Setting the selectedBackgroundView of a UICollectionViewCell when the view reloads - ios

Question

I am working with a UICollectionView and am having a bit of difficulty replicating something that I have working in a UITableView. I am looking to set the selectedBackgroundView of a selected UICollectionView cell and have that selection maintained every time the view is loaded.
I have a basic application with two tabs in a Tab Bar controller where both tabs are UITableViewControllers. The second tab is the In-App Settings and I have two cells in there; one for App Themes and one for Keyboard themes. The keyboard themes is another Table View but the App Themes is a UICollectionView with a grid of 3x4 cells. Although this is dynamically created, there's not going to be any more cells and this is it.
Working
Right now, I can select a UICollectionViewCell and happily apply a custom image on the top; that works very well.
Problem
The problem I am facing is the fact that the selected cell does not maintain that custom image on the top when the view reloads even though the value is saved in NSUserDefaults.
Because I have the same concept working with my Keyboard Themes (UITableView), I have copied the principles here, but am not sure if what I have done is actually correct.
Here's some code:
- (void)collectionView:(UICollectionView *)collectionView didSelectItemAtIndexPath:(NSIndexPath *)indexPath
{
ThemeCell *themeCell = (ThemeCell *)[self.cView cellForItemAtIndexPath:indexPath];
self.selectedThemeString = themeCell.cellLabel.text;
if(self.checkedIndexPath)
{
UICollectionViewCell *uncheckCell = [self.cView cellForItemAtIndexPath:self.checkedIndexPath];
uncheckCell.selectedBackgroundView = nil;
}
themeCell.selectedBackgroundView = dot;
[themeCell addSubview:dot];
self.checkedIndexPath = indexPath;
UIImageView *dot = [[UIImageView alloc]initWithFrame:CGRectMake(5, 0, 1, 2)];
dot.image=[UIImage imageNamed:#"check-white-hi.png"];
themeCell.selectedBackgroundView = dot;
[themeCell addSubview:dot];
[[NSUserDefaults standardUserDefaults] setObject:self.selectedThemeString forKey:#"Selection"];
[[NSUserDefaults standardUserDefaults] synchronize];
}
In the cellForItemAtIndexPath, I have:
- (UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath
{
ThemeCell *themeCell = (ThemeCell *)[collectionView dequeueReusableCellWithReuseIdentifier:#"Theme Cell" forIndexPath:indexPath];
NSString *cellData = [self.themeLabels objectAtIndex:indexPath.row];
themeCell.cellLabel.text = cellData;
themeCell.cellImages.image = self.themeImages[indexPath.row];
UIImageView *dot = [[UIImageView alloc]initWithFrame:CGRectMake(5, 0, 1, 2)];
dot.image=[UIImage imageNamed:#"check-white-hi.png"];
self.selectedThemeString = [[NSUserDefaults standardUserDefaults] objectForKey:#"Selection"];
NSLog(#"Selected Theme String = %#", self.selectedThemeString);
if (!self.selectedThemeString)
{
NSLog(#"111");
self.checkedIndexPath = [NSIndexPath indexPathForRow:0 inSection:0];
themeCell.selectedBackgroundView = dot;
[themeCell addSubview:dot];
}
if ([self.selectedThemeString isEqualToString:#"Original"])
{
NSLog(#"222");
self.checkedIndexPath = [NSIndexPath indexPathForRow:0 inSection:0];
themeCell.selectedBackgroundView = dot;
[themeCell addSubview:dot];
}
if ([self.selectedThemeString isEqualToString:#"Mystical"])
{
NSLog(#"333");
self.checkedIndexPath = [NSIndexPath indexPathForRow:2 inSection:0];
themeCell.selectedBackgroundView = dot;
[themeCell addSubview:dot];
}
return themeCell;
My viewWillAppear has:
self.selectedThemeString = [[NSUserDefaults standardUserDefaults] objectForKey:#"Selection"];
if ([self.selectedThemeString isEqualToString:#"Original"])
{
self.checkedIndexPath = [NSIndexPath indexPathForRow:0 inSection:0];
