Leave call when participant was remotely disconnected from the call

Currently whether the local user is in the call or not from the point of
view of the Nextcloud server is mostly ignored; the UI is based only on
whether the user explicitly joined or left the call. The reason is that
after the user joined the response from a previous request to get the
room information done when the user had not joined yet could be
received, so honouring that could make the UI jump between "in the call"
and "not in the call" (as it happened in older versions).

However, in the WebRTC related code whether the local user is in the
call or not is only based on the user events sent by the signaling
server, so in that case the state is always up to date.

Due to this, it is possible to detect whether the local user was kicked
out from the call by a moderator (for example, because the call was
ended for everyone) by comparing the local state ("localUserInCall",
which is updated when locally joining and leaving a call) with the
remote state provided by the signaling server.

Note that there is no rollback of "localUserInCall" if the join or leave
call request fails; the error is currently ignored by other parts of the
code, so handling it here does not provide any benefit.

An alternative approach would have been to ignore the "in call" state
provided by the server while a "join call" request is on-going, so the
local state and the server state would match except when the user was
kicked out from the call. This would have required deeper changes, so
even if it could be a better approach in the end for now the simpler
(but less clean) approach was used.

Signed-off-by: Daniel Calviño Sánchez <danxuliu@gmail.com>

1 files changed, 4 insertions, 0 deletions

diff --git a/src/utils/signaling.js b/src/utils/signaling.js
index 28b699c10..98edcb0bb 100644
--- a/src/utils/signaling.js
+++ b/src/utils/signaling.js
@@ -266,6 +266,8 @@ Signaling.Base.prototype._joinCallSuccess = function(/* token */) {
 
 Signaling.Base.prototype.joinCall = function(token, flags) {
 	return new Promise((resolve, reject) => {
+		this._trigger('beforeJoinCall', [token])
+
 		axios.post(generateOcsUrl('apps/spreed/api/v4/call/{token}', { token }), {
 			flags,
 		})
@@ -318,6 +320,8 @@ Signaling.Base.prototype.leaveCall = function(token, keepToken, all = false) {
 			return
 		}
 
+		this._trigger('beforeLeaveCall', [token, keepToken])
+
 		axios.delete(generateOcsUrl('apps/spreed/api/v4/call/{token}', { token }), {
 			data: {
 				all,