewrite closes #72, #106 and #120.

tracker/gioui/popup_alert.go

@@ -0,0 +1,81 @@
+package gioui
+
+import (
+	"image"
+	"image/color"
+	"time"
+
+	"gioui.org/layout"
+	"gioui.org/op"
+	"gioui.org/op/clip"
+	"gioui.org/op/paint"
+	"gioui.org/text"
+	"gioui.org/unit"
+	"github.com/vsariola/sointu/tracker"
+)
+
+type PopupAlert struct {
+	alerts     *tracker.Alerts
+	prevUpdate time.Time
+	shaper     *text.Shaper
+}
+
+var alertSpeed = 150 * time.Millisecond
+var alertMargin = layout.UniformInset(unit.Dp(6))
+var alertInset = layout.UniformInset(unit.Dp(6))
+
+func NewPopupAlert(alerts *tracker.Alerts, shaper *text.Shaper) *PopupAlert {
+	return &PopupAlert{alerts: alerts, shaper: shaper, prevUpdate: time.Now()}
+}
+
+func (a *PopupAlert) Layout(gtx C) D {
+	now := time.Now()
+	if a.alerts.Update(now.Sub(a.prevUpdate)) {
+		op.InvalidateOp{At: now.Add(50 * time.Millisecond)}.Add(gtx.Ops)
+	}
+	a.prevUpdate = now
+
+	var totalY float64
+	a.alerts.Iterate(func(alert tracker.Alert) {
+		var color, textColor, shadeColor color.NRGBA
+		switch alert.Priority {
+		case tracker.Warning:
+			color = warningColor
+			textColor = black
+		case tracker.Error:
+			color = errorColor
+			textColor = black
+		default:
+			color = popupSurfaceColor
+			textColor = white
+			shadeColor = black
+		}
+		bgWidget := func(gtx C) D {
+			paint.FillShape(gtx.Ops, color, clip.Rect{
+				Max: gtx.Constraints.Min,
+			}.Op())
+			return D{Size: gtx.Constraints.Min}
+		}
+		labelStyle := LabelStyle{Text: alert.Message, Color: textColor, ShadeColor: shadeColor, Font: labelDefaultFont, Alignment: layout.Center, FontSize: unit.Sp(16), Shaper: a.shaper}
+		alertMargin.Layout(gtx, func(gtx C) D {
+			return layout.S.Layout(gtx, func(gtx C) D {
+				defer op.Offset(image.Point{}).Push(gtx.Ops).Pop()
+				gtx.Constraints.Min.X = gtx.Constraints.Max.X
+				recording := op.Record(gtx.Ops)
+				dims := layout.Stack{Alignment: layout.Center}.Layout(gtx,
+					layout.Expanded(bgWidget),
+					layout.Stacked(func(gtx C) D {
+						return alertInset.Layout(gtx, labelStyle.Layout)
+					}),
+				)
+				macro := recording.Stop()
+				delta := float64(dims.Size.Y + gtx.Dp(alertMargin.Bottom))
+				op.Offset(image.Point{0, int(-totalY*alert.FadeLevel + delta*(1-alert.FadeLevel))}).Add((gtx.Ops))
+				totalY += delta
+				macro.Add(gtx.Ops)
+				return dims
+			})
+		})
+	})
+	return D{}
+}