}
else if ([self.selectedThemeString isEqualToString:#"Peacock"])
{
self.checkedIndexPath = [NSIndexPath indexPathForRow:1 inSection:0];
}
else if ([self.selectedThemeString isEqualToString:#"Mystical"])
{
self.checkedIndexPath = [NSIndexPath indexPathForRow:2 inSection:0];
}
else if ([self.selectedThemeString isEqualToString:#"Zebra"])
{
self.checkedIndexPath = [NSIndexPath indexPathForRow:3 inSection:0];
}
else if ([self.selectedThemeString isEqualToString:#"Simplicity"])
{
self.checkedIndexPath = [NSIndexPath indexPathForRow:4 inSection:0];
}
else if ([self.selectedThemeString isEqualToString:#"Rainbow"])
{
self.checkedIndexPath = [NSIndexPath indexPathForRow:5 inSection:0];
}
else if ([self.selectedThemeString isEqualToString:#"Prosperity"])
{
self.checkedIndexPath = [NSIndexPath indexPathForRow:6 inSection:0];
}
else if ([self.selectedThemeString isEqualToString:#"Leopard"])
{
self.checkedIndexPath = [NSIndexPath indexPathForRow:7 inSection:0];
}
else if ([self.selectedThemeString isEqualToString:#"Hypnotic"])
{
self.checkedIndexPath = [NSIndexPath indexPathForRow:8 inSection:0];
}
else if ([self.selectedThemeString isEqualToString:#"Dunes"])
{
self.checkedIndexPath = [NSIndexPath indexPathForRow:9 inSection:0];
}
else if ([self.selectedThemeString isEqualToString:#"Twirl"])
{
self.checkedIndexPath = [NSIndexPath indexPathForRow:10 inSection:0];
}
else if ([self.selectedThemeString isEqualToString:#"Oceanic"])
{
self.checkedIndexPath = [NSIndexPath indexPathForRow:11 inSection:0];
}
[self.cView reloadData];
The order of the cells are defined above, so the first row first cell is called Original. The second cell first row is called Peacock and the third cell first row is called Mystical, etc.
My thinking was, I could define the indexPathForRow for each string and in the cellForItemAtIndexPath, when the string hits, it would apply the selectedBackgroundView to the image.
Status
What's happening now is, I can successfully select a cell and the image appears; if I reload the view (by going out and coming back in), the selectedBackgroundView from the cell doesn't exist. However, I know NSUserDefaults is working because in my cellForItemAtIndexPath, the "111", or the "222" or "333" is getting logged successfully, but it's just not setting the highlight state of the selected UICollectionCell.
What I require is to:
1) Have a selected cell display the selectedBackgroundView image when the view has been reloaded.
Update:
In the cellForItemAtIndexPath, if I put themeCell.backgroundView = dot instead of themeCell.selectedBackgroundView = dot, when I reload the view, every single cell highlights with the custom image instead of just the selected cell, so I think I'm making progress somewhat, but still lost.
Any guidance would be really appreciated.

Answer 1

Situation averted.
I have fixed this issue.
For reference, I will put the fixed code here for anyone experiencing the same issue.
In the cellForItemAtIndexPath, I did the following:
if (!self.selectedThemeString)
{
NSLog(#"111");
self.checkedIndexPath = [NSIndexPath indexPathForRow:0 inSection:0];
themeCell.backgroundView = dot;
[themeCell addSubview:dot];
}
if([self.checkedIndexPath isEqual:indexPath])
{
NSLog(#"Loaded");
themeCell.backgroundView = dot;
[themeCell addSubview:dot];
}
else
{
NSLog(#"Not Loaded");
themeCell.backgroundView = nil;
}
This is similar to the code earlier, but essentially copied from my UITableView code which checks the indexPath.
The other change is the fact that I used the backgroundView property rather than selectedBackgroundView.
I did this change throughout my class, so wherever I had the selectedBackgroundView, I changed that to backgroundView.
I'm happy and this works like a treat.