From 8a476b326136f5c03790fa168686848884c8cd5a Mon Sep 17 00:00:00 2001
From: Simon Rozman <simon@rozman.si>
Date: Thu, 14 Nov 2019 09:27:05 +0100
Subject: l18n: add localization support

Revise the messages to make them localizable.

Note: The log messages are not marked for localization. Probably, we
want to keep log files in English for easier global troubleshooting.

Having a user run `go generate` requires a valid and up-to-date Go
environment. Rather than instructing users how to setup the environment
correctly, the `go generate` was integrated into build.bat. This reuses
the Go building environment downloaded and prepared by build.bat to
provide controllable and consistent result.

Use `make generate` on Linux.

As the zgotext.go output varies for GOARCH=386 and amd64, one had to be
chosen to provide stable output. The former is the first one to build in
build.bat.

Signed-off-by: Simon Rozman <simon@rozman.si>
---
 ui/aboutdialog.go  | 12 ++++----
 ui/confview.go     | 54 +++++++++++++++++------------------
 ui/editdialog.go   | 34 +++++++++++-----------
 ui/filesave.go     |  7 +++--
 ui/iconprovider.go | 11 ++++----
 ui/logpage.go      | 19 +++++++------
 ui/managewindow.go |  7 +++--
 ui/raise.go        |  5 ++--
 ui/tray.go         | 41 ++++++++++++++-------------
 ui/tunnelspage.go  | 83 +++++++++++++++++++++++++++++-------------------------
 ui/ui.go           |  7 +++--
 ui/updatepage.go   | 23 +++++++--------
 12 files changed, 159 insertions(+), 144 deletions(-)

(limited to 'ui')

diff --git a/ui/aboutdialog.go b/ui/aboutdialog.go
index d87727aa..238ba5e2 100644
--- a/ui/aboutdialog.go
+++ b/ui/aboutdialog.go
@@ -6,7 +6,6 @@
 package ui
 
 import (
-	"fmt"
 	"runtime"
 	"strings"
 
@@ -14,6 +13,7 @@ import (
 	"github.com/lxn/win"
 	"golang.org/x/sys/windows"
 	"golang.zx2c4.com/wireguard/device"
+	"golang.zx2c4.com/wireguard/windows/l18n"
 	"golang.zx2c4.com/wireguard/windows/version"
 )
 
@@ -47,7 +47,7 @@ func runAboutDialog(owner walk.Form) error {
 		showingAboutDialog = nil
 	}()
 	disposables.Add(showingAboutDialog)
-	showingAboutDialog.SetTitle("About WireGuard")
+	showingAboutDialog.SetTitle(l18n.Sprintf("About WireGuard"))
 	showingAboutDialog.SetLayout(vbl)
 	if icon, err := loadLogoIcon(32); err == nil {
 		showingAboutDialog.SetIcon(icon)
@@ -79,7 +79,7 @@ func runAboutDialog(owner walk.Form) error {
 	if logo, err := loadLogoIcon(128); err == nil {
 		iv.SetImage(logo)
 	}
-	iv.Accessibility().SetName("WireGuard logo image")
+	iv.Accessibility().SetName(l18n.Sprintf("WireGuard logo image"))
 
 	wgLbl, err := walk.NewTextLabel(showingAboutDialog)
 	if err != nil {
@@ -95,7 +95,7 @@ func runAboutDialog(owner walk.Form) error {
 		return err
 	}
 	detailsLbl.SetTextAlignment(walk.AlignHCenterVNear)
-	detailsLbl.SetText(fmt.Sprintf("App version: %s\nGo backend version: %s\nGo version: %s\nOperating system: %s\nArchitecture: %s", version.Number, device.WireGuardGoVersion, strings.TrimPrefix(runtime.Version(), "go"), version.OsName(), runtime.GOARCH))
+	detailsLbl.SetText(l18n.Sprintf("App version: %s\nGo backend version: %s\nGo version: %s\nOperating system: %s\nArchitecture: %s", version.Number, device.WireGuardGoVersion, strings.TrimPrefix(runtime.Version(), "go"), version.OsName(), runtime.GOARCH))
 
 	copyrightLbl, err := walk.NewTextLabel(showingAboutDialog)
 	if err != nil {
@@ -119,14 +119,14 @@ func runAboutDialog(owner walk.Form) error {
 		return err
 	}
 	closePB.SetAlignment(walk.AlignHCenterVNear)
-	closePB.SetText("Close")
+	closePB.SetText(l18n.Sprintf("Close"))
 	closePB.Clicked().Attach(showingAboutDialog.Accept)
 	donatePB, err := walk.NewPushButton(buttonCP)
 	if err != nil {
 		return err
 	}
 	donatePB.SetAlignment(walk.AlignHCenterVNear)
-	donatePB.SetText("♥ &Donate!")
+	donatePB.SetText(l18n.Sprintf("♥ &Donate!"))
 	donatePB.Clicked().Attach(func() {
 		if easterEggIndex == -1 {
 			easterEggIndex = 0
diff --git a/ui/confview.go b/ui/confview.go
index 1c378aa1..d080db30 100644
--- a/ui/confview.go
+++ b/ui/confview.go
@@ -6,7 +6,6 @@
 package ui
 
 import (
-	"fmt"
 	"strconv"
 	"strings"
 	"time"
@@ -15,6 +14,7 @@ import (
 	"github.com/lxn/win"
 
 	"golang.zx2c4.com/wireguard/windows/conf"
+	"golang.zx2c4.com/wireguard/windows/l18n"
 	"golang.zx2c4.com/wireguard/windows/manager"
 )
 
@@ -108,7 +108,7 @@ func newLabelStatusLine(parent walk.Container) (*labelStatusLine, error) {
 		return nil, err
 	}
 	disposables.Add(lsl.label)
-	lsl.label.SetText("Status:")
+	lsl.label.SetText(l18n.Sprintf("Status:"))
 	lsl.label.SetTextAlignment(walk.AlignHFarVNear)
 
 	if lsl.statusComposite, err = walk.NewComposite(parent); err != nil {
@@ -180,7 +180,7 @@ func newLabelTextLine(fieldName string, parent walk.Container) (*labelTextLine,
 		return nil, err
 	}
 	disposables.Add(lt.label)
-	lt.label.SetText(fieldName + ":")
+	lt.label.SetText(fieldName)
 	lt.label.SetTextAlignment(walk.AlignHFarVNear)
 	lt.label.SetVisible(false)
 
@@ -216,9 +216,9 @@ func (tal *toggleActiveLine) update(state manager.TunnelState) {
 
 	switch state {
 	case manager.TunnelStarted:
-		text = "&Deactivate"
+		text = l18n.Sprintf("&Deactivate")
 	case manager.TunnelStopped:
-		text = "&Activate"
+		text = l18n.Sprintf("&Activate")
 	case manager.TunnelStarting, manager.TunnelStopping:
 		text = textForState(state, true)
 	default:
@@ -300,11 +300,11 @@ func newInterfaceView(parent walk.Container) (*interfaceView, error) {
 	disposables.Add(iv.status)
 
 	items := []labelTextLineItem{
-		{"Public key", &iv.publicKey},
-		{"Listen port", &iv.listenPort},
-		{"MTU", &iv.mtu},
-		{"Addresses", &iv.addresses},
-		{"DNS servers", &iv.dns},
+		{l18n.Sprintf("Public key:"), &iv.publicKey},
+		{l18n.Sprintf("Listen port:"), &iv.listenPort},
+		{l18n.Sprintf("MTU:"), &iv.mtu},
+		{l18n.Sprintf("Addresses:"), &iv.addresses},
+		{l18n.Sprintf("DNS servers:"), &iv.dns},
 	}
 	if iv.lines, err = createLabelTextLines(items, parent, &disposables); err != nil {
 		return nil, err
@@ -328,13 +328,13 @@ func newPeerView(parent walk.Container) (*peerView, error) {
 	pv := new(peerView)
 
