chore: add power event code for windows

component/power/event.go

@@ -0,0 +1,22 @@
+package power
+
+type Type uint8
+
+const (
+	SUSPEND Type = iota
+	RESUME
+	RESUMEAUTOMATIC // Because the user is not present, most applications should do nothing.
+)
+
+func (t Type) String() string {
+	switch t {
+	case SUSPEND:
+		return "SUSPEND"
+	case RESUME:
+		return "RESUME"
+	case RESUMEAUTOMATIC:
+		return "RESUMEAUTOMATIC"
+	default:
+		return ""
+	}
+}

component/power/event_other.go

@@ -0,0 +1,9 @@
+//go:build !windows
+
+package power
+
+import "errors"
+
+func NewEventListener(cb func(Type)) (func(), error) {
+	return nil, errors.New("not support on this platform")
+}

component/power/event_windows.go

@@ -0,0 +1,74 @@
+package power
+
+// modify from https://github.com/golang/go/blob/b634f6fdcbebee23b7da709a243f3db217b64776/src/runtime/os_windows.go#L257
+
+import (
+	"runtime"
+	"unsafe"
+
+	"golang.org/x/sys/windows"
+)
+
+var (
+	libPowrProf                              = windows.NewLazySystemDLL("powrprof.dll")
+	powerRegisterSuspendResumeNotification   = libPowrProf.NewProc("PowerRegisterSuspendResumeNotification")
+	powerUnregisterSuspendResumeNotification = libPowrProf.NewProc("PowerUnregisterSuspendResumeNotification")
+)
+
+func NewEventListener(cb func(Type)) (func(), error) {
+	if err := powerRegisterSuspendResumeNotification.Find(); err != nil {
+		return nil, err // Running on Windows 7, where we don't need it anyway.
+	}
+	if err := powerUnregisterSuspendResumeNotification.Find(); err != nil {
+		return nil, err // Running on Windows 7, where we don't need it anyway.
+	}
+
+	// Defines the type of event
+	const (
+		PBT_APMSUSPEND         uint32 = 4
+		PBT_APMRESUMESUSPEND   uint32 = 7
+		PBT_APMRESUMEAUTOMATIC uint32 = 18
+	)
+
+	const (
+		_DEVICE_NOTIFY_CALLBACK = 2
+	)
+	type _DEVICE_NOTIFY_SUBSCRIBE_PARAMETERS struct {
+		callback uintptr
+		context  uintptr
+	}
+
+	var fn interface{} = func(context uintptr, changeType uint32, setting uintptr) uintptr {
+		switch changeType {
+		case PBT_APMSUSPEND:
+			cb(SUSPEND)
+		case PBT_APMRESUMESUSPEND:
+			cb(RESUME)
+		case PBT_APMRESUMEAUTOMATIC:
+			cb(RESUMEAUTOMATIC)
+		}
+		return 0
+	}
+
+	params := _DEVICE_NOTIFY_SUBSCRIBE_PARAMETERS{
+		callback: windows.NewCallback(fn),
+	}
+	handle := uintptr(0)
+
+	_, _, err := powerRegisterSuspendResumeNotification.Call(
+		_DEVICE_NOTIFY_CALLBACK,
+		uintptr(unsafe.Pointer(&params)),
+		uintptr(unsafe.Pointer(&handle)),
+	)
+	if err != nil {
+		return nil, err
+	}
+
+	return func() {
+		_, _, _ = powerUnregisterSuspendResumeNotification.Call(
+			uintptr(unsafe.Pointer(&handle)),
+		)
+		runtime.KeepAlive(params)
+		runtime.KeepAlive(handle)
+	}, nil
+}