1 files changed, 102 insertions, 0 deletions
diff --git a/termui/sparkline.go b/termui/sparkline.go
new file mode 100644
index 0000000..2f27d9e
--- /dev/null
+++ b/termui/sparkline.go
@@ -0,0 +1,102 @@
+package termui
+
+import (
+	"image"
+	"log"
+
+	. "github.com/gizak/termui/v3"
+)
+
+// Sparkline is like: ▅▆▂▂▅▇▂▂▃▆▆▆▅▃. The data points should be non-negative integers.
+type Sparkline struct {
+	Data       []int
+	Title1     string
+	Title2     string
+	TitleColor Color
+	LineColor  Color
+}
+
+// SparklineGroup is a renderable widget which groups together the given sparklines.
+type SparklineGroup struct {
+	*Block
+	Lines []*Sparkline
+}
+
+// Add appends a given Sparkline to the *SparklineGroup.
+func (self *SparklineGroup) Add(sl Sparkline) {
+	self.Lines = append(self.Lines, &sl)
+}
+
+// NewSparkline returns an unrenderable single sparkline that intended to be added into a SparklineGroup.
+func NewSparkline() *Sparkline {
+	return &Sparkline{}
+}
+
+// NewSparklineGroup return a new *SparklineGroup with given Sparklines, you can always add a new Sparkline later.
+func NewSparklineGroup(ss ...*Sparkline) *SparklineGroup {
+	return &SparklineGroup{
+		Block: NewBlock(),
+		Lines: ss,
+	}
+}
+
+func (self *SparklineGroup) Draw(buf *Buffer) {
+	self.Block.Draw(buf)
+
+	lc := len(self.Lines) // lineCount
+
+	// renders each sparkline and its titles
+	for i, line := range self.Lines {
+
+		// prints titles
+		title1Y := self.Inner.Min.Y + 1 + (self.Inner.Dy()/lc)*i
+		title2Y := self.Inner.Min.Y + 2 + (self.Inner.Dy()/lc)*i
+		title1 := TrimString(line.Title1, self.Inner.Dx())
+		title2 := TrimString(line.Title2, self.Inner.Dx())
+		if self.Inner.Dy() > 5 {
+			buf.SetString(
+				title1,
+				NewStyle(line.TitleColor, ColorClear, ModifierBold),
+				image.Pt(self.Inner.Min.X, title1Y),
+			)
+		}
+		if self.Inner.Dy() > 6 {
+			buf.SetString(
+				title2,
+				NewStyle(line.TitleColor, ColorClear, ModifierBold),
+				image.Pt(self.Inner.Min.X, title2Y),
+			)
+		}
+
+		sparkY := (self.Inner.Dy() / lc) * (i + 1)
+		// finds max data in current view used for relative heights
+		max := 1
+		for i := len(line.Data) - 1; i >= 0 && self.Inner.Dx()-((len(line.Data)-1)-i) >= 1; i-- {
+			if line.Data[i] > max {
+				max = line.Data[i]
+			}
+		}
+		// prints sparkline
+		for x := self.Inner.Dx(); x >= 1; x-- {
+			char := BARS[1]
+			if (self.Inner.Dx() - x) < len(line.Data) {
+				offset := self.Inner.Dx() - x
+				curItem := line.Data[(len(line.Data)-1)-offset]
+				percent := float64(curItem) / float64(max)
+				index := int(percent*float64(len(BARS)-2)) + 1
+				if index < 1 || index >= len(BARS) {
+					log.Printf(
+						"invalid sparkline data value. index: %v, percent: %v, curItem: %v, offset: %v",
+						index, percent, curItem, offset,
+					)
+				} else {
+					char = BARS[index]
+				}
+			}
+			buf.SetCell(
+				NewCell(char, NewStyle(line.LineColor)),
+				image.Pt(self.Inner.Min.X+x-1, self.Inner.Min.Y+sparkY-1),
+			)
+		}
+	}
+}