 	items := []labelTextLineItem{
-		{"Public key", &pv.publicKey},
-		{"Preshared key", &pv.presharedKey},
-		{"Allowed IPs", &pv.allowedIPs},
-		{"Endpoint", &pv.endpoint},
-		{"Persistent keepalive", &pv.persistentKeepalive},
-		{"Latest handshake", &pv.latestHandshake},
-		{"Transfer", &pv.transfer},
+		{l18n.Sprintf("Public key:"), &pv.publicKey},
+		{l18n.Sprintf("Preshared key:"), &pv.presharedKey},
+		{l18n.Sprintf("Allowed IPs:"), &pv.allowedIPs},
+		{l18n.Sprintf("Endpoint:"), &pv.endpoint},
+		{l18n.Sprintf("Persistent keepalive:"), &pv.persistentKeepalive},
+		{l18n.Sprintf("Latest handshake:"), &pv.latestHandshake},
+		{l18n.Sprintf("Transfer:"), &pv.transfer},
 	}
 	var err error
 	if pv.lines, err = createLabelTextLines(items, parent, nil); err != nil {
@@ -383,7 +383,7 @@ func (iv *interfaceView) apply(c *conf.Interface) {
 		for i, address := range c.Addresses {
 			addrStrings[i] = address.String()
 		}
-		iv.addresses.show(strings.Join(addrStrings[:], ", "))
+		iv.addresses.show(strings.Join(addrStrings[:], l18n.EnumerationSeparator()))
 	} else {
 		iv.addresses.hide()
 	}
@@ -393,7 +393,7 @@ func (iv *interfaceView) apply(c *conf.Interface) {
 		for i, address := range c.DNS {
 			addrStrings[i] = address.String()
 		}
-		iv.dns.show(strings.Join(addrStrings[:], ", "))
+		iv.dns.show(strings.Join(addrStrings[:], l18n.EnumerationSeparator()))
 	} else {
 		iv.dns.hide()
 	}
@@ -407,7 +407,7 @@ func (pv *peerView) apply(c *conf.Peer) {
 	pv.publicKey.show(c.PublicKey.String())
 
 	if !c.PresharedKey.IsZero() {
-		pv.presharedKey.show("enabled")
+		pv.presharedKey.show(l18n.Sprintf("enabled"))
 	} else {
 		pv.presharedKey.hide()
 	}
@@ -417,7 +417,7 @@ func (pv *peerView) apply(c *conf.Peer) {
 		for i, address := range c.AllowedIPs {
 			addrStrings[i] = address.String()
 		}
-		pv.allowedIPs.show(strings.Join(addrStrings[:], ", "))
+		pv.allowedIPs.show(strings.Join(addrStrings[:], l18n.EnumerationSeparator()))
 	} else {
 		pv.allowedIPs.hide()
 	}
@@ -441,7 +441,7 @@ func (pv *peerView) apply(c *conf.Peer) {
 	}
 
 	if c.RxBytes > 0 || c.TxBytes > 0 {
-		pv.transfer.show(fmt.Sprintf("%s received, %s sent", c.RxBytes.String(), c.TxBytes.String()))
+		pv.transfer.show(l18n.Sprintf("%s received, %s sent", c.RxBytes.String(), c.TxBytes.String()))
 	} else {
 		pv.transfer.hide()
 	}
@@ -552,11 +552,11 @@ func (cv *ConfView) onToggleActiveClicked() {
 		if err != nil {
 			cv.Synchronize(func() {
 				if oldState == manager.TunnelUnknown {
-					showErrorCustom(cv.Form(), "Failed to determine tunnel state", err.Error())
+					showErrorCustom(cv.Form(), l18n.Sprintf("Failed to determine tunnel state"), err.Error())
 				} else if oldState == manager.TunnelStopped {
-					showErrorCustom(cv.Form(), "Failed to activate tunnel", err.Error())
+					showErrorCustom(cv.Form(), l18n.Sprintf("Failed to activate tunnel"), err.Error())
 				} else if oldState == manager.TunnelStarted {
-					showErrorCustom(cv.Form(), "Failed to deactivate tunnel", err.Error())
+					showErrorCustom(cv.Form(), l18n.Sprintf("Failed to deactivate tunnel"), err.Error())
 				}
 			})
 		}
@@ -612,7 +612,7 @@ func (cv *ConfView) setTunnel(tunnel *manager.Tunnel, config *conf.Config, state
 		return
 	}
 
-	title := "Interface: " + config.Name
+	title := l18n.Sprintf("Interface: %s", config.Name)
 	if cv.name.Title() != title {
 		cv.SetSuspended(true)
 		defer cv.SetSuspended(false)
@@ -656,7 +656,7 @@ func (cv *ConfView) setTunnel(tunnel *manager.Tunnel, config *conf.Config, state
 			if err != nil {
 				continue
 			}
-			group.SetTitle("Peer")
+			group.SetTitle(l18n.Sprintf("Peer"))
 			pv, err := newPeerView(group)
 			if err != nil {
 				group.Dispose()
diff --git a/ui/editdialog.go b/ui/editdialog.go
index 4d25dd79..ade6c498 100644
--- a/ui/editdialog.go
+++ b/ui/editdialog.go
@@ -6,7 +6,6 @@
 package ui
 
 import (
-	"fmt"
 	"strings"
 
 	"github.com/lxn/walk"
@@ -14,6 +13,7 @@ import (
 	"golang.org/x/sys/windows"
 
 	"golang.zx2c4.com/wireguard/windows/conf"
+	"golang.zx2c4.com/wireguard/windows/l18n"
 	"golang.zx2c4.com/wireguard/windows/manager"
 	"golang.zx2c4.com/wireguard/windows/ui/syntax"
 )
@@ -52,9 +52,9 @@ func newEditDialog(owner walk.Form, tunnel *manager.Tunnel) (*EditDialog, error)
 
 	var title string
 	if tunnel == nil {
-		title = "Create new tunnel"
+		title = l18n.Sprintf("Create new tunnel")
 	} else {
-		title = "Edit tunnel"
+		title = l18n.Sprintf("Edit tunnel")
 	}
 
 	if tunnel == nil {
@@ -88,7 +88,7 @@ func newEditDialog(owner walk.Form, tunnel *manager.Tunnel) (*EditDialog, error)
 	}
 	layout.SetRange(nameLabel, walk.Rectangle{0, 0, 1, 1})
 	nameLabel.SetTextAlignment(walk.AlignHFarVCenter)
-	nameLabel.SetText("&Name:")
+	nameLabel.SetText(l18n.Sprintf("&Name:"))
 
 	if dlg.nameEdit, err = walk.NewLineEdit(dlg); err != nil {
 		return nil, err
@@ -102,14 +102,14 @@ func newEditDialog(owner walk.Form, tunnel *manager.Tunnel) (*EditDialog, error)
 	}
 	layout.SetRange(pubkeyLabel, walk.Rectangle{0, 1, 1, 1})
 	pubkeyLabel.SetTextAlignment(walk.AlignHFarVCenter)
-	pubkeyLabel.SetText("&Public key:")
+	pubkeyLabel.SetText(l18n.Sprintf("&Public key:"))
 
 	if dlg.pubkeyEdit, err = walk.NewLineEdit(dlg); err != nil {
 		return nil, err
 	}
 	layout.SetRange(dlg.pubkeyEdit, walk.Rectangle{1, 1, 1, 1})
 	dlg.pubkeyEdit.SetReadOnly(true)
-	dlg.pubkeyEdit.SetText("(unknown)")
+	dlg.pubkeyEdit.SetText(l18n.Sprintf("(unknown)"))
 	dlg.pubkeyEdit.Accessibility().SetRole(walk.AccRoleStatictext)
 
