# hs.audiodevice.watcher

Watch for system level audio hardware events

# API Overview

Functions - API calls offered directly by the extension

isRunning
setCallback
start
stop

# API Documentation

# Functions

# isRunning


Signature	`hs.audiodevice.watcher.isRunning() -> boolean`
Type	Function
Description	Gets the status of the audio device watcher
Parameters	None
Returns	A boolean, true if the watcher is running, false if not
Notes	None
Examples	None
Source	extensions/audiodevice/libaudiodevice_watcher.m line 198

# setCallback


Signature	`hs.audiodevice.watcher.setCallback(fn)`
Type	Function
Description	Sets the callback function for the audio device watcher
Parameters	fn - A callback function, or nil to remove a previously set callback. The callback function should accept a single argument (see Notes below)
Returns	None
Notes	This watcher will call the callback when various audio device related events occur (e.g. an audio device appears/disappears, a system default audio device setting changes, etc) To watch for changes within an audio device, see `hs.audiodevice:newWatcher()` The callback function argument is a string which may be one of the following strings, but might also be a different string entirely: dIn - Default audio input device setting changed (Note that there is a space character after `dIn`, because these values always have to be four characters long) dOut - Default audio output device setting changed sOut - Default system audio output setting changed (i.e. the device that system sound effects use. This may also be triggered by dOut, depending on the user's settings) dev# - An audio device appeared or disappeared The callback will be called for each individual audio device event received from the OS, so you may receive multiple events for a single physical action (e.g. unplugging the default audio device will cause `dOut` and `dev#` events, and possibly `sOut` too) Passing nil will cause the watcher to stop if it is already running
Examples	None
Source	extensions/audiodevice/libaudiodevice_watcher.m line 77

# start


Signature	`hs.audiodevice.watcher.start()`
Type	Function
Description	Starts the audio device watcher
Parameters	None
Returns	None
Notes	None
Examples	None
Source	extensions/audiodevice/libaudiodevice_watcher.m line 128

# stop


Signature	`hs.audiodevice.watcher.stop() -> hs.audiodevice.watcher`
Type	Function
Description	Stops the audio device watcher
Parameters	None
Returns	The `hs.audiodevice.watcher` object
Notes	None
Examples	None
Source	extensions/audiodevice/libaudiodevice_watcher.m line 166