select the language from registry

README.md

@@ -18,6 +18,7 @@ In addition to this [`README.md`](README.md), the following documents are also a
 - [`buildrun.md`](docs/buildrun.md) – Instructions on building, localizing, running, and developing for this repository.
 - [`enterprise.md`](docs/enterprise.md) – A summary of various features and tips for making the application usable in enterprise settings.
 - [`netquirk.md`](docs/netquirk.md) – A description of various networking quirks and "kill-switch" semantics.
+- [`userregistry.md`](docs/userregistry.md) – A list of registry keys settable by the user for changing the behavior of the application.
 
 ## License
 

docs/userregistry.md

@@ -0,0 +1,9 @@
+# Registry Keys for Users
+
+#### `HKCU\Software\AmneziaWG\Language`
+
+When this key is set, the UI will try to use the specified language as display language.
+
+```
+> reg add HKCU\Software\AmneziaWG /v LimitedOperatorUI /t REG_SZ /d "en" /f
+```

l18n/l18n.go

@@ -8,11 +8,16 @@ package l18n
 import (
 	"sync"
 
+	"github.com/amnezia-vpn/amneziawg-windows-client/services"
 	"golang.org/x/sys/windows"
 	"golang.org/x/text/language"
 	"golang.org/x/text/message"
 )
 
+const (
+	LanguageUserKey = "Language"
+)
+
 var (
 	printer     *message.Printer
 	printerLock sync.Mutex
@@ -35,6 +40,14 @@ func prn() *message.Printer {
 
 // lang returns the user preferred UI language we have most confident translation in the default catalog available.
 func lang() (tag language.Tag) {
+	keyString, res := services.UserKeyString(LanguageUserKey)
+	if res {
+		keyTag := message.MatchLanguage(keyString)
+		if keyTag.String() == keyString {
+			tag = keyTag
+			return
+		}
+	}
 	tag = language.English
 	confidence := language.No
 	languages, err := windows.GetUserPreferredUILanguages(windows.MUI_LANGUAGE_NAME)

services/registry.go

@@ -0,0 +1,65 @@
+package services
+
+import (
+	"golang.org/x/sys/windows/registry"
+)
+
+const userRegKey = `Software\AmneziaWG`
+
+var userKey registry.Key
+
+func openUserKey() (registry.Key, error) {
+	if userKey != 0 {
+		return userKey, nil
+	}
+	var err error
+	userKey, err = registry.OpenKey(registry.CURRENT_USER, userRegKey, registry.QUERY_VALUE)
+	if err != nil {
+		return 0, err
+	}
+	return userKey, nil
+}
+
+func createUserKey() (registry.Key, error) {
+	closeUserKey()
+	var err error
+	userKey, _, err = registry.CreateKey(registry.CURRENT_USER, userRegKey, registry.SET_VALUE)
+	if err != nil {
+		return 0, err
+	}
+	return userKey, nil
+}
+
+func closeUserKey() {
+	if userKey == 0 {
+		return
+	}
+
+	userKey.Close()
+	userKey = 0
+}
+
+func UserKeyString(name string) (string, bool) {
+	key, err := openUserKey()
+	if err != nil {
+		return err.Error(), false
+	}
+	val, _, err := key.GetStringValue(name)
+	if err != nil {
+		return err.Error(), false
+	}
+	return val, true
+}
+
+func SetUserKeyString(name string, value string) error {
+	key, err := createUserKey()
+	if err != nil {
+		return err
+	}
+	defer closeUserKey()
+	err = key.SetStringValue(name, value)
+	if err != nil {
+		return err
+	}
+	return nil
+}