 	if dlg.syntaxEdit, err = syntax.NewSyntaxEdit(dlg); err != nil {
@@ -128,8 +128,8 @@ func newEditDialog(owner walk.Form, tunnel *manager.Tunnel) (*EditDialog, error)
 	if dlg.blockUntunneledTrafficCB, err = walk.NewCheckBox(buttonsContainer); err != nil {
 		return nil, err
 	}
-	dlg.blockUntunneledTrafficCB.SetText("&Block untunneled traffic (kill-switch)")
-	dlg.blockUntunneledTrafficCB.SetToolTipText("When a configuration has exactly one peer, and that peer has an allowed IPs containing at least one of 0.0.0.0/0 or ::/0, then the tunnel service engages a firewall ruleset to block all traffic that is neither to nor from the tunnel interface, with special exceptions for DHCP and NDP.")
+	dlg.blockUntunneledTrafficCB.SetText(l18n.Sprintf("&Block untunneled traffic (kill-switch)"))
+	dlg.blockUntunneledTrafficCB.SetToolTipText(l18n.Sprintf("When a configuration has exactly one peer, and that peer has an allowed IPs containing at least one of 0.0.0.0/0 or ::/0, then the tunnel service engages a firewall ruleset to block all traffic that is neither to nor from the tunnel interface, with special exceptions for DHCP and NDP."))
 	dlg.blockUntunneledTrafficCB.SetVisible(false)
 	dlg.blockUntunneledTrafficCB.CheckedChanged().Attach(dlg.onBlockUntunneledTrafficCBCheckedChanged)
 
@@ -138,14 +138,14 @@ func newEditDialog(owner walk.Form, tunnel *manager.Tunnel) (*EditDialog, error)
 	if dlg.saveButton, err = walk.NewPushButton(buttonsContainer); err != nil {
 		return nil, err
 	}
-	dlg.saveButton.SetText("&Save")
+	dlg.saveButton.SetText(l18n.Sprintf("&Save"))
 	dlg.saveButton.Clicked().Attach(dlg.onSaveButtonClicked)
 
 	cancelButton, err := walk.NewPushButton(buttonsContainer)
 	if err != nil {
 		return nil, err
 	}
-	cancelButton.SetText("Cancel")
+	cancelButton.SetText(l18n.Sprintf("Cancel"))
 	cancelButton.Clicked().Attach(dlg.Cancel)
 
 	dlg.SetCancelButton(cancelButton)
@@ -160,7 +160,7 @@ func newEditDialog(owner walk.Form, tunnel *manager.Tunnel) (*EditDialog, error)
 	syntaxEditWnd := dlg.syntaxEdit.Handle()
 	parentWnd := win.GetParent(syntaxEditWnd)
 	labelWnd := win.CreateWindowEx(0,
-		windows.StringToUTF16Ptr("STATIC"), windows.StringToUTF16Ptr("&Configuration:"),
+		windows.StringToUTF16Ptr("STATIC"), windows.StringToUTF16Ptr(l18n.Sprintf("&Configuration:")),
 		win.WS_CHILD|win.WS_GROUP|win.SS_LEFT, 0, 0, 0, 0,
 		parentWnd, win.HMENU(^uintptr(0)), win.HINSTANCE(win.GetWindowLongPtr(parentWnd, win.GWLP_HINSTANCE)), nil)
 	prevWnd := win.GetWindow(syntaxEditWnd, win.GW_HWNDPREV)
@@ -301,18 +301,18 @@ func (dlg *EditDialog) onSyntaxEditPrivateKeyChanged(privateKey string) {
 	if key != nil {
 		dlg.pubkeyEdit.SetText(key.Public().String())
 	} else {
-		dlg.pubkeyEdit.SetText("(unknown)")
+		dlg.pubkeyEdit.SetText(l18n.Sprintf("(unknown)"))
 	}
 }
 
 func (dlg *EditDialog) onSaveButtonClicked() {
 	newName := dlg.nameEdit.Text()
 	if newName == "" {
-		showWarningCustom(dlg, "Invalid name", "A name is required.")
+		showWarningCustom(dlg, l18n.Sprintf("Invalid name"), l18n.Sprintf("A name is required."))
 		return
 	}
 	if !conf.TunnelNameIsValid(newName) {
-		showWarningCustom(dlg, "Invalid name", fmt.Sprintf("Tunnel name ‘%s’ is invalid.", newName))
+		showWarningCustom(dlg, l18n.Sprintf("Invalid name"), l18n.Sprintf("Tunnel name ‘%s’ is invalid.", newName))
 		return
 	}
 	newNameLower := strings.ToLower(newName)
@@ -320,12 +320,12 @@ func (dlg *EditDialog) onSaveButtonClicked() {
 	if newNameLower != strings.ToLower(dlg.config.Name) {
 		existingTunnelList, err := manager.IPCClientTunnels()
 		if err != nil {
-			showWarningCustom(dlg, "Unable to list existing tunnels", err.Error())
+			showWarningCustom(dlg, l18n.Sprintf("Unable to list existing tunnels"), err.Error())
 			return
 		}
 		for _, tunnel := range existingTunnelList {
 			if strings.ToLower(tunnel.Name) == newNameLower {
-				showWarningCustom(dlg, "Tunnel already exists", fmt.Sprintf("Another tunnel already exists with the name ‘%s’.", newName))
+				showWarningCustom(dlg, l18n.Sprintf("Tunnel already exists"), l18n.Sprintf("Another tunnel already exists with the name ‘%s’.", newName))
 				return
 			}
 		}
@@ -333,7 +333,7 @@ func (dlg *EditDialog) onSaveButtonClicked() {
 
 	cfg, err := conf.FromWgQuick(dlg.syntaxEdit.Text(), newName)
 	if err != nil {
-		showErrorCustom(dlg, "Unable to create new configuration", err.Error())
+		showErrorCustom(dlg, l18n.Sprintf("Unable to create new configuration"), err.Error())
 		return
 	}
 
diff --git a/ui/filesave.go b/ui/filesave.go
index 4b5c2947..7ca8a2c2 100644
--- a/ui/filesave.go
+++ b/ui/filesave.go
@@ -6,10 +6,11 @@
 package ui
 
 import (
-	"fmt"
 	"os"
 
 	"github.com/lxn/walk"
+
+	"golang.zx2c4.com/wireguard/windows/l18n"
 )
 
 func writeFileWithOverwriteHandling(owner walk.Form, filePath string, write func(file *os.File) error) bool {
@@ -18,7 +19,7 @@ func writeFileWithOverwriteHandling(owner walk.Form, filePath string, write func
 			return false
 		}
 
-		showErrorCustom(owner, "Writing file failed", err.Error())
+		showErrorCustom(owner, l18n.Sprintf("Writing file failed"), err.Error())
 
 		return true
 	}
@@ -26,7 +27,7 @@ func writeFileWithOverwriteHandling(owner walk.Form, filePath string, write func
 	file, err := os.OpenFile(filePath, os.O_CREATE|os.O_WRONLY|os.O_EXCL, 0600)
 	if err != nil {
 		if os.IsExist(err) {
-			if walk.DlgCmdNo == walk.MsgBox(owner, "Writing file failed", fmt.Sprintf(`File ‘%s’ already exists.
+			if walk.DlgCmdNo == walk.MsgBox(owner, l18n.Sprintf("Writing file failed"), l18n.Sprintf(`File ‘%s’ already exists.
 
