Refactor main and display hibernating logic from eachother

afterlock/afterlock.go

@@ -0,0 +1,101 @@
+package afterlock
+
+import(
+	"after-lock/evdev"
+	"after-lock/lockscreen"
+	"after-lock/display"
+	"after-lock/atomicflag"
+	"time"
+	"sync"
+	"errors"
+)
+
+
+// AfterLock suspends the display when the lockscreen is active
+type AfterLock struct {
+	InitialDelay uint
+	LoopDelay uint
+	keyboardDeviceNode string
+	wg sync.WaitGroup
+	stopFlag *atomicflag.AtomicFlag
+	keypressFlag *atomicflag.AtomicFlag
+}
+
+// New constructs a new AfterLock instance
+func New(keyboardDeviceNode string) *AfterLock {
+	return &AfterLock{
+		keyboardDeviceNode: keyboardDeviceNode,
+		stopFlag: atomicflag.New(false),
+		keypressFlag: atomicflag.New(false),
+	}
+}
+
+// Start starts monitoring the lockscreen/keyboard status to determine
+// when to suspend the display.
+// Exits after the computer is unlocked
+func (af *AfterLock) Start() {
+	af.checkDelaysConfigured()
+
+	af.wg.Add(1)
+	go af.detectKeypresses()
+
+	time.Sleep(time.Duration(af.InitialDelay) * time.Second)
+	af.hybernateDisplayLoop()
+}
+
+func (af *AfterLock) checkDelaysConfigured() {
+	if af.InitialDelay == 0 {
+		panic(errors.New("InitialDelay not configured"))
+	}
+	if af.LoopDelay == 0 {
+		panic(errors.New("LoopDelay not configured"))
+	}
+}
+
+func (af *AfterLock) detectKeypresses() {
+	for {
+		err := evdev.BlockUntilKeypress(af.keyboardDeviceNode)
+		if err != nil {
+			panic(err)
+		}
+		if af.stopFlag.Get() {
+			af.wg.Done()
+			return
+		}
+		af.keypressFlag.Set(true)
+	}
+}
+
+func (af *AfterLock) hybernateDisplayLoop() {
+	for {
+		screenLocked, err := lockscreen.IsActive()
+		if err != nil {
+			panic(err)
+		}
+		if !screenLocked {
+			af.stopFlag.Set(true)
+			af.wg.Wait()
+			return
+		}
+
+		displayOn, err := display.IsOn()
+		if err != nil {
+			panic(err)
+		}
+		if displayOn {
+			err := display.Suspend()
+			if err != nil {
+				panic(err)
+			}
+			for {
+				time.Sleep(time.Duration(af.LoopDelay) * time.Second)
+				if af.keypressFlag.Get() {
+					af.keypressFlag.Set(false)
+					continue
+				} else {
+					break
+				}
+			}
+		}
+	}
+}