Null check readMarkerEventId, update comment

This commit is contained in:
Luke Barnard 2017-04-27 16:52:40 +01:00
parent 8f7359fce1
commit 6313193aa8

View file

@ -767,13 +767,16 @@ var TimelinePanel = React.createClass({
}, },
canJumpToReadMarker: function() { canJumpToReadMarker: function() {
// Only show jump bar if RR !== RM. If they are the same, there are only fully // 1. Do not show jump bar if neither the RM nor the RR are set.
// 2. Only show jump bar if RR !== RM. If they are the same, there are only fully
// read messages and unread messages. We already have a badge count and the bottom // read messages and unread messages. We already have a badge count and the bottom
// bar to jump to "live" when we have unread messages. // bar to jump to "live" when we have unread messages.
// We want to show the bar if the read-marker is off the top of the screen. // 3. We want to show the bar if the read-marker is off the top of the screen.
// Also, if pos === null, the event might not be paginated - show the unread bar // 4. Also, if pos === null, the event might not be paginated - show the unread bar
const pos = this.getReadMarkerPosition(); const pos = this.getReadMarkerPosition();
return this.state.readMarkerEventId !== this._getCurrentReadReceipt() && (pos < 0 || pos === null); return this.state.readMarkerEventId !== null && // 1.
this.state.readMarkerEventId !== this._getCurrentReadReceipt() && // 2.
(pos < 0 || pos === null); // 3., 4.
}, },
/** /**