The XestiMonitors framework provides more than three dozen fully-functional monitor classes right out of the box that make it easy for your app to detect and respond to many common system-generated events.
Among other things, you can think of XestiMonitors as a better way to manage
the most common notifications (primarily on iOS and tvOS). At present,
XestiMonitors provides “wrappers” around most UIKit notifications (see
UIKit Monitors) and some Foundation notifications (see
Foundation Monitors).
XestiMonitors also provides convenient “wrappers” around several frameworks and programming interfaces to make them easier for your app to use:
- It wraps the Core Location framework to make it easier for your app to make easier for your app to determine the device’s geographic location, altitude, or orientation; or its position relative to a nearby iBeacon. See Core Location Monitors for details.
- It wraps the Core Motion framework to make it easier for your app to obtain both raw and processed motion measurements from the device. See Core Motion Monitors for details.
- It wraps the
SCNetworkReachabilityprogramming interface to make it super easy for your app to determine the reachability of a target host. See Other Monitors for details.
Additional monitors targeting more parts of all four platforms will be rolled out in future releases of XestiMonitors!
Finally, XestiMonitors is extensible—you can easily create your own custom monitors. See Custom Monitors for details.
Full reference documentation is available courtesy of Jazzy.
- iOS 9.0+ / macOS 10.10+ / tvOS 9.0+ / watchOS 2.0+
- Xcode 9.0+
- Swift 4.0+
CocoaPods is a dependency manager for Cocoa projects. You can install it with the following command:
$ gem install cocoapodsTo integrate XestiMonitors into your Xcode project using CocoaPods, specify it
in your Podfile:
source 'https://github.com/CocoaPods/Specs.git'
platform :ios, '9.0'
use_frameworks!
target '<Your Target Name>' do
pod 'XestiMonitors'
endThen, run the following command:
$ pod installCarthage is a decentralized dependency manager that builds your dependencies and provides you with binary frameworks.
You can install Carthage with Homebrew using the following command:
$ brew update
$ brew install carthageTo integrate XestiMonitors into your Xcode project using Carthage, specify it
in your Cartfile:
github "eBardX/XestiMonitors"
Run carthage update to build the framework and drag the built
XestiMonitors.framework into your Xcode project.
The Swift Package Manager is a tool for automating the distribution of Swift code and is integrated into the swift compiler. It is in early development, but XestiMonitors does support its use on supported platforms.
Once you have your Swift package set up, adding XestiMonitors as a dependency
is as easy as adding it to the dependencies value of your Package.swift.
dependencies: [
.Package(url: "https://github.com/eBardX/XestiMonitors.git")
]All monitor classes conform to the Monitor protocol, thus enabling you to create arrays of monitors that can be started or stopped uniformly—fewer lines of code!
For example, in a view controller, you can lazily instantiate several monitors and, in addition, lazily instantiate an array variable containing these monitors:
import XestiMonitors
lazy var keyboardMonitor = KeyboardMonitor { [unowned self] in
// do something…
}
lazy var memoryMonitor = MemoryMonitor { [unowned self] in
// do something…
}
lazy var orientationMonitor = OrientationMonitor { [unowned self] in
// do something…
}
lazy var monitors: [Monitor] = [keyboardMonitor,
memoryMonitor,
orientationMonitor]Then, in the viewWillAppear(_:) and viewWillDisappear(_:) methods, you can
simply start or stop all these monitors with a single line of code:
override func viewWillAppear(_ animated: Bool) {
super.viewWillAppear(animated)
monitors.forEach { $0.startMonitoring() }
}
override func viewWillDisappear(_ animated: Bool) {
monitors.forEach { $0.stopMonitoring() }
super.viewWillDisappear(animated)
}Easy peasy!
