# hs.caffeinate.watcher

Watch for display and system sleep/wake/power events and for fast user switching session events.

This module is based primarily on code from the previous incarnation of Mjolnir by Steven Degutis.

# API Overview

Constants - Useful values which cannot be changed

Constructors - API calls which return an object, typically one that offers API methods

Methods - API calls which can only be made on an object returned by a constructor


Signature	`hs.caffeinate.watcher.screensaverDidStart`
Type	Constant
Description	The screensaver started
Notes	None
Source	extensions/caffeinate/libcaffeinate_watcher.m line 42


Signature	`hs.caffeinate.watcher.screensaverDidStop`
Type	Constant
Description	The screensaver stopped
Notes	None
Source	extensions/caffeinate/libcaffeinate_watcher.m line 50


Signature	`hs.caffeinate.watcher.screensaverWillStop`
Type	Constant
Description	The screensaver is about to stop
Notes	None
Source	extensions/caffeinate/libcaffeinate_watcher.m line 46


Signature	`hs.caffeinate.watcher.screensDidLock`
Type	Constant
Description	The screen was locked
Notes	None
Source	extensions/caffeinate/libcaffeinate_watcher.m line 54


Signature	`hs.caffeinate.watcher.screensDidSleep`
Type	Constant
Description	The displays have gone to sleep
Notes	None
Source	extensions/caffeinate/libcaffeinate_watcher.m line 26


Signature	`hs.caffeinate.watcher.screensDidUnlock`
Type	Constant
Description	The screen was unlocked
Notes	None
Source	extensions/caffeinate/libcaffeinate_watcher.m line 58


Signature	`hs.caffeinate.watcher.screensDidWake`
Type	Constant
Description	The displays have woken from sleep
Notes	None
Source	extensions/caffeinate/libcaffeinate_watcher.m line 30


Signature	`hs.caffeinate.watcher.sessionDidBecomeActive`
Type	Constant
Description	The session became active, due to fast user switching
Notes	None
Source	extensions/caffeinate/libcaffeinate_watcher.m line 38


Signature	`hs.caffeinate.watcher.sessionDidResignActive`
Type	Constant
Description	The session is no longer active, due to fast user switching
Notes	None
Source	extensions/caffeinate/libcaffeinate_watcher.m line 34


Signature	`hs.caffeinate.watcher.systemDidWake`
Type	Constant
Description	The system woke from sleep
Notes	None
Source	extensions/caffeinate/libcaffeinate_watcher.m line 14


Signature	`hs.caffeinate.watcher.systemWillPowerOff`
Type	Constant
Description	The user requested a logout or shutdown
Notes	None
Source	extensions/caffeinate/libcaffeinate_watcher.m line 22


Signature	`hs.caffeinate.watcher.systemWillSleep`
Type	Constant
Description	The system is preparing to sleep
Notes	None
Source	extensions/caffeinate/libcaffeinate_watcher.m line 18


Signature	`hs.caffeinate.watcher.new(fn) -> watcher`
Type	Constructor
Description	Creates a watcher object for system and display sleep/wake/power events
Parameters	fn - A function that will be called when system/display events happen. It should accept one parameter:
An event type (see the constants defined above)
Returns	An `hs.caffeinate.watcher` object
Notes	None
Examples	None
Source	extensions/caffeinate/libcaffeinate_watcher.m line 170


Signature	`hs.caffeinate.watcher:start()`
Type	Method
Description	Starts the sleep/wake watcher
Parameters	None
Returns	An `hs.caffeinate.watcher` object
Notes	None
Examples	None
Source	extensions/caffeinate/libcaffeinate_watcher.m line 277


Signature	`hs.caffeinate.watcher:stop()`
Type	Method
Description	Stops the sleep/wake watcher
Parameters	None
Returns	An `hs.caffeinate.watcher` object
Notes	None
Examples	None
Source	extensions/caffeinate/libcaffeinate_watcher.m line 301