Application and RunLoop
For a GUI application to work it needs to run an event loop
(sometimes called a runloop) that processes user interactions
and drawing events. In Fyne this is started using the App.Run()
or Window.ShowAndRun() functions. One of these must be called
from the end of your setup code in the main() function.
An application should only have one runloop and so you should only
call Run() once in your code. Calling it a second time will cause
errors.
package main
import (
"fmt"
"fyne.io/fyne/v2/app"
"fyne.io/fyne/v2/widget"
)
func main() {
myApp := app.New()
myWindow := myApp.NewWindow("Hello")
myWindow.SetContent(widget.NewLabel("Hello"))
myWindow.Show()
myApp.Run()
tidyUp()
}
func tidyUp() {
fmt.Println("Exited")
}
For desktop runtimes an app can be quit directly by calling App.Quit()
(mobile apps do not support this) - normally not needed in developer code.
An application will also quit once all the windows are closed.
See also that functions executed after Run() will not be called
until the application exits.