watcher

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Watch for application launch/terminate events
This module is based primarily on code from the previous incarnation of Mjolnir by Markus Engelbrecht and Steven Degutis.
API Overview
Constants - Useful values which cannot be changed
​activated​
​deactivated​
​hidden​
​launched​
​launching​
​terminated​
​unhidden​
Constructors - API calls which return an object, typically one that offers API methods
​new​
Methods - API calls which can only be made on an object returned by a constructor
​start​
​stop​
API Documentation
Constants
​activated​
Signature
hs.application.watcher.activated
Type
Constant
Description
An application has been activated (i.e. given keyboard/mouse focus)
​deactivated​
Signature
hs.application.watcher.deactivated
Type
Constant
Description
An application has been deactivated (i.e. lost keyboard/mouse focus)
​hidden​
Signature
hs.application.watcher.hidden
Type
Constant
Description
An application has been hidden
​launched​
Signature
hs.application.watcher.launched
Type
Constant
Description
An application has been launched
​launching​
Signature
hs.application.watcher.launching
Type
Constant
Description
An application is in the process of being launched
​terminated​
Signature
hs.application.watcher.terminated
Type
Constant
Description
An application has been terminated
​unhidden​
Signature
hs.application.watcher.unhidden
Type
Constant
Description
An application has been unhidden
Constructors
​new​
Signature
hs.application.watcher.new(fn) -> watcher
Type
Constructor
Description
Creates an application event watcher
Parameters
fn - A function that will be called when application events happen. It should accept three parameters:
A string containing the name of the application
An event type (see the constants defined above)
An hs.application object representing the application, or nil if the application couldn't be found
Returns
An hs.application.watcher object
Notes
If the function is called with an event type of hs.application.watcher.terminated then the application name parameter will be nil and the hs.application parameter, will only be useful for getting the UNIX process ID (i.e. the PID) of the application
Methods
​start​
Signature
hs.application.watcher:start()
Type
Method
Description
Starts the application watcher
Parameters
None
Returns
The hs.application.watcher object
​stop​
Signature
hs.application.watcher:stop()
Type
Method
Description
Stops the application watcher
Parameters
None
Returns
The hs.application.watcher object