 Do you want to overwrite it?`, filePath), walk.MsgBoxYesNo|walk.MsgBoxDefButton2|walk.MsgBoxIconWarning) {
 				return false
diff --git a/ui/iconprovider.go b/ui/iconprovider.go
index e5177ac3..8db841c5 100644
--- a/ui/iconprovider.go
+++ b/ui/iconprovider.go
@@ -8,6 +8,7 @@ package ui
 import (
 	"github.com/lxn/walk"
 
+	"golang.zx2c4.com/wireguard/windows/l18n"
 	"golang.zx2c4.com/wireguard/windows/manager"
 )
 
@@ -87,15 +88,15 @@ func iconForState(state manager.TunnelState, size int) (icon *walk.Icon, err err
 func textForState(state manager.TunnelState, withEllipsis bool) (text string) {
 	switch state {
 	case manager.TunnelStarted:
-		text = "Active"
+		text = l18n.Sprintf("Active")
 	case manager.TunnelStarting:
-		text = "Activating"
+		text = l18n.Sprintf("Activating")
 	case manager.TunnelStopped:
-		text = "Inactive"
+		text = l18n.Sprintf("Inactive")
 	case manager.TunnelStopping:
-		text = "Deactivating"
+		text = l18n.Sprintf("Deactivating")
 	case manager.TunnelUnknown:
-		text = "Unknown state"
+		text = l18n.Sprintf("Unknown state")
 	}
 	if withEllipsis {
 		switch state {
diff --git a/ui/logpage.go b/ui/logpage.go
index b8febcbb..1de5c920 100644
--- a/ui/logpage.go
+++ b/ui/logpage.go
@@ -12,6 +12,7 @@ import (
 	"time"
 
 	"github.com/lxn/walk"
+	"golang.zx2c4.com/wireguard/windows/l18n"
 	"golang.zx2c4.com/wireguard/windows/ringlogger"
 )
 
@@ -41,7 +42,7 @@ func NewLogPage() (*LogPage, error) {
 		lp.model.quit <- true
 	})
 
-	lp.SetTitle("Log")
+	lp.SetTitle(l18n.Sprintf("Log"))
 	lp.SetLayout(walk.NewVBoxLayout())
 
 	if lp.logView, err = walk.NewTableView(lp); err != nil {
@@ -57,19 +58,19 @@ func NewLogPage() (*LogPage, error) {
 	}
 	lp.logView.AddDisposable(contextMenu)
 	copyAction := walk.NewAction()
-	copyAction.SetText("&Copy")
+	copyAction.SetText(l18n.Sprintf("&Copy"))
 	copyAction.SetShortcut(walk.Shortcut{walk.ModControl, walk.KeyC})
 	copyAction.Triggered().Attach(lp.onCopy)
 	contextMenu.Actions().Add(copyAction)
 	lp.ShortcutActions().Add(copyAction)
 	selectAllAction := walk.NewAction()
-	selectAllAction.SetText("Select &all")
+	selectAllAction.SetText(l18n.Sprintf("Select &all"))
 	selectAllAction.SetShortcut(walk.Shortcut{walk.ModControl, walk.KeyA})
 	selectAllAction.Triggered().Attach(lp.onSelectAll)
 	contextMenu.Actions().Add(selectAllAction)
 	lp.ShortcutActions().Add(selectAllAction)
 	saveAction := walk.NewAction()
-	saveAction.SetText("&Save to file…")
+	saveAction.SetText(l18n.Sprintf("&Save to file…"))
 	saveAction.SetShortcut(walk.Shortcut{walk.ModControl, walk.KeyS})
 	saveAction.Triggered().Attach(lp.onSave)
 	contextMenu.Actions().Add(saveAction)
@@ -83,14 +84,14 @@ func NewLogPage() (*LogPage, error) {
 
 	stampCol := walk.NewTableViewColumn()
 	stampCol.SetName("Stamp")
-	stampCol.SetTitle("Time")
+	stampCol.SetTitle(l18n.Sprintf("Time"))
 	stampCol.SetFormat("2006-01-02 15:04:05.000")
 	stampCol.SetWidth(140)
 	lp.logView.Columns().Add(stampCol)
 
 	msgCol := walk.NewTableViewColumn()
 	msgCol.SetName("Line")
-	msgCol.SetTitle("Log message")
+	msgCol.SetTitle(l18n.Sprintf("Log message"))
 	lp.logView.Columns().Add(msgCol)
 
 	lp.model = newLogModel(lp)
@@ -111,7 +112,7 @@ func NewLogPage() (*LogPage, error) {
 	if err != nil {
 		return nil, err
 	}
-	saveButton.SetText("&Save")
+	saveButton.SetText(l18n.Sprintf("&Save"))
 	saveButton.Clicked().Attach(lp.onSave)
 
 	disposables.Spare()
@@ -146,9 +147,9 @@ func (lp *LogPage) onSelectAll() {
 
 func (lp *LogPage) onSave() {
 	fd := walk.FileDialog{
-		Filter:   "Text Files (*.txt)|*.txt|All Files (*.*)|*.*",
+		Filter:   l18n.Sprintf("Text Files (*.txt)|*.txt|All Files (*.*)|*.*"),
 		FilePath: fmt.Sprintf("wireguard-log-%s.txt", time.Now().Format("2006-01-02T150405")),
-		Title:    "Export log to file",
+		Title:    l18n.Sprintf("Export log to file"),
 	}
 
 	form := lp.Form()
diff --git a/ui/managewindow.go b/ui/managewindow.go
index 542c91b9..e6855d5d 100644
--- a/ui/managewindow.go
+++ b/ui/managewindow.go
@@ -13,6 +13,7 @@ import (
 	"github.com/lxn/win"
 	"golang.org/x/sys/windows"
 
+	"golang.zx2c4.com/wireguard/windows/l18n"
 	"golang.zx2c4.com/wireguard/windows/manager"
 )
 
@@ -118,7 +119,7 @@ func NewManageTunnelsWindow() (*ManageTunnelsWindow, error) {
 			CbSize:     uint32(unsafe.Sizeof(win.MENUITEMINFO{})),
 			FMask:      win.MIIM_ID | win.MIIM_STRING | win.MIIM_FTYPE,
 			FType:      win.MIIM_STRING,
-			DwTypeData: windows.StringToUTF16Ptr("&About WireGuard…"),
+			DwTypeData: windows.StringToUTF16Ptr(l18n.Sprintf("&About WireGuard…")),
 			WID:        uint32(aboutWireGuardCmd),
 		})
 		win.InsertMenuItem(systemMenu, 1, true, &win.MENUITEMINFO{
@@ -169,7 +170,7 @@ func (mtw *ManageTunnelsWindow) onTunnelChange(tunnel *manager.Tunnel, state man
 			if len(errMsg) > 0 && errMsg[len(errMsg)-1] != '.' {
 				errMsg += "."
 			}
-			showWarningCustom(mtw, "Tunnel Error", errMsg+"\n\nPlease consult the log for more information.")
+			showWarningCustom(mtw, l18n.Sprintf("Tunnel Error"), l18n.Sprintf("%s\n\nPlease consult the log for more information.", errMsg))
 		}
 	})
 }
@@ -178,7 +179,7 @@ func (mtw *ManageTunnelsWindow) UpdateFound() {
 	if mtw.updatePage != nil {
 		return
 	}
-	mtw.SetTitle(mtw.Title() + " (out of date)")
+	mtw.SetTitle(l18n.Sprintf("%s (out of date)", mtw.Title()))
 	updatePage, err := NewUpdatePage()
 	if err == nil {
 		mtw.updatePage = updatePage
diff --git a/ui/raise.go b/ui/raise.go
index 42509994..0eac828a 100644
--- a/ui/raise.go
+++ b/ui/raise.go
@@ -6,12 +6,13 @@
 package ui
 
 import (
-	"fmt"
 	"os"
 	"runtime"
 
