Implement FirstThrottler, to gain 200 ms for first refresh

vector/src/main/java/im/vector/app/core/extensions/LiveData.kt

@@ -39,7 +39,7 @@ inline fun <T> LiveData<LiveEvent<T>>.observeEventFirstThrottle(owner: Lifecycle
     val firstThrottler = FirstThrottler(minimumInterval)
 
     this.observe(owner, EventObserver {
-        if (firstThrottler.canHandle()) {
+        if (firstThrottler.canHandle() is FirstThrottler.CanHandlerResult.Yes) {
             it.run(observer)
         }
     })

vector/src/main/java/im/vector/app/core/utils/FirstThrottler.kt

@@ -24,14 +24,27 @@ import android.os.SystemClock
 class FirstThrottler(private val minimumInterval: Long = 800) {
     private var lastDate = 0L
 
-    fun canHandle(): Boolean {
+    sealed class CanHandlerResult {
+        object Yes : CanHandlerResult()
+        data class No(val shouldWaitMillis: Long) : CanHandlerResult()
+
+        fun waitMillis(): Long {
+            return when (this) {
+                Yes   -> 0
+                is No -> shouldWaitMillis
+            }
+        }
+    }
+
+    fun canHandle(): CanHandlerResult {
         val now = SystemClock.elapsedRealtime()
-        if (now > lastDate + minimumInterval) {
+        val delaySinceLast = now - lastDate
+        if (delaySinceLast > minimumInterval) {
             lastDate = now
-            return true
+            return CanHandlerResult.Yes
         }
 
         // Too soon
-        return false
+        return CanHandlerResult.No(minimumInterval - delaySinceLast)
     }
 }

vector/src/main/java/im/vector/app/features/notifications/NotificationDrawerManager.kt

@@ -26,6 +26,7 @@ import im.vector.app.ActiveSessionDataSource
 import im.vector.app.BuildConfig
 import im.vector.app.R
 import im.vector.app.core.resources.StringProvider
+import im.vector.app.core.utils.FirstThrottler
 import im.vector.app.features.settings.VectorPreferences
 import me.gujun.android.span.span
 import org.matrix.android.sdk.api.session.Session
@@ -194,10 +195,14 @@ class NotificationDrawerManager @Inject constructor(private val context: Context
         notificationUtils.cancelNotificationMessage(roomId, ROOM_INVITATION_NOTIFICATION_ID)
     }
 
+    private var firstThrottler = FirstThrottler(200)
+
     fun refreshNotificationDrawer() {
         // Implement last throttler
-        Timber.v("refreshNotificationDrawer()")
+        val canHandle = firstThrottler.canHandle()
+        Timber.v("refreshNotificationDrawer(), delay: ${canHandle.waitMillis()} ms")
         backgroundHandler.removeCallbacksAndMessages(null)
+
         backgroundHandler.postDelayed(
                 {
                     try {
@@ -206,7 +211,8 @@ class NotificationDrawerManager @Inject constructor(private val context: Context
                         // It can happen if for instance session has been destroyed. It's a bit ugly to try catch like this, but it's safer
                         Timber.w(throwable, "refreshNotificationDrawerBg failure")
                     }
-                }, 200)
+                },
+                canHandle.waitMillis())
     }
 
     @WorkerThread

vector/src/main/java/im/vector/app/features/settings/VectorSettingsHelpAboutFragment.kt

@@ -101,7 +101,7 @@ class VectorSettingsHelpAboutFragment @Inject constructor(
         // third party notice
         findPreference<VectorPreference>(VectorPreferences.SETTINGS_THIRD_PARTY_NOTICES_PREFERENCE_KEY)!!
                 .onPreferenceClickListener = Preference.OnPreferenceClickListener {
-            if (firstThrottler.canHandle()) {
+            if (firstThrottler.canHandle() is FirstThrottler.CanHandlerResult.Yes) {
                 activity?.displayInWebView(VectorSettingsUrls.THIRD_PARTY_LICENSES)
             }
             false