objective-c : making basic UICollectionView

making basic UICollectionView.m

//making basic UICollectionView

//UICollectionView 주요 메소드 (UITableView와 비교)

//UICollectionView vs UITableView 
//Item(Cell) 갯수(필수)
 - (NSInteger)collectionView:(UICollectionView *)collectionView numberOfItemsInSection:(NSInteger)section
 - (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
 
//Item(Cell) 꾸미기(필수)
 - (UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath
 - (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
 
//Item(Cell) 클릭시(선택)
 - (void) collectionView:(UICollectionView *)collectionView didSelectItemAtIndexPath:(NSIndexPath *)indexPath
 - (void) tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
 
//Item(Cell) 클릭해제시(선택) 
 - (void) collectionView:(UICollectionView *)collectionView didDeselectItemAtIndexPath:(NSIndexPath *)indexPath
 - (void) tableView:(UITableView *)tableView didDeselectRowAtIndexPath:(NSIndexPath *)indexPath

//Object Library 아이템
//1. Collection View - (Base 가 되는 View, TableView와 동일 하다고 생각하면 된다.)
//2. Collection View Cell - (Collection View 에 하나하나의 Item, TableViewCell과 동일 하다고 생각하면 된다.)
//3. Collection Reusable View  - (Header 나 Footer 를 설정할때 사용되는 View)



//1. making basic UICollectionView

//UICollectionViewDemo1ViewController.h
//프로토콜 상속 : <UICollectionViewDataSource, UICollectionViewDelegate, UICollectionViewDelegateFlowLayout>

@interface UICollectionViewDemo1ViewController : UIViewController <UICollectionViewDataSource, UICollectionViewDelegate, UICollectionViewDelegateFlowLayout>
 
@property (strong, nonatomic) IBOutlet UICollectionView *collectionView;
 
@end


//UICollectionViewDemo1ViewController.m
 
@implementation UICollectionViewDemo1ViewController
@synthesize collectionView;
 
- (void)viewDidLoad
{
    [super viewDidLoad];
    self.navigationItem.title = @"UICollection Sample...";
    
    // DataSource... Delegate...
    [collectionView setDataSource:self];
    [collectionView setDelegate:self];
}

 
// Section for Item Count...
- (NSInteger) collectionView:(UICollectionView *)collectionView numberOfItemsInSection:(NSInteger)section{
    return 15;
}
 

// CollectionViewCell Item Create...
- (UICollectionViewCell *) collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath {
    
    UICollectionViewCell *cell = [self.collectionView dequeueReusableCellWithReuseIdentifier:@"Cell" forIndexPath:indexPath];
    
    UIImageView *imgView = [[UIImageView alloc] initWithFrame:cell.contentView.frame];
    imgView.image = [UIImage imageNamed:@"sample.png"];
    
    [cell.contentView addSubview:imgView];
    
    UILabel *lable = [[UILabel alloc] initWithFrame:CGRectMake(0, 70, 100, 30)];
    [lable setText:[NSString stringWithFormat:@"[JW]%d-%d",indexPath.section,indexPath.row]];
    
    [cell.contentView addSubview:lable];
    
    return cell;
}
 
@end




//2. section 나누기

//1) 프로그램 방

//UICollectionViewDemo2ViewController.m

// CollectionView Sections Count...
- (NSInteger) numberOfSectionsInCollectionView:(UICollectionView *)collectionView {
    return 3;
}


- (void)viewDidLoad
{
    //...
    
    // Section Size... Layout Setting...
    UICollectionViewFlowLayout *collectionViewLayout = (UICollectionViewFlowLayout *)self.collectionView.collectionViewLayout;
    collectionViewLayout.sectionInset = UIEdgeInsetsMake(20, 0, 20, 0); //top 20, left, bottom 20, right
}


//2) 스토리보드 이용

//StoryBoard에서 Collection Reusable View를 상단에 배치
//1. Attributes inspector > Reusable ID : @"Header"
//2. Size : H 30 적용

// Section Header Create...
- (UICollectionReusableView *) collectionView:(UICollectionView *)collectionView viewForSupplementaryElementOfKind:(NSString *)kind atIndexPath:(NSIndexPath *)indexPath{
    
    if([kind isEqualToString:UICollectionElementKindSectionHeader]){
        
        UICollectionReusableView *rView = [self.collectionView dequeueReusableSupplementaryViewOfKind:UICollectionElementKindSectionHeader withReuseIdentifier:@"Header" forIndexPath:indexPath];
        
        UILabel *lable = [[UILabel alloc] initWithFrame:CGRectMake(0, 0, self.view.bounds.size.width, 30)];
        
        [lable setText:[NSString stringWithFormat:@"%d번 라인",indexPath.section]];
        [lable setTextAlignment:NSTextAlignmentRight];
        [lable setFont:[UIFont systemFontOfSize:20.0f]];
        [lable setBackgroundColor:[UIColor yellowColor]];
        
        [rView addSubview:lable];
        
        return rView;
    }
    return Nil;
}



//3. Selecting, DeSelecting Cell

//UICollectionViewDemo2ViewController.m

// Select Item...
- (void) collectionView:(UICollectionView *)collectionView didSelectItemAtIndexPath:(NSIndexPath *)indexPath {
    NSLog(@"did SelectItem %d-%d",indexPath.section,indexPath.row);
    
    UICollectionViewCell *cell = [self.collectionView cellForItemAtIndexPath:indexPath];
    
    cell.layer.borderColor = [UIColor blueColor].CGColor;
    cell.layer.borderWidth = 3.0f;
}

// De Select Item...
- (void) collectionView:(UICollectionView *)collectionView didDeselectItemAtIndexPath:(NSIndexPath *)indexPath {
    NSLog(@"did De selectItem %d-%d",indexPath.section,indexPath.row);
    
    UICollectionViewCell *cell = [self.collectionView cellForItemAtIndexPath:indexPath];
    
    cell.layer.borderColor = nil;
    cell.layer.borderWidth = 0.0f;
}