elves/elvish

// Command widget allows manually testing a single widget.
package main

import (
    "flag"
    "fmt"
    "os"
    "strconv"

    "src.elv.sh/pkg/cli"
    "src.elv.sh/pkg/cli/term"
    "src.elv.sh/pkg/cli/tk"
    "src.elv.sh/pkg/ui"
)

var (
    maxHeight  = flag.Int("max-height", 10, "maximum height")
    horizontal = flag.Bool("horizontal", false, "use horizontal listbox layout")
)

func makeWidget() tk.Widget {
    items := tk.TestItems{Prefix: "list item "}
    w := tk.NewComboBox(tk.ComboBoxSpec{
        CodeArea: tk.CodeAreaSpec{
            Prompt: func() ui.Text {
                return ui.Concat(ui.T(" NUMBER ", ui.Bold, ui.BgMagenta), ui.T(" "))
            },
        },
        ListBox: tk.ListBoxSpec{
            State:       tk.ListBoxState{Items: &items},
            Placeholder: ui.T("(no items)"),
            Horizontal:  *horizontal,
        },
        OnFilter: func(w tk.ComboBox, filter string) {
            if n, err := strconv.Atoi(filter); err == nil {
                items.NItems = n
            }
        },
    })
    return w
}

func main() {
    flag.Parse()
    widget := makeWidget()

    tty := cli.NewTTY(os.Stdin, os.Stderr)
    restore, err := tty.Setup()
    if err != nil {
        fmt.Fprintln(os.Stderr, err)
        return
    }
    defer restore()
    defer tty.CloseReader()
    for {
        h, w := tty.Size()
        if h > *maxHeight {
            h = *maxHeight
        }
        tty.UpdateBuffer(nil, widget.Render(w, h), false)
        event, err := tty.ReadEvent()
        if err != nil {
            errBuf := term.NewBufferBuilder(w).Write(err.Error(), ui.FgRed).Buffer()
            tty.UpdateBuffer(nil, errBuf, true)
            break
        }
        handled := widget.Handle(event)
        if !handled && event == term.K('D', ui.Ctrl) {
            tty.UpdateBuffer(nil, term.NewBufferBuilder(w).Buffer(), true)
            break
        }
    }
}