Add multi-window support

Previously Alacritty would always initialize only a single terminal
emulator window feeding into the winit event loop, however some
platforms like macOS expect all windows to be spawned by the same
process and this "daemon-mode" can also come with the advantage of
increased memory efficiency.

The event loop has been restructured to handle all window-specific
events only by the event processing context with the associated window
id. This makes it possible to add new terminal windows at any time using
the WindowContext::new function call.

Some preliminary tests have shown that for empty terminals, this reduces
the cost of additional terminal emulators from ~100M to ~6M. However at
this point the robustness of the daemon against issues with individual
terminals has not been refined, making the reliability of this system
questionable.

New windows can be created either by using the new `CreateNewWindow`
action, or with the `alacritty msg create-window` subcommand. The
subcommand sends a message to an IPC socket which Alacritty listens on,
its location can be found in the `ALACRITTY_SOCKET` environment
variable.

Fixes #607.

1 files changed, 46 insertions, 16 deletions

diff --git a/extra/completions/alacritty.fish b/extra/completions/alacritty.fish
index 6f8da9b0..fa399ffb 100644
--- a/extra/completions/alacritty.fish
+++ b/extra/completions/alacritty.fish
@@ -1,74 +1,104 @@
+# Available subcommands
+set -l commands msg help
+
+complete -c alacritty \
+  -n "not __fish_seen_subcommand_from $commands" \
+  -a "msg help"
+
 # Meta
 complete -c alacritty \
+  -n "not __fish_seen_subcommand_from help" \
   -s "v" \
   -l "version" \
   -d "Prints version information"
 complete -c alacritty \
+  -n "not __fish_seen_subcommand_from help" \
   -s "h" \
   -l "help" \
   -d "Prints help information"
 
 # Config
 complete -c alacritty \
+  -n "not __fish_seen_subcommand_from $commands" \
   -f \
   -l "config-file" \
   -d "Specify an alternative config file"
 complete -c alacritty \
+  -n "not __fish_seen_subcommand_from $commands" \
   -s "t" \
   -l "title" \
   -d "Defines the window title"
 complete -c alacritty \
+  -n "not __fish_seen_subcommand_from $commands" \
   -l "class" \
   -d "Defines the window class"
 complete -c alacritty \
+  -n "not __fish_seen_subcommand_from $commands" \
   -l "embed" \
   -d "Defines the X11 window ID (as a decimal integer) to embed Alacritty within"
 complete -c alacritty \
+  -n "not __fish_seen_subcommand_from $commands" \
   -x \
   -a '(__fish_complete_directories (commandline -ct))' \
   -l "working-directory" \
   -d "Start shell in specified directory"
 complete -c alacritty \
+  -n "not __fish_seen_subcommand_from $commands" \
   -l "hold" \
   -d "Remain open after child process exits"
 complete -c alacritty \
+  -n "not __fish_seen_subcommand_from $commands" \
   -s "o" \
   -l "option" \
   -d "Override config file options"
+complete -c alacritty \
+  -n "not __fish_seen_subcommand_from $commands" \
+  -l "socket" \
+  -d "Path for IPC socket creation"
 
 # Output
-complete \
-  -c alacritty \
+complete -c alacritty \
+  -n "not __fish_seen_subcommand_from $commands" \
   -l "print-events" \
   -d "Print all events to stdout"
-complete \
-  -c alacritty \
+complete -c alacritty \
+  -n "not __fish_seen_subcommand_from $commands" \
   -s "q" \
   -d "Reduces the level of verbosity (min is -qq)"
-complete \
-  -c alacritty \
+complete -c alacritty \
+  -n "not __fish_seen_subcommand_from $commands" \
   -s "qq" \
   -d "Reduces the level of verbosity"
-complete \
-  -c alacritty \
+complete -c alacritty \
+  -n "not __fish_seen_subcommand_from $commands" \
   -s "v" \
   -d "Increases the level of verbosity"
-complete \
-  -c alacritty \
+complete -c alacritty \
+  -n "not __fish_seen_subcommand_from $commands" \
   -s "vv" \
   -d "Increases the level of verbosity"
-complete \
-  -c alacritty \
+complete -c alacritty \
+  -n "not __fish_seen_subcommand_from $commands" \
   -s "vvv" \
   -d "Increases the level of verbosity"
 
-complete \
-  -c alacritty \
+complete -c alacritty \
+  -n "not __fish_seen_subcommand_from $commands" \
   -l "ref-test" \
   -d "Generates ref test"
 
-complete \
-  -c alacritty \
+complete -c alacritty \
+  -n "not __fish_seen_subcommand_from $commands" \
   -s "e" \
   -l "command" \
   -d "Execute command (must be last arg)"
+
+# Subcommand `msg`
+complete -c alacritty \
+  -n "__fish_seen_subcommand_from msg" \
+  -s "s" \
+  -l "socket" \
+  -d "Socket path override"
+complete -c alacritty \
+  -n "__fish_seen_subcommand_from msg" \
+  -a "create-window help"