enhance window switch debugging

README.md

@@ -5,12 +5,16 @@ floating  ones or  windows  in sub-containers.   So  it simulates  the
 behavior of other window managers  and desktop environments. Just bind
 the tool to `ALT-tab` and there you go.
 
-![Screenshot](https://github.com/TLINDEN/swaycycle/blob/main/.github/assets/screenshot.png)
 
 ## Installation
 
-Checkout the repo and execute `make`. You'll need the go toolkit. Then
+Download  the   binary  for   your  architecture  from   the  [release
-copy the binary `swaycycle` to some location within your `$PATH`.
+page](https://github.com/TLINDEN/swaycycle/releases) and copy to
+some location within your `$PATH`.
+
+To  build  the  tool  from  source,  checkout  the  repo  and  execute
+`make`. You'll need  the go toolkit. Then copy  the binary `swaycycle`
+to some location within your `$PATH`.
 
 ## Configuration
 
@@ -35,6 +39,29 @@ It's also possible to debug an instance executed by sway using the
 bindsym $mod+Tab exec ~/bin/swaycycle -d -l /tmp/cycle.log
 ```
 
+## How does it work?
+
+`swaycycle` is being executed by sway when the user presses a key
+(e.g. `ALT-tab`). It then connects to the running sway instance via
+the provided IPC unix domain socket as available in the environment
+variable `SWAYSOCK`. Via that connection it sends the `GET_TREE`
+command and processes the retrieved JSON response. This JSON tree
+contains all information about the running instance such as outputs,
+workspaces and containers.
+
+Then it determines which workspace is the current active one and
+builds a list of all windows visible on that workspace, whether
+floating or not.
+
+Next it determines which window is following the one in the list with
+the current active focus. If the active one is at the end of the list,
+it starts from the top.
+
+Finally `swaycycle` sends the propper switch focus command via the IPC
+connection to sway, e.g.:
+
+`[con_id=14] focus`
+
 ## Getting help
 
 Although I'm happy to hear from swaycycle users in private email, that's the
@@ -44,6 +71,12 @@ In order to report a bug,  unexpected behavior, feature requests or to
 submit    a    patch,    please    open   an    issue    on    github:
 https://github.com/tlinden/swaycycle/issues.
 
+## See also
+
+- [sway-ipc(7)](https://www.mankier.com/7/sway-ipc)
+- [swaywm](https://github.com/swaywm/sway/)
+- [swayfx](https://github.com/WillPower3309/swayfx)
+
 ## Copyright and license
 
 This software is licensed under the GNU GENERAL PUBLIC LICENSE version 3.

go.mod

@@ -9,6 +9,7 @@ require (
 	github.com/mattn/go-colorable v0.1.13 // indirect
 	github.com/mattn/go-isatty v0.0.20 // indirect
 	github.com/spf13/pflag v1.0.7 // indirect
+	github.com/tlinden/i3ipc v0.0.0-20250815101608-4f7e27528be3 // indirect
 	github.com/tlinden/yadu v0.1.3 // indirect
 	golang.org/x/sys v0.14.0 // indirect
 	gopkg.in/yaml.v3 v3.0.1 // indirect

go.sum

@@ -11,6 +11,8 @@ github.com/mattn/go-isatty v0.0.20 h1:xfD0iDuEKnDkl03q4limB+vH+GxLEtL/jb4xVJSWWE
 github.com/mattn/go-isatty v0.0.20/go.mod h1:W+V8PltTTMOvKvAeJH7IuucS94S2C6jfK/D7dTCTo3Y=
 github.com/spf13/pflag v1.0.7 h1:vN6T9TfwStFPFM5XzjsvmzZkLuaLX+HS+0SeFLRgU6M=
 github.com/spf13/pflag v1.0.7/go.mod h1:McXfInJRrz4CZXVZOBLb0bTZqETkiAhM9Iw0y3An2Bg=
+github.com/tlinden/i3ipc v0.0.0-20250815101608-4f7e27528be3 h1:/kIZO4852sAVemXtqnsBid0r4Q1h87jDwHa8f7v1h5I=
