UISegmentedControl to Display Multiple Datasets on UITableView

Question

I have a ViewController in my UITabBarController that takes a gnawing 5-8 seconds to load.

No heavy processing, no significant callback chains and no network calls.

I asked this question earlier:

ViewController transition bottleneck in UITabBarController

And I think I have pinpointed the source of the problem, so I will go into more detail here.

I have a UITableView whose dataSource changes based on the value of a UISegmentedControl. I am displaying friend requests, and the segmented control manages the display of Outgoing and Incoming ones.

override func viewDidLoad() {
    super.viewDidLoad()

    friendRequestsToDisplay = FriendRequestManager.instance.incomingFriendRequests

    tableView.delegate = self
    tableView.dataSource = self

    self.refreshControl = UIRefreshControl()
    self.refreshControl.addTarget(self, action: "refreshRequests:", forControlEvents: UIControlEvents.ValueChanged)
    self.tableView.addSubview(refreshControl)

    incomingFriendRequests = FriendRequestManager.instance.incomingFriendRequests
    outgoingFriendRequests = FriendRequestManager.instance.outgoingFriendRequests
}

func numberOfSectionsInTableView(tableView: UITableView) -> Int {
    return 1
}

func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
    return friendRequestsToDisplay.count
}

func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
    let bookRequest = self.friendRequestsToDisplay[indexPath.row]

    if let cell = tableView.dequeueReusableCellWithIdentifier("RequestCell", forIndexPath: indexPath) as? RequestCell {
        cell.configureCell(friendRequest, isAnIncomingRequest: isAnIncomingRequest)
        return cell

    } else {
        return UITableViewCell()
    }
}

According to breakpoints and for some odd reason, numberOfSectionsInTableView and numberOfRowsInSection gets called exactly twice the number of total friendRequests loaded

And dequeueReusableCellWithIdentifier takes about 4 seconds to load with a breakpoint.

Here are the results from the Time Profile in Instruments:

Anybody have an idea as to what could be the source of the lag?

@Paulw11 just edited with a screenshot of the results of the Time Profiler (link at the bottom) — Eric Johnson, Nov 27 '15 at 21:23
It seems to be taking a long time to load a custom font, but that is just a guess — Paulw11, Nov 27 '15 at 21:26
@Paulw11 How could I help you help me identify the problem ? — Eric Johnson, Nov 27 '15 at 21:27
all of the methods shown in the time profile screen shot were system methods; how does this correlate to your code? Until you can identify where in your code the time is being spent you are just guessing. — Paulw11, Nov 27 '15 at 21:29
@Paulw11 Nevermind, the font was the problem! Yeah!!! If you write it up as an answer I'll accept it... — Eric Johnson, Nov 27 '15 at 21:29
@Paulw11 For future notice, how do I identify where in my code the time is being spent ??? — Eric Johnson, Nov 27 '15 at 21:30
Have a look at this tutorial - http://www.raywenderlich.com/23037/how-to-use-instruments-in-xcode - use the settings under "drilling deep" — Paulw11, Nov 27 '15 at 21:34

UISegmentedControl to Display Multiple Datasets on UITableView

0 Answers0