Update joystick package error handling

platforms/joystick/joystick_adaptor.go

@@ -1,6 +1,7 @@
 package joystick
 
 import (
+	"errors"
 	"github.com/hybridgroup/go-sdl2/sdl"
 	"github.com/hybridgroup/gobot"
 )
@@ -15,7 +16,7 @@ type joystick interface {
 type JoystickAdaptor struct {
 	gobot.Adaptor
 	joystick joystick
-	connect  func(*JoystickAdaptor)
+	connect  func(*JoystickAdaptor) (err error)
 }
 
 // NewJoysctickAdaptor creates a new adaptor with specified name.
@@ -27,21 +28,20 @@ func NewJoystickAdaptor(name string) *JoystickAdaptor {
 			name,
 			"JoystickAdaptor",
 		),
-		connect: func(j *JoystickAdaptor) {
+		connect: func(j *JoystickAdaptor) (err error) {
 			sdl.Init(sdl.INIT_JOYSTICK)
 			if sdl.NumJoysticks() > 0 {
 				j.joystick = sdl.JoystickOpen(0)
-			} else {
+				return
-				panic("No joystick available")
 			}
+			return errors.New("No joystick available")
 		},
 	}
 }
 
 // Connect returns true if connection to device is succesfull
 func (j *JoystickAdaptor) Connect() error {
-	j.connect(j)
+	return j.connect(j)
-	return nil
 }
 
 // Finalize closes connection to device

platforms/joystick/joystick_adaptor_test.go

@@ -8,8 +8,9 @@ import (
 
 func initTestJoystickAdaptor() *JoystickAdaptor {
 	a := NewJoystickAdaptor("bot")
-	a.connect = func(j *JoystickAdaptor) {
+	a.connect = func(j *JoystickAdaptor) (err error) {
 		j.joystick = &testJoystick{}
+		return nil
 	}
 	return a
 }

platforms/joystick/joystick_driver.go

@@ -5,6 +5,7 @@ import (
 	"errors"
 	"fmt"
 	"io/ioutil"
+	"time"
 
 	"github.com/hybridgroup/go-sdl2/sdl"
 	"github.com/hybridgroup/gobot"
@@ -14,8 +15,9 @@ var _ gobot.DriverInterface = (*JoystickDriver)(nil)
 
 type JoystickDriver struct {
 	gobot.Driver
-	config joystickConfig
+	configPath string
-	poll   func() sdl.Event
+	config     joystickConfig
+	poll       func() sdl.Event
 }
 
 // pair is a JSON representation of name and id
@@ -52,28 +54,13 @@ func NewJoystickDriver(a *JoystickAdaptor, name string, config string) *Joystick
 			"JoystickDriver",
 			a,
 		),
+		configPath: config,
 		poll: func() sdl.Event {
 			return sdl.PollEvent()
 		},
 	}
 
-	file, e := ioutil.ReadFile(config)
+	d.AddEvent("error")
-	if e != nil {
-		panic(fmt.Sprintf("File error: %v\n", e))
-	}
-	var jsontype joystickConfig
-	json.Unmarshal(file, &jsontype)
-	d.config = jsontype
-	for _, value := range d.config.Buttons {
-		d.AddEvent(fmt.Sprintf("%s_press", value.Name))
-		d.AddEvent(fmt.Sprintf("%s_release", value.Name))
-	}
-	for _, value := range d.config.Axis {
-		d.AddEvent(value.Name)
-	}
-	for _, value := range d.config.Hats {
-		d.AddEvent(value.Name)
-	}
 	return d
 }
 
