# hs.redshift

Inverts and/or lowers the color temperature of the screen(s) on a schedule, for a more pleasant experience at night

Usage:

-- make a windowfilterDisable for redshift: VLC, Photos and screensaver/login window will disable color adjustment and inversion
local wfRedshift=hs.window.filter.new({VLC={focused=true},Photos={focused=true},loginwindow={visible=true,allowRoles='*'}},'wf-redshift')
-- start redshift: 2800K + inverted from 21 to 7, very long transition duration (19->23 and 5->9)
hs.redshift.start(2800,'21:00','7:00','4h',true,wfRedshift)
-- allow manual control of inverted colors
hs.hotkey.bind(HYPER,'f1','Invert',hs.redshift.toggleInvert)

Note:

As of macOS 10.12.4, Apple provides "Night Shift", which implements a simple red-shift effect, as part of the OS. It seems unlikely that hs.redshift will see significant future development.

# API Overview

Variables - Configurable values

COLORRAMP

Functions - API calls offered directly by the extension

invertSubscribe
invertUnsubscribe
isInverted
requestInvert
start
stop
toggle
toggleInvert

# API Documentation

# Variables

# COLORRAMP


Signature	`hs.redshift.COLORRAMP`
Type	Variable
Description	A table holding the gamma values for given color temperatures; each key must be a color temperature number in K (useful values are between
Notes	`hs.inspect(hs.redshift.COLORRAMP)` from the console will show you how the table is built the default ramp has entries from 1000K to 10000K every 100K
Source	extensions/redshift/redshift.lua line 342

# Functions

# invertSubscribe


Signature	`hs.redshift.invertSubscribe([id,]fn)`
Type	Function
Description	Subscribes a callback to be notified when the color inversion status changes
Parameters	id - (optional) a string identifying the requester (usually the module name); if omitted, `fn` itself will be the identifier; this identifier must be passed to `hs.redshift.invertUnsubscribe()` fn - a function that will be called whenever color inversion status changes; it must accept a single parameter, a string or false as per the return value of `hs.redshift.isInverted()`
Returns	None
Notes	You can use this to dynamically adjust the UI colors in your modules or configuration, if appropriate.
Examples	None
Source	extensions/redshift/redshift.lua line 107

# invertUnsubscribe


Signature	`hs.redshift.invertUnsubscribe(id)`
Type	Function
Description	Unsubscribes a previously subscribed color inversion change callback
Parameters	id - a string identifying the requester or the callback function itself, depending on how you called `hs.redshift.invertSubscribe()`
Returns	None
Notes	None
Examples	None
Source	extensions/redshift/redshift.lua line 128

# isInverted


Signature	`hs.redshift.isInverted() -> string or false`
Type	Function
Description	Checks if the colors are currently inverted
Parameters	None
Returns	false if the colors are not currently inverted; otherwise, a string indicating the reason, one of: "user" for the user override (see `hs.redshift.toggleInvert()`) "redshift-night" if `hs.redshift.start()` was called with `invertAtNight` set to true, and it's currently night time the ID string (usually the module name) provided to `hs.redshift.requestInvert()`, if another module requested color inversion
Notes	None
Examples	None
Source	extensions/redshift/redshift.lua line 144

# requestInvert


Signature	`hs.redshift.requestInvert(id,v)`
Type	Function
Description	Sets or clears a request for color inversion
Parameters	id - a string identifying the requester (usually the module name) v - a boolean indicating whether to invert the colors (if true) or clear any previous requests (if false or nil)
Returns	None
Notes	you can use this function e.g. to automatically invert colors if the ambient light sensor reading drops below a certain threshold (`hs.brightness.DDCauto()` can optionally do exactly that) if the user's configuration doesn't explicitly start the redshift module, calling this will have no effect
Examples	None
Source	extensions/redshift/redshift.lua line 161

# start


Signature	`hs.redshift.start(colorTemp,nightStart,nightEnd[,transition[,invertAtNight[,windowfilterDisable[,dayColorTemp]]]])`
Type	Function
Description	Sets the schedule and (re)starts the module
Parameters	colorTemp - a number indicating the desired color temperature (Kelvin) during the night cycle; the recommended range is between 3600K and 1400K; lower values (minimum 1000K) result in a more pronounced adjustment nightStart - a string in the format "HH:MM" (24-hour clock) or number of seconds after midnight (see `hs.timer.seconds()`) indicating when the night cycle should start nightEnd - a string in the format "HH:MM" (24-hour clock) or number of seconds after midnight (see `hs.timer.seconds()`) indicating when the night cycle should end transition - (optional) a string or number of seconds (see `hs.timer.seconds()`) indicating the duration of the transition to the night color temperature and back; if omitted, defaults to 1 hour invertAtNight - (optional) a boolean indicating whether the colors should be inverted (in addition to the color temperature shift) during the night; if omitted, defaults to false windowfilterDisable - (optional) an `hs.window.filter` instance that will disable color adjustment (and color inversion) whenever any window is allowed; alternatively, you can just provide a list of application names (typically media apps and/or apps for color-sensitive work) and a windowfilter will be created for you that disables color adjustment whenever one of these apps is focused dayColorTemp - (optional) a number indicating the desired color temperature (in Kelvin) during the day cycle; you can use this to maintain some degree of "redshift" during the day as well, or, if desired, you can specify a value higher than 6500K (up to 10000K) for more bluish colors, although that's not recommended; if omitted, defaults to 6500K, which disables color adjustment and restores your screens' original color profiles
Returns	None
Notes	None
Examples	None
Source	extensions/redshift/redshift.lua line 273

# stop


Signature	`hs.redshift.stop()`
Type	Function
Description	Stops the module and disables color adjustment and color inversion
Parameters	None
Returns	None
Notes	None
Examples	None
Source	extensions/redshift/redshift.lua line 243

# toggle


Signature	`hs.redshift.toggle([v])`
Type	Function
Description	Sets or clears the user override for color temperature adjustment.
Parameters	v - (optional) a boolean; if true, the override will enable color temperature adjustment on the given schedule; if false, the override will disable color temperature adjustment; if omitted or nil, it will toggle the override, i.e. clear it if it's currently enforced, or set it to the opposite of the current color temperature adjustment status otherwise.
Returns	None
Notes	This function should be bound to a hotkey, e.g.: `hs.hotkey.bind('ctrl-cmd','-','Redshift',hs.redshift.toggle)`
Examples	None
Source	extensions/redshift/redshift.lua line 218

# toggleInvert


Signature	`hs.redshift.toggleInvert([v])`
Type	Function
Description	Sets or clears the user override for color inversion.
Parameters	v - (optional) a boolean; if true, the override will invert the colors no matter what; if false, the override will disable color inversion no matter what; if omitted or nil, it will toggle the override, i.e. clear it if it's currently enforced, or set it to the opposite of the current color inversion status otherwise.
Returns	None
Notes	This function should be bound to a hotkey, e.g.: `hs.hotkey.bind('ctrl-cmd','=','Invert',hs.redshift.toggleInvert)`
Examples	None
Source	extensions/redshift/redshift.lua line 195