android [nfc]: Move notif intent-handling function into notifications/

Author: chrisbobbe

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

@@ -6,10 +6,7 @@ import android.os.Bundle
 import android.webkit.WebView
 import com.facebook.react.ReactActivity
 import com.facebook.react.ReactActivityDelegate
-import com.zulipmobile.notifications.EXTRA_NOTIFICATION_DATA
-import com.zulipmobile.notifications.NOTIFICATION_URL_AUTHORITY
-import com.zulipmobile.notifications.logNotificationData
-import com.zulipmobile.notifications.notifyReact
+import com.zulipmobile.notifications.maybeHandleViewNotif
 import com.zulipmobile.sharing.handleSend
 import expo.modules.ReactActivityDelegateWrapper
 
@@ -32,26 +29,22 @@ open class MainActivity : ReactActivity() {
     /* Returns true just if we did handle the intent. */
     private fun maybeHandleIntent(intent: Intent?): Boolean {
         intent ?: return false
-        val url = intent.data
         when (intent.action) {
             // Share-to-Zulip
             Intent.ACTION_SEND, Intent.ACTION_SEND_MULTIPLE -> {
                 handleSend(intent, reactApplication.tryGetReactContext(), contentResolver)
                 return true
             }
 
-            Intent.ACTION_VIEW -> when {
-                // Launch MainActivity on tapping a notification
-                url?.scheme == "zulip" && url.authority == NOTIFICATION_URL_AUTHORITY -> {
-                    val data = intent.getBundleExtra(EXTRA_NOTIFICATION_DATA) ?: return false
-                    logNotificationData("notif opened", data)
-                    notifyReact(reactApplication.tryGetReactContext(), data)
+            Intent.ACTION_VIEW -> {
+                if (maybeHandleViewNotif(intent, reactApplication.tryGetReactContext())) {
+                    // Notification tapped
                     return true
                 }
 
                 // Let RN handle other intents.  In particular web-auth intents (parsed in
                 // src/start/webAuth.js) have ACTION_VIEW, scheme "zulip", and authority "login".
-                else -> return false
+                return false
             }
 
             // For other intents, let RN handle it.

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

@@ -2,13 +2,12 @@
 
 package com.zulipmobile.notifications
 
+import android.content.Intent
 import android.os.Bundle
 import android.util.Log
 import com.facebook.react.bridge.Arguments
 import com.facebook.react.bridge.ReactContext
-import com.zulipmobile.ReactAppStatus
-import com.zulipmobile.appStatus
-import com.zulipmobile.emitEvent
+import com.zulipmobile.*
 
 /**
  * Methods for telling React about a notification.
@@ -17,6 +16,31 @@ import com.zulipmobile.emitEvent
  * TODO: Replace this with a fresh implementation based on RN upstream docs.
  */
 
+/**
+ * Recognize if an ACTION_VIEW intent came from tapping a notification; handle it if so
+ *
+ * Just if the intent is recognized,
+ * sends a 'notificationOpened' event to the JavaScript layer
+ * and returns true.
+ * Else does nothing and returns false.
+ *
+ * Do not call if `intent.action` is not ACTION_VIEW.
+ */
+internal fun maybeHandleViewNotif(intent: Intent, maybeReactContext: ReactContext?): Boolean {
+    assert(intent.action == Intent.ACTION_VIEW)
+
+    val url = intent.data
+    // Launch MainActivity on tapping a notification
+    if (url?.scheme == "zulip" && url.authority == NOTIFICATION_URL_AUTHORITY) {
+        val data = intent.getBundleExtra(EXTRA_NOTIFICATION_DATA) ?: return false
+        logNotificationData("notif opened", data)
+        notifyReact(maybeReactContext, data)
+        return true
+    }
+
+    return false
+}
+
 internal fun notifyReact(reactContext: ReactContext?, data: Bundle) {
     // TODO deduplicate this with handleSend in SharingHelper.kt; see
     // https://github.com/zulip/zulip-mobile/pull/5146#discussion_r764437055