git-annex/Assistant/Alert/Utility.hs
Joey Hess e426fac273 add desktop notifications
Motivation: Hook scripts for nautilus or other file managers
need to provide the user with feedback that a file is being downloaded.

This commit was sponsored by THM Schoemaker.
2014-03-22 14:12:19 -04:00

130 lines
3.9 KiB
Haskell

{- git-annex assistant alert utilities
-
- Copyright 2012, 2013 Joey Hess <joey@kitenet.net>
-
- Licensed under the GNU GPL version 3 or higher.
-}
module Assistant.Alert.Utility where
import Common.Annex
import Assistant.Types.Alert
import Utility.Tense
import qualified Data.Text as T
import Data.Text (Text)
import qualified Data.Map as M
{- This is as many alerts as it makes sense to display at a time.
- A display might be smaller, or larger, the point is to not overwhelm the
- user with a ton of alerts. -}
displayAlerts :: Int
displayAlerts = 6
{- This is not a hard maximum, but there's no point in keeping a great
- many filler alerts in an AlertMap, so when there's more than this many,
- they start being pruned, down toward displayAlerts. -}
maxAlerts :: Int
maxAlerts = displayAlerts * 2
type AlertPair = (AlertId, Alert)
{- The desired order is the reverse of:
-
- - Pinned alerts
- - High priority alerts, newest first
- - Medium priority Activity, newest first (mostly used for Activity)
- - Low priority alerts, newest first
- - Filler priorty alerts, newest first
- - Ties are broken by the AlertClass, with Errors etc coming first.
-}
compareAlertPairs :: AlertPair -> AlertPair -> Ordering
compareAlertPairs
(aid, Alert { alertClass = aclass, alertPriority = aprio })
(bid, Alert { alertClass = bclass, alertPriority = bprio })
= compare aprio bprio
`mappend` compare aid bid
`mappend` compare aclass bclass
sortAlertPairs :: [AlertPair] -> [AlertPair]
sortAlertPairs = sortBy compareAlertPairs
{- Renders an alert's header for display, if it has one. -}
renderAlertHeader :: Alert -> Maybe Text
renderAlertHeader alert = renderTense (alertTense alert) <$> alertHeader alert
{- Renders an alert's message for display. -}
renderAlertMessage :: Alert -> Text
renderAlertMessage alert = renderTense (alertTense alert) $
(alertMessageRender alert) alert
showAlert :: Alert -> String
showAlert alert = T.unpack $ T.unwords $ catMaybes
[ renderAlertHeader alert
, Just $ renderAlertMessage alert
]
alertTense :: Alert -> Tense
alertTense alert
| alertClass alert == Activity = Present
| otherwise = Past
{- Checks if two alerts display the same. -}
effectivelySameAlert :: Alert -> Alert -> Bool
effectivelySameAlert x y = all id
[ alertClass x == alertClass y
, alertHeader x == alertHeader y
, alertData x == alertData y
, alertBlockDisplay x == alertBlockDisplay y
, alertClosable x == alertClosable y
, alertPriority x == alertPriority y
]
makeAlertFiller :: Bool -> Alert -> Alert
makeAlertFiller success alert
| isFiller alert = alert
| otherwise = alert
{ alertClass = if c == Activity then c' else c
, alertPriority = Filler
, alertClosable = True
, alertButtons = []
, alertIcon = Just $ if success then SuccessIcon else ErrorIcon
}
where
c = alertClass alert
c'
| success = Success
| otherwise = Error
isFiller :: Alert -> Bool
isFiller alert = alertPriority alert == Filler
{- Updates the Alertmap, adding or updating an alert.
-
- Any old filler that looks the same as the alert is removed.
-
- Or, if the alert has an alertCombiner that combines it with
- an old alert, the old alert is replaced with the result, and the
- alert is removed.
-
- Old filler alerts are pruned once maxAlerts is reached.
-}
mergeAlert :: AlertId -> Alert -> AlertMap -> AlertMap
mergeAlert i al m = maybe updatePrune updateCombine (alertCombiner al)
where
pruneSame k al' = k == i || not (effectivelySameAlert al al')
pruneBloat m'
| bloat > 0 = M.fromList $ pruneold $ M.toList m'
| otherwise = m'
where
bloat = M.size m' - maxAlerts
pruneold l =
let (f, rest) = partition (\(_, a) -> isFiller a) l
in drop bloat f ++ rest
updatePrune = pruneBloat $ M.filterWithKey pruneSame $
M.insertWith' const i al m
updateCombine combiner =
let combined = M.mapMaybe (combiner al) m
in if M.null combined
then updatePrune
else M.delete i $ M.union combined m