Stop a UITableView from reloading data on orientation change - ios

Question

My uitableview calls reloaddata when the orientation of the device changes (makes sense, since the number of cells displayed changes, is called in layout subviews as far as I could understand from the documentation), however this is problematic for me, because I am performing a download in the background and I don't want some of the files to suddenly appear. Is there a way to stop the default behaviour and let me reload manually when I want to?
EDIT:
I will try to explain better. on the top of my tableview, I have a button called "sync" which starts a syncing request from the server, this sync request first get a JSON object, which holds the information I would like to display in the tableview, but each of the uitableview items represents a file I'm downloading from the internet.
While the files are downloading I have an activity indicator on screen, only when the files finish downloading I want to reload the table. The problem is, the UITableview automatically calls reloaddata when the user changes orientation, so the cells fill with the information from the json before the downloaded files finished downloading.
code:
#implementation BIDManageFilesViewController
- (id)initWithStyle:(UITableViewStyle)style
{
self = [super initWithStyle:style];
if (self) {
// Custom initialization
}
return self;
}
- (void)viewDidLoad
{
[super viewDidLoad];
[[NSNotificationCenter defaultCenter] addObserver:self selector:#selector(newDataFinishedDownloading) name:kBIDContentManagerContentDidChangeNotification object:nil];
[[NSNotificationCenter defaultCenter] addObserver:self selector:#selector(newDataStartedDownloading:) name:kBIDContentManagerStartedDownloadingContent object:nil];
[[NSNotificationCenter defaultCenter] addObserver:self selector:#selector(contentAlreadyUpToDate) name:kBIDContentUpToDate object:nil];
[[NSNotificationCenter defaultCenter] addObserver:self selector:#selector(contentStartingSync) name:kBIDContentStartingSync object:nil];
[[NSNotificationCenter defaultCenter] addObserver:self selector:#selector(contentEndingSync) name:kBIDContentEndingSync object:nil];
[[NSNotificationCenter defaultCenter] addObserver:self selector:#selector(singleDownloadFinished) name:kBIDFinishedDownloadingSingleContent object:nil];
self.navigationController.navigationBarHidden = NO;
UIBarButtonItem *leftButton = [[UIBarButtonItem alloc] initWithTitle:#"Sync"
style:UIBarButtonItemStyleDone target:self action:#selector(Sync)];
self.navigationItem.leftBarButtonItem = leftButton;
UIBarButtonItem *rightButton = [[UIBarButtonItem alloc] initWithTitle:#"Display Mode"
style:UIBarButtonItemStyleDone target:self action:#selector(dismissSelf)];
self.navigationItem.rightBarButtonItem = rightButton;
self.navigationItem.title = #"Content Manager";
self.navigationBar = [[UINavigationBar alloc] initWithFrame:CGRectZero];
[self.view addSubview:_navigationBar];
[self.navigationBar pushNavigationItem:self.navigationItem animated:NO];
}
-(void)viewWillAppear:(BOOL)animated
{
[super viewWillAppear:animated];
[[UIApplication sharedApplication] setStatusBarHidden:NO withAnimation:UIStatusBarAnimationFade];
}
-(void)layoutNavigationBar{
if([[UIApplication sharedApplication] statusBarOrientation] == UIInterfaceOrientationPortrait || [[UIApplication sharedApplication] statusBarOrientation] == UIInterfaceOrientationPortraitUpsideDown)
{
self.navigationBar.frame = CGRectMake(0, self.tableView.contentOffset.y, self.view.frame.size.width, self.topLayoutGuide.length + 44);
}
else
{
self.navigationBar.frame = CGRectMake(0, self.tableView.contentOffset.y, self.view.frame.size.height, self.topLayoutGuide.length + 44);
}
