Add support for setting window icon and title on MacOS

[georgefst]

We need a Mac version of Util.Window (introduced in georgefst/lifx-manager#8)

XQuartz

(I abandoned this as it's all clunkier than expected, even once set up properly. And, crucially, I couldn't get openDisplay to return anything other than null for a Gloss window, probably because Gloss is using an OpenGL that targets Quartz, rather than X11.)

None/little of the below should be necessary:

• See Can't build X11 due to ld linking error on OSX 10.9.2 xmonad/X11#24.
• Cabal is being weird about not propagating lib and include dirs.

nix-shell -p xorg.libX11 -p xorg.libXext -p xorg.libXrender -p xorg.libXrandr -p xorg.libXScrnSaver

#TODO this errors out for some (error: path '/nix/store/m76c8x2qxc42vc9g9gmbi5vh3kqq2lj1-libX11-1.7.0-man' is not valid)
    # so we've hardcoded Church paths below (12/12/21), rather than using e.g. `$X11`
#TODO also for some of these, there are multiple paths
X11=$(nix path-info $(nix-instantiate '<nixpkgs>' -A xorg.libX11))
Xrandr=$(nix path-info $(nix-instantiate '<nixpkgs>' -A xorg.libXrandr))
# ...

rm cabal.project.local
echo '
package X11
    extra-lib-dirs:
        /nix/store/gfipvaizlslshnphk65582pcv2mqqj2v-libX11-1.7.0/lib
        /nix/store/lh8s4vv95dirn11fj89ax2x6w9sqk9d5-libXrandr-1.5.2/lib
        /nix/store/pl0f3wanll5phixlxm011ql1rrzdj2xk-libXScrnSaver-1.2.3/lib
        /nix/store/bpvrd298qm3dvvzclav8hb39394i4c0x-libXext-1.3.4/lib
' > cabal.project.local
CPPFLAGS=" \
    -I/nix/store/kp8lx4z07lhwffr6dr0gz6x7v3cdbi7i-xorgproto-2020.1/include \
    -I/nix/store/5czbg1s55qy00ia03xpjgx2r3h88z21x-libX11-1.7.0-dev/include \
    -I/nix/store/731lhdqg9vs44ikzhl3kwg44zz808pdd-libXrandr-1.5.2-dev/include \
    -I/nix/store/gq4v0d7wvbzqxm28zjf8ci26m463x1lm-libXrender-0.9.10-dev/include \
    -I/nix/store/pl0f3wanll5phixlxm011ql1rrzdj2xk-libXScrnSaver-1.2.3/include \
    " \
LDFLAGS=" \
    -L/nix/store/gfipvaizlslshnphk65582pcv2mqqj2v-libX11-1.7.0/lib \
    -L/nix/store/lh8s4vv95dirn11fj89ax2x6w9sqk9d5-libXrandr-1.5.2/lib \
    -L/nix/store/pl0f3wanll5phixlxm011ql1rrzdj2xk-libXScrnSaver-1.2.3/lib \
    -L/nix/store/bpvrd298qm3dvvzclav8hb39394i4c0x-libXext-1.3.4/lib \
    " \
cabb

Quartz API via macos-corelibs ^>= 0.0.1.0

This library is unmaintained and the API messy (plus no Hackage docs), but it actually seems pretty solid. I sense the author really knows what they're doing, and has thought through a lot of the hard problems involved in building a Haskell wrapper for Quartz. Unfortunately, it seems that Quartz doesn't allow for arbitrarily setting window title and icon like X11 and Win32 do. Very possibly for security reasons (it actually surprises me a little that the other two are so cavalier). I only realised this restriction after spending a few hours fiddling, and writing the exploratory code below.

{-# OPTIONS_GHC -Wno-unused-top-binds #-}

module Util.Window.Quartz (
    Window,
    findByName,
    setTitle,
    setIcon,
) where

import Data.ByteString (ByteString)
import Data.Text (Text)

import MacSdk

test = do
    Just widsArray <- windowListCopyWindowInfo [] Nothing
    wids <- arrayValues $ getDictionary <$> widsArray
    traverse mkWID wids

data WID = WID
    { kCGWindowNumber :: Int
    , kCGWindowStoreType :: Int
    , kCGWindowLayer :: Int
    -- , kCGWindowBounds :: Dictionary
    , kCGWindowSharingState :: Int
    -- , kCGWindowAlpha :: Float
    , kCGWindowOwnerPID :: Int
    , kCGWindowMemoryUsage :: Int
    , kCGWindowOwnerName :: Maybe String
    , kCGWindowName :: Maybe String
    , kCGWindowIsOnscreen :: Maybe Bool
    , kCGWindowBackingLocationVideoMemory :: Maybe Bool
    }
    deriving (Show)

-- mkWID :: WindowInfoDictionary -> IO WID
-- mkWID (getDictionary -> wid) = do
mkWID :: Dictionary -> IO WID
mkWID wid = do
    kCGWindowNumber <- int =<< dictLookup "kCGWindowNumber"
    kCGWindowStoreType <- int =<< dictLookup "kCGWindowStoreType"
    kCGWindowLayer <- int =<< dictLookup "kCGWindowLayer"
    -- kCGWindowBounds <- fromString CFStringEncodingUTF8 "kCGWindowBounds"
    kCGWindowSharingState <- int =<< dictLookup "kCGWindowSharingState"
    -- kCGWindowAlpha <- float =<< dictLookup "kCGWindowAlpha"
    kCGWindowOwnerPID <- int =<< dictLookup "kCGWindowOwnerPID"
    kCGWindowMemoryUsage <- int =<< dictLookup "kCGWindowMemoryUsage"
    kCGWindowOwnerName <- traverse string =<< dictLookup' "kCGWindowOwnerName"
    kCGWindowName <- traverse string =<< dictLookup' "kCGWindowName"
    kCGWindowIsOnscreen <- traverse bool =<< dictLookup' "kCGWindowIsOnscreen"
    kCGWindowBackingLocationVideoMemory <- traverse bool =<< dictLookup' "kCGWindowBackingLocationVideoMemory"
    pure $ WID{..}
  where
    dictLookup s = getDictValue wid =<< fromString CFStringEncodingUTF8 s
    dictLookup' s = do
        s' <- fromString CFStringEncodingUTF8 s
        withCFPtr s' $ getDictValueSafe wid
    int x = do
        Just n <- numberGetValue x NumberIntType
        pure $ fromIntegral n
    string s = do
        Just r <- toString CFStringEncodingUTF8 s
        pure r
    bool x = withCFPtr x refToBool

data Window = Window
    deriving (Eq, Ord)

findByName ::
    -- | substring which must appear in the window title
    Text ->
    IO Window
findByName name = do
    undefined

setTitle :: Window -> Text -> IO ()
setTitle (Window) t = do
    undefined

setIcon ::
    Window ->
    -- | PNG image
    ByteString ->
    IO ()
setIcon (Window) img = do
    undefined

AppKit?

I don't know much about it, but it looks like this may be the way.

• How easy is it to bind Haskell to Objective-C? I think it uses the C calling convention.
• I should check this will work (and that Quartz API is a dead end) by asking at e.g. https://www.reddit.com/r/MacOS/ (or r/macosprogramming).
• See e.g. https://developer.apple.com/documentation/appkit/nsdocktile.

[georgefst]

The complexity of this is another reason why I don't really like this library, and feel it may be better to just use proper packaging where possible. See #2 (comment).