Application icon

The Icon field on AppConfig is the one place to configure the icon shown by the OS while your app is running: macOS dock, Windows taskbar and title bar, Linux window manager.

g.RunWithConfig(g.AppConfig{
    Title: "Notes",
    Icon:  "assets/icon.png",
}, App)

Missing files are a silent no-op, so a forgotten asset never crashes the app — the OS simply shows its default placeholder.

On macOS, Gova calls [NSApp setApplicationIconImage:] directly, so the dock icon updates for unbundled binaries too — including processes started by go run. Fyne's own SetIcon does not do this, so if you set the icon through Fyne alone the dock keeps the default Go terminal icon.

Recommended asset

One square PNG with transparency, either 256×256 or 512×512. Fyne scales the same resource up and down for every surface (dock, taskbar, title bar, about box), so there is no need to ship multiple sizes at runtime.

Embedding with go:embed

Shipping a single-file binary is cleaner than a binary plus a sibling PNG. Use IconBytes with embed.FS:

package main
 
import (
    _ "embed"
 
    g "github.com/nv404/gova"
)
 
//go:embed assets/icon.png
var appIcon []byte
 
func main() {
    g.RunWithConfig(g.AppConfig{
        Title:     "Notes",
        IconBytes: appIcon,
    }, App)
}

IconBytes takes precedence over Icon when both are set.

Bundling for distribution

The runtime icon above is what the OS shows while the app is running. It is not what the Finder or Start menu shows for the binary itself — that comes from platform bundle metadata.

macOS (.app bundle). Use Fyne's packager:

go install fyne.io/tools/cmd/fyne@latest
fyne package -os darwin -icon assets/icon.png -name "Notes"

This produces Notes.app with the icon embedded as Icon.icns.

Windows (.exe resource).

fyne package -os windows -icon assets/icon.png -name "Notes"

Embeds the PNG as a Windows resource so Explorer shows it.

Linux (.desktop + tarball).

fyne package -os linux -icon assets/icon.png -name "Notes"

Produces a tarball with a .desktop file pointing at the icon.

You usually want both AppConfig.Icon (for the running process) and the packaged icon (for the binary on disk). They can be the same PNG.

Changing the icon at runtime

There is no supported API for replacing the icon after Run has started. If you need per-window icons (a browser-style favicon), open an issue describing the use case — most desktop conventions push you toward a single stable identity instead.