PLT-6890 Fix various scrolling issues (#6727)

* Fix various scrolling issues

* Move reaction scrolling to reaction list

* Handle scrolling when RHS opens

* Only run scroll update code when posts change

1 files changed, 27 insertions, 0 deletions

diff --git a/webapp/utils/global_event_emitter.jsx b/webapp/utils/global_event_emitter.jsx
new file mode 100644
index 000000000..0d231d2a2
--- /dev/null
+++ b/webapp/utils/global_event_emitter.jsx
@@ -0,0 +1,27 @@
+// Copyright (c) 2017-present Mattermost, Inc. All Rights Reserved.
+// See License.txt for license information.
+
+import AppDispatcher from 'dispatcher/app_dispatcher.jsx';
+import EventEmitter from 'events';
+
+import EventTypes from 'utils/event_types.jsx';
+
+class GlobalEventEmitterClass extends EventEmitter {
+    constructor() {
+        super();
+        this.dispatchToken = AppDispatcher.register(this.handleEventPayload);
+    }
+
+    handleEventPayload = (payload) => {
+        const {type, value, ...args} = payload.action; //eslint-disable-line no-use-before-define
+
+        switch (type) {
+        case EventTypes.POST_LIST_SCROLL_CHANGE:
+            this.emit(type, value, args);
+            break;
+        }
+    }
+}
+
+const GlobalEventEmitter = new GlobalEventEmitterClass();
+export default GlobalEventEmitter;