+github.com/tlinden/i3ipc v0.0.0-20250815101608-4f7e27528be3/go.mod h1:mc0toDHmgqgX6FpE69U5yMPnHuLTdekHRslSLDp8xSE=
 github.com/tlinden/yadu v0.1.3 h1:5cRCUmj+l5yvlM2irtpFBIJwVV2DPEgYSaWvF19FtcY=
 github.com/tlinden/yadu v0.1.3/go.mod h1:l3bRmHKL9zGAR6pnBHY2HRPxBecf7L74BoBgOOpTcUA=
 golang.org/x/sys v0.0.0-20220811171246-fbc7d0a398ab/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=

main.go

@@ -18,35 +18,21 @@ along with this program. If not, see <http://www.gnu.org/licenses/>.
 package main
 
 import (
-	"bytes"
-	"encoding/json"
 	"fmt"
 	"io"
 	"log"
 	"log/slog"
 	"os"
-	"os/exec"
 	"runtime/debug"
 
 	"github.com/lmittmann/tint"
 	"github.com/mattn/go-isatty"
+	"github.com/tlinden/i3ipc"
 	"github.com/tlinden/yadu"
 
 	flag "github.com/spf13/pflag"
 )
 
-type Node struct {
-	Id                int    `json:"id"`
-	Nodetype          string `json:"type"` // output, workspace or container
-	Name              string `json:"name"` // workspace number or app name
-	Nodes             []Node `json:"nodes"`
-	FloatingNodes     []Node `json:"floating_nodes"`
-	Focused           bool   `json:"focused"`
-	Window            int    `json:"window"` // wayland native
-	X11Window         string `json:"app_id"` // x11 compat
-	Current_workspace string `json:"current_workspace"`
-}
-
 const (
 	root = iota + 1
 	output
@@ -56,14 +42,22 @@ const (
 
 	LevelNotice = slog.Level(2)
 
-	VERSION = "v0.1.3"
+	VERSION = "v0.3.0"
+
+	IPC_HEADER_SIZE = 14
+	IPC_MAGIC       = "i3-ipc"
+
+	// message types
+	IPC_GET_TREE    = 4
+	IPC_RUN_COMMAND = 0
 )
 
 var (
-	Visibles         = []Node{}
+	Visibles         = []*i3ipc.Node{}
 	CurrentWorkspace = ""
 	Debug            = false
 	Dumptree         = false
+	Dumpvisibles     = false
 	Version          = false
 	Verbose          = false
 	Notswitch        = false
@@ -73,15 +67,15 @@ var (
 
 const Usage string = `This is swaycycle - cycle focus through all visible windows on a sway workspace.
 
-Usage: swaycycle [-vVdDn] [-l <log>]
+Usage: swaycycle [-vdDn] [-l <log>]
 
 Options:
   -n, --no-switch        do not switch windows
   -d, --debug            enable debugging
   -D, --dump             dump the sway tree (needs -d as well)
+      --dump-visibles    dump a list of visible windows on current workspace (needs -d)
   -l, --logfile string   write output to logfile
-  -v, --verbose          enable verbose logging
+  -v, --version          show program version
-  -V, --version          show program version
 
 Copyleft (L) 2025 Thomas von Dein.
 Licensed under the terms of the GNU GPL version 3.
@@ -90,9 +84,9 @@ Licensed under the terms of the GNU GPL version 3.
 func main() {
 	flag.BoolVarP(&Debug, "debug", "d", false, "enable debugging")
 	flag.BoolVarP(&Dumptree, "dump", "D", false, "dump the sway tree (needs -d as well)")
-	flag.BoolVarP(&Verbose, "verbose", "v", false, "enable verbose logging")
+	flag.BoolVarP(&Dumpvisibles, "dump-visibles", "", false, "dump a list of visible windows on current workspace (needs -d)")
 	flag.BoolVarP(&Notswitch, "no-switch", "n", false, "do not switch windows")
-	flag.BoolVarP(&Version, "version", "V", false, "show program version")
+	flag.BoolVarP(&Version, "version", "v", false, "show program version")
 	flag.BoolVarP(&Showhelp, "help", "h", Showhelp, "show help")
 
 	flag.StringVarP(&Logfile, "logfile", "l", "", "write output to logfile")
@@ -120,60 +114,62 @@ func main() {
 		setupLogging(os.Stdout)
