Animation in TableViewCell at reloading data time - ios

Question

I have UITableViewCell with detailed arrow that points to top or to down.
Than I tap on this cell I want to expand it. So I will reload UITableView and I want to animate rotation ofUIImageView`.
Question - is it possible to animate rotation of UIImageView simultaneously with reloading data in UITableView?

Answer 1

Yes, you can create a table with expandable/contactable cell's, also while expanding you can animate the containers of the cell's.
But, one thing until and unless it is a requirement to reload table, I'll suggest you to reload row with the animations performed simultaneously.
Also as you asked in comment what's the best way to track whether the cell needs to be shown simple or detailed, I think it depends on your requirements, like if you need to show only one cell expanded at a time, then you just keep the index of current expanded cell in the class else if you need to show more than one cell expanded at a time than you can use the data source to keep the information whether the cell needs to be show as simple or detailed. If you do not have the data source then you can do the same by creating a list of cell's index path keeping track of detailed cells.
Programmatically you need to do following things to show simple/ detailed cells-
Note: I have assumed to show only one cell expanded at a time.
1) Create a member variable to keep track of expanded cell.
NSIndexPath *expandedCellIndexPath;
2) Return height for expanded cell(if expanded) otherwise for simple cell
- (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath
{
if([expandedCellIndexPath compare:indexPath] == NSOrderedSame)
return 100.0f;
return 50.0f;
}
3) Create cell as-
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
static NSString *cellIdentifier = #"cellId";
CustomCell *customCell = nil;
customCell = (CustomCell *) [tableView dequeueReusableCellWithIdentifier:cellIdentifier];
if(customCell == nil)
{
NSString *nibName = #"CustomCell_iPhone";
customCell = (CustomCell *)[[[NSBundle mainBundle] loadNibNamed:nibName owner:self options:nil] lastObject];
customCell.selectionStyle = UITableViewCellSelectionStyleNone;
}
if([expandedCellIndexPath compare:indexPath] == NSOrderedSame)
{
[customCell.m_arrowImageView setImage:[UIImage imageNamed:DOWN_ARROW_KEY]];
[self showSelectedCellAnimations:customCell];
}
else
{
[customCell.m_arrowImageView setImage:[UIImage imageNamed:UP_ARROW_KEY]];
[self showUnSelectedCellAnimations:customCell];
}
// you can also set default up arrow image and rotate it with down arrow image and vice versa
return customCell;
}
4) Rotate Up/Down arrow image using-
- (void)rotateImage:(UIImageView *)image duration:(NSTimeInterval)duration
curve:(int)curve degrees:(CGFloat)degrees
{
[UIView beginAnimations:nil context:NULL];
[UIView setAnimationDuration:duration];
[UIView setAnimationCurve:curve];
[UIView setAnimationBeginsFromCurrentState:YES];
CGAffineTransform transform =
CGAffineTransformMakeRotation(DEGREES_TO_RADIANS(degrees));
image.transform = transform;
[UIView commitAnimations];
}
5) Call above method as-
[self rotateImage:customCell.m_helpImage duration:0.25
curve:UIViewAnimationCurveEaseIn degrees:0.0];
6) Inside didSelectRowAtIndexPath: set the expandedCellIndexPath to the current index path which needs to be expanded and reload previous expanded row to contract and reload current expandedCellIndexPath row to expand, like-
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
[tableView deselectRowAtIndexPath:indexPath animated:NO];
CustomCell *customCell = nil;
customCell = (CustomCell *)[tableView cellForRowAtIndexPath:indexPath];
NSIndexPath *previousIndexPath = expandedCellIndexPath;
if([expandedCellIndexPath compare:indexPath] != NSOrderedSame)
expandedCellIndexPath = indexPath;
[self.m_tableView reloadRowsAtIndexPaths:#[previousIndexPath]
withRowAnimation:UITableViewRowAnimationFade];
[self.m_tableView reloadRowsAtIndexPaths:#[expandedCellIndexPath]
withRowAnimation:UITableViewRowAnimationFade];
[self.m_tableView scrollToRowAtIndexPath:indexPath
atScrollPosition:UITableViewScrollPositionBottom animated:YES];
}