Nimbus Core

Modules
	Actions
	For attaching actions to objects.
	Button Utilities
	For manipulating UIButton objects.
	Common Metrics
	For common system metrics.
	Data Structures
	For classic computer science data structures.
	Debugging Tools
	For inspecting code and writing to logs in debug builds.
	Device Orientation
	For dealing with device orientations.
	Errors
	For defining various error types used throughout the Nimbus framework.
	Foundation Methods
	For filling in gaps in Apple's Foundation framework.
	Image Utilities
	For manipulating UIImage objects.
	In-Memory Caches
	For storing and accessing objects in memory.
	Network Activity
	For showing network activity in the device's status bar.
	Non-Empty Collection Testing
	For testing whether a collection is of a certain type and is non-empty.
	Non-Retaining Collections
	For collections that don't retain their objects.
	Operations
	For writing code that runs concurrently.
	Paths
	For creating standard system paths.
	Preprocessor Macros
	Preprocessor macros are added to Nimbus with care.
	Runtime Class Modifications
	For modifying class implementations at runtime.
	SDK Availability
	For checking SDK feature availibility.
	Snapshot Rotation
	An object designed to easily implement snapshot rotation.
	State
	For modifying Nimbus state information.
	View Recyling
	For recycling views in scroll views.

Classes
class	NINavigationAppearance
	The NINavigationAppearance provides support for saving and restoring the navigation appearance state. More...

Overview

Nimbus' Core defines the foundation upon which all other Nimbus features are built. Within the core you will find common elements used to build iOS applications including in-memory caches, path manipulation, and SDK availability. These features form the foundation upon which all other Nimbus libraries are built.

How Features are Added to the Core

As a general rule of thumb, if something is used between multiple independent libraries or applications with little variation, it likely qualifies to be added to the Core.

Exceptions

Standalone user interface components are rarely acceptable features to add to the Core. For example: photo viewers, pull to refresh, launchers, attributed labels.

Nimbus is not UIKit: we don't have the privilege of being an assumed cost on every iOS device. Developers must carefully weigh whether it is worth adding a Nimbus feature - along with its dependencies - over building the feature themselves or using another library. This means that an incredible amount of care must be placed into deciding what gets added to the Core.

How Features are Removed from the Core

It is inevitable that certain aspects of the Core will grow and develop over time. If a feature gets to the point where the value of being a separate library is greater than the overhead of managing such a library, then the feature should be considered for removal from the Core.

Great care must be taken to ensure that Nimbus doesn't become a framework composed of hundreds of miniscule libraries.

Common autoresizing masks

Nimbus provides the following macros: UIViewAutoresizingFlexibleMargins, UIViewAutoresizingFlexibleDimensions, UIViewAutoresizingNavigationBar, and UIViewAutoresizingToolbarBar.

// Create a view that fills its superview's bounds.
UIView* contentView = [[UIView alloc] initWithFrame:self.view.bounds];
contentView.autoresizingMask = UIViewAutoresizingFlexibleDimensions;
[self.view addSubview:contentView];

// Create a view that is always centered in the superview's bounds.
UIView* centeredView = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 50, 50)];
centeredView.autoresizingMask = UIViewAutoresizingFlexibleMargins;
// Center the view within the superview however you choose.
[self.view addSubview:centeredView];

// Create a navigation bar that stays fixed to the top.
UINavigationBar* navBar = [[UINavigationBar alloc] initWithFrame:CGRectZero];
[navBar sizeToFit];
navBar.autoresizingMask = UIViewAutoresizingNavigationBar;
[self.view addSubview:navBar];

// Create a toolbar that stays fixed to the bottom.
UIToolbar* toolBar = [[UIToolbar alloc] initWithFrame:CGRectZero];
[toolBar sizeToFit];
toolBar.autoresizingMask = UIViewAutoresizingToolbarBar;
[self.view addSubview:toolBar];

Why they exist

Using the existing UIViewAutoresizing flags can be tedious for common flags.

For example, to make a view have flexible margins you would need to write four flags:

view.autoresizingMask = (UIViewAutoresizingFlexibleLeftMargin
                         | UIViewAutoresizingFlexibleTopMargin
                         | UIViewAutoresizingFlexibleRightMargin
                         | UIViewAutoresizingFlexibleBottomMargin);