XestiMonitors provides seven monitor classes wrapping the Core Location framework that you can use to determine the device’s geographic location, altitude, or orientation; or its position relative to a nearby iBeacon:
- BeaconRangingMonitor to monitor a region for changes to the ranges (i.e., the relative proximity) to the Bluetooth low-energy beacons within. (iOS)
- HeadingMonitor to monitor the device for changes to its current heading. (iOS)
- LocationAuthorizationMonitor to monitor the app for updates to its authorization to use location services. (iOS, macOS, tvOS, watchOS)
- RegionMonitor to monitor a region for changes to its state (which indicate boundary transitions). (iOS, macOS)
- SignificantLocationMonitor to monitor the device for significant changes to its current location. (iOS, macOS)
- StandardLocationMonitor to monitor the device for changes to its current location. (iOS, macOS, tvOS, watchOS)
- VisitMonitor to monitor for locations that the user stops at for a “noteworthy” amount of time. (iOS)
XestiMonitors provides seven monitor classes wrapping the Core Motion framework that you can use to obtain raw and processed motion measurements from the device:
- AccelerometerMonitor to monitor the device’s accelerometer for periodic raw measurements of the acceleration along the three spatial axes. (iOS, watchOS)
- AltimeterMonitor to monitor the device for changes in relative altitude. (iOS, watchOS)
- DeviceMotionMonitor to monitor the device’s accelerometer, gyroscope, and magnetometer for periodic raw measurements which are processed into device motion measurements. (iOS, watchOS)
- GyroscopeMonitor to monitor the device’s gyroscope for periodic raw measurements of the rotation rate around the three spatial axes. (iOS, watchOS)
- MagnetometerMonitor to monitor the device’s magnetometer for periodic raw measurements of the magnetic field around the three spatial axes. (iOS, watchOS)
- MotionActivityMonitor to monitor the device for live and historic motion data. (iOS, watchOS)
- PedometerMonitor to monitor the device for live and historic walking data. (iOS, watchOS)
XestiMonitors provides three monitors wrapping Foundation
notifications:
- MetadataQueryMonitor to monitor a metadata query for changes to its results. (iOS, macOS, tvOS, watchOS)
- UbiquitousKeyValueStoreMonitor to monitor the iCloud (“ubiquitous”) key-value store for changes due to incoming data pushed from iCloud. (iOS, macOS, tvOS)
- UbiquityIdentityMonitor to monitor the system for changes to the iCloud (”ubiquity”) identity. (iOS, macOS, tvOS, watchOS)
XestiMonitors provides numerous monitors wrapping UIKit
notifications.
XestiMonitors provides three monitor classes that you can use to observe accessibility events generated by the system:
- AccessibilityAnnouncementMonitor to monitor the system for accessibility announcements that VoiceOver has finished outputting. (iOS, tvOS)
- AccessibilityElementMonitor to monitor the system for changes to element focus by an assistive technology. (iOS, tvOS)
- AccessibilityStatusMonitor to monitor the system for changes to the status of various accessibility settings. (iOS, tvOS)
XestiMonitors provides seven monitor classes that you can use to observe common events generated by the system about the app:
- ApplicationStateMonitor to monitor the app for changes to its runtime state. (iOS, tvOS)
- BackgroundRefreshMonitor to monitor the app for changes to its status for downloading content in the background. (iOS)
- MemoryMonitor to monitor the app for memory warnings from the operating system. (iOS, tvOS)
- ProtectedDataMonitor to monitor the app for changes to the accessibility of protected files. (iOS, tvOS)
- ScreenshotMonitor to monitor the app for screenshots. (iOS, tvOS)
- StatusBarMonitor to monitor the app for changes to the orientation of its user interface or to the frame of the status bar. (iOS)
- TimeMonitor to monitor the app for significant changes in time. (iOS, tvOS)
XestiMonitors provides three monitor classes that you can use to detect changes in the characteristics of the device:
- BatteryMonitor to monitor the device for changes to the charge state and charge level of its battery. (iOS)
