Implement Tray Icons

This commit implements the StatusNotifierItem protocol, and enables
swaybar to show tray icons. It also uses `xembedsniproxy` in order to
communicate with xembed applications.
The tray is completely optional, and can be disabled on compile time
with the `enable-tray` option. Or on runtime with the bar config option
`tray_output none`.

Overview of changes:
In swaybar very little is changed outside the tray subfolder except
that all events are now polled in `event_loop.c`, this creates no
functional difference.

Six bar configuration options were added, these are detailed in
sway-bar(5)

The tray subfolder is where all protocol implementation takes place and
is organised as follows:

tray/sni_watcher.c:
	This file contains the StatusNotifierWatcher. It keeps track of
	items and hosts and reports when they come or go.
tray/tray.c
	This file contains the StatusNotifierHost. It keeps track of
	sway's version of the items and represents the tray itself.
tray/sni.c
	This file contains the StatusNotifierItem struct and all
	communication with individual items.
tray/icon.c
	This file implements the icon theme protocol. It allows for
	finding icons by name, rather than by pixmap.
tray/dbus.c
	This file allows for asynchronous DBus communication.

See #986 #343

1 files changed, 13 insertions, 0 deletions

diff --git a/CMakeLists.txt b/CMakeLists.txt
index edf486ca..c80f6361 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -47,6 +47,7 @@ option(enable-swaybar "Enables the swaybar utility" YES)
 option(enable-swaygrab "Enables the swaygrab utility" YES)
 option(enable-swaymsg "Enables the swaymsg utility" YES)
 option(enable-gdk-pixbuf "Use Pixbuf to support more image formats" YES)
+option(enable-tray "Enables the swaybar tray" YES)
 option(zsh-completions "Zsh shell completions" NO)
 option(default-wallpaper "Installs the default wallpaper" YES)
 option(LD_LIBRARY_PATH "Configure sway's default LD_LIBRARY_PATH")
@@ -64,6 +65,7 @@ find_package(Cairo REQUIRED)
 find_package(Pango REQUIRED)
 find_package(GdkPixbuf)
 find_package(PAM)
+find_package(DBus)
 
 find_package(LibInput REQUIRED)
 
@@ -90,6 +92,17 @@ else()
 	message(STATUS "Building without gdk-pixbuf, only png images supported.")
 endif()
 
+if (enable-tray)
+	if (DBUS_FOUND)
+		set(ENABLE_TRAY)
+		add_definitions(-DENABLE_TRAY)
+	else()
+		message(WARNING "Tray required but DBus was not found. Tray will not be included")
+	endif()
+else()
+	message(STATUS "Building without the tray.")
+endif()
+
 include_directories(include)
 
 add_subdirectory(protocols)