i3-session-manager/main.go

package main

import (
	// Standard
	"fmt"
	"net"
	"os"
	"strings"
	"time"
)

var (
	session I3Session
	sessionSubscription I3Session
	workspaces []I3Workspace
	outputIndices map[string]int
	subscriptions []string
)

func init() {
	outputIndices = make(map[string]int)
	subscriptions = []string{
		"binding",
		"shutdown",
	}

	workspaces = []I3Workspace{
		{ Num: 0, Name: "Development" },
		{ Num: 1, Name: "Terminal" },
		{ Num: 2, Name: "Browser" },
		{ Num: 3, Name: "Communication" },
		{ Num: 4, Name: "Multimedia" },
		{ Num: 5, Name: "Graphics" },
		{ Num: 6, Name: "SQL" },
		{ Num: 7, Name: "Debug" },
		{ Num: 8, Name: "Email" },
		{ Num: 9, Name: "Virtualization" },
	}
}

func main() {
	var err error

	go SessionLoop()

	// Socket server reading commands and acting upon them
	var listener net.Listener
	listener, err = net.Listen("unix", "/tmp/i3-session.sock")
	if err != nil {
		fmt.Printf("Socket listener: %s\n", err)
		os.Exit(1)
	}

	// Listen for external commands
	var conn net.Conn
	var n int
	for {
		conn, err = listener.Accept()
		if err != nil {
			fmt.Printf("Connection accept: %s\n", err)
		}
		buf := make([]byte, 1024)
		n, err = conn.Read(buf)
		if err != nil {
			fmt.Printf("Connection read: %s\n", err)
		}

		cmd := strings.TrimSpace(string(buf[:n]))
		switch(cmd) {
		case "fix workspaces":
			err = session.FixWorkspaces()
			if err != nil {
				fmt.Printf("Fix workspaces: %s\n", err)
			}

			conn.Close()
		}
	}
}

func SessionLoop() {
	var err error
	for {
		fmt.Printf("-------- SessionLoop --------\n")

		// session is used for interactively communicating with i3,
		// like getting workspace and output data.
		if err = session.Open(); err != nil {
			fmt.Printf("%s\n", err)
			continue
		}

		// sessionSubscription is used for listening to subscribed
		// events from i3.
		if err = sessionSubscription.Open(); err != nil {
			fmt.Printf("%s\n", err)
			continue
		}

		// i3-session-manager reacts to keybindings and i3 restarts.
		sessionSubscription.Subscribe(subscriptions)

		// Find outputs and assign an index to them
		err = session.UpdateOutputIndices()
		if err != nil {
			fmt.Printf("Output error: %s\n", err)
			os.Exit(1)
		}


		/* Loop will return on socket errors, for example when an i3
		 * restart occurs. The socket will not be immediately available
		 * then. Some connection errors can thus occur until i3 has
		 * initialized the socket again. */
		err = sessionSubscription.Loop()
		fmt.Printf("Loop error: %s\n", err)
		time.Sleep(time.Millisecond*100)
	}
}