plugin.go

package path_provider

import (
	"os"
	"path/filepath"
	"runtime"

	flutter "github.com/go-flutter-desktop/go-flutter"
	"github.com/go-flutter-desktop/go-flutter/plugin"
	homedir "github.com/mitchellh/go-homedir"
	"github.com/pkg/errors"
)

const channelName = "plugins.flutter.io/path_provider"

// PathProviderPlugin implements flutter.Plugin and handles method calls to
// the plugins.flutter.io/path_provider channel.
type PathProviderPlugin struct {
	// VendorName must be set to a nonempty value. Use company name or a domain
	// that you own. Note that the value must be valid as a cross-platform directory name.
	VendorName string
	// ApplicationName must be set to a nonempty value. Use the unique name for
	// this application. Note that the value must be valid as a cross-platform
	// directory name.
	ApplicationName string

	userConfigFolder string
}

var _ flutter.Plugin = &PathProviderPlugin{} // compile-time type check

// InitPlugin initializes the path provider plugin.
func (p *PathProviderPlugin) InitPlugin(messenger plugin.BinaryMessenger) error {
	if p.VendorName == "" {
		// returned immediately because this is likely a programming error
		return errors.New("PathProviderPlugin.VendorName must be set")
	}
	if p.ApplicationName == "" {
		// returned immediately because this is likely a programming error
		return errors.New("PathProviderPlugin.ApplicationName must be set")
	}

	switch runtime.GOOS {
	case "darwin":
		home, err := homedir.Dir()
		if err != nil {
			return errors.Wrap(err, "failed to resolve user home dir")
		}
		p.userConfigFolder = filepath.Join(home, "Library", "Application Support")
	case "windows":
		p.userConfigFolder = os.Getenv("APPDATA")
	default:
		// https://specifications.freedesktop.org/basedir-spec/basedir-spec-latest.html
		if os.Getenv("XDG_CONFIG_HOME") != "" {
			p.userConfigFolder = os.Getenv("XDG_CONFIG_HOME")
		} else {
			home, err := homedir.Dir()
			if err != nil {
				return errors.Wrap(err, "failed to resolve user home dir")
			}
			p.userConfigFolder = filepath.Join(home, ".config")
		}
	}

	channel := plugin.NewMethodChannel(messenger, channelName, plugin.StandardMethodCodec{})
	channel.HandleFunc("getTemporaryDirectory", p.handleTempDir)
	channel.HandleFunc("getApplicationDocumentsDirectory", p.handleAppDir)
	return nil
}

func (p *PathProviderPlugin) handleTempDir(arguments interface{}) (reply interface{}, err error) {
	cacheDir, err := os.UserCacheDir()
	if err != nil {
		return nil, err
	}
	return filepath.Join(cacheDir, p.VendorName, p.ApplicationName), nil
}

func (p *PathProviderPlugin) handleAppDir(arguments interface{}) (reply interface{}, err error) {
	return filepath.Join(p.userConfigFolder, p.VendorName, p.ApplicationName), nil
}