/
dbus_suspend.go
84 lines (69 loc) · 1.58 KB
/
dbus_suspend.go
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package lis
import (
"os"
"github.com/coreos/go-systemd/login1"
"github.com/godbus/dbus"
)
// DBusHandler handles a DBus connection to receive signal on suspend.
type DBusHandler struct {
login1 *login1.Conn
Signal chan *dbus.Signal
closeCh chan struct{}
lis *Lis
inhibit *os.File
}
// NewDBusHandler initializes a new DBusHandler.
func NewDBusHandler(lis *Lis) (*DBusHandler, error) {
l, err := login1.New()
if err != nil {
return nil, err
}
return &DBusHandler{
login1: l,
closeCh: make(chan struct{}, 1),
lis: lis,
}, nil
}
// Run starts the DBusHandler event loop.
func (d *DBusHandler) Run(errCh chan error) {
var err error
d.Signal = d.login1.Subscribe("PrepareForSleep")
// take inhibit lock
d.takeLock(errCh)
for {
signal := <-d.Signal
switch signal.Name {
case "org.freedesktop.login1.Manager.PrepareForSleep":
prepareForSleep := signal.Body[0].(bool)
if prepareForSleep { // prepare for suspend
err = d.lis.storeState()
if err != nil {
errCh <- err
}
err = d.inhibit.Close()
if err != nil {
errCh <- err
}
d.inhibit = nil
} else { // go back from suspend
d.lis.loadState()
// take new lock
d.takeLock(errCh)
}
}
}
}
// take inhibitor lock if not already taken.
func (d *DBusHandler) takeLock(errCh chan error) {
var err error
if d.inhibit == nil {
d.inhibit, err = d.login1.Inhibit("sleep", "Backlight daemon", "Saving backlight level", "delay")
if err != nil {
errCh <- err
}
}
}
// Close closes the inhibit file.
func (d *DBusHandler) Close() {
d.closeCh <- struct{}{}
}