Anatomy of a Fyne application

As we saw in Chapter 2, The Future According to Fyne, the toolkit took the opportunity to start from scratch, throwing away the old and sometimes confusing constraints of previous toolkits. As a result, the APIs need to define everything involved in building a graphical application. In this section, we will explore the main concepts in running a Fyne-based application and producing visible components on screen, starting with the application itself.

Application

The application, defined in the fyne.App interface, models the capabilities of a Fyne-based application. Each app using Fyne will typically create and run a single fyne.App instance from within their main() function. Because of the way that graphical applications work, they must be started from the main function and not through a goroutine or other background thread.

To create an app instance, we make use of the app package within Fyne, which can be imported using fyne.io/fyne/v2/app. This...