termui/barchart.go
2016-10-14 13:48:50 +02:00

150 lines
3.4 KiB
Go

// Copyright 2016 Zack Guo <gizak@icloud.com>. All rights reserved.
// Use of this source code is governed by a MIT license that can
// be found in the LICENSE file.
package termui
import "fmt"
// BarChart creates multiple bars in a widget:
/*
bc := termui.NewBarChart()
data := []int{3, 2, 5, 3, 9, 5}
bclabels := []string{"S0", "S1", "S2", "S3", "S4", "S5"}
bc.BorderLabel = "Bar Chart"
bc.Data = data
bc.Width = 26
bc.Height = 10
bc.DataLabels = bclabels
bc.TextColor = termui.ColorGreen
bc.BarColor = termui.ColorRed
bc.NumColor = termui.ColorYellow
*/
type BarChart struct {
Block
BarColor Attribute
TextColor Attribute
NumColor Attribute
Data []int
DataLabels []string
BarWidth int
BarGap int
CellChar rune
labels [][]rune
dataNum [][]rune
numBar int
scale float64
max int
}
// NewBarChart returns a new *BarChart with current theme.
func NewBarChart() *BarChart {
bc := &BarChart{Block: *NewBlock()}
bc.BarColor = ThemeAttr("barchart.bar.bg")
bc.NumColor = ThemeAttr("barchart.num.fg")
bc.TextColor = ThemeAttr("barchart.text.fg")
bc.BarGap = 1
bc.BarWidth = 3
bc.CellChar = ' '
return bc
}
func (bc *BarChart) layout() {
bc.numBar = bc.innerArea.Dx() / (bc.BarGap + bc.BarWidth)
bc.labels = make([][]rune, bc.numBar)
bc.dataNum = make([][]rune, len(bc.Data))
for i := 0; i < bc.numBar && i < len(bc.DataLabels) && i < len(bc.Data); i++ {
bc.labels[i] = trimStr2Runes(bc.DataLabels[i], bc.BarWidth)
n := bc.Data[i]
s := fmt.Sprint(n)
bc.dataNum[i] = trimStr2Runes(s, bc.BarWidth)
}
//bc.max = bc.Data[0] // what if Data is nil? Sometimes when bar graph is nill it produces panic with panic: runtime error: index out of range
// Asign a negative value to get maxvalue auto-populates
if bc.max == 0 {
bc.max = -1
}
for i := 0; i < len(bc.Data); i++ {
if bc.max < bc.Data[i] {
bc.max = bc.Data[i]
}
}
bc.scale = float64(bc.max) / float64(bc.innerArea.Dy()-1)
}
func (bc *BarChart) SetMax(max int) {
if max > 0 {
bc.max = max
}
}
// Buffer implements Bufferer interface.
func (bc *BarChart) Buffer() Buffer {
buf := bc.Block.Buffer()
bc.layout()
for i := 0; i < bc.numBar && i < len(bc.Data) && i < len(bc.DataLabels); i++ {
h := int(float64(bc.Data[i]) / bc.scale)
oftX := i * (bc.BarWidth + bc.BarGap)
barBg := bc.Bg
barFg := bc.BarColor
if bc.CellChar == ' ' {
barBg = bc.BarColor
barFg = ColorDefault
if bc.BarColor == ColorDefault { // the same as above
barBg |= AttrReverse
}
}
// plot bar
for j := 0; j < bc.BarWidth; j++ {
for k := 0; k < h; k++ {
c := Cell{
Ch: bc.CellChar,
Bg: barBg,
Fg: barFg,
}
x := bc.innerArea.Min.X + i*(bc.BarWidth+bc.BarGap) + j
y := bc.innerArea.Min.Y + bc.innerArea.Dy() - 2 - k
buf.Set(x, y, c)
}
}
// plot text
for j, k := 0, 0; j < len(bc.labels[i]); j++ {
w := charWidth(bc.labels[i][j])
c := Cell{
Ch: bc.labels[i][j],
Bg: bc.Bg,
Fg: bc.TextColor,
}
y := bc.innerArea.Min.Y + bc.innerArea.Dy() - 1
x := bc.innerArea.Min.X + oftX + k
buf.Set(x, y, c)
k += w
}
// plot num
for j := 0; j < len(bc.dataNum[i]); j++ {
c := Cell{
Ch: bc.dataNum[i][j],
Fg: bc.NumColor,
Bg: barBg,
}
if h == 0 {
c.Bg = bc.Bg
}
x := bc.innerArea.Min.X + oftX + (bc.BarWidth-len(bc.dataNum[i]))/2 + j
y := bc.innerArea.Min.Y + bc.innerArea.Dy() - 2
buf.Set(x, y, c)
}
}
return buf
}