NSTimer not passing parameters correctly? - ios

Question

I have a UITableViewCell. It has 2 AVPlayers, 2 AVPlayerItems, and 2 AVPlayerLayers. One AVPlayer and its contents are on the right side of the cell, and one on the left side of the cell. I am using the AVAssetResourceLoader to cache and play videos at the same time. This works great, except the second video does not display. It does cache properly, because after scrolling the tableview, it plays correctly as it should from the cache. But just the AVPlayerLayer does not display the video content as it should.
The AVAssetResourceLoader can not handle 2 simultaneous downloads. Upon first loading the tableview, the video on the left starts to download/play. The code for playing the video on the right side is read immediately after the code for downloading/playing the video on the left side--meaning of course, that the download process has not yet finished. To fix this problem, I have created a timer, like so:
if (self.downloadInProgress) {
// download is in progress. wait to start next download
self.downloadQueueCount++;
NSDictionary *videoSettings = #{#"id": activity2.objectId,
#"activity": activity2, #"cell": videoCell, #"left": #NO}
self.timer = [NSTimer scheduledTimerWithTimeInterval:0.2
target:self selector:#selector(DownloadNextVideo:)
userInfo:videoSettings repeats:YES];
} else {
[self playStreamingVideoOnRightInCell:videoCell withActivity:activity2];
}
And then the selector method:
- (void)DownloadNextVideo:(NSTimer *)timer {
if (self.downloadInProgress == NO) {
NSString *activityId = [[timer userInfo] objectForKey:#"id"];
self.videoChallengeID1 = activityId;
CompletedTableViewCell *videoCell = (CompletedTableViewCell *)[[timer userInfo]objectForKey:#"cell"];
Activity *activity = [[timer userInfo] objectForKey:#"activity"];
BOOL left = [[timer userInfo] objectForKey:#"left"];
[self.timer invalidate];
if (left) {
[self playStreamingVideoOnLeftInCell:videoCell withActivity:activity];
} else {
[self playStreamingVideoOnRightInCell:videoCell withActivity:activity];
}
}
}
Basically, this works correctly--the AVAssetResourceLoader gets the correct URL, correct activityID, and downloads/caches the correct video--except the video does not play as it downloads. I changed background colors, and I can confirm that the AVPlayerLayer is indeed present in the frame it should be. Just no video shows up.
I tried switching left and right videos and download order--and in that case, the right video played, and the left video didn't play. Basically, whichever video has to use this timer and continually check if a download is in progress or not, is the video that does not display correctly, and that makes me think it is something I am doing wrong with the timer concerning scope/passing variables.
One last detail, in case it may help. If I say the following (instead of the first method I had here):
if (self.downloadInProgress) {
[self playStreamingVideoOnRightInCell:videoCell withActivity:activity2];
}
Then, the playerLayer DOES show video--but it's the wrong video. It shows the same video as in the left side of the cell.
This has been a nightmare to debug, and I am fairly certain at this point that it has something to do with using a timer here to play the video instead of doing it inside the regular scope. Anyone have any ideas what I could be doing wrong?

Answer 1

In order to fix the proper video playing, you need to change the following. You are using the NSNumber value instead of a BOOL for the left value.
Your code:
BOOL left = [[timer userInfo] objectForKey:#"left"];
Should be:
BOOL left = [[[timer userInfo] objectForKey:#"left"] boolValue];