 	"github.com/lxn/win"
 	"golang.org/x/sys/windows"
+
+	"golang.zx2c4.com/wireguard/windows/l18n"
 )
 
 func raise(hwnd win.HWND) {
@@ -66,7 +67,7 @@ func WaitForRaiseUIThenQuit() {
 		return 0
 	}, 0, 0, win.WINEVENT_SKIPOWNPROCESS|win.WINEVENT_OUTOFCONTEXT)
 	if err != nil {
-		showErrorCustom(nil, "WireGuard Detection Error", fmt.Sprintf("Unable to wait for WireGuard window to appear: %v", err))
+		showErrorCustom(nil, l18n.Sprintf("WireGuard Detection Error"), l18n.Sprintf("Unable to wait for WireGuard window to appear: %v", err))
 	}
 	for {
 		var msg win.MSG
diff --git a/ui/tray.go b/ui/tray.go
index 810c759b..f1fb727e 100644
--- a/ui/tray.go
+++ b/ui/tray.go
@@ -6,12 +6,12 @@
 package ui
 
 import (
-	"fmt"
 	"sort"
 	"strings"
 	"time"
 
 	"golang.zx2c4.com/wireguard/windows/conf"
+	"golang.zx2c4.com/wireguard/windows/l18n"
 	"golang.zx2c4.com/wireguard/windows/manager"
 
 	"github.com/lxn/walk"
@@ -53,7 +53,7 @@ func NewTray(mtw *ManageTunnelsWindow) (*Tray, error) {
 func (tray *Tray) setup() error {
 	tray.clicked = tray.onManageTunnels
 
-	tray.SetToolTip("WireGuard: Deactivated")
+	tray.SetToolTip(l18n.Sprintf("WireGuard: Deactivated"))
 	tray.SetVisible(true)
 	if icon, err := loadLogoIcon(16); err == nil {
 		tray.SetIcon(icon)
@@ -76,15 +76,15 @@ func (tray *Tray) setup() error {
 		separator bool
 		defawlt   bool
 	}{
-		{label: "Status: Unknown"},
-		{label: "Addresses: None", hidden: true},
+		{label: l18n.Sprintf("Status: Unknown")},
+		{label: l18n.Sprintf("Addresses: None"), hidden: true},
 		{separator: true},
 		{separator: true},
-		{label: "&Manage tunnels…", handler: tray.onManageTunnels, enabled: true, defawlt: true},
-		{label: "&Import tunnel(s) from file…", handler: tray.onImport, enabled: true},
+		{label: l18n.Sprintf("&Manage tunnels…"), handler: tray.onManageTunnels, enabled: true, defawlt: true},
+		{label: l18n.Sprintf("&Import tunnel(s) from file…"), handler: tray.onImport, enabled: true},
 		{separator: true},
-		{label: "&About WireGuard…", handler: tray.onAbout, enabled: true},
-		{label: "E&xit", handler: onQuit, enabled: true},
+		{label: l18n.Sprintf("&About WireGuard…"), handler: tray.onAbout, enabled: true},
+		{label: l18n.Sprintf("E&xit"), handler: onQuit, enabled: true},
 	} {
 		var action *walk.Action
 		if item.separator {
@@ -160,11 +160,11 @@ func (tray *Tray) addTunnelAction(tunnel *manager.Tunnel) {
 					tray.mtw.tunnelsPage.listView.selectTunnel(tclosure.Name)
 					tray.mtw.tabs.SetCurrentIndex(0)
 					if oldState == manager.TunnelUnknown {
-						showErrorCustom(tray.mtw, "Failed to determine tunnel state", err.Error())
+						showErrorCustom(tray.mtw, l18n.Sprintf("Failed to determine tunnel state"), err.Error())
 					} else if oldState == manager.TunnelStopped {
-						showErrorCustom(tray.mtw, "Failed to activate tunnel", err.Error())
+						showErrorCustom(tray.mtw, l18n.Sprintf("Failed to activate tunnel"), err.Error())
 					} else if oldState == manager.TunnelStarted {
-						showErrorCustom(tray.mtw, "Failed to deactivate tunnel", err.Error())
+						showErrorCustom(tray.mtw, l18n.Sprintf("Failed to deactivate tunnel"), err.Error())
 					}
 				})
 			}
@@ -213,7 +213,7 @@ func (tray *Tray) onTunnelChange(tunnel *manager.Tunnel, state manager.TunnelSta
 		tray.updateGlobalState(globalState)
 		tray.SetTunnelState(tunnel, state, err == nil)
 		if !tray.mtw.Visible() && err != nil {
-			tray.ShowError("WireGuard Tunnel Error", err.Error())
+			tray.ShowError(l18n.Sprintf("WireGuard Tunnel Error"), err.Error())
 		}
 	})
 }
@@ -234,8 +234,9 @@ func (tray *Tray) updateGlobalState(globalState manager.TunnelState) {
 		}
 	}
 
-	tray.SetToolTip(fmt.Sprintf("WireGuard: %s", textForState(globalState, true)))
-	statusAction.SetText(fmt.Sprintf("Status: %s", textForState(globalState, false)))
+	tray.SetToolTip(l18n.Sprintf("WireGuard: %s", textForState(globalState, true)))
+	stateText := textForState(globalState, false)
+	statusAction.SetText(l18n.Sprintf("Status: %s", stateText))
 
 	switch globalState {
 	case manager.TunnelStarting:
@@ -274,13 +275,13 @@ func (tray *Tray) SetTunnelState(tunnel *manager.Tunnel, state manager.TunnelSta
 				var sb strings.Builder
 				for i, addr := range config.Interface.Addresses {
 					if i > 0 {
-						sb.WriteString(", ")
+						sb.WriteString(l18n.EnumerationSeparator())
 					}
 
 					sb.WriteString(addr.String())
 				}
 				tray.mtw.Synchronize(func() {
-					activeCIDRsAction.SetText(fmt.Sprintf("Addresses: %s", sb.String()))
+					activeCIDRsAction.SetText(l18n.Sprintf("Addresses: %s", sb.String()))
 				})
 			}
 		}()
@@ -288,21 +289,21 @@ func (tray *Tray) SetTunnelState(tunnel *manager.Tunnel, state manager.TunnelSta
 		tunnelAction.SetChecked(true)
 		if !wasChecked && showNotifications {
 			icon, _ := iconWithOverlayForState(state, 128)
-			tray.ShowCustom("WireGuard Activated", fmt.Sprintf("The %s tunnel has been activated.", tunnel.Name), icon)
+			tray.ShowCustom(l18n.Sprintf("WireGuard Activated"), l18n.Sprintf("The %s tunnel has been activated.", tunnel.Name), icon)
 		}
 
 	case manager.TunnelStopped:
 		tunnelAction.SetChecked(false)
 		if wasChecked && showNotifications {
 			icon, _ := loadSystemIcon("imageres", 26, 128) // TODO: this icon isn't very good...
-			tray.ShowCustom("WireGuard Deactivated", fmt.Sprintf("The %s tunnel has been deactivated.", tunnel.Name), icon)
+			tray.ShowCustom(l18n.Sprintf("WireGuard Deactivated"), l18n.Sprintf("The %s tunnel has been deactivated.", tunnel.Name), icon)
 		}
 	}
 }
 
 func (tray *Tray) UpdateFound() {
 	action := walk.NewAction()
-	action.SetText("An Update is Available!")
+	action.SetText(l18n.Sprintf("An Update is Available!"))
 	menuIcon, _ := loadSystemIcon("imageres", 1, 16)
 	action.SetImage(menuIcon)
 	action.SetDefault(true)
@@ -319,7 +320,7 @@ func (tray *Tray) UpdateFound() {
 
 	showUpdateBalloon := func() {
 		icon, _ := loadSystemIcon("imageres", 1, 128)
-		tray.ShowCustom("WireGuard Update Available", "An update to WireGuard is now available. You are advised to update as soon as possible.", icon)
+		tray.ShowCustom(l18n.Sprintf("WireGuard Update Available"), l18n.Sprintf("An update to WireGuard is now available. You are advised to update as soon as possible."), icon)
 	}
 
 	timeSinceStart := time.Now().Sub(startTime)
diff --git a/ui/tunnelspage.go b/ui/tunnelspage.go
index aed8d157..d5933143 100644
--- a/ui/tunnelspage.go
+++ b/ui/tunnelspage.go
@@ -7,6 +7,7 @@ package ui
 
 import (
 	"archive/zip"
+	"errors"
 	"fmt"
 	"io/ioutil"
 	"os"
@@ -17,6 +18,7 @@ import (
 	"github.com/lxn/walk"
 
