[v3 linux] implement single_instance plugin

v3/pkg/application/linux_cgo.go

@@ -269,7 +269,7 @@ func hideAllWindows(application pointer) {
 
 func showAllWindows(application pointer) {
 	for _, window := range getWindows(application) {
-		C.gtk_widget_show_all((*C.GtkWidget)(window))
+		C.gtk_window_present((*C.GtkWindow)(window))
 	}
 }
 

v3/plugins/single_instance/README.md

@@ -1,6 +1,6 @@
 # single-instance Plugin
 
-This example plugin provides a way to generate hashes of strings.
+This plugin provides a way to prevent multiple launches of your application.
 
 ## Installation
 
@@ -28,4 +28,4 @@ Please do not contact the Wails team for support.
 ## Credit
 
 This plugin contains modified code from the awesome [go-singleinstance](https://github.com/allan-simon/go-singleinstance) module (c) 2015 Allan Simon.
-Original license file has been renamed `go-singleinstance.LICENSE` and is available [here](./singleinstance_LICENSE).
+Original license file has been renamed `go-singleinstance.LICENSE` and is available [here](./singleinstance_LICENSE).

v3/plugins/single_instance/plugin.go

@@ -2,9 +2,10 @@ package single_instance
 
 import (
 	"fmt"
-	"github.com/wailsapp/wails/v3/pkg/application"
 	"os"
 	"path/filepath"
+
+	"github.com/wailsapp/wails/v3/pkg/application"
 )
 
 type Config struct {

v3/plugins/single_instance/plugin_linux.go

@@ -2,16 +2,29 @@
 
 package single_instance
 
-/*
-#cgo CFLAGS:
-#cgo LDFLAGS:
+import (
+	"fmt"
+	"os"
+	"os/signal"
+	"syscall"
 
-*/
-import "C"
-import "fmt"
+	"github.com/wailsapp/wails/v3/pkg/application"
+)
+
+func init() {
+	sigc := make(chan os.Signal, 1)
+	signal.Notify(sigc,
+		syscall.SIGUSR2,
+	)
+	go func() {
+		for {
+			s := <-sigc
+			application.Get().Show()
+		}
+	}()
+}
 
 func (p *Plugin) activeInstance(pid int) error {
-	//	C.activateApplicationWithProcessID(C.int(pid))
-	fmt.Println("[linux] activateInstance - not implemented: ", pid)
+	syscall.Kill(pid, syscall.SIGUSR2)
 	return nil
 }