How to prevent overflow of adjustable height tableview cell on delete - ios

Question

In a UITableView Controller, I have just added 'swipe to delete' by implementing tableView: commitEditingStyle: forRowAtIndexPath. Additionally, the rows can be selected to expand showing more content.
The undesired result after swiping:
The two lower rows remain in view after swiping until about about 0.5 seconds after the undelete animation completes.
A screenshot of IB:
The cell's contents have grown into the lower cell without it showing that it has been selected. (Selection causes the cell to increase height and give it a grayish background color.) This is occurring on every row in 2 similarly operating view controllers.
I have tried (without success) to intercept the 'selection' in several UITableViewDelegate methods, and cannot find out how to stop this from occurring. I have also tried setting the IB dynamic prototype cells to height: 85.
Looking for ideas on how to prevent this expansion from occurring.
EDIT
- (void)viewDidLoad {
....
self.tableView.rowHeight = UITableViewAutomaticDimension;
self.tableView.estimatedRowHeight = kCellHeight;
....
}
#pragma mark - TableView delegate
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView {
return [[self.fetchedResultsController sections] count];
}
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
id <NSFetchedResultsSectionInfo> sectionInfo = [self.fetchedResultsController sections][section];
NSInteger *rows = (NSInteger *)[sectionInfo numberOfObjects];
if (!self.rowsInSection)
self.rowsInSection = rows;
if (rows > 0)
return [sectionInfo numberOfObjects];
else {
[tableView setSeparatorColor:[UIColor clearColor]];
[tableView setBounces:NO];
return 1;
}
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
NSString *identifier = self.rowsInSection > 0 ? #"numberIdentifier" : #"noNumbersIdentifier";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:identifier forIndexPath:indexPath];
if (self.rowsInSection > 0)
[self configureCell:cell atIndexPath:indexPath];
else
cell.selectionStyle = UITableViewCellSelectionStyleNone;
// [self.arrayOfIndexPaths addObject:indexPath];
return cell;
}
- (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath {
NSIndexPath *selectedIndexPath = [self.tableView indexPathForSelectedRow];
if (selectedIndexPath) {
if (tableView.editing)
return 85.0;
else if (selectedIndexPath.row == indexPath.row)
return 185.0;
}
return 85.0;
}
- (NSIndexPath *)tableView:(UITableView *)tableView willSelectRowAtIndexPath:(NSIndexPath *)path {
if (tableView.editing)
return nil;
// If real rows exist, return the path, making row selectable
if (self.rowsInSection > 0)
return path;
// Otherwise do not allow the row to be selected
return nil;
}
- (UIView *)tableView:(UITableView *)tableView viewForHeaderInSection:(NSInteger)section {
id <NSFetchedResultsSectionInfo> sectionInfo = [self.fetchedResultsController sections][0];
if ([sectionInfo numberOfObjects] > 0)
// Return the contentView to stop the header from sliding with delete
return [tableView dequeueReusableCellWithIdentifier:#"numberHeaderIdentifier"].contentView;
else
return [tableView dequeueReusableCellWithIdentifier:#"emptyHeaderIdentifier"];
}
- (CGFloat)tableView:(UITableView *)tableView heightForHeaderInSection:(NSInteger)section {
return 75;
}
- (void)configureCell:(UITableViewCell *)cell atIndexPath:(NSIndexPath *)indexPath {
Number *aNumber = [self.fetchedResultsController objectAtIndexPath:indexPath];
[cell configureSubviewsInCell:cell withNumber:aNumber];
}
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
[tableView beginUpdates];
[tableView endUpdates];
}
- (void)tableView:(UITableView *)tableView commitEditingStyle:(UITableViewCellEditingStyle)editingStyle forRowAtIndexPath:(NSIndexPath *)indexPath {
if (editingStyle == UITableViewCellEditingStyleDelete) {
NSManagedObjectContext *context = [self.fetchedResultsController managedObjectContext];
[context deleteObject:[self.fetchedResultsController objectAtIndexPath:indexPath]];
}
}

Answer 1

You should set the hidden property of the labels that you don't want to show when the table view cell is not selected. For example:
- (void)configureCell:(UITableViewCell *)cell atIndexPath:(NSIndexPath *)indexPath {
Number *aNumber = [self.fetchedResultsController objectAtIndexPath:indexPath];
UILabel *label1 = (UILabel *)[cell.contentView viewWithTag:501];
label1.text = [aNumber valueForKey:#"number"];
if (!cell.selected)
{
label1.hidden = YES;
}
else
{
label1.hidden = NO;
}
.....
}
Then in didSelectRowAtIndexPath:
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
[tableView beginUpdates];
UITableViewCell *cell = [tableView cellForRowAtIndexPath:indexPath];
UILabel *label1 = (UILabel *)[cell.contentView viewWithTag:501];
label1.text = [aNumber valueForKey:#"number"];
label1.hidden = NO;
[tableView endUpdates];
}
You should look into subclassing UITableViewCell so you don't have to use tags to access subviews.

Answer 2

The 'hiding' solution posted by beowulf is a valid option. In addition and because the swipe (to begin editing) was causing subviews in the cell to become 'unclipped', a method needed to be overrided, like so:
// this method is called as the swipe to delete is started
- (void)tableView:(UITableView *)tableView willBeginEditingRowAtIndexPath:(nonnull NSIndexPath *)indexPath
{
// only hide for unexpanded (unselected) cells
if ([self.selectedRowIndex compare:indexPath] != NSOrderedSame)
{
NumberTableViewCell *cell = [self.tableView cellForRowAtIndexPath:indexPath];
// a cell subclass method to hide/unhide subviews that fall into
// the next cell below
[cell subViewsInCellShouldBeHidden:YES];
}
}