Day Calendar

.h file

@interface ViewController : UIViewController {    

UIImageView *_topBackground;

UIButton *_leftArrow, *_rightArrow;

UILabel *_dateLabel;

IBOutlet UILabel *result;

NSDate *day1;

}

.m file

#import <QuartzCore/QuartzCore.h> 

static NSString *TOP_BACKGROUND_IMAGE                    = @"ma_topBackground.png";

static NSString *LEFT_ARROW_IMAGE                        = @"ma_leftArrow.png";

static NSString *RIGHT_ARROW_IMAGE                       = @"ma_rightArrow.png";

static const unsigned int ARROW_LEFT                     = 100;

static const unsigned int ARROW_RIGHT                    = 101;

static const unsigned int ARROW_WIDTH                    = 48;

static const unsigned int ARROW_HEIGHT                   = 38;

static const unsigned int TOP_BACKGROUND_HEIGHT          = 95; 

#define CURRENT_CALENDAR [NSCalendar currentCalendar]

#define DATE_COMPONENTS (NSYearCalendarUnit| NSMonthCalendarUnit | NSDayCalendarUnit)

@interface ViewController()

- (void)changeDay:(UIButton *)sender;

- (NSDate *)nextDayFromDate:(NSDate *)date;

- (NSDate *)previousDayFromDate:(NSDate *)date;

@property (readonly) UIImageView *topBackground;

@property (readonly) UIButton *leftArrow;

@property (readonly) UIButton *rightArrow;

@property (readonly) UILabel *dateLabel; 

@property (readonly) UIFont *regularFont;

@property (readonly) UIFont *boldFont;

@property (readonly) NSString *titleText;

@end

@implementation ViewController

- (UIImageView *)topBackground {

if (!_topBackground) {

_topBackground = [[UIImageView alloc] initWithImage:[UIImage imageNamed:TOP_BACKGROUND_IMAGE]];

}

return _topBackground;

}

- (UIButton *)leftArrow {

if (!_leftArrow) {

_leftArrow = [UIButton buttonWithType:UIButtonTypeCustom];

_leftArrow.tag = ARROW_LEFT;

[_leftArrow setImage:[UIImage imageNamed:LEFT_ARROW_IMAGE] forState:0];

[_leftArrow addTarget:self action:@selector(changeDay:) forControlEvents:UIControlEventTouchUpInside];

}

return _leftArrow;

}

- (UIButton *)rightArrow {

if (!_rightArrow) {

_rightArrow = [UIButton buttonWithType:UIButtonTypeCustom];

_rightArrow.tag = ARROW_RIGHT;

[_rightArrow setImage:[UIImage imageNamed:RIGHT_ARROW_IMAGE] forState:0];

[_rightArrow addTarget:self action:@selector(changeDay:) forControlEvents:UIControlEventTouchUpInside];

}

return _rightArrow;

}

- (UILabel *)dateLabel {

if (!_dateLabel) {

_dateLabel = [[UILabel alloc] init];

_dateLabel.textAlignment = NSTextAlignmentCenter;

_dateLabel.backgroundColor = [UIColor clearColor];

_dateLabel.font = [UIFont boldSystemFontOfSize:18];

_dateLabel.textColor = [UIColor colorWithRed:59/255. green:73/255. blue:88/255. alpha:1];

}

return _dateLabel;

}

- (void)setDay:(NSDate *)date {     

NSDateComponents *components = [CURRENT_CALENDAR components:DATE_COMPONENTS fromDate:date];

day1 = [CURRENT_CALENDAR dateFromComponents:components];

    [day1 copy];

  self.dateLabel.text = [self titleText];

    

    NSString *str = self.dateLabel.text;

    NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];

    [dateFormatter setDateFormat:@"MM/dd/yyyy"];

    NSDate *date1 = [dateFormatter dateFromString: str];

    dateFormatter = [[NSDateFormatter alloc] init] ;

    [dateFormatter setDateFormat:@"yyyy-MM-dd"];

    NSString *convertedString = [dateFormatter stringFromDate:date1];

    result.text = convertedString;

    

    NSDate *today = [NSDate date];

    NSDateFormatter *dateFormat = [[NSDateFormatter alloc] init];

    [dateFormat setDateFormat:@"MM/dd/yyyy"];

    NSString *dateString = [dateFormat stringFromDate:today];

    NSLog(@"datestring %@",dateString);

    NSLog(@"cur1: %@",self.dateLabel.text);

       

}

- (void)changeDay:(UIButton *)sender {

   

if (ARROW_LEFT == sender.tag) {

self.day = [self previousDayFromDate:day1];

} else if (ARROW_RIGHT == sender.tag) {

      self.day = [self nextDayFromDate:day1];

}   

}

- (NSDate *)nextDayFromDate:(NSDate *)date {

NSDateComponents *components = [CURRENT_CALENDAR components:DATE_COMPONENTS fromDate:date];

[components setDay:[components day] + 1];

return [CURRENT_CALENDAR dateFromComponents:components];

}

- (NSDate *)previousDayFromDate:(NSDate *)date {

    

    NSDate *today = [NSDate date];

    NSDateFormatter *dateFormat = [[NSDateFormatter alloc] init];

    [dateFormat setDateFormat:@"MM/dd/yyyy"];

    NSString *dateString = [dateFormat stringFromDate:today];

    NSLog(@"datestring %@",dateString);

    NSLog(@"cur1: %@",self.dateLabel.text);

     

    if (dateString == self.dateLabel.text) {    

        NSDateComponents *components = [CURRENT_CALENDAR components:DATE_COMPONENTS fromDate:date];

        [components setDay:[components day]];

        return [CURRENT_CALENDAR dateFromComponents:components];       

    }else{

         NSDateComponents *components = [CURRENT_CALENDAR components:DATE_COMPONENTS fromDate:date];

        [components setDay:[components day] - 1];

        return [CURRENT_CALENDAR dateFromComponents:components];

       

    }

}

- (NSString *)titleText {

NSDateFormatter *formatter = [[NSDateFormatter alloc] init];

    [formatter setDateFormat:@"MM/dd/yyyy"]; 

return [NSString stringWithFormat:@"%@",

[formatter stringFromDate:day1]];

} 

- (void)viewDidLoad

{

     self.rightArrow.frame = CGRectMake(280, 60, 20, 20);

    [self.view addSubview:_rightArrow];

    self.leftArrow.frame = CGRectMake(10, 60, 20, 20);

    [self.view addSubview:_leftArrow];

   

    self.day = [NSDate date];

    

    [self.view addSubview:_dateLabel];

    self.dateLabel.frame = CGRectMake(60, 0, 200, 150);

    self.topBackground.frame = CGRectMake(0, 0, 320, 45);

   [self.view addSubview:_topBackground];

       

   [super viewDidLoad];

}

@end