 	}
 
-	// fills Visibles node list
+	// connect to sway unix socket
-	fetchSwayTree()
+	ipc := i3ipc.NewI3ipc()
+
+	err := ipc.Connect()
+	if err != nil {
+		log.Fatal(err)
+	}
+	defer ipc.Close()
+
+	sway, err := ipc.GetTree()
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	// traverse the tree and find visible windows
+	if err := processJSON(sway); err != nil {
+		log.Fatalf("%s", err)
+	}
 
 	if len(Visibles) == 0 {
 		os.Exit(0)
 	}
 
 	id := findNextWindow()
+	slog.Debug("findNextWindow", "nextid", id)
 
 	if id > 0 && !Notswitch {
-		switchFocus(id)
+		switchFocus(id, ipc)
 	}
 }
 
-func setupLogging(output io.Writer) {
+// get into the sway tree, determine current workspace and extract all
-	logLevel := &slog.LevelVar{}
+// its visible windows, store them in the global var Visibles
-
+func processJSON(sway *i3ipc.Node) error {
-	if !Debug {
+	if !istype(sway, root) && len(sway.Nodes) == 0 {
-		// default logging
+		return fmt.Errorf("Invalid or empty JSON structure")
-		opts := &tint.Options{
-			Level:     logLevel,
-			AddSource: false,
-			NoColor:   IsNoTty(),
-		}
-
-		if Verbose {
-			logLevel.Set(slog.LevelInfo)
-		} else {
-			logLevel.Set(LevelNotice)
-		}
-
-		handler := tint.NewHandler(output, opts)
-		logger := slog.New(handler)
-
-		slog.SetDefault(logger)
-	} else {
-		// we're using a more verbose logger in debug mode
-		buildInfo, _ := debug.ReadBuildInfo()
-		opts := &yadu.Options{
-			Level:     logLevel,
-			AddSource: true,
-		}
-
-		logLevel.Set(slog.LevelDebug)
-
-		handler := yadu.NewHandler(output, opts)
-		debuglogger := slog.New(handler).With(
-			slog.Group("program_info",
-				slog.Int("pid", os.Getpid()),
-				slog.String("go_version", buildInfo.GoVersion),
-			),
-		)
-		slog.SetDefault(debuglogger)
 	}
+
+	if Dumptree {
+		slog.Debug("processed sway tree", "sway", sway)
+	}
+
+	for _, node := range sway.Nodes {
+		if node.Current_workspace != "" {
+			// this is an output node containing the current workspace
+			CurrentWorkspace = node.Current_workspace
+			recurseNodes(node.Nodes)
+			break
+		}
+	}
+
+	if Dumpvisibles {
+		dumpVisibles()
+	}
+
+	return nil
 }
 
 // find the next window after the  one with current focus. if the last
@@ -204,107 +200,20 @@ func findNextWindow() int {
 }
 
 // actually switch focus using a swaymsg command
-func switchFocus(id int) {
+func switchFocus(id int, ipc *i3ipc.I3ipc) error {
-	var cmd *exec.Cmd
+	responses, err := ipc.RunContainerCommand(id, "focus")
-	arg := fmt.Sprintf("[con_id=%d]", id)
-
-	slog.Debug("executing", "command", "swaymsg "+arg+" focus")
-
-	cmd = exec.Command("swaymsg", arg, "focus")
-
-	errbuf := &bytes.Buffer{}
-	cmd.Stderr = errbuf
-
-	out, err := cmd.Output()
-
 	if err != nil {
-		slog.Debug("failed to execute swaymsg", "output", out)
+		log.Fatalf("failed to send focus command to container %d: %w (%s)",
-		log.Fatalf("Failed to execute swaymsg to switch focus: %s", err)
+			id, responses[0].Error, err)
-	}
-
-	if errbuf.String() != "" {
-		log.Fatalf("swaymsg error: %s", errbuf.String())
 	}
 
 	slog.Info("switched focus", "con_id", id)
-}
-
-// execute swaymsg to get its internal tree
-func fetchSwayTree() {
-	var cmd *exec.Cmd
-
-	slog.Debug("executing", "command", "swaymsg -t get_tree -r")
-
-	cmd = exec.Command("swaymsg", "-t", "get_tree", "-r")
-
-	errbuf := &bytes.Buffer{}
-	cmd.Stderr = errbuf
-
-	out, err := cmd.Output()
