func main() {
X, err := xgb.NewConn()
if err != nil {
log.Fatal(err)
}
// Get the window id of the root window.
setup := xproto.Setup(X)
root := setup.DefaultScreen(X).Root
// Get the atom id (i.e., intern an atom) of "_NET_ACTIVE_WINDOW".
aname := "_NET_ACTIVE_WINDOW"
query1, buf := xproto.InternAtom(X, nil, true, uint16(len(aname)), aname)
activeAtom, err := query1.Reply()
if err != nil {
log.Fatal(err)
}
// Get the atom id (i.e., intern an atom) of "_NET_WM_NAME".
aname = "_NET_WM_NAME"
query2, buf := xproto.InternAtom(X, buf, true, uint16(len(aname)),
aname)
nameAtom, err := query2.Reply()
if err != nil {
log.Fatal(err)
}
// Get the actual value of _NET_ACTIVE_WINDOW.
// Note that 'reply.Value' is just a slice of bytes, so we use an
// XGB helper function, 'Get32', to pull an unsigned 32-bit integer out
// of the byte slice. We then convert it to an X resource id so it can
// be used to get the name of the window in the next GetProperty request.
query3, buf := xproto.GetProperty(X, buf, false, root, activeAtom.Atom,
xproto.GetPropertyTypeAny, 0, (1<<32)-1)
reply, err := query3.Reply()
if err != nil {
log.Fatal(err)
}
windowId := xproto.Window(xgb.Get32(reply.Value))
fmt.Printf("Active window id: %X\n", windowId)
// Now get the value of _NET_WM_NAME for the active window.
// Note that this time, we simply convert the resulting byte slice,
// reply.Value, to a string.
query4, buf := xproto.GetProperty(X, buf, false, windowId, nameAtom.Atom,
xproto.GetPropertyTypeAny, 0, (1<<32)-1)
reply, err = query4.Reply()
if err != nil {
log.Fatal(err)
}
fmt.Printf("Active window name: %s\n", string(reply.Value))
}
func main() {
X, _ := xgb.NewConn()
// Every extension must be initialized before it can be used.
err := randr.Init(X)
if err != nil {
log.Fatal(err)
}
// Get the root window on the default screen.
root := xproto.Setup(X).DefaultScreen(X).Root
// Gets the current screen resources. Screen resources contains a list
// of names, crtcs, outputs and modes, among other things.
query1, buf := randr.GetScreenResources(X, nil, root)
resources, err := query1.Reply()
if err != nil {
log.Fatal(err)
}
// Iterate through all of the outputs and show some of their info.
for _, output := range resources.Outputs {
var query2 randr.GetOutputInfoCookie
query2, buf = randr.GetOutputInfo(X, buf, output, 0)
info, err := query2.Reply()
if err != nil {
log.Fatal(err)
}
bestMode := info.Modes[0]
for _, mode := range resources.Modes {
if mode.Id == uint32(bestMode) {
fmt.Printf("Width: %d, Height: %d\n", mode.Width, mode.Height)
}
}
}
fmt.Println("\n")
// Iterate through all of the crtcs and show some of their info.
for _, crtc := range resources.Crtcs {
var query3 randr.GetCrtcInfoCookie
query3, buf = randr.GetCrtcInfo(X, buf, crtc, 0)
info, err := query3.Reply()
if err != nil {
log.Fatal(err)
}
fmt.Printf("X: %d, Y: %d, Width: %d, Height: %d\n",
info.X, info.Y, info.Width, info.Height)
}
// Tell RandR to send us events. (I think these are all of them, as of 1.3.)
query4, buf := randr.SelectInputChecked(X, buf, root,
randr.NotifyMaskScreenChange|
randr.NotifyMaskCrtcChange|
randr.NotifyMaskOutputChange|
randr.NotifyMaskOutputProperty)
err = query4.Check()
if err != nil {
log.Fatal(err)
}
// Listen to events and just dump them to standard out.
// A more involved approach will have to read the 'U' field of
// RandrNotifyEvent, which is a union (really a struct) of type
// RanrNotifyDataUnion.
for {
ev, err := X.WaitForEvent()
if err != nil {
log.Fatal(err)
}
fmt.Println(ev)
}
}
func main() {
X, err := xgb.NewConn()
if err != nil {
fmt.Println(err)
return
}
// xproto.Setup retrieves the Setup information from the setup bytes
// gathered during connection.
setup := xproto.Setup(X)
// This is the default screen with all its associated info.
screen := setup.DefaultScreen(X)
// Any time a new resource (i.e., a window, pixmap, graphics context, etc.)
// is created, we need to generate a resource identifier.
// If the resource is a window, then use xproto.NewWindowId. If it's for
// a pixmap, then use xproto.NewPixmapId. And so on...
wid, _ := xproto.NewWindowId(X)
// CreateWindow takes a boatload of parameters.
xproto.CreateWindow(X, nil, screen.RootDepth, wid, screen.Root,
0, 0, 500, 500, 0,
xproto.WindowClassInputOutput, screen.RootVisual, 0, []uint32{})
// This call to ChangeWindowAttributes could be factored out and
// included with the above CreateWindow call, but it is left here for
// instructive purposes. It tells X to send us events when the 'structure'
// of the window is changed (i.e., when it is resized, mapped, unmapped,
// etc.) and when a key press or a key release has been made when the
// window has focus.
// We also set the 'BackPixel' to white so that the window isn't butt ugly.
xproto.ChangeWindowAttributes(X, nil, wid,
xproto.CwBackPixel|xproto.CwEventMask,
[]uint32{ // values must be in the order defined by the protocol
0xffffffff,
xproto.EventMaskStructureNotify |
xproto.EventMaskKeyPress |
xproto.EventMaskKeyRelease})
// MapWindow makes the window we've created appear on the screen.
// We demonstrated the use of a 'checked' request here.
// A checked request is a fancy way of saying, "do error handling
// synchronously." Namely, if there is a problem with the MapWindow request,
// we'll get the error *here*. If we were to do a normal unchecked
// request (like the above CreateWindow and ChangeWindowAttributes
// requests), then we would only see the error arrive in the main event
// loop.
//
// Typically, checked requests are useful when you need to make sure they
// succeed. Since they are synchronous, they incur a round trip cost before
// the program can continue, but this is only going to be noticeable if
// you're issuing tons of requests in succession.
//
// Note that requests without replies are by default unchecked while
// requests *with* replies are checked by default.
query, buf := xproto.MapWindowChecked(X, nil, wid)
err = query.Check()
if err != nil {
fmt.Printf("Checked Error for mapping window %d: %s\n", wid, err)
} else {
fmt.Printf("Map window %d successful!\n", wid)
}
// This is an example of an invalid MapWindow request and what an error
// looks like.
query, buf = xproto.MapWindowChecked(X, buf, 0)
err = query.Check()
if err != nil {
fmt.Printf("Checked Error for mapping window 0x1: %s\n", err)
} else { // neva
fmt.Printf("Map window 0x1 successful!\n")
}
// Start the main event loop.
for {
// WaitForEvent either returns an event or an error and never both.
// If both are nil, then something went wrong and the loop should be
// halted.
//
// An error can only be seen here as a response to an unchecked
// request.
ev, xerr := X.WaitForEvent()
if ev == nil && xerr == nil {
fmt.Println("Both event and error are nil. Exiting...")
return
}
if ev != nil {
fmt.Printf("Event: %s\n", ev)
}
if xerr != nil {
fmt.Printf("Error: %s\n", xerr)
}
}
}