package main

import (
        "log"
        "os"

        "gioui.org/app"
        "gioui.org/io/system"
)

func main() {
        go func() {
                w := new(app.Window)
                w.Perform(system.ActionRaise)
                if err := loop(w); err != nil {
                        log.Fatal(err)
                }
                os.Exit(0)
        }()
        app.Main()
}

func loop(w *app.Window) error {
        go func() {
                for {
                        w.Invalidate()
                }
        }()
        for {
                switch e := w.Event().(type) {
                case app.DestroyEvent:
                        return e.Err
                case app.FrameEvent:
                        // Crash if we actually get a frame event, to make it easier
                        // to spot a successful run.
                        log.Fatal(e)
                }
        }
}