 	"golang.zx2c4.com/wireguard/windows/conf"
+	"golang.zx2c4.com/wireguard/windows/l18n"
 	"golang.zx2c4.com/wireguard/windows/manager"
 )
 
@@ -45,7 +47,7 @@ func NewTunnelsPage() (*TunnelsPage, error) {
 	}
 	disposables.Add(tp)
 
-	tp.SetTitle("Tunnels")
+	tp.SetTitle(l18n.Sprintf("Tunnels"))
 	tp.SetLayout(walk.NewHBoxLayout())
 
 	tp.listContainer, _ = walk.NewComposite(tp)
@@ -101,7 +103,7 @@ func NewTunnelsPage() (*TunnelsPage, error) {
 	tp.listView.CurrentIndexChanged().Attach(func() {
 		editTunnel.SetEnabled(tp.listView.CurrentIndex() > -1)
 	})
-	editTunnel.SetText("&Edit")
+	editTunnel.SetText(l18n.Sprintf("&Edit"))
 	editTunnel.Clicked().Attach(tp.onEditTunnel)
 
 	disposables.Spare()
@@ -142,7 +144,7 @@ func (tp *TunnelsPage) CreateToolbar() error {
 	}
 	tp.AddDisposable(addMenu)
 	importAction := walk.NewAction()
-	importAction.SetText("&Import tunnel(s) from file…")
+	importAction.SetText(l18n.Sprintf("&Import tunnel(s) from file…"))
 	importActionIcon, _ := loadSystemIcon("imageres", 3, 16)
 	importAction.SetImage(importActionIcon)
 	importAction.SetShortcut(walk.Shortcut{walk.ModControl, walk.KeyO})
@@ -150,7 +152,7 @@ func (tp *TunnelsPage) CreateToolbar() error {
 	importAction.Triggered().Attach(tp.onImport)
 	addMenu.Actions().Add(importAction)
 	addAction := walk.NewAction()
-	addAction.SetText("Add &empty tunnel…")
+	addAction.SetText(l18n.Sprintf("Add &empty tunnel…"))
 	addActionIcon, _ := loadSystemIcon("imageres", 2, 16)
 	addAction.SetImage(addActionIcon)
 	addAction.SetShortcut(walk.Shortcut{walk.ModControl, walk.KeyN})
@@ -159,7 +161,7 @@ func (tp *TunnelsPage) CreateToolbar() error {
 	addMenuAction := walk.NewMenuAction(addMenu)
 	addMenuActionIcon, _ := loadSystemIcon("shell32", 149, 16)
 	addMenuAction.SetImage(addMenuActionIcon)
-	addMenuAction.SetText("Add Tunnel")
+	addMenuAction.SetText(l18n.Sprintf("Add Tunnel"))
 	addMenuAction.SetToolTip(importAction.Text())
 	addMenuAction.Triggered().Attach(tp.onImport)
 	tp.listToolbar.Actions().Add(addMenuAction)
@@ -170,7 +172,7 @@ func (tp *TunnelsPage) CreateToolbar() error {
 	deleteActionIcon, _ := loadSystemIcon("shell32", 131, 16)
 	deleteAction.SetImage(deleteActionIcon)
 	deleteAction.SetShortcut(walk.Shortcut{0, walk.KeyDelete})
-	deleteAction.SetToolTip("Remove selected tunnel(s)")
+	deleteAction.SetToolTip(l18n.Sprintf("Remove selected tunnel(s)"))
 	deleteAction.Triggered().Attach(tp.onDelete)
 	tp.listToolbar.Actions().Add(deleteAction)
 	tp.listToolbar.Actions().Add(walk.NewSeparatorAction())
@@ -178,7 +180,7 @@ func (tp *TunnelsPage) CreateToolbar() error {
 	exportAction := walk.NewAction()
 	exportActionIcon, _ := loadSystemIcon("imageres", 165, 16) // Or "shell32", 45?
 	exportAction.SetImage(exportActionIcon)
-	exportAction.SetToolTip("Export all tunnels to zip…")
+	exportAction.SetToolTip(l18n.Sprintf("Export all tunnels to zip"))
 	exportAction.Triggered().Attach(tp.onExportTunnels)
 	tp.listToolbar.Actions().Add(exportAction)
 
@@ -195,42 +197,42 @@ func (tp *TunnelsPage) CreateToolbar() error {
 	}
 	tp.listView.AddDisposable(contextMenu)
 	toggleAction := walk.NewAction()
-	toggleAction.SetText("&Toggle")
+	toggleAction.SetText(l18n.Sprintf("&Toggle"))
 	toggleAction.SetDefault(true)
 	toggleAction.Triggered().Attach(tp.onTunnelsViewItemActivated)
 	contextMenu.Actions().Add(toggleAction)
 	contextMenu.Actions().Add(walk.NewSeparatorAction())
 	importAction2 := walk.NewAction()
-	importAction2.SetText("&Import tunnel(s) from file…")
+	importAction2.SetText(l18n.Sprintf("&Import tunnel(s) from file…"))
 	importAction2.SetShortcut(walk.Shortcut{walk.ModControl, walk.KeyO})
 	importAction2.Triggered().Attach(tp.onImport)
 	contextMenu.Actions().Add(importAction2)
 	tp.ShortcutActions().Add(importAction2)
 	addAction2 := walk.NewAction()
-	addAction2.SetText("Add &empty tunnel…")
+	addAction2.SetText(l18n.Sprintf("Add &empty tunnel…"))
 	addAction2.SetShortcut(walk.Shortcut{walk.ModControl, walk.KeyN})
 	addAction2.Triggered().Attach(tp.onAddTunnel)
 	contextMenu.Actions().Add(addAction2)
 	tp.ShortcutActions().Add(addAction2)
 	exportAction2 := walk.NewAction()
-	exportAction2.SetText("Export all tunnels to &zip…")
+	exportAction2.SetText(l18n.Sprintf("Export all tunnels to &zip…"))
 	exportAction2.Triggered().Attach(tp.onExportTunnels)
 	contextMenu.Actions().Add(exportAction2)
 	contextMenu.Actions().Add(walk.NewSeparatorAction())
 	editAction := walk.NewAction()
-	editAction.SetText("Edit &selected tunnel…")
+	editAction.SetText(l18n.Sprintf("Edit &selected tunnel…"))
 	editAction.SetShortcut(walk.Shortcut{walk.ModControl, walk.KeyE})
 	editAction.Triggered().Attach(tp.onEditTunnel)
 	contextMenu.Actions().Add(editAction)
 	tp.ShortcutActions().Add(editAction)
 	deleteAction2 := walk.NewAction()
-	deleteAction2.SetText("&Remove selected tunnel(s)")
+	deleteAction2.SetText(l18n.Sprintf("&Remove selected tunnel(s)"))
 	deleteAction2.SetShortcut(walk.Shortcut{0, walk.KeyDelete})
 	deleteAction2.Triggered().Attach(tp.onDelete)
 	contextMenu.Actions().Add(deleteAction2)
 	tp.listView.ShortcutActions().Add(deleteAction2)
 	selectAllAction := walk.NewAction()
-	selectAllAction.SetText("Select &all")
+	selectAllAction.SetText(l18n.Sprintf("Select &all"))
 	selectAllAction.SetShortcut(walk.Shortcut{walk.ModControl, walk.KeyA})
 	selectAllAction.Triggered().Attach(tp.onSelectAll)
 	contextMenu.Actions().Add(selectAllAction)
@@ -324,7 +326,7 @@ func (tp *TunnelsPage) importFiles(paths []string) {
 		}
 
 		if lastErr != nil || unparsedConfigs == nil {
-			syncedMsgBox("Error", fmt.Sprintf("Could not import selected configuration: %v", lastErr), walk.MsgBoxIconWarning)
+			syncedMsgBox(l18n.Sprintf("Error"), l18n.Sprintf("Could not import selected configuration: %v", lastErr), walk.MsgBoxIconWarning)
 			return
 		}
 
