Alexey Kuznetsov eofster

iOS and Mac developer

eofster / UnsafeMutablePointerMove.swift

Last active October 1, 2015 18:37

	private func audioBufferListWithObjectID(objectID: AudioObjectID, scope: AudioObjectPropertyScope) throws -> AudioBufferList {
	var address = audioBufferListAddressWithScope(scope)
	var length = try propertyDataSizeWithObjectID(objectID, address: address)
	let bytes = UnsafeMutablePointer<AudioBufferList>.alloc(Int(length))
	defer { bytes.destroy() }
	let status = AudioObjectGetPropertyData(objectID, &address, 0, nil, &length, bytes)
	if status != noErr {
	throw TelephoneError.SystemAudioDevicePropertyDataGetError(systemErrorCode: Int(status))
	}
	return bytes.memory

eofster / ObserverPattern.swift

Last active February 1, 2016 17:20

An example of using the observer pattern instead of NSnotifications and KVO

	class UserAgent {

	let observer: UserAgentObserver

	init(observer: UserAgentObserver) {
	self.observer = observer
	}

	func start() {
	observer.userAgentDidFinishStarting(self)

eofster / CompositeObserver.swift

Last active November 8, 2015 14:42

An example of using a composite observer

	class UserAgent {

	let observer: UserAgentObserver

	init(observer: UserAgentObserver) {
	self.observer = observer
	}

	func start() {
	observer.userAgentDidFinishStarting(self)

eofster / PhoneCallRegistryOptionalPhoneCall.swift

Last active November 10, 2015 11:26

Phone call registry returning an optional phone call

	protocol PhoneCallRegistry {
	func callWithIdentifier(identifier: Int) -> PhoneCall?
	}

	func hangUpCallWithIdentifier(identifier: Int) {
	if let call = phoneCallRegistry.callWithIdentifier(identifier) {
	call.hangUp()
	} else {
	print("Could not hang up call")
	}

eofster / PhoneCallRegistryNonOptionalPhoneCall.swift

Created November 10, 2015 11:01

Phone call registry returning non-optional phone call

	protocol PhoneCallRegistry {
	func callWithIdentifier(identifier: Int) -> PhoneCall
	}

	func hangUpCallWithIdentifier(identifier: Int) {
	phoneCallRegistry.callWithIdentifier(identifier).hangUp()
	}

eofster / AccountPhoneCallPyramidOfDoom.swift

Last active November 10, 2015 11:29

Pyramid of Doom when accessing first call of an account with identifier

	func hangUpFirstCallOnAccountWithIdentifier(identifier: Int) {
	if let account = accountRegistry.accountWithIdentifier(identifier) {
	if let call = account.firstCall {
	call.hangUp()
	} else {
	print("Could not find first call for an account")
	}
	} else {
	print("Could not find account")
	}

eofster / AccountPhoneCallNullObject.swift

Created November 10, 2015 11:23

Usage of the Null Object pattern when hanging up call on account with identifier

	func hangUpFirstCallOnAccountWithIdentifier(identifier: Int) {
	accountRegistry.accountWithIdentifier(identifier).firstCall.hangUp()
	}

eofster / NullObjectReferenceTypeInheritance.swift

Last active November 10, 2015 13:11

An example implementation of Null Object pattern for reference types using inheritance

	class PhoneCall {

	static let nullPhoneCall: PhoneCall = NullPhoneCall()

	let identifier: Int

	init(identifier: Int) {
	self.identifier = identifier
	}

eofster / NullObjectReferenceTypeProtocol.swift

Last active August 3, 2017 16:17

An example implementation of Null Object pattern for reference types using protocol

	protocol PhoneCall {
	var identifier: Int { get }
	var isNil: Bool { get }
	func hangUp()
	}

	class RealPhoneCall: PhoneCall {

	let identifier: Int
	let isNil = false

eofster / AccountPhoneCallGuard.swift

Created November 10, 2015 12:20

Guard statements when accessing first call of an account with identifier

	func hangUpFirstCallOnAccountWithIdentifier(identifier: Int) {
	guard let account = accountRegistry.accountWithIdentifier(identifier) else {
	print("Could not find account")
	return
	}
	guard let call = account.firstCall else {
	print("Could not find first call for an account")
	return
	}
	call.hangUp()