bubbles/input/input.go
2020-01-29 21:52:03 -05:00

112 lines
1.9 KiB
Go

package input
import (
"time"
"github.com/charmbracelet/tea"
)
type Model struct {
Prompt string
Value string
Cursor string
HiddenCursor string
BlinkSpeed time.Duration
blink bool
pos int
}
type CursorBlinkMsg struct{}
func DefaultModel() Model {
return Model{
Prompt: "> ",
Value: "",
BlinkSpeed: time.Millisecond * 600,
blink: false,
pos: 0,
}
}
func Update(msg tea.Msg, m Model) (Model, tea.Cmd) {
switch msg := msg.(type) {
case tea.KeyMsg:
switch msg.Type {
case tea.KeyBackspace:
fallthrough
case tea.KeyDelete:
if len(m.Value) > 0 {
m.Value = m.Value[:m.pos-1] + m.Value[m.pos:]
m.pos--
}
return m, nil
case tea.KeyLeft:
if m.pos > 0 {
m.pos--
}
return m, nil
case tea.KeyRight:
if m.pos < len(m.Value) {
m.pos++
}
return m, nil
case tea.KeyCtrlA: // ^A, beginning
m.pos = 0
return m, nil
case tea.KeyCtrlE: // ^E, end
m.pos = len(m.Value) - 1
return m, nil
case tea.KeyCtrlK: // ^K, kill text after cursor
m.Value = m.Value[:m.pos]
m.pos = len(m.Value)
return m, nil
case tea.KeyRune:
m.Value = m.Value[:m.pos] + msg.String() + m.Value[m.pos:]
m.pos++
return m, nil
default:
return m, nil
}
case CursorBlinkMsg:
m.blink = !m.blink
return m, nil
default:
return m, nil
}
}
func View(model tea.Model) string {
m, _ := model.(Model)
v := m.Value[:m.pos]
if m.pos < len(m.Value) {
v += cursor(string(m.Value[m.pos]), m.blink)
v += m.Value[m.pos+1:]
} else {
v += cursor(" ", m.blink)
}
return m.Prompt + v
}
// Style the cursor
func cursor(s string, blink bool) string {
if blink {
return s
}
return tea.Invert(s)
}
// Subscription
func Blink(model tea.Model) tea.Msg {
m, ok := model.(Model)
if !ok {
return tea.NewErrMsg("could not assert given model to the model we expected; make sure you're passing as input model")
}
time.Sleep(m.BlinkSpeed)
return CursorBlinkMsg{}
}