@@ -335,7 +337,7 @@ func (tp *TunnelsPage) importFiles(paths []string) {
 
 		existingTunnelList, err := manager.IPCClientTunnels()
 		if err != nil {
-			syncedMsgBox("Error", fmt.Sprintf("Could not enumerate existing tunnels: %v", lastErr), walk.MsgBoxIconWarning)
+			syncedMsgBox(l18n.Sprintf("Error"), l18n.Sprintf("Could not enumerate existing tunnels: %v", lastErr), walk.MsgBoxIconWarning)
 			return
 		}
 		existingLowerTunnels := make(map[string]bool, len(existingTunnelList))
@@ -347,7 +349,7 @@ func (tp *TunnelsPage) importFiles(paths []string) {
 		tp.listView.SetSuspendTunnelsUpdate(true)
 		for _, unparsedConfig := range unparsedConfigs {
 			if existingLowerTunnels[strings.ToLower(unparsedConfig.Name)] {
-				lastErr = fmt.Errorf("Another tunnel already exists with the name ‘%s’", unparsedConfig.Name)
+				lastErr = errors.New(l18n.Sprintf("Another tunnel already exists with the name ‘%s’", unparsedConfig.Name))
 				continue
 			}
 			config, err := conf.FromWgQuickWithUnknownEncoding(unparsedConfig.Config, unparsedConfig.Name)
@@ -367,13 +369,13 @@ func (tp *TunnelsPage) importFiles(paths []string) {
 		m, n := configCount, len(unparsedConfigs)
 		switch {
 		case n == 1 && m != n:
-			syncedMsgBox("Error", fmt.Sprintf("Unable to import configuration: %v", lastErr), walk.MsgBoxIconWarning)
+			syncedMsgBox(l18n.Sprintf("Error"), l18n.Sprintf("Unable to import configuration: %v", lastErr), walk.MsgBoxIconWarning)
 		case n == 1 && m == n:
 			// nothing
 		case m == n:
-			syncedMsgBox("Imported tunnels", fmt.Sprintf("Imported %d tunnels", m), walk.MsgBoxIconInformation)
+			syncedMsgBox(l18n.Sprintf("Imported tunnels"), l18n.Sprintf("Imported %d tunnels", m), walk.MsgBoxIconInformation)
 		case m != n:
-			syncedMsgBox("Imported tunnels", fmt.Sprintf("Imported %d of %d tunnels", m, n), walk.MsgBoxIconWarning)
+			syncedMsgBox(l18n.Sprintf("Imported tunnels"), l18n.Sprintf("Imported %d of %d tunnels", m, n), walk.MsgBoxIconWarning)
 		}
 	}()
 }
@@ -405,7 +407,7 @@ func (tp *TunnelsPage) exportTunnels(filePath string) {
 func (tp *TunnelsPage) addTunnel(config *conf.Config) {
 	_, err := manager.IPCClientNewTunnel(config)
 	if err != nil {
-		showErrorCustom(tp.Form(), "Unable to create tunnel", err.Error())
+		showErrorCustom(tp.Form(), l18n.Sprintf("Unable to create tunnel"), err.Error())
 	}
 
 }
@@ -422,11 +424,11 @@ func (tp *TunnelsPage) onTunnelsViewItemActivated() {
 		if err != nil {
 			tp.Synchronize(func() {
 				if oldState == manager.TunnelUnknown {
-					showErrorCustom(tp.Form(), "Failed to determine tunnel state", err.Error())
+					showErrorCustom(tp.Form(), l18n.Sprintf("Failed to determine tunnel state"), err.Error())
 				} else if oldState == manager.TunnelStopped {
-					showErrorCustom(tp.Form(), "Failed to activate tunnel", err.Error())
+					showErrorCustom(tp.Form(), l18n.Sprintf("Failed to activate tunnel"), err.Error())
 				} else if oldState == manager.TunnelStarted {
-					showErrorCustom(tp.Form(), "Failed to deactivate tunnel", err.Error())
+					showErrorCustom(tp.Form(), l18n.Sprintf("Failed to deactivate tunnel"), err.Error())
 				}
 			})
 			return
@@ -466,16 +468,20 @@ func (tp *TunnelsPage) onDelete() {
 		return
 	}
 
-	var topic string
+	var title, question string
 	if len(indices) > 1 {
-		topic = fmt.Sprintf("%d tunnels", len(indices))
+		tunnelCount := len(indices)
+		title = l18n.Sprintf("Delete %d tunnels", tunnelCount)
+		question = l18n.Sprintf("Are you sure you would like to delete %d tunnels?", tunnelCount)
 	} else {
-		topic = fmt.Sprintf("‘%s’", tp.listView.model.tunnels[indices[0]].Name)
+		tunnelName := tp.listView.model.tunnels[indices[0]].Name
+		title = l18n.Sprintf("Delete tunnel ‘%s’", tunnelName)
+		question = l18n.Sprintf("Are you sure you would like to delete tunnel ‘%s’?", tunnelName)
 	}
 	if walk.DlgCmdNo == walk.MsgBox(
 		tp.Form(),
-		fmt.Sprintf("Delete %s", topic),
-		fmt.Sprintf("Are you sure you would like to delete %s? You cannot undo this action.", topic),
+		title,
+		l18n.Sprintf("%s You cannot undo this action.", question),
 		walk.MsgBoxYesNo|walk.MsgBoxIconWarning) {
 		return
 	}
@@ -515,9 +521,9 @@ func (tp *TunnelsPage) onDelete() {
 		if len(errors) > 0 {
 			tp.listView.Synchronize(func() {
 				if len(errors) == 1 {
-					showErrorCustom(tp.Form(), "Unable to delete tunnel", fmt.Sprintf("A tunnel was unable to be removed: %s", errors[0].Error()))
+					showErrorCustom(tp.Form(), l18n.Sprintf("Unable to delete tunnel"), l18n.Sprintf("A tunnel was unable to be removed: %s", errors[0].Error()))
 				} else {
-					showErrorCustom(tp.Form(), "Unable to delete tunnels", fmt.Sprintf("%d tunnels were unable to be removed.", len(errors)))
+					showErrorCustom(tp.Form(), l18n.Sprintf("Unable to delete tunnels"), l18n.Sprintf("%d tunnels were unable to be removed.", len(errors)))
 				}
 			})
 		}
@@ -530,8 +536,8 @@ func (tp *TunnelsPage) onSelectAll() {
 
