From 186df36c2c12451c8601ad4201102c1aaaba1c5e Mon Sep 17 00:00:00 2001
From: vcaesar <vzvway@gmail.com>
Date: Tue, 10 Jul 2018 20:02:18 +0800
Subject: [PATCH] update active pid try to fix #140

---
 robotgo.go         | 20 ++++++++-----
 robotgo_mac_win.go | 14 +++++++++
 robotgo_unix.go    | 74 ++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 100 insertions(+), 8 deletions(-)
 create mode 100644 robotgo_mac_win.go
 create mode 100644 robotgo_unix.go

diff --git a/robotgo.go b/robotgo.go
index 48c61e5..aea1f56 100644
--- a/robotgo.go
+++ b/robotgo.go
@@ -1536,17 +1536,21 @@ func FindIds(name string) ([]int32, error) {
 	return pids, err
 }
 
-// ActivePID active window by PID,
-// If args[0] > 0 on the Windows platform via a window handle to active
-func ActivePID(pid int32, args ...int) {
-	var hwnd int
-	if len(args) > 0 {
-		hwnd = args[0]
-	}
-
+func internalActive(pid int32, hwnd int) {
 	C.active_PID(C.uintptr(pid), C.uintptr(hwnd))
 }
 
+// ActivePID active the window by PID,
+// If args[0] > 0 on the Windows platform via a window handle to active
+// func ActivePID(pid int32, args ...int) {
+// 	var hwnd int
+// 	if len(args) > 0 {
+// 		hwnd = args[0]
+// 	}
+
+// 	C.active_PID(C.uintptr(pid), C.uintptr(hwnd))
+// }
+
 // ActiveName active window by name
 func ActiveName(name string) error {
 	pids, err := FindIds(name)
diff --git a/robotgo_mac_win.go b/robotgo_mac_win.go
new file mode 100644
index 0000000..2471c92
--- /dev/null
+++ b/robotgo_mac_win.go
@@ -0,0 +1,14 @@
+// +build darwin windows
+
+package robotgo
+
+// ActivePID active the window by PID,
+// If args[0] > 0 on the Windows platform via a window handle to active
+func ActivePID(pid int32, args ...int) {
+	var hwnd int
+	if len(args) > 0 {
+		hwnd = args[0]
+	}
+
+	internalActive(pid, hwnd)
+}
diff --git a/robotgo_unix.go b/robotgo_unix.go
new file mode 100644
index 0000000..75077e4
--- /dev/null
+++ b/robotgo_unix.go
@@ -0,0 +1,74 @@
+// +build !darwin,!windows
+
+package robotgo
+
+import (
+	"errors"
+
+	"github.com/BurntSushi/xgb/xproto"
+	"github.com/BurntSushi/xgbutil"
+	"github.com/BurntSushi/xgbutil/ewmh"
+)
+
+var xu *xgbutil.XUtil
+
+// ActivePID active the window by PID,
+// If args[0] > 0 on the unix platform via a xid to active
+func ActivePID(pid int32, args ...int) {
+	var hwnd int
+	if len(args) > 0 {
+		hwnd = args[0]
+
+		internalActive(pid, hwnd)
+		return
+	}
+
+	xid, err := getXidFromPid(xu, pid)
+	if err != nil {
+		return
+	}
+
+	internalActive(int32(xid), hwnd)
+}
+
+// ActivePIDXgb makes the window of the PID the active window
+func ActivePIDXgb(pid int32) error {
+	if xu == nil {
+		var err error
+		xu, err = xgbutil.NewConn()
+		if err != nil {
+			return err
+		}
+	}
+
+	xid, err := getXidFromPid(xu, pid)
+	if err != nil {
+		return err
+	}
+
+	err = ewmh.ActiveWindowReq(xu, xid)
+	if err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func getXidFromPid(xu *xgbutil.XUtil, pid int32) (xproto.Window, error) {
+	windows, err := ewmh.ClientListGet(xu)
+	if err != nil {
+		return 0, err
+	}
+
+	for _, window := range windows {
+		wmPid, err := ewmh.WmPidGet(xu, window)
+		if err != nil {
+			return 0, err
+		}
+		if uint(pid) == wmPid {
+			return window, nil
+		}
+	}
+
+	return 0, errors.New("failed to find a window with a matching pid")
+}