Adding upstream version 0.0~git20250520.a1d9079+dfsg.

Signed-off-by: Daniel Baumann <daniel@debian.org>

exp/sensor/sensor.go

@@ -0,0 +1,130 @@
+// Copyright 2015 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package sensor provides sensor events from various movement sensors.
+package sensor
+
+import (
+	"errors"
+	"sync"
+	"time"
+)
+
+// Type represents a sensor type.
+type Type int
+
+var sensorNames = map[Type]string{
+	Accelerometer: "Accelerometer",
+	Gyroscope:     "Gyroscope",
+	Magnetometer:  "Magnetometer",
+}
+
+// String returns the string representation of the sensor type.
+func (t Type) String() string {
+	if n, ok := sensorNames[t]; ok {
+		return n
+	}
+	return "Unknown sensor"
+}
+
+const (
+	Accelerometer = Type(0)
+	Gyroscope     = Type(1)
+	Magnetometer  = Type(2)
+	nTypes        = Type(3)
+)
+
+// Event represents a sensor event.
+type Event struct {
+	// Sensor is the type of the sensor the event is coming from.
+	Sensor Type
+
+	// Timestamp is a device specific event time in nanoseconds.
+	// Timestamps are not Unix times, they represent a time that is
+	// only valid for the device's default sensor.
+	Timestamp int64
+
+	// Data is the event data.
+	//
+	// If the event source is Accelerometer,
+	//  - Data[0]: acceleration force in x axis in m/s^2
+	//  - Data[1]: acceleration force in y axis in m/s^2
+	//  - Data[2]: acceleration force in z axis in m/s^2
+	//
+	// If the event source is Gyroscope,
+	//  - Data[0]: rate of rotation around the x axis in rad/s
+	//  - Data[1]: rate of rotation around the y axis in rad/s
+	//  - Data[2]: rate of rotation around the z axis in rad/s
+	//
+	// If the event source is Magnetometer,
+	//  - Data[0]: force of gravity along the x axis in m/s^2
+	//  - Data[1]: force of gravity along the y axis in m/s^2
+	//  - Data[2]: force of gravity along the z axis in m/s^2
+	//
+	Data []float64
+}
+
+// TODO(jbd): Move Sender interface definition to a top-level package.
+
+var (
+	// senderMu protects sender.
+	senderMu sync.Mutex
+
+	// sender is notified with the sensor data each time a new event is available.
+	sender Sender
+)
+
+// Sender sends an event.
+type Sender interface {
+	Send(event interface{})
+}
+
+// Notify registers a Sender and sensor events will be sent to s.
+// A typical example of Sender implementations is app.App.
+// Once you call Notify, you are not allowed to call it again.
+// You cannot call Notify with a nil Sender.
+func Notify(s Sender) {
+	senderMu.Lock()
+	defer senderMu.Unlock()
+
+	if s == nil {
+		panic("sensor: cannot set a nil sender")
+	}
+	if sender != nil {
+		panic("sensor: another sender is being notified, cannot set s as the sender")
+	}
+	sender = s
+}
+
+// Enable enables the specified sensor type with the given delay rate.
+// Users must set a non-nil Sender via Notify before enabling a sensor,
+// otherwise an error will be returned.
+func Enable(t Type, delay time.Duration) error {
+	if t < 0 || int(t) >= len(sensorNames) {
+		return errors.New("sensor: unknown sensor type")
+	}
+	if err := validSender(); err != nil {
+		return err
+	}
+	return enable(t, delay)
+}
+
+// Disable disables to feed the manager with the specified sensor.
+// Disable is not safe for concurrent use.
+func Disable(t Type) error {
+	if t < 0 || int(t) >= len(sensorNames) {
+		return errors.New("sensor: unknown sensor type")
+	}
+	return disable(t)
+}
+
+func validSender() error {
+	senderMu.Lock()
+	defer senderMu.Unlock()
+
+	if sender == nil {
+		return errors.New("sensor: no senders to be notified; cannot enable the sensor")
+	}
+	return nil
+}