Putting iPhone to sleep hides tableview cells [duplicate] - ios

Question

This question already has answers here:
UITableView cells strangely disappearing
(2 answers)
Closed 9 years ago.
Very strange problem here.
Essentially what is happening is that our Tableview cells are becoming hidden in some cases when we simply put the app to sleep and then re-unlock. Our normal tableview looks like this:
And then when we re-open the app it will look like this:
All the rows and sections are set correctly, yet the cells are hidden.:
When this happens, our cellForRowAtIndexPath no longer gets called. This surely has to be the problem. Has anyone ever seen behavior like this? Here is how we set up the tableview. (sorry it is long)
//
// SPHomeViewController.m
// Spek
#interface SPHomeViewController () <UITableViewDataSource, UITableViewDelegate, MKMapViewDelegate, SPCreationViewDelegate, UIAlertViewDelegate, CLLocationManagerDelegate>
#property (nonatomic, strong) UITableView* tableView;
#property (nonatomic, strong) NSMutableArray* tableDatasource;
#property (nonatomic, strong) NSMutableArray* datasource;
#property (nonatomic, strong) NSMutableArray* friendsDatasource;
#property (nonatomic, strong) UISegmentedControl* userFilterSegment;
#property (nonatomic) BOOL isLoadingData;
#end
#implementation SPHomeViewController
#synthesize datasource = _datasource;
#synthesize friendsDatasource = _friendsDatasource;
#synthesize tableDatasource = _tableDatasource;
- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
if (self) {
// Custom initialization
}
return self;
}
- (void)viewDidLoad {
[super viewDidLoad];
//[[SPLocationManager locationManager] startUpdatingLocationForSig];
[self setNeedsStatusBarAppearanceUpdate];
self.view.backgroundColor = [UIColor colorWithRed:230.0f/255.0f green:230.0f/255.0f blue:230.0f/255.0f alpha:1.0];
self.tableView = [[UITableView alloc] initWithFrame:CGRectMake(0, 0, self.view.frame.size.width, self.view.frame.size.height - kTopBarHeight)];
self.tableView.separatorColor = [UIColor clearColor];
self.tableView.backgroundColor = [UIColor clearColor];
self.tableView.delegate = self;
self.tableView.dataSource = self;
[self.view addSubview:self.tableView];
}
- (void)didReceiveMemoryWarning {
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
if (self.creationView.center.y > self.view.frame.size.height) {
self.creationView = nil;
}
NSLog(#"Mem warning");
}
//****************************************
//****************************************
#pragma mark - UITableViewDelegate/DataSource
//****************************************
//****************************************
- (UITableViewCell*)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
NSLog(#"INDEX PATH ROW: %d AND SECTION: %d", indexPath.row, indexPath.section);
if (indexPath.section == 0) {
UITableViewCell* cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:#"SPMapCellSpace"];
cell.backgroundColor = [UIColor clearColor];
cell.backgroundView = [[UIView alloc] init];
cell.selectedBackgroundView = [[UIView alloc] init];
return cell;
} else if (indexPath.section == self.tableDatasource.count + 1) {
UITableViewCell* cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:#"SPBottomCellSpace"];
cell.backgroundColor = [UIColor clearColor];
cell.backgroundView = [[UIView alloc] init];
cell.selectedBackgroundView = [[UIView alloc] init];
return cell;
}
SPMark* mark = self.tableDatasource[indexPath.section - 1];
NSString* reuseId = [SPHomeViewController cellIdentifierFromData:mark];
SPTableViewCell* cell = [tableView dequeueReusableCellWithIdentifier:reuseId];
if (cell == nil) {
cell = [SPTableViewCell cellFromMark:mark reuseID:reuseId];
[cell updateView:YES];
}
[cell addDataToCell:mark];
if (indexPath.section >= self.tableDatasource.count - 2 && !self.isLoadingData && self.pageNumber != -1) {
self.fetchNextPage = YES; // When the scrollview stops it will load more data if available.
}
return cell;
}
- (unsigned int)getPageNumber {
return (self.userFilterSegment.selectedSegmentIndex == 0) ? self.pageNumber : self.friendsPageNumber;
}
- (void)setCurrentPageNumber:(unsigned int)page {
if (self.userFilterSegment.selectedSegmentIndex == 0) {
self.pageNumber = page;
} else {
self.friendsPageNumber = page;
}
}
- (void)incrementCurrentPageNumber {
if (self.userFilterSegment.selectedSegmentIndex == 0) {
self.pageNumber++;
} else {
self.friendsPageNumber++;
}
}
// Every cell has a section header so this should be equal to the number of speks returned from the server
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView {
NSLog(#"section count is: %d",self.tableDatasource.count + 2 );
return self.tableDatasource.count + 2; // Add two because the mapview needs to go on the top and extra spacing at the bottom.
