termdash/widgets/linechart/linechartdemo/linechartdemo.go

114 lines
2.9 KiB
Go

// Copyright 2019 Google Inc.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
// Binary linechartdemo displays a linechart widget.
// Exist when 'q' is pressed.
package main
import (
"context"
"math"
"time"
"github.com/mum4k/termdash"
"github.com/mum4k/termdash/cell"
"github.com/mum4k/termdash/container"
"github.com/mum4k/termdash/linestyle"
"github.com/mum4k/termdash/terminal/termbox"
"github.com/mum4k/termdash/terminal/terminalapi"
"github.com/mum4k/termdash/widgets/linechart"
)
// sineInputs generates values from -1 to 1 for display on the line chart.
func sineInputs() []float64 {
var res []float64
for i := 0; i < 200; i++ {
v := math.Sin(float64(i) / 100 * math.Pi)
res = append(res, v)
}
return res
}
// playLineChart continuously adds values to the LineChart, once every delay.
// Exits when the context expires.
func playLineChart(ctx context.Context, lc *linechart.LineChart, delay time.Duration) {
inputs := sineInputs()
ticker := time.NewTicker(delay)
defer ticker.Stop()
for i := 0; ; {
select {
case <-ticker.C:
i = (i + 1) % len(inputs)
rotated := append(inputs[i:], inputs[:i]...)
if err := lc.Series("first", rotated,
linechart.SeriesCellOpts(cell.FgColor(cell.ColorBlue)),
linechart.SeriesXLabels(map[int]string{
0: "zero",
}),
); err != nil {
panic(err)
}
i2 := (i + 100) % len(inputs)
rotated2 := append(inputs[i2:], inputs[:i2]...)
if err := lc.Series("second", rotated2, linechart.SeriesCellOpts(cell.FgColor(cell.ColorWhite))); err != nil {
panic(err)
}
case <-ctx.Done():
return
}
}
}
func main() {
t, err := termbox.New()
if err != nil {
panic(err)
}
defer t.Close()
const redrawInterval = 250 * time.Millisecond
ctx, cancel := context.WithCancel(context.Background())
lc, err := linechart.New(
linechart.AxesCellOpts(cell.FgColor(cell.ColorRed)),
linechart.YLabelCellOpts(cell.FgColor(cell.ColorGreen)),
linechart.XLabelCellOpts(cell.FgColor(cell.ColorCyan)),
)
if err != nil {
panic(err)
}
go playLineChart(ctx, lc, redrawInterval/3)
c, err := container.New(
t,
container.Border(linestyle.Light),
container.BorderTitle("PRESS Q TO QUIT"),
container.PlaceWidget(lc),
)
if err != nil {
panic(err)
}
quitter := func(k *terminalapi.Keyboard) {
if k.Key == 'q' || k.Key == 'Q' {
cancel()
}
}
if err := termdash.Run(ctx, t, c, termdash.KeyboardSubscriber(quitter), termdash.RedrawInterval(redrawInterval)); err != nil {
panic(err)
}
}