From 7cc64497a5afa1563dbb2dd4cc094fdedfb5f22f Mon Sep 17 00:00:00 2001
From: Christian Pauly <christian-pauly@posteo.de>
Date: Fri, 29 Nov 2019 11:12:04 +0000
Subject: [PATCH] [Timeline] Add get event by id method

---
 lib/src/Room.dart     |  7 +------
 lib/src/Timeline.dart | 16 ++++++++++++++++
 2 files changed, 17 insertions(+), 6 deletions(-)

diff --git a/lib/src/Room.dart b/lib/src/Room.dart
index 95ca366..3ae71b8 100644
--- a/lib/src/Room.dart
+++ b/lib/src/Room.dart
@@ -758,13 +758,8 @@ class Room {
     return user;
   }
 
-  /// Searches for the event in the store. If it isn't found, try to request it
-  /// from the server. Returns null if not found.
+  /// Searches for the event on the server. Returns null if not found.
   Future<Event> getEventById(String eventID) async {
-    if (client.store != null) {
-      final Event storeEvent = await client.store.getEventById(eventID, this);
-      if (storeEvent != null) return storeEvent;
-    }
     final dynamic resp = await client.connection.jsonRequest(
         type: HTTPType.GET, action: "/client/r0/rooms/$id/event/$eventID");
     if (resp is ErrorResponse) return null;
diff --git a/lib/src/Timeline.dart b/lib/src/Timeline.dart
index ab0e16c..cf11323 100644
--- a/lib/src/Timeline.dart
+++ b/lib/src/Timeline.dart
@@ -44,6 +44,22 @@ class Timeline {
   StreamSubscription<EventUpdate> sub;
   bool _requestingHistoryLock = false;
 
+  Map<String, Event> _eventCache = {};
+
+  /// Searches for the event in this timeline. If not
+  /// found, requests from the server. Requested events
+  /// are cached.
+  Future<Event> getEventById(String id) async {
+    for (int i = 0; i < events.length; i++) {
+      if (events[i].eventId == id) return events[i];
+    }
+    if (_eventCache.containsKey(id)) return _eventCache[id];
+    final Event requestedEvent = await room.getEventById(id);
+    if (requestedEvent == null) return null;
+    _eventCache[id] = requestedEvent;
+    return _eventCache[id];
+  }
+
   Future<void> requestHistory(
       {int historyCount = Room.DefaultHistoryCount}) async {
     if (!_requestingHistoryLock) {