haven/nexgb/examples/randr/main.go

85 lines
2.3 KiB
Go

// Example randr uses the randr protocol to get information about the active
// heads. It also listens for events that are sent when the head configuration
// changes. Since it listens to events, you'll have to manually kill this
// process when you're done (i.e., ctrl+c.)
//
// While this program is running, if you use 'xrandr' to reconfigure your
// heads, you should see event information dumped to standard out.
//
// For more information, please see the RandR protocol spec:
// http://www.x.org/releases/X11R7.6/doc/randrproto/randrproto.txt
package main
import (
"fmt"
"log"
"github.com/BurntSushi/xgb"
)
func main() {
X, _ := xgb.NewConn()
// Every extension must be initialized before it can be used.
err := X.RandrInit()
if err != nil {
log.Fatal(err)
}
// Gets the current screen resources. Screen resources contains a list
// of names, crtcs, outputs and modes, among other things.
resources, err := X.RandrGetScreenResources(X.DefaultScreen().Root).Reply()
if err != nil {
log.Fatal(err)
}
// Iterate through all of the outputs and show some of their info.
for _, output := range resources.Outputs {
info, err := X.RandrGetOutputInfo(output, 0).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 {
info, err := X.RandrGetCrtcInfo(crtc, 0).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.)
err = X.RandrSelectInputChecked(X.DefaultScreen().Root,
xgb.RandrNotifyMaskScreenChange|
xgb.RandrNotifyMaskCrtcChange|
xgb.RandrNotifyMaskOutputChange|
xgb.RandrNotifyMaskOutputProperty).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)
}
}