legend improvement: show +/- delta sign

config.yml

@@ -33,6 +33,7 @@ runcharts:
   - label: BING
     script: curl -o /dev/null -s -w '%{time_total}'  https://www.bing.com
 - title: MONGO COLLECTIONS COUNT
+  precision: 0
   position:
     w: 17
     h: 14
@@ -40,8 +41,10 @@ runcharts:
     w: 17
     h: 10
   items:
-  - label: POSTS
-    script: mongo --quiet --host=localhost blog --eval "db.getCollection('post').find({}).size()"
+  - label: ACTIVE
+    script: mongo --quiet --host=localhost blog --eval "db.getCollection('posts').find({status:'ACTIVE'}).size()"
+  - label: INACTIVE
+    script: mongo --quiet --host=localhost blog --eval "db.getCollection('posts').find({status:'INACTIVE'}).size()"
 asciiboxes:
 - title: COUNT
   position:

widgets/barchart/barchart.go

@@ -0,0 +1,83 @@
+package barchart
+
+//
+//import (
+//	"fmt"
+//	"image"
+//)
+//
+//type BarChart struct {
+//	Block
+//	BarColors   []Color
+//	LabelStyles []Style
+//	NumStyles   []Style // only Fg and Modifier are used
+//	NumFmt      func(float64) string
+//	Data        []float64
+//	Labels      []string
+//	BarWidth    int
+//	BarGap      int
+//	MaxVal      float64
+//}
+//
+//func NewBarChart() *BarChart {
+//	return &BarChart{
+//		Block:       *NewBlock(),
+//		BarColors:   Theme.BarChart.Bars,
+//		NumStyles:   Theme.BarChart.Nums,
+//		LabelStyles: Theme.BarChart.Labels,
+//		NumFmt:      func(n float64) string { return fmt.Sprint(n) },
+//		BarGap:      1,
+//		BarWidth:    3,
+//	}
+//}
+//
+//func (self *BarChart) Draw(buf *Buffer) {
+//	self.Block.Draw(buf)
+//
+//	maxVal := self.MaxVal
+//	if maxVal == 0 {
+//		maxVal, _ = GetMaxFloat64FromSlice(self.Data)
+//	}
+//
+//	barXCoordinate := self.Inner.Min.X
+//
+//	for i, data := range self.Data {
+//		// draw bar
+//		height := int((data / maxVal) * float64(self.Inner.Dy()-1))
+//		for x := barXCoordinate; x < MinInt(barXCoordinate+self.BarWidth, self.Inner.Max.X); x++ {
+//			for y := self.Inner.Max.Y - 2; y > (self.Inner.Max.Y-2)-height; y-- {
+//				c := NewCell(' ', NewStyle(ColorClear, SelectColor(self.BarColors, i)))
+//				buf.SetCell(c, image.Pt(x, y))
+//			}
+//		}
+//
+//		// draw label
+//		if i < len(self.Labels) {
+//			labelXCoordinate := barXCoordinate +
+//				int((float64(self.BarWidth) / 2)) -
+//				int((float64(rw.StringWidth(self.Labels[i])) / 2))
+//			buf.SetString(
+//				self.Labels[i],
+//				SelectStyle(self.LabelStyles, i),
+//				image.Pt(labelXCoordinate, self.Inner.Max.Y-1),
+//			)
+//		}
+//
+//		// draw number
+//		numberXCoordinate := barXCoordinate + int((float64(self.BarWidth) / 2))
+//		if numberXCoordinate <= self.Inner.Max.X {
+//			buf.SetString(
+//				self.NumFmt(data),
+//				NewStyle(
+//					SelectStyle(self.NumStyles, i+1).Fg,
+//					SelectColor(self.BarColors, i),
+//					SelectStyle(self.NumStyles, i+1).Modifier,
+//				),
+//				image.Pt(numberXCoordinate, self.Inner.Max.Y-2),
+//			)
+//		}
+//
+//		barXCoordinate += (self.BarWidth + self.BarGap)
+//	}
+//}
+//

widgets/runchart/legend.go

@@ -71,7 +71,7 @@ func (c *RunChart) renderLegend(buffer *ui.Buffer, rectangle image.Rectangle) {
 
 			details := [4]string{
 				fmt.Sprintf("cur  %s", formatValue(getCurrentValue(line), c.precision)),
-				fmt.Sprintf("dlt %s", formatValue(getDiffWithPreviousValue(line), c.precision)),
+				fmt.Sprintf("dlt %s", formatValueWithSign(getDiffWithPreviousValue(line), c.precision)),
 				fmt.Sprintf("max  %s", formatValue(line.extrema.max, c.precision)),
 				fmt.Sprintf("min  %s", formatValue(line.extrema.min, c.precision)),
 			}
@@ -102,7 +102,7 @@ func getDiffWithPreviousValue(line TimeLine) float64 {
 	if len(line.points) < 2 {
 		return 0
 	} else {
-		return math.Abs(line.points[len(line.points)-1].value - line.points[len(line.points)-2].value)
+		return line.points[len(line.points)-1].value - line.points[len(line.points)-2].value
 	}
 }
 

widgets/runchart/runchart.go

@@ -336,6 +336,16 @@ func formatValue(value float64, precision int) string {
 	}
 }
 
+func formatValueWithSign(value float64, precision int) string {
+	if value == 0 {
+		return " 0"
+	} else if value > 0 {
+		return "+" + formatValue(value, precision)
+	} else {
+		return formatValue(value, precision)
+	}
+}
+
 // time duration between grid lines
 func calculateTimescale(refreshRateMs int) time.Duration {