Added MVP

go.mod

@@ -0,0 +1,5 @@
+module gitea.ashishdsouza.com/ashish/i3-last-scratchpad
+
+go 1.21.12
+
+require github.com/mdirkse/i3ipc v0.0.0-20171212230543-ac599a872375 // indirect

go.sum

@@ -0,0 +1,2 @@
+github.com/mdirkse/i3ipc v0.0.0-20171212230543-ac599a872375 h1:PPiUjQrUS1oVKBPeRBa4uP8z6jkRgbwsD88QAzXM6Eo=
+github.com/mdirkse/i3ipc v0.0.0-20171212230543-ac599a872375/go.mod h1:QCgFg+QImlvQdfX7W8i1ueSJJYNOeOKEApyCXQnyt+w=

main.go

@@ -0,0 +1,22 @@
+package main
+
+import "github.com/mdirkse/i3ipc"
+
+import "gitea.ashishdsouza.com/ashish/i3-last-scratchpad/notify"
+import "gitea.ashishdsouza.com/ashish/i3-last-scratchpad/scratchpad"
+
+
+func main() {
+	var ipcSocket, socketErr = i3ipc.GetIPCSocket()
+	if socketErr != nil {
+		notify.SendNotification("Failed to acquire i3 IPC socket", notify.CriticalPriority)
+		panic(socketErr)
+	}
+
+	var lastScratchpadNode = scratchpad.GetLastScratchpadNode(ipcSocket)
+	if lastScratchpadNode == nil {
+		notify.SendNotification("Scratchpad is empty", notify.NormalPriority)
+	} else {
+		scratchpad.ShowScratchpadNode(ipcSocket, lastScratchpadNode)
+	}
+}

notify/i3.go

@@ -0,0 +1,24 @@
+package notify
+
+import "os/exec"
+
+
+type i3Urgency string
+
+const (
+	LowPriority i3Urgency = "low"
+	NormalPriority i3Urgency = "normal"
+	CriticalPriority i3Urgency = "critical"
+)
+
+func SendNotification(msg string, priority i3Urgency) {
+	var cmd = exec.Command("notify-send", "-u", string(priority), msg)
+	if err := cmd.Start(); err != nil {
+		panic(err)
+	}
+}
+
+func FatalNotification(msg string) {
+	SendNotification(msg, CriticalPriority)
+	panic(msg)
+}

scratchpad/last_window.go

@@ -0,0 +1,27 @@
+package scratchpad
+
+import "github.com/mdirkse/i3ipc"
+
+import "gitea.ashishdsouza.com/ashish/i3-last-scratchpad/notify"
+
+
+func GetLastScratchpadNode(ipcSocket *i3ipc.IPCSocket) *i3ipc.I3Node {
+	var root, err = ipcSocket.GetTree()
+	if err != nil {
+		notify.SendNotification("Failed to fetch layout tree", notify.CriticalPriority)
+		panic(err)
+	}
+
+	var leaves = root.Leaves()
+	for i := len(leaves) - 1; i >= 0; i-- {
+		if leaves[i].Parent == nil {
+			notify.FatalNotification("Leaf node nas no parent")
+		}
+
+		// https://i3wm.org/docs/ipc.html#_tree_reply
+		if leaves[i].Parent.Scratchpad_State != "none" {
+			return leaves[i]
+		}
+	}
+	return nil
+}

scratchpad/show.go

@@ -0,0 +1,16 @@
+package scratchpad
+
+import "fmt"
+
+import "github.com/mdirkse/i3ipc"
+
+import "gitea.ashishdsouza.com/ashish/i3-last-scratchpad/notify"
+
+
+func ShowScratchpadNode(ipcSocket *i3ipc.IPCSocket, node *i3ipc.I3Node) {
+	var i3Command = fmt.Sprintf("[con_id=%d] scratchpad show", node.ID)
+	if success, err := ipcSocket.Command(i3Command); !success {
+		notify.SendNotification("Failed to show scratchpad window", notify.CriticalPriority)
+		panic(err)
+	}
+}