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ProgressBar

widget.ProgressBar renders a horizontal progress indicator for values between 0.0 and 1.0. It is a display-only widget with no interactive key bindings.

Basic usage​

pb := widget.NewProgressBar()
pb.SetValue(0.65)   // 65%

Builder options​

MethodDescription
WithStyle(s latte.Style)Override the display style (colour, background)
WithID(id string)Set a stable identifier for Canvas.GetValue(id)
WithShowPercent(show bool)Show or hide the 100% label at the right edge (default true)
WithFillChar(r rune)Rune used for the filled portion (default █)
WithEmptyChar(r rune)Rune used for the empty portion (default ░)

Hide the percentage label​

pb := widget.NewProgressBar().WithShowPercent(false)

Custom fill characters​

pb := widget.NewProgressBar().
    WithFillChar('=').
    WithEmptyChar('-')
// Renders as:  ======-------- 60%

Per-item colour​

After theme application you can override the fill colour per-item using WithStyle:

pb := widget.NewProgressBar().
    WithStyle(latte.Style{FG: latte.ColorRed})

SetStyle is still available as a deprecated alias for WithStyle when you need to mutate the style after construction (e.g. in a list renderer).

In a flex layout​

ProgressBar grows to fill available horizontal space when given a flex weight:

row := layout.NewHBox()
row.AddChild(widget.NewText("Progress: "))
row.AddFlexChild(pb, 1)
row.AddChild(widget.NewText(" 4/10"))

Reading the value​

v := pb.Progress() // float64, 0.0–1.0

ProgressBar also implements oat.ValueGetter: Canvas.GetValue(id) returns the current value as a float64.

Updating from a goroutine​

SetValue is safe to call from any goroutine. After updating, send to app.NotifyChannel() to trigger a re-render:

go func() {
    for i := 0; i <= 100; i++ {
        pb.SetValue(float64(i) / 100.0)
        app.NotifyChannel() <- time.Now()
        time.Sleep(50 * time.Millisecond)
    }
}()