NSLog(#"width: %f", self.view.frame.size.width);
NSLog(#"height: %f", self.view.frame.size.height);
self.tableView.contentInset = UIEdgeInsetsMake(self.navigationBar.frame.size.height, 0, 0, 0);
}
-(void)scrollViewDidScroll:(UIScrollView *)scrollView{
//no need to call super
[self layoutNavigationBar];
}
-(void)willRotateToInterfaceOrientation:(UIInterfaceOrientation)toInterfaceOrientation duration:(NSTimeInterval)duration
{
[self layoutNavigationBar];
[super willRotateToInterfaceOrientation:toInterfaceOrientation duration:duration];
}
-(void)viewDidLayoutSubviews{
[super viewDidLayoutSubviews];
[self layoutNavigationBar];
}
- (void)didReceiveMemoryWarning
{
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}
/*
#pragma mark - Navigation
// In a story board-based application, you will often want to do a little preparation before navigation
- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
{
// Get the new view controller using [segue destinationViewController].
// Pass the selected object to the new view controller.
}
*/
-(void)viewDidDisappear:(BOOL)animated
{
[super viewDidDisappear:animated];
self.navigationController.navigationBarHidden = YES;
}
-(void)newDataStartedDownloading: (NSNotification *)notif
{
self.hud = [MBProgressHUD showHUDAddedTo:self.view animated:YES];
_hud.labelText = #"Downloading...";
_hud.detailsLabelText = [NSString stringWithFormat:#"1/%#",[notif.userInfo objectForKey:#"downloadFileNumber"]];
}
-(void)singleDownloadFinished
{
NSString *currentText = _hud.detailsLabelText;
NSArray *subStrings = [currentText componentsSeparatedByString:#"/"];
NSInteger downloadsPlusOne = [[subStrings objectAtIndex:0] integerValue]+1;
NSString *newTextForLabel = [NSString stringWithFormat:#"%d/%#", downloadsPlusOne, [subStrings objectAtIndex:1]];
_hud.detailsLabelText = newTextForLabel;
}
-(void)newDataFinishedDownloading
{
_thereIsNewInfo = TRUE;
[MBProgressHUD hideHUDForView:self.view animated:YES];
[self.tableView reloadData];
[[NSNotificationCenter defaultCenter] postNotificationName:kBIDnewDownloadedContentReadyToBeDispayedNotification object:nil userInfo:nil];
}
-(void)contentAlreadyUpToDate
{
UIAlertView *alert = [[UIAlertView alloc] initWithTitle:#"Sync Alert"
message:#"Files Are Already Up To Date"
delegate:nil
cancelButtonTitle:#"OK"
otherButtonTitles: nil];
[alert show];
}
-(void)contentStartingSync
{
MBProgressHUD *hud = [MBProgressHUD showHUDAddedTo:self.view animated:YES];
hud.labelText = #"Syncing...";
}
-(void)contentEndingSync
{
[MBProgressHUD hideHUDForView:self.view animated:YES];
}
-(void)Sync
{
[AppDelegate.appContentManager downloadContent];
}
-(void)dismissSelf
{
if (![AppDelegate.appContentManager subsetArrayFromFileArrayWithNonVidContentThatShouldDisplay] && ![AppDelegate.appContentManager subsetArrayFromFileArrayWithVideoContentThatShouldDisplay]) {
UIAlertView *alert = [[UIAlertView alloc] initWithTitle:#"No Files to Display"
message:#"Please update or enable content"
delegate:nil
cancelButtonTitle:#"OK"
otherButtonTitles: nil];
[alert show];
return;
}
else if ([AppDelegate.appContentManager subsetArrayFromFileArrayWithNonVidContentThatShouldDisplay])
{
[self dismissViewControllerAnimated:YES completion:Nil];
}
else
{
[self performSegueWithIdentifier:#"goToVideos" sender:self];
}
}
-(void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
{
if ([segue.identifier isEqualToString:#"goToVideos"])
{
((BIDViewController *)segue.destinationViewController).stackedByManager = TRUE;
}
}
#end

Answer 1

It's not necessary to reloaddata on orientation change but if you want to reload table try to call [myTable reloadData] after the completion of the background download and only if the orientation has changed (you can set a bool for this on orient. change).