gio/app/app.go

// SPDX-License-Identifier: Unlicense OR MIT

package app

import (
	"os"
	"path/filepath"
	"strings"
)

// extraArgs contains extra arguments to append to
// os.Args. The arguments are separated with |.
// Useful for running programs on mobiles where the
// command line is not available.
// Set with the go linker flag -X.
var extraArgs string

// ID is the app id exposed to the platform.
//
// On Android ID is the package property of AndroidManifest.xml,
// on iOS ID is the CFBundleIdentifier of the app Info.plist,
// on Wayland it is the toplevel app_id,
// on X11 it is the X11 XClassHint
//
// ID is set by the gogio tool or manually with the -X linker flag. For example,
//
//	go build -ldflags="-X 'gioui.org/app.ID=org.gioui.example.Kitchen'" .
//
// Note that ID is treated as a constant, and that changing it at runtime
// is not supported. Default value of ID is filepath.Base(os.Args[0]).
var ID = ""

func init() {
	if extraArgs != "" {
		args := strings.Split(extraArgs, "|")
		os.Args = append(os.Args, args...)
	}
	if ID == "" {
		ID = filepath.Base(os.Args[0])
	}
}

// DataDir returns a path to use for application-specific
// configuration data.
// On desktop systems, DataDir use os.UserConfigDir.
// On iOS NSDocumentDirectory is queried.
// For Android Context.getFilesDir is used.
//
// BUG: DataDir blocks on Android until init functions
// have completed.
func DataDir() (string, error) {
	return dataDir()
}

// Main must be called last from the program main function.
// On most platforms Main blocks forever, for Android and
// iOS it returns immediately to give control of the main
// thread back to the system.
//
// Calling Main is necessary because some operating systems
// require control of the main thread of the program for
// running windows.
func Main() {
	osMain()
}