android [nfc]: Move generic event-emitting function out of notifications/

Using Kotlin's handy "extension function" feature:
  https://kotlinlang.org/docs/extensions.html#extension-functions

Author: chrisbobbe

android/app/src/main/java/com/zulipmobile/ReactExtensions.kt

@@ -5,6 +5,13 @@ import com.facebook.react.ReactApplication
 import com.facebook.react.ReactInstanceManager
 import com.facebook.react.ReactNativeHost
 import com.facebook.react.bridge.ReactContext
+import com.facebook.react.modules.core.DeviceEventManagerModule
+
+// A convenience shortcut.
+fun ReactContext.emitEvent(eventName: String, data: Any?) {
+    getJSModule(DeviceEventManagerModule.RCTDeviceEventEmitter::class.java)
+        .emit(eventName, data)
+}
 
 /**
  * Like getReactInstanceManager, but just return what exists; avoid trying to create.

android/app/src/main/java/com/zulipmobile/notifications/NotificationsModule.kt

@@ -8,6 +8,7 @@ import androidx.core.app.NotificationManagerCompat
 import com.facebook.react.bridge.*
 import com.google.android.gms.common.ConnectionResult
 import com.google.android.gms.common.GoogleApiAvailability
+import com.zulipmobile.emitEvent
 import java.lang.Exception
 
 internal class NotificationsModule(reactContext: ReactApplicationContext) :
@@ -81,7 +82,7 @@ internal class NotificationsModule(reactContext: ReactApplicationContext) :
                 return
             }
             Log.i(TAG, "Got token; emitting event")
-            emit(reactContext, "remoteNotificationsRegistered", token)
+            reactContext.emitEvent("remoteNotificationsRegistered", token)
         }
     }
 }

android/app/src/main/java/com/zulipmobile/notifications/NotifyReact.kt

@@ -7,7 +7,7 @@ import android.util.Log
 import com.facebook.react.bridge.Arguments
 import com.facebook.react.bridge.ReactContext
 import com.facebook.react.common.LifecycleState
-import com.facebook.react.modules.core.DeviceEventManagerModule
+import com.zulipmobile.emitEvent
 
 /**
  * Methods for telling React about a notification.
@@ -76,12 +76,6 @@ internal fun notifyReact(reactContext: ReactContext?, data: Bundle) {
         ReactAppStatus.BACKGROUND, ReactAppStatus.FOREGROUND ->
             // JS is running and has already reached foreground.  It won't check
             // initialNotification again, but it will see a notificationOpened event.
-            emit(reactContext, "notificationOpened", Arguments.fromBundle(data))
+            reactContext.emitEvent("notificationOpened", Arguments.fromBundle(data))
     }
 }
-
-fun emit(reactContext: ReactContext, eventName: String, data: Any?) {
-    reactContext
-        .getJSModule(DeviceEventManagerModule.RCTDeviceEventEmitter::class.java)
-        .emit(eventName, data)
-}

android/app/src/main/java/com/zulipmobile/sharing/SharingHelper.kt

@@ -13,7 +13,7 @@ import com.facebook.react.bridge.WritableMap
 import com.zulipmobile.ZLog
 import com.zulipmobile.notifications.ReactAppStatus
 import com.zulipmobile.notifications.appStatus
-import com.zulipmobile.notifications.emit
+import com.zulipmobile.emitEvent
 
 @JvmField
 val TAG = "ShareToZulip"
@@ -43,7 +43,7 @@ internal fun handleSend(
         ReactAppStatus.BACKGROUND, ReactAppStatus.FOREGROUND ->
             // JS is running and has already reached foreground. It won't check
             // initialSharedData again, but it will see a shareReceived event.
-            emit(reactContext, "shareReceived", params)
+            reactContext.emitEvent("shareReceived", params)
     }
 }