-
-	if err != nil {
-		log.Fatalf("Failed to execute swaymsg to get json tree: %s", err)
-	}
-
-	if errbuf.String() != "" {
-		log.Fatalf("swaymsg error: %s", errbuf.String())
-	}
-
-	if err := processJSON(out); err != nil {
-		log.Fatalf("%s", err)
-	}
-}
-
-func istype(nd Node, which int) bool {
-	switch nd.Nodetype {
-	case "root":
-		return which == root
-	case "output":
-		return which == output
-	case "workspace":
-		return which == workspace
-	case "con":
-		return which == con
-	case "floating_con":
-		return which == floating
-	}
-
-	return false
-}
-
-// get into the sway tree, determine current workspace and extract all
-// its visible windows, store them in the global var Visibles
-func processJSON(jsoncode []byte) error {
-	sway := Node{}
-
-	if err := json.Unmarshal(jsoncode, &sway); err != nil {
-		return fmt.Errorf("Failed to unmarshal json: %w", err)
-	}
-
-	if !istype(sway, root) && len(sway.Nodes) == 0 {
-		return fmt.Errorf("Invalid or empty JSON structure")
-	}
-
-	if Dumptree {
-		slog.Debug("processed sway tree", "sway", sway)
-	}
-
-	for _, node := range sway.Nodes {
-		if node.Current_workspace != "" {
-			// this is an output node containing the current workspace
-			CurrentWorkspace = node.Current_workspace
-			recurseNodes(node.Nodes)
-			break
-		}
-	}
-
-	slog.Debug("processed visible windows", "visibles", Visibles)
 
 	return nil
 }
 
 // iterate recursively over given node list extracting visible windows
-func recurseNodes(nodes []Node) {
+func recurseNodes(nodes []*i3ipc.Node) {
 	for _, node := range nodes {
 		// we handle nodes and floating_nodes identical
 		node.Nodes = append(node.Nodes, node.FloatingNodes...)
@@ -330,6 +239,74 @@ func recurseNodes(nodes []Node) {
 	}
 }
 
+func dumpVisibles() {
+	windows := make([]string, len(Visibles))
+
+	for idx, node := range Visibles {
+		windows[idx] = fmt.Sprintf("id: %02d, focus: %5t, name: %s", node.Id, node.Focused, node.Name)
+	}
+
+	slog.Debug("visible windows on current workspace", "visibles", windows)
+}
+
+// we use line wise logging, unless debugging is enabled
+func setupLogging(output io.Writer) {
+	logLevel := &slog.LevelVar{}
+
+	if !Debug {
+		// default logging
+		opts := &tint.Options{
+			Level:     logLevel,
+			AddSource: false,
+			NoColor:   IsNoTty(),
+		}
+
+		logLevel.Set(slog.LevelInfo)
+
+		handler := tint.NewHandler(output, opts)
+		logger := slog.New(handler)
+
+		slog.SetDefault(logger)
+	} else {
+		// we're using a more verbose logger in debug mode
+		buildInfo, _ := debug.ReadBuildInfo()
+		opts := &yadu.Options{
+			Level:     logLevel,
+			AddSource: true,
+		}
+
+		logLevel.Set(slog.LevelDebug)
+
+		handler := yadu.NewHandler(output, opts)
+		debuglogger := slog.New(handler).With(
+			slog.Group("program_info",
+				slog.Int("pid", os.Getpid()),
+				slog.String("go_version", buildInfo.GoVersion),
+			),
+		)
+
+		slog.SetDefault(debuglogger)
+	}
+}
+
+// little helper to distinguish sway tree node types
+func istype(nd *i3ipc.Node, which int) bool {
+	switch nd.Type {
+	case "root":
+		return which == root
+	case "output":
+		return which == output
+	case "workspace":
+		return which == workspace
+	case "con":
+		return which == con
+	case "floating_con":
+		return which == floating
+	}
+
+	return false
+}
+
 // returns TRUE if stdout is NOT a tty or windows
 func IsNoTty() bool {
 	if !isatty.IsTerminal(os.Stdout.Fd()) {