This project is a To-Do list app that employs an Eisenhower-Matrix approach to task organization. Basically, it categorizes tasks into 4 categories to help with sorting out less urgent and important tasks which you should either delegate or not do at all:

1. Important & Urgent
2. Important & Not Urgent
3. Not Important & Urgent
4. Not Important & NotUrgent

This is an iOS app written in Objective-C. You can add tasks by tapping the "+" UIBarButton in the top-right corner, and delete tasks by swiping their cell in the tableView and tapping the delete button.

This project creates all of its views programmatically. The main window & controller are instantiated in the AppDelegate.

The app's data is stored locally in NSUserDefauts. A singleton class, ActivityDataManager, handles data loading and manipulation through methods like getActivities, etc.

The ActivityDataManager singleton instance is used in both controllers of the app. To access the manager, import its h file and reference the shared instance:

#import "ActivityDataManager.h"

ActivityDataManager *manager = [ActivityDataManager shared];

An array of user's Activity objects is archived when encoded to NSUserDefaults, and unarchived when decoded. The getActivities method retrieves all of the user's activities. The encodeActivityArray method stores an array of activities.

-(NSMutableArray<Activity *> *)getActivities {
    NSMutableArray<Activity *> *list = [NSMutableArray<Activity *> new];
    
    NSUserDefaults *ud = [NSUserDefaults standardUserDefaults];
    
    NSData *storedData = [ud objectForKey:activitiesKey];
    NSMutableArray *storedArray = [NSKeyedUnarchiver unarchiveObjectWithData:storedData];
    [list addObjectsFromArray:storedArray];
    
    return list;
}

-(void)encodeActivityArray:(NSArray<Activity *> *)array {
    NSError *error = nil;
    NSData *encodedArray = [NSKeyedArchiver archivedDataWithRootObject:array requiringSecureCoding:NO error:&error];
    
    NSUserDefaults *ud = [NSUserDefaults standardUserDefaults];
    [ud setObject:encodedArray forKey:activitiesKey];
    [ud synchronize];
}

The NSObject subclass Activity is encodable and decodable, allowing it to be archived/unarchived. If you'd like to add more attributes to the Activity type, add them in the NSCoding Protocol methods found in the @implementation of Activity as well:

NSString * const titleKey = @"title";
NSString * const importanceKey = @"impotance";
NSString * const urgencyKey = @"urgency";

- (void)encodeWithCoder:(NSCoder *)coder {
    [coder encodeObject:self.title forKey:titleKey];
    [coder encodeBool:self.important forKey:importanceKey];
    [coder encodeBool:self.urgent forKey:urgencyKey];
}

- (id)initWithCoder:(NSCoder *)coder {
    if (self = [super init]) {
        title = [coder decodeObjectForKey:titleKey];
        important = [coder decodeBoolForKey:importanceKey];
        urgent = [coder decodeBoolForKey:urgencyKey];
    }
    
    return self;
}