Trim one round-trip out of xmu.ClientWindow

1 files changed, 16 insertions, 14 deletions

diff --git a/xmu.go b/xmu.go
index bc2bf3e..d7a6a13 100644
--- a/xmu.go
+++ b/xmu.go
@@ -13,23 +13,13 @@ import (
    This change allows us to avoid as many round-trips as possible.
  */
 
-func tryChildren(c *xgob.Connection, parent xproto.Window) xproto.Window {
+func tryChildren(c *xgob.Connection, children []xproto.Window) xproto.Window {
 	queryCookies := make([]chan xproto.QueryTreeReply, 0)
 	propCookies := make([]chan xproto.GetPropertyReply, 0)
 
 	state := atom.Atom(c, "WM_STATE")
 
-	queryCookies = append(queryCookies, xproto.QueryTree(c, parent))
-	c.Flush()
-
-	children := make([]xproto.Window, 0)
-
 	for {
-		children = children[:0]
-		for _, cookie := range queryCookies {
-			children = append(children, (<-cookie).Children...)
-		}
-
 		if len(children) == 0 {
 			break
 		}
@@ -49,17 +39,29 @@ func tryChildren(c *xgob.Connection, parent xproto.Window) xproto.Window {
 				return children[i]
 			}
 		}
+
+		children = children[:0]
+		for _, cookie := range queryCookies {
+			children = append(children, (<-cookie).Children...)
+		}
+
 	}
-	return parent
+	return 0
 }
 
 func ClientWindow(c *xgob.Connection, win xproto.Window) xproto.Window {
 	stateCookie := xproto.GetProperty(c, false, win, atom.Atom(c, "WM_STATE"), xproto.Atom(0), 0, 0)
+	treeCookie := xproto.QueryTree(c, win)
 	c.Flush()
 	state := <- stateCookie
 	if state.Error != nil && state.Type != xproto.Atom(0) {
 		return win
 	}
-	
-	return tryChildren(c, win)
+
+	tree := <- treeCookie
+	rv := tryChildren(c, tree.Children)
+	if rv == 0 {
+		return win
+	}
+	return rv
 }