From 90669b36f149c3f2c0bdd6e0e7f5b9ff0a52d919 Mon Sep 17 00:00:00 2001
From: Martyn R <m@rtyn.berlin>
Date: Thu, 23 Dec 2021 15:58:11 +0000
Subject: [PATCH] half-working peakMeter, minsize settable

---
 examples/nuvumeter/main.go |  4 +++
 pkg/numeter/numeter.go     | 52 +++++++++++++++++++++++++++++++++++++-
 2 files changed, 55 insertions(+), 1 deletion(-)

diff --git a/examples/nuvumeter/main.go b/examples/nuvumeter/main.go
index 80cc483..9910b66 100644
--- a/examples/nuvumeter/main.go
+++ b/examples/nuvumeter/main.go
@@ -1,6 +1,8 @@
 package main
 
 import (
+	"time"
+
 	"fyne.io/fyne/v2/app"
 	"fyne.io/fyne/v2/container"
 	"fyne.io/fyne/v2/data/binding"
@@ -16,6 +18,7 @@ func main() {
 	levelPB := numeter.NewVUMeterWithData(level)
 	level.Set(0.95)
 	levelPB.TextFormatter = func() string { return "                                                            " }
+	levelPB.Peakhold = 3 * time.Second
 	progress := widget.NewProgressBarWithData(level)
 	setLevel := binding.NewFloat()
 	setLevel.Set(75.0)
@@ -26,6 +29,7 @@ func main() {
 
 	vLevelPB := numeter.NewVUMeterWithData(level)
 	vLevelPB.VUMeterDirection = numeter.VUMeterVertical
+	levelPB.Peakhold = 3 * time.Second
 	levelPB.TextFormatter = func() string { return "                                                            " }
 	contain := container.New(layout.NewVBoxLayout(), levelPB, progress, slider)
 	w.SetContent(container.New(layout.NewHBoxLayout(), contain, vLevelPB))
diff --git a/pkg/numeter/numeter.go b/pkg/numeter/numeter.go
index b57d5b3..1560830 100644
--- a/pkg/numeter/numeter.go
+++ b/pkg/numeter/numeter.go
@@ -1,9 +1,11 @@
 package numeter
 
 import (
+	"fmt"
 	"image"
 	"image/color"
 	"math"
+	"time"
 
 	"fyne.io/fyne/v2"
 	"fyne.io/fyne/v2/canvas"
@@ -14,6 +16,8 @@ import (
 
 type vuRenderer struct {
 	currentframe *canvas.Raster
+	lastPeakTime time.Time
+	lastPeakVal  float64
 	meter        *vuMeter
 }
 
@@ -59,6 +63,34 @@ func vuSet(i *image.RGBA, w int, h int, o VUMeterDirectionEnum, val float64, col
 	}
 }
 
+func drawPeakBar(i *image.RGBA, w int, h int, o VUMeterDirectionEnum, val float64, colGrn color.Color, colAmber color.Color, colRed color.Color) {
+	valPixel := int(math.Round(float64(w) * val))
+	c := colGrn
+	if o == VUMeterVertical {
+		valPixel = int(math.Round(float64(h) * val))
+		if float64(valPixel)/float64(h) > 0.75 {
+			c = colAmber
+		}
+		if float64(valPixel)/float64(h) > 0.85 {
+			c = colRed
+		}
+		for x := 0; x < w; x++ {
+			i.Set(x, valPixel-h, c)
+		}
+	} else {
+		valPixel = int(math.Round(float64(w) * val))
+		if float64(valPixel)/float64(w) > 0.75 {
+			c = colAmber
+		}
+		if float64(valPixel)/float64(w) > 0.85 {
+			c = colRed
+		}
+		for y := 0; y < h; y++ {
+			i.Set(valPixel, y, c)
+		}
+	}
+}
+
 func (v *vuRenderer) Render(w int, h int) image.Image {
 	i := image.NewRGBA(image.Rect(0, 0, w, h))
 	g := color.RGBA{0, 0x1f, 0, 0xff}
@@ -70,6 +102,20 @@ func (v *vuRenderer) Render(w int, h int) image.Image {
 	r = color.RGBA{0xff, 0, 0, 0xff}
 	val := (v.meter.Value - v.meter.Min) / (v.meter.Max - v.meter.Min) * 100
 	vuSet(i, w, h, v.meter.VUMeterDirection, val, g, a, r)
+	if v.meter.Value > v.lastPeakVal {
+		fmt.Printf("New peak: %f, expires at %s\n", v.meter.Value, time.Now().Add(v.meter.Peakhold))
+		v.lastPeakTime = time.Now()
+		v.lastPeakVal = v.meter.Value
+	}
+	if v.lastPeakTime.Add(v.meter.Peakhold).Before(time.Now()) {
+		fmt.Printf("Previous peak good, bar at %f\n", v.lastPeakVal)
+		drawPeakBar(i, w, h, v.meter.VUMeterDirection, v.lastPeakVal, g, a, r)
+	}
+	if v.lastPeakTime.Add(v.meter.Peakhold).After(time.Now()) {
+		fmt.Printf("Previous peak expired, holding at %f\n", v.meter.Value)
+		v.lastPeakVal = v.meter.Value
+		v.lastPeakTime = time.Now()
+	}
 	return i
 }
 
@@ -113,6 +159,7 @@ type vuMeter struct {
 	TextFormatter func() string
 	Value, Min, Max,
 	OptimumValueMin, OptimumValueMax float64
+	Peakhold         time.Duration
 	VUMeterDirection VUMeterDirectionEnum
 
 	binder basicBinder
@@ -120,9 +167,11 @@ type vuMeter struct {
 
 func NewVUMeterRenderer(m *vuMeter) *vuRenderer {
 	c := canvas.NewRaster(func(w int, h int) image.Image { return image.NewNRGBA(image.Rect(0, 0, 200, 200)) })
-	renderer := vuRenderer{c, m}
+	renderer := vuRenderer{c, time.Now(), 0, m}
 	c.Generator = renderer.Render
 	renderer.currentframe = c
+	renderer.lastPeakTime = time.Now()
+	renderer.lastPeakVal = 0
 
 	return &renderer
 }
@@ -182,6 +231,7 @@ func NewVUMeter(value float64) *vuMeter {
 	meter.Max = 100
 	meter.ExtendBaseWidget(meter)
 	meter.VUMeterDirection = VUMeterHorizontal
+	meter.Peakhold = 0
 	return meter
 }