Rebased

src/nim_status_client.nim

@@ -1,4 +1,4 @@
-import NimQml, chronicles, os, strformat, times
+import NimQml, chronicles, os, strformat, times, md5
 
 import app/chat/core as chat
 import app/wallet/v1/core as wallet
@@ -66,6 +66,12 @@ proc mainProc() =
       "/../resources.rcc"
   QResource.registerResource(app.applicationDirPath & resources)
 
+  let singleInstance = newSingleInstance($toMD5(getAppDir()))
+  defer: singleInstance.delete()
+  if singleInstance.secondInstance():
+    info "Terminating the app as the second instance"
+    quit()
+
   let statusAppIcon =
     if defined(production):
       if defined(macosx):
@@ -207,6 +213,7 @@ proc mainProc() =
 
   engine.setRootContextProperty("loginModel", login.variant)
   engine.setRootContextProperty("onboardingModel", onboarding.variant)
+  engine.setRootContextProperty("singleInstance", newQVariant(singleInstance))
 
   let isExperimental = if getEnv("EXPERIMENTAL") == "1": "1" else: "0" # value explicity passed to avoid trusting input
   let experimentalFlag = newQVariant(isExperimental)

ui/main.qml

@@ -120,6 +120,18 @@ StatusWindow {
             }
         }
     }
+	
+	Connections {
+        target: singleInstance
+
+        onSecondInstanceDetected: {
+            console.log("User attempted to run the second instance of the application")
+            // activating this instance to give user visual feedback
+            applicationWindow.show()
+            applicationWindow.raise()
+            applicationWindow.requestActivate()
+        }
+    }
 
     // The easiest way to get current system theme (is it light or dark) without using
     // OS native methods is to check lightness (0 - 1.0) of the window color.