- OrientationMonitor to monitor the device for changes to its physical orientation. (iOS)
- ProximityMonitor to monitor the device for changes to the state of its proximity sensor. (iOS)
XestiMonitors provides four monitor classes that you can use to detect changes in the properties associated with a screen:
- ScreenBrightnessMonitor to monitor a screen for changes to its brightness level. (iOS, tvOS)
- ScreenCapturedMonitor to monitor a screen for changes to its captured status. (iOS, tvOS)
- ScreenConnectionMonitor to monitor the device for screen connections and disconnections. (iOS, tvOS)
- ScreenModeMonitor to monitor a screen for changes to its current mode. (iOS, tvOS)
XestiMonitors provides three monitor classes that you can use to detect changes in text input mode and content:
- TextFieldTextMonitor to monitor a text field for changes to its text. (iOS, tvOS)
- TextInputModeMonitor to monitor the responder chain for changes to the current input mode. (iOS, tvOS)
- TextViewTextMonitor to monitor a text view for changes to its text. (iOS, tvOS)
In addition, XestiMonitors provides seven other UIKit monitors:
- DocumentStateMonitor to monitor a document for changes to its state. (iOS)
- FocusMonitor to monitor the app for changes to the current focus in the view hierarchy. (iOS, tvOS)
- KeyboardMonitor to monitor the keyboard for changes to its visibility or to its frame. (iOS)
- MenuControllerMonitor to monitor the menu controller for changes to the visibility of the editing menu or to the frame of the editing menu. (iOS)
- PasteboardMonitor to monitor a pasteboard for changes to its contents or for its removal from the app. (iOS)
- ViewControllerShowDetailTargetMonitor to monitor the app for changes to a split view controller’s display mode in the view hierarchy. (iOS, tvOS)
- WindowMonitor to monitor a window for changes to its visibility or key status. (iOS, tvOS)
KeyboardMonitor is especially handy in removing lots of boilerplate code from your app. This is how keyboard monitoring is typically handled in a custom view controller:
func keyboardWillHide(_ notification: Notification) {
let userInfo = notification.userInfo
var animationDuration: TimeInterval = 0
if let value = (userInfo?[UIKeyboardAnimationDurationUserInfoKey] as? NSNumber)?.doubleValue {
animationDuration = value
}
constraint.constant = 0
UIView.animate(withDuration: animationDuration) {
self.view.layoutIfNeeded()
}
}
func keyboardWillShow(_ notification: Notification) {
let userInfo = notification.userInfo
var animationDuration: TimeInterval = 0
if let value = (userInfo?[UIKeyboardAnimationDurationUserInfoKey] as? NSNumber)?.doubleValue {
animationDuration = value
}
var frameEnd = CGRect.zero
if let value = (userInfo?[UIKeyboardFrameEndUserInfoKey] as? NSValue)?.cgRectValue {
frameEnd = value
}
constraint.constant = frameEnd.height
UIView.animate(withDuration: animationDuration) {
self.view.layoutIfNeeded()
}
}
override func viewWillAppear(_ animated: Bool) {
super.viewWillAppear(animated)
let nc = NotificationCenter.`default`
nc.addObserver(self, selector: #selector(keyboardWillHide(_:)),
name: .UIKeyboardWillHide, object: nil)
nc.addObserver(self, selector: #selector(keyboardWillShow(_:)),
name: .UIKeyboardWillShow, object: nil)
}
override func viewWillDisappear(_ animated: Bool) {
NotificationCenter.`default`.removeObserver(self)
super.viewWillDisappear(animated)
}And this is the XestiMonitors way using KeyboardMonitor:
import XestiMonitors
lazy var keyboardMonitor = KeyboardMonitor { [unowned self] event in
guard let constraint = self?.constraint,
let view = self?.view else { return }
switch event {
case let .willHide(info):
constraint.constant = 0
UIView.animate(withDuration: info.animationDuration) {
view.layoutIfNeeded()
}
case let .willShow(info):
constraint.constant = info.frameEnd.height
UIView.animate(withDuration: info.animationDuration) {
view.layoutIfNeeded()
}
default:
break
}
}
override func viewWillAppear(_ animated: Bool) {
super.viewWillAppear(animated)
keyboardMonitor.startMonitoring()
}
override func viewWillDisappear(_ animated: Bool) {
keyboardMonitor.stopMonitoring()
super.viewWillDisappear(animated)
}What’s in your wallet?
