obj-c collectionView adding header - objective-c

Question

I try to add a header to each section of the collectionView.
The collectionView without header works fine. When I checkmark the Accessories Section Header in Interfacebilder, the header will be shown in the simulator.
I added a UICollectionViewFlowLayout Class (as File) and called it within the viewDidLoad of my UICollectionView Controller. In the FlowLayout I want to configure the zIndex and Size.
Now the header will not be shown in the simulator, additionaly I added breakpoints in the UICollectionViewFlowLayout but they will never be hit...
How do I get the headers shown in the collectionview, and how do I influence the zIndex and size of the header in the correct way?
SurroundViewController.h
#import <UIKit/UIKit.h>
#interface SurroundViewController : UICollectionViewController
#end
SurroundViewController.m
#import "SurroundViewController.h"
#import "MagazineCell.h"
#import "LazyJoeHeaderLayout.h"
static NSString * const cellID = #"cellID";
#interface SurroundViewController ()
#end
#implementation SurroundViewController
- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
if (self) {
// Custom initialization
}
return self;
}
- (void)viewDidLoad
{
[super viewDidLoad];
// Do any additional setup after loading the view.
self.collectionView.collectionViewLayout = [[LazyJoeHeaderLayout alloc] init];
}
- (void)didReceiveMemoryWarning
{
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}
- (NSInteger)numberOfSectionsInCollectionView:(UICollectionView *)collectionView {
return 2;
}
- (NSInteger)collectionView:(UICollectionView *)collectionView numberOfItemsInSection:(NSInteger)section {
return 30;
}
- (UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath {
MagazineCell *mCell = (MagazineCell *)[collectionView dequeueReusableCellWithReuseIdentifier:cellID forIndexPath:indexPath];
mCell.backgroundColor = [UIColor lightGrayColor];
return mCell;
}
#pragma mark Collection view Layout things
// Layout set cell size
- (CGSize)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout *)collectionViewLayout sizeForItemAtIndexPath:(NSIndexPath *)indexPath {
NSLog(#"Settings Size for Item at index %d", indexPath.row);
CGSize mElementSize = CGSizeMake(104, 104);
return mElementSize;
}
- (CGFloat)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout *)collectionViewLayout minimumInteritemSpacingForSectionAtIndex:(NSInteger)section {
return 2.0;
}
-(CGFloat)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout *)collectionViewLayout minimumLineSpacingForSectionAtIndex:(NSInteger)section {
return 2.0;
}
// Layout: Set Edgees of whole screen - not mElementsize
- (UIEdgeInsets)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout *)collectionViewLayout insetForSectionAtIndex:(NSInteger)section {
return UIEdgeInsetsMake(0, 0, 0, 0);
}
#end
LazyJoeHeaderLayout.h
#import <UIKit/UIKit.h>
#interface LazyJoeHeaderLayout : UICollectionViewFlowLayout
#end
LazyJoeHeaderLayout.m
#import "LazyJoeHeaderLayout.h"
#implementation LazyJoeHeaderLayout
- (UICollectionViewLayoutAttributes *)layoutAttributesForSupplementaryViewOfKind:UICollectionElementKindSectionHeader atIndexPath:(NSIndexPath *)indexPath {
UICollectionViewLayoutAttributes *attributes = [super layoutAttributesForSupplementaryViewOfKind:UICollectionElementKindSectionHeader atIndexPath:indexPath];
attributes.frame = CGRectMake(0, 0, 100, 100);
attributes.zIndex = 1024;
return attributes;
}
#end
MagazineCell.h and MagazineCell.m not listed as not needed for this problem.

Answer 1

Found a solution to show the header, below the updated code to my question, regarding the headersize.
SurroundViewController
#import "SurroundViewController.h"
#import "MagazineCell.h"
#import "LazyJoe.h"
static NSString * const cellID = #"cellID";
#interface SurroundViewController ()
#property (nonatomic, strong) LazyJoe *lazyJoe;
#end
#implementation SurroundViewController
- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
if (self) {
// Custom initialization
}
return self;
}
- (void)viewDidLoad
{
[super viewDidLoad];
// Do any additional setup after loading the view.
self.lazyJoe = [[LazyJoe alloc]init];
self.collectionView.collectionViewLayout = self.lazyJoe; // Layout things are in the Flowlayout
}
- (void)didReceiveMemoryWarning
{
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}
- (NSInteger)numberOfSectionsInCollectionView:(UICollectionView *)collectionView {
return 2;
}
- (NSInteger)collectionView:(UICollectionView *)collectionView numberOfItemsInSection:(NSInteger)section {
return 30;
}
- (UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath {
MagazineCell *mCell = (MagazineCell *)[collectionView dequeueReusableCellWithReuseIdentifier:cellID forIndexPath:indexPath];
mCell.backgroundColor = [UIColor lightGrayColor];
return mCell;
}
LazyJoe.m
#import "LazyJoe.h"
#implementation LazyJoe
- (id)init {
if (!(self = [super init])) return nil;
self.itemSize = CGSizeMake(104, 104);
self.sectionInset = UIEdgeInsetsMake(0,0,0,0); // That the items can align as nearest as possible
self.minimumInteritemSpacing = 2.0f; // spacing between items in one row
self.minimumLineSpacing = 2.0f; // spacing between lines
self.headerReferenceSize = CGSizeMake(self.collectionView.frame.size.width, 140);
return self;
}
#end