}
// There is a section for every cell, so there is only one cell per section
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
return 1;
}
- (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath {
if (indexPath.section == 0) {
return kMapHeight+2;
} else if (indexPath.section == self.tableDatasource.count + 1) {
return kExtraSpaceBelowHomeView;
}
SPMark* mark = self.tableDatasource[indexPath.section - 1];
return [SPTableViewCell cellHeightForMark:mark];
}
- (void)tableView:(UITableView *)tableView willDisplayCell:(UITableViewCell *)cell forRowAtIndexPath:(NSIndexPath *)indexPath {
if (indexPath.section == 0 || indexPath.section == self.tableDatasource.count + 1) {
cell.backgroundColor = [UIColor clearColor];
}
}
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
if (indexPath.section == 0 || indexPath.section == self.tableDatasource.count + 1)
return;
SPMark* mark = self.datasource[indexPath.section - 1 ];
SPMarkViewController* markVC = [SPMarkViewController withMark:mark];
[markVC displayData];
[self.navigationController pushViewController:markVC animated:YES];
}
-(void)reloadTableview {
[self.tableView setDelegate:self];
dispatch_async(dispatch_get_main_queue(), ^{
[self.tableView reloadData];
[self.tableView setNeedsDisplay];
});
}
- (void)showNoItems {
if (self.tableDatasource.count == 0 && self.accuracyBad == NO) {
self.opaqueIcon.hidden = NO;
self.noItems.hidden = NO;
self.beTheFirst.hidden = NO;
self.downArrow.hidden = NO;
self.noItemsBackround.hidden = NO;
[self.view bringSubviewToFront:self.noItemsBackround];
[self.view bringSubviewToFront:self.downArrow];
[self.view bringSubviewToFront:self.beTheFirst];
[self.view bringSubviewToFront:self.noItems];
[self.view bringSubviewToFront:self.opaqueIcon];
}
}
- (void)showTableView {
if (self.tableDatasource.count != 0) {
self.noItems.hidden = YES;
self.beTheFirst.hidden = YES;
self.downArrow.hidden = YES;
self.noItemsBackround.hidden = YES;
self.opaqueIcon.hidden = YES;
[self.view sendSubviewToBack:self.noItemsBackround];
[self.view sendSubviewToBack:self.downArrow];
[self.view sendSubviewToBack:self.beTheFirst];
[self.view sendSubviewToBack:self.noItems];
[self.view sendSubviewToBack:self.opaqueIcon];
}
}
//****************************************
//****************************************
#pragma mark - Setters/Getters
//****************************************
//****************************************
- (NSMutableArray*)datasource {
if (!_datasource) {
_datasource = [NSMutableArray array];
if (!self.firstLoad) {
[self loadDataForPagination:NO];
}
}
return _datasource;
}
- (NSMutableArray*)friendsDatasource {
if (!_friendsDatasource) {
_friendsDatasource = [NSMutableArray array];
if (!self.firstLoad) {
[self loadDataForPagination:NO];
}
}
return _friendsDatasource;
}
- (NSMutableArray*)tableDatasource {
if (!_tableDatasource) {
_tableDatasource = (self.userFilterSegment.selectedSegmentIndex == 0) ? self.datasource : self.friendsDatasource;
}
return _tableDatasource;
}
- (SPCreationView*)creationView {
if (!_creationView) {
UIView* window = [SPUtils getAppDelegate].window;
CGSize viewSize = window.frame.size;
CGRect startFrame = CGRectMake(0, viewSize.height, [SPUtils screenWidth], [SPUtils screenHeight]);
_creationView = [SPCreationView creationView:startFrame delegate:self];
[window insertSubview:_creationView belowSubview:self.creationButton];
_creationView.frame = startFrame;
}
return _creationView;
}
- (void)setTableDatasource:(NSMutableArray *)tableDatasource {
_tableDatasource = tableDatasource;
[self preFetchImages];
dispatch_async(dispatch_get_main_queue(), ^{
if(_tableDatasource == nil || _tableDatasource.count == 0) {
[self showNoItems];
} else {
[self showTableView];
}
[self reloadTableview];
});
}
- (void)setDatasource:(NSMutableArray *)datasource {
_datasource = datasource;
}
- (void)setFriendsDatasource:(NSMutableArray *)friendsDatasource {
_friendsDatasource = friendsDatasource;
}
#end
If you think it's a AppDelegate problem, we don't do anything with this controller in there, so I don't see how it could be.

Answer 1

I've only seen this occur previously when I was reloading data (incorrectly) from a background thread. I see you're trying to push the reloads onto the main thread already.
It looks like you're flailing a bit trying to be sure updates are occurring on the main thread. You should probably just verify that your actions are occurring on main by checking [NSThread isMainThread] rather than making your code async to the main thread, making lots of async flow changes can lead to unexpected behavior.
That said, since this only happens on wake from sleep maybe you have some background mode on and you aren't updating the UI from the correct thread there?