PBJHexagon issue iOS 8 interleave value from Items per Row Obj-C - objective-c

Question

How interleave value form Items per Row using PBJHexagon Class Flow Layout on my custom UICollectionView?
hi guys I'm Using iOS hexagon grid layout for UICollectionViews PBJHEXAGON
if you look the file .h is like:
#import <UIKit/UIKit.h>
// iOS hexagon grid layout for UICollectionViews
#interface PBJHexagonFlowLayout : UICollectionViewFlowLayout
#property (nonatomic) NSInteger itemsPerRow;
#end
file.m :
#import "PBJHexagonFlowLayout.h"
CG_INLINE CGFloat CGFloat_nearbyint(CGFloat cgfloat) {
#if defined(__LP64__) && __LP64__
return nearbyint(cgfloat);
#else
return nearbyintf(cgfloat);
#endif
}
CG_INLINE CGFloat CGFloat_floor(CGFloat cgfloat) {
#if defined(__LP64__) && __LP64__
return floor(cgfloat);
#else
return floorf(cgfloat);
#endif
}
#interface PBJHexagonFlowLayout ()
{
NSInteger _itemsPerRow;
}
#end
#implementation PBJHexagonFlowLayout
#synthesize itemsPerRow = _itemsPerRow;
#pragma mark - UICollectionViewLayout Subclass hooks
- (void)prepareLayout
{
[super prepareLayout];
if (_itemsPerRow == 0)
_itemsPerRow = 4;
}
- (NSArray *)layoutAttributesForElementsInRect:(CGRect)rect
{
NSMutableArray *layoutAttributes = [[NSMutableArray alloc] init];
NSInteger numberOfItems = [self.collectionView numberOfItemsInSection:0];
for (NSInteger i = 0 ; i < numberOfItems; i++) {
NSIndexPath *indexPath = [NSIndexPath indexPathForItem:i inSection:0];
[layoutAttributes addObject:[self layoutAttributesForItemAtIndexPath:indexPath]];
}
return layoutAttributes;
}
- (UICollectionViewLayoutAttributes *)layoutAttributesForItemAtIndexPath:(NSIndexPath *)indexPath
{
NSInteger row = (NSInteger) CGFloat_nearbyint( CGFloat_floor(indexPath.row / _itemsPerRow) );
NSInteger col = indexPath.row % _itemsPerRow;
CGFloat horiOffset = ((row % 2) != 0) ? 0 : self.itemSize.width * 0.5f;
CGFloat vertOffset = 0;
UICollectionViewLayoutAttributes *attributes = [UICollectionViewLayoutAttributes layoutAttributesForCellWithIndexPath:indexPath];
attributes.size = self.itemSize;
attributes.center = CGPointMake( ( (col * self.itemSize.width) + (0.5f * self.itemSize.width) + horiOffset),
( ( (row * 0.75f) * self.itemSize.height) + (0.5f * self.itemSize.height) + vertOffset) );
return attributes;
}
- (BOOL)shouldInvalidateLayoutForBoundsChange:(CGRect)newBounds
{
return NO;
}
- (CGSize)collectionViewContentSize
{
NSInteger numberOfItems = [self.collectionView numberOfItemsInSection:0];
CGFloat contentWidth = self.collectionView.bounds.size.width;
CGFloat contentHeight = ( ((numberOfItems / _itemsPerRow) * 0.75f) * self.itemSize.height) + (0.5f + self.itemSize.height);
CGSize contentSize = CGSizeMake(contentWidth, contentHeight);
return contentSize;
}
now in my ViewController I have:
ViewController.h :
#import <UIKit/UIKit.h>
#import "PBJHexagonFlowLayout.h"
#import "customCell.h"
#interface ViewController : UIViewController<UICollectionViewDelegate,UICollectionViewDataSource>
{
IBOutlet UICollectionView *collectionView;
}
#end
ViewController.m :
#import "ViewController.h"
#interface ViewController ()
#end
#implementation ViewController
- (void)viewDidLoad
{
[super viewDidLoad];
// Do any additional setup after loading the view, typically from a nib.
PBJHexagonFlowLayout *flowLayout = [[PBJHexagonFlowLayout alloc] init];
flowLayout.scrollDirection = UICollectionViewScrollDirectionVertical;
flowLayout.sectionInset = UIEdgeInsetsMake(3, 3, 3, 3);
flowLayout.minimumInteritemSpacing = 3;
flowLayout.minimumLineSpacing = 3;
flowLayout.headerReferenceSize = CGSizeZero;
flowLayout.footerReferenceSize = CGSizeZero;
flowLayout.itemSize = CGSizeMake(100.0f, 115.0f);
flowLayout.itemsPerRow = 3; // I NEED 3 and 2 Dinamically!! HELP!!
[collectionView setCollectionViewLayout:flowLayout];
//------------------------------------------//
// THANKS GUYS //
// GRETTINGS FROM BOLIVIA //
// ROCK ON!!!! n_n' //
//------------------------------------------//
}
- (void)didReceiveMemoryWarning
{
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}
# pragma mark - Collection Functions
-(NSInteger)numberOfSectionsInCollectionView:(UICollectionView *)collectionView
{
return 1;
}
- (NSInteger)collectionView:(UICollectionView *)collectionView numberOfItemsInSection:(NSInteger)section
{
return 18;
}
- (UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath
{
static NSString *identifier = #"Cell_Bolivia";
customCell *cell = [collectionView dequeueReusableCellWithReuseIdentifier:identifier forIndexPath:indexPath];
cell.hexagonImage.image = [UIImage imageNamed:#"orangeHexagon.png"];
return cell;
}
#end
I did try to do the test randomly in:
flowLayout.itemsPerRow = [self getRandomValueBetween:2 and:3];
with:
-(int) getRandomValueBetween:(int)lowerBound and:(int)upperBound
{
int rndValue = lowerBound + arc4random() % (upperBound - lowerBound);
return rndValue;
}
but the PBJHexagon Class only show in static way:
How interleave value for Items per Row as shown in the example:
thanks a lot guys!!!

Answer 1

1.Just make the collection view frame wider and move left with half width of the cell.
Then you can set the first and the last cell in the short row with an empty cell.
Here is sample code in Swift
override func viewDidLoad() {
super.viewDidLoad()
//...
flowLayout.itemSize = CGSizeMake(80.0, 92.0)
flowLayout.itemsPerRow = 6 // only 4 item will displayed fully, the first and the last cells will only show half
self.collectionView!.setCollectionViewLayout(flowLayout, animated: false)
self.collectionView!.frame = CGRectMake(-40, 0, self.view.frame.width+80, self.view.frame.height) // move the frame to left with 80/2 and modify the width.
//....
}
override func collectionView(collectionView: UICollectionView, cellForItemAtIndexPath indexPath: NSIndexPath) -> UICollectionViewCell {
let cell = collectionView.dequeueReusableCellWithReuseIdentifier("hexagon", forIndexPath: indexPath) as! HexagonCell
// set a null image if is the first or last one in short row
// ..............
return cell
}