// IsFocusProtocol checks whether a ClientMessage event satisfies the
// WM_TAKE_FOCUS protocol.
func IsFocusProtocol(X *xgbutil.XUtil, ev xevent.ClientMessageEvent) bool {
// Make sure the Format is 32. (Meaning that each data item is
// 32 bits.)
if ev.Format != 32 {
return false
}
// Check to make sure the Type atom is WM_PROTOCOLS.
typeName, err := xprop.AtomName(X, ev.Type)
if err != nil || typeName != "WM_PROTOCOLS" { // not what we want
return false
}
// Check to make sure the first data item is WM_TAKE_FOCUS.
protocolType, err := xprop.AtomName(X,
xproto.Atom(ev.Data.Data32[0]))
if err != nil || protocolType != "WM_TAKE_FOCUS" {
return false
}
return true
}
func main() {
X, err := xgbutil.NewConn()
if err != nil {
log.Fatal(err)
}
// Start generating other source events.
otherChan := otherSource()
// Start generating X events (by sending client messages to root window).
go xSource(X)
// Listen to those X events.
xwindow.New(X, X.RootWin()).Listen(xproto.EventMaskSubstructureNotify)
// Respond to those X events.
xevent.ClientMessageFun(
func(X *xgbutil.XUtil, ev xevent.ClientMessageEvent) {
atmName, err := xprop.AtomName(X, ev.Type)
if err != nil {
log.Fatal(err)
}
fmt.Printf("ClientMessage: %d. %s\n", ev.Data.Data32[0], atmName)
}).Connect(X, X.RootWin())
// Instead of using the usual xevent.Main, we use xevent.MainPing.
// It runs the main event loop inside a goroutine and returns ping
// channels, which are sent benign values right before an event is
// dequeued and right after that event has finished running all callbacks
// associated with it, respectively.
pingBefore, pingAfter, pingQuit := xevent.MainPing(X)
for {
select {
case <-pingBefore:
// Wait for the event to finish processing.
<-pingAfter
case otherVal := <-otherChan:
fmt.Printf("Processing other event: %d\n", otherVal)
case <-pingQuit:
fmt.Printf("xevent loop has quit")
return
}
}
}