 func (tp *TunnelsPage) onImport() {
 	dlg := walk.FileDialog{
-		Filter: "Configuration Files (*.zip, *.conf)|*.zip;*.conf|All Files (*.*)|*.*",
-		Title:  "Import tunnel(s) from file",
+		Filter: l18n.Sprintf("Configuration Files (*.zip, *.conf)|*.zip;*.conf|All Files (*.*)|*.*"),
+		Title:  l18n.Sprintf("Import tunnel(s) from file"),
 	}
 
 	if ok, _ := dlg.ShowOpenMultiple(tp.Form()); !ok {
@@ -543,8 +549,8 @@ func (tp *TunnelsPage) onImport() {
 
 func (tp *TunnelsPage) onExportTunnels() {
 	dlg := walk.FileDialog{
-		Filter: "Configuration ZIP Files (*.zip)|*.zip",
-		Title:  "Export tunnels to zip",
+		Filter: l18n.Sprintf("Configuration ZIP Files (*.zip)|*.zip"),
+		Title:  l18n.Sprintf("Export tunnels to zip"),
 	}
 
 	if ok, _ := dlg.ShowSave(tp.Form()); !ok {
@@ -571,7 +577,7 @@ func (tp *TunnelsPage) swapFiller(enabled bool) bool {
 
 func (tp *TunnelsPage) onTunnelsChanged() {
 	if tp.swapFiller(tp.listView.model.RowCount() == 0) {
-		tp.fillerButton.SetText("Import tunnel(s) from file")
+		tp.fillerButton.SetText(l18n.Sprintf("Import tunnel(s) from file"))
 		tp.fillerHandler = tp.onImport
 	}
 }
@@ -581,8 +587,9 @@ func (tp *TunnelsPage) onSelectedTunnelsChanged() {
 		return
 	}
 	indices := tp.listView.SelectedIndexes()
-	if tp.swapFiller(len(indices) > 1) {
-		tp.fillerButton.SetText(fmt.Sprintf("Delete %d tunnels", len(indices)))
+	tunnelCount := len(indices)
+	if tp.swapFiller(tunnelCount > 1) {
+		tp.fillerButton.SetText(l18n.Sprintf("Delete %d tunnels", tunnelCount))
 		tp.fillerHandler = tp.onDelete
 	}
 }
diff --git a/ui/ui.go b/ui/ui.go
index 22354d12..0279a8dd 100644
--- a/ui/ui.go
+++ b/ui/ui.go
@@ -15,6 +15,7 @@ import (
 	"github.com/lxn/win"
 	"golang.org/x/sys/windows"
 
+	"golang.zx2c4.com/wireguard/windows/l18n"
 	"golang.zx2c4.com/wireguard/windows/manager"
 	"golang.zx2c4.com/wireguard/windows/version"
 )
@@ -75,7 +76,7 @@ func RunUI() {
 					tray.UpdateFound()
 				}
 			case manager.UpdateStateUpdatesDisabledUnofficialBuild:
-				mtw.SetTitle(mtw.Title() + " (unsigned build, no updates)")
+				mtw.SetTitle(l18n.Sprintf("%s (unsigned build, no updates)", mtw.Title()))
 			}
 		})
 	}
@@ -100,7 +101,7 @@ func RunUI() {
 	if shouldQuitManagerWhenExiting {
 		_, err := manager.IPCClientQuit(true)
 		if err != nil {
-			showErrorCustom(nil, "Error Exiting WireGuard", fmt.Sprintf("Unable to exit service due to: %v. You may want to stop WireGuard from the service manager.", err))
+			showErrorCustom(nil, l18n.Sprintf("Error Exiting WireGuard"), l18n.Sprintf("Unable to exit service due to: %v. You may want to stop WireGuard from the service manager.", err))
 		}
 	}
 }
@@ -115,7 +116,7 @@ func showError(err error, owner walk.Form) bool {
 		return false
 	}
 
-	showErrorCustom(owner, "Error", err.Error())
+	showErrorCustom(owner, l18n.Sprintf("Error"), err.Error())
 
 	return true
 }
diff --git a/ui/updatepage.go b/ui/updatepage.go
index 9e73781f..1ed0b74c 100644
--- a/ui/updatepage.go
+++ b/ui/updatepage.go
@@ -6,10 +6,9 @@
 package ui
 
 import (
-	"fmt"
-
 	"github.com/lxn/walk"
 
+	"golang.zx2c4.com/wireguard/windows/l18n"
 	"golang.zx2c4.com/wireguard/windows/manager"
 	"golang.zx2c4.com/wireguard/windows/updater"
 )
@@ -30,7 +29,7 @@ func NewUpdatePage() (*UpdatePage, error) {
 	}
 	disposables.Add(up)
 
-	up.SetTitle("An Update is Available!")
+	up.SetTitle(l18n.Sprintf("An Update is Available!"))
 
 	tabIcon, _ := loadSystemIcon("imageres", 1, 16)
 	up.SetImage(tabIcon)
@@ -41,14 +40,14 @@ func NewUpdatePage() (*UpdatePage, error) {
 	if err != nil {
 		return nil, err
 	}
-	instructions.SetText("An update to WireGuard is available. It is highly advisable to update without delay.")
+	instructions.SetText(l18n.Sprintf("An update to WireGuard is available. It is highly advisable to update without delay."))
 	instructions.SetMinMaxSize(walk.Size{1, 0}, walk.Size{0, 0})
 
 	status, err := walk.NewTextLabel(up)
 	if err != nil {
 		return nil, err
 	}
-	status.SetText("Status: Waiting for user")
+	status.SetText(l18n.Sprintf("Status: Waiting for user"))
 	status.SetMinMaxSize(walk.Size{1, 0}, walk.Size{0, 0})
 
 	bar, err := walk.NewProgressBar(up)
@@ -63,7 +62,7 @@ func NewUpdatePage() (*UpdatePage, error) {
 	}
 	updateIcon, _ := loadSystemIcon("shell32", 46, 32)
 	button.SetImage(updateIcon)
-	button.SetText("Update Now")
+	button.SetText(l18n.Sprintf("Update Now"))
 
 	walk.NewVSpacer(up)
 
@@ -75,7 +74,7 @@ func NewUpdatePage() (*UpdatePage, error) {
 			bar.SetVisible(true)
 			bar.SetMarqueeMode(true)
 			up.SetSuspended(false)
-			status.SetText("Status: Waiting for updater service")
+			status.SetText(l18n.Sprintf("Status: Waiting for updater service"))
 		}
 	}
 
@@ -97,7 +96,7 @@ func NewUpdatePage() (*UpdatePage, error) {
 		err := manager.IPCClientUpdate()
 		if err != nil {
 			switchToReadyState()
-			status.SetText(fmt.Sprintf("Error: %v. Please try again.", err))
+			status.SetText(l18n.Sprintf("Error: %v. Please try again.", err))
 		}
 	})
 
@@ -106,11 +105,13 @@ func NewUpdatePage() (*UpdatePage, error) {
 			switchToUpdatingState()
 			if dp.Error != nil {
 				switchToReadyState()
-				status.SetText(fmt.Sprintf("Error: %v. Please try again.", dp.Error))
+				err := dp.Error
+				status.SetText(l18n.Sprintf("Error: %v. Please try again.", err))
 				return
 			}
 			if len(dp.Activity) > 0 {
-				status.SetText(fmt.Sprintf("Status: %s", dp.Activity))
+				stateText := dp.Activity
+				status.SetText(l18n.Sprintf("Status: %s", stateText))
 			}
 			if dp.BytesTotal > 0 {
 				bar.SetMarqueeMode(false)
@@ -123,7 +124,7 @@ func NewUpdatePage() (*UpdatePage, error) {
 			}
 			if dp.Complete {
 				switchToReadyState()
-				status.SetText("Status: Complete!")
+				status.SetText(l18n.Sprintf("Status: Complete!"))
 				return
 			}
 		})
-- 
cgit v1.2.3-59-g8ed1b