@@ -83,13 +70,38 @@ func (j *JoystickDriver) adaptor() *JoystickAdaptor {
 }
 
 // Start initiallizes event polling with defined interval
-func (j *JoystickDriver) Start() error {
+func (j *JoystickDriver) Start() (err error) {
-	gobot.Every(j.Interval(), func() {
+	file, err := ioutil.ReadFile(j.configPath)
-		event := j.poll()
+	if err != nil {
-		if event != nil {
+		return err
-			j.handleEvent(event)
+	}
+
+	var jsontype joystickConfig
+	json.Unmarshal(file, &jsontype)
+	j.config = jsontype
+
+	for _, value := range j.config.Buttons {
+		j.AddEvent(fmt.Sprintf("%s_press", value.Name))
+		j.AddEvent(fmt.Sprintf("%s_release", value.Name))
+	}
+	for _, value := range j.config.Axis {
+		j.AddEvent(value.Name)
+	}
+	for _, value := range j.config.Hats {
+		j.AddEvent(value.Name)
+	}
+
+	go func() {
+		for {
+			event := j.poll()
+			if event != nil {
+				if err = j.handleEvent(event); err != nil {
+					gobot.Publish(j.Event("error"), err)
+				}
+			}
+			<-time.After(j.Interval())
 		}
-	})
+	}()
 	return nil
 }
 
@@ -100,9 +112,7 @@ func (j *JoystickDriver) handleEvent(event sdl.Event) error {
 		if data.Which == j.adaptor().joystick.InstanceID() {
 			axis := j.findName(data.Axis, j.config.Axis)
 			if axis == "" {
-				e := errors.New(fmt.Sprintf("Unknown Axis: %v", data.Axis))
+				return errors.New(fmt.Sprintf("Unknown Axis: %v", data.Axis))
-				fmt.Println(e.Error())
-				return e
 			} else {
 				gobot.Publish(j.Event(axis), data.Value)
 			}
@@ -111,9 +121,7 @@ func (j *JoystickDriver) handleEvent(event sdl.Event) error {
 		if data.Which == j.adaptor().joystick.InstanceID() {
 			button := j.findName(data.Button, j.config.Buttons)
 			if button == "" {
-				e := errors.New(fmt.Sprintf("Unknown Button: %v", data.Button))
+				return errors.New(fmt.Sprintf("Unknown Button: %v", data.Button))
-				fmt.Println(e.Error())
-				return e
 			} else {
 				if data.State == 1 {
 					gobot.Publish(j.Event(fmt.Sprintf("%s_press", button)), nil)
@@ -126,9 +134,7 @@ func (j *JoystickDriver) handleEvent(event sdl.Event) error {
 		if data.Which == j.adaptor().joystick.InstanceID() {
 			hat := j.findHatName(data.Value, data.Hat, j.config.Hats)
 			if hat == "" {
-				e := errors.New(fmt.Sprintf("Unknown Hat: %v %v", data.Hat, data.Value))
+				return errors.New(fmt.Sprintf("Unknown Hat: %v %v", data.Hat, data.Value))
-				fmt.Println(e.Error())
-				return e
 			} else {
 				gobot.Publish(j.Event(hat), true)
 			}

platforms/joystick/joystick_driver_test.go

@@ -10,8 +10,9 @@ import (
 
 func initTestJoystickDriver() *JoystickDriver {
 	a := NewJoystickAdaptor("bot")
-	a.connect = func(j *JoystickAdaptor) {
+	a.connect = func(j *JoystickAdaptor) (err error) {
 		j.joystick = &testJoystick{}
+		return nil
 	}
 	a.Connect()
 	d := NewJoystickDriver(a, "bot", "./configs/xbox360_power_a_mini_proex.json")
@@ -21,17 +22,6 @@ func initTestJoystickDriver() *JoystickDriver {
 	return d
 }
 
-func TestJoystickDriver(t *testing.T) {
-	defer func() {
-		r := recover()
-		if r != nil {
-			gobot.Assert(t, "File error: open ./fake_config.json: no such file or directory\n", r)
-		} else {
-			t.Errorf("Did not return Unknown Event error")
-		}
-	}()
-	NewJoystickDriver(NewJoystickAdaptor("bot"), "bot", "./fake_config.json")
-}
 func TestJoystickDriverStart(t *testing.T) {
 	d := initTestJoystickDriver()
 	d.SetInterval(1 * time.Millisecond)
@@ -47,6 +37,7 @@ func TestJoystickDriverHalt(t *testing.T) {
 func TestJoystickDriverHandleEvent(t *testing.T) {
 	sem := make(chan bool)
 	d := initTestJoystickDriver()
+	d.Start()
 	d.handleEvent(&sdl.JoyAxisEvent{
 		Which: 0,
 		Axis:  0,