In addition, XestiMonitors provides two other monitors:
- FileSystemObjectMonitor to monitor a file-system object for changes. (iOS, macOS, tvOS, watchOS)
- NetworkReachabilityMonitor to monitor a network node name or address for changes to its reachability. (iOS, macOS, tvOS)
Best of all, the XestiMonitors framework provides several ways to create your own custom monitors quite easily.
You can create a new class, or extend an existing class, that conforms to the Monitor protocol. You need only implement the startMonitoring() and stopMonitoring() methods, as well as the isMonitoring property:
import XestiMonitors
extension MegaHoobieWatcher: Monitor {
var isMonitoring: Bool { return watchingForHoobiesCount() > 0 }
func startMonitoring() -> Bool {
guard !isMonitoring else { return }
beginWatchingForHoobies()
}
func stopMonitoring() -> Bool {
guard isMonitoring else { return }
endWatchingForHoobies()
}
}Note: The guard statements in both startMonitoring() and stopMonitoring() protect against starting or stopping the monitor if it is in the incorrect state. This is considered good coding practice.
Typically, you will want to create a subclass of BaseMonitor.
The advantage of using this abstract base class is that the basic guard logic
is taken care of for you. Specifically, the
startMonitoring() method does not attempt to start the
monitor if it is already active, and the stopMonitoring()
method does not attempt to stop the monitor if it is not active. Instead of
directly implementing the required protocol methods and properties, you need
only override the configureMonitor() and
cleanupMonitor() methods of this base class. In fact, you
will not be able to override the startMonitoring() and
stopMonitoring() methods or the
isMonitoring property—they are declared final in
BaseMonitor.
import XestiMonitors
class GigaHoobieMonitor: BaseMonitor {
let handler: (Float) -> Void
@objc let hoobie: GigaHoobie
private var observation: NSKeyValueObservation?
init(_ hoobie: GigaHoobie, handler: @escaping (Float) -> Void) {
self.handler = handler
self.hoobie = hoobie
}
override func configureMonitor() -> Bool {
super.configureMonitor()
observation = hoobie.observe(\.nefariousActivityLevel) { [unowned self] hoobie, _ in
self.handler(hoobie.nefariousActivityLevel) }
}
override func cleanupMonitor() -> Bool {
observation?.invalidate()
observation = nil
super.cleanupMonitor()
}
}Note: Be sure to invoke the superclass implementations of both configureMonitor() and cleanupMonitor().
If your custom monitor determines events by observing notifications, you should
consider creating a subclass of
BaseNotificationMonitor instead. In most cases you
need only override the
addNotificationObservers(_:) method. You can
also override the
removeNotificationObservers(_:) method if
you require extra cleanup when the notification observers are removed upon
stopping the monitor. Although this base class inherits from
BaseMonitor, you will not be able to override the
configureMonitor() and
cleanupMonitor() methods—they are declared final in
BaseNotificationMonitor.
import XestiMonitors
class TeraHoobieMonitor: BaseNotificationMonitor {
let handler: (Bool) -> Void
let hoobie: TeraHoobie
init(hoobie: TeraHoobie, queue: OperationQueue = .main,
handler: @escaping (Bool) -> Void) {
self.handler = handler
self.hoobie = hoobie
super.init(queue: queue)
}
override func addNotificationObservers() -> Bool {
super.addNotificationObservers()
observe(.teraHoobieDidChange) { [unowned self] _ in
self.handler(self.hoobie.value) }
}
}Note: Be sure to invoke the superclass implementations of both addNotificationObservers(_:) and removeNotificationObservers(_:) in your overrides.
J. G. Pusey ([email protected])
XestiMonitors is available under the MIT license.