add basic keyboard driver using stty

Author: stewart

examples/keyboard.go

@@ -0,0 +1,36 @@
+package main
+
+import (
+	"fmt"
+
+	"github.com/hybridgroup/gobot"
+	"github.com/hybridgroup/gobot/platforms/keyboard"
+)
+
+func main() {
+	gbot := gobot.NewGobot()
+
+	keys := keyboard.NewKeyboardDriver("keyboard")
+
+	work := func() {
+		gobot.On(keys.Event("key"), func(data interface{}) {
+			key := data.(keyboard.KeyEvent)
+
+			if key.Key == keyboard.A {
+				fmt.Println("A pressed!")
+			} else {
+				fmt.Println("keyboard event!", key, key.Char)
+			}
+		})
+	}
+
+	robot := gobot.NewRobot("keyboardbot",
+		[]gobot.Connection{},
+		[]gobot.Device{keys},
+		work,
+	)
+
+	gbot.AddRobot(robot)
+
+	gbot.Start()
+}

platforms/keyboard/LICENSE

@@ -0,0 +1,13 @@
+Copyright (c) 2014 The Hybrid Group
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+   http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.

platforms/keyboard/README.md

@@ -0,0 +1,52 @@
+# Keyboard
+
+This module implements support for keyboard events, wrapping the `stty` utility.
+
+## How to Install
+
+```
+go get github.com/hybridgroup/gobot && go install github.com/hybridgroup/gobot/platforms/ardrone
+```
+
+## How to Use
+
+Example parsing key events
+
+```go
+package main
+
+import (
+	"fmt"
+
+	"github.com/hybridgroup/gobot"
+	"github.com/hybridgroup/gobot/platforms/keyboard"
+)
+
+func main() {
+	gbot := gobot.NewGobot()
+
+	keys := keyboard.NewKeyboardDriver("keyboard")
+
+	work := func() {
+		gobot.On(keys.Event("key"), func(data interface{}) {
+			key := data.(keyboard.KeyEvent)
+
+			if key.Key == keyboard.A {
+				fmt.Println("A pressed!")
+			} else {
+				fmt.Println("keyboard event!", key, key.Char)
+			}
+		})
+	}
+
+	robot := gobot.NewRobot("keyboardbot",
+		[]gobot.Connection{},
+		[]gobot.Device{keys},
+		work,
+	)
+
+	gbot.AddRobot(robot)
+
+	gbot.Start()
+}
+```

platforms/keyboard/doc.go

@@ -0,0 +1,52 @@
+/*
+Packge keyboard contains the Gobot drivers for keyboard support.
+
+Installing:
+
+Then you can install the package with:
+
+	go get github.com/hybridgroup/gobot && go install github.com/hybridgroup/gobot/platforms/keyboard
+
+Example:
+
+	package main
+
+	import (
+		"fmt"
+
+		"github.com/hybridgroup/gobot"
+		"github.com/hybridgroup/gobot/platforms/keyboard"
+	)
+
+	func main() {
+		gbot := gobot.NewGobot()
+
+		keys := keyboard.NewKeyboardDriver("keyboard")
+
+		work := func() {
+			gobot.On(keys.Event("key"), func(data interface{}) {
+				key := data.(keyboard.KeyEvent)
+
+				if key.Key == keyboard.A {
+					fmt.Println("A pressed!")
+				} else {
+					fmt.Println("keyboard event!", key, key.Char)
+				}
+			})
+		}
+
+		robot := gobot.NewRobot("keyboardbot",
+			[]gobot.Connection{},
+			[]gobot.Device{keys},
+			work,
+		)
+
+		gbot.AddRobot(robot)
+
+		gbot.Start()
+	}
+
+For further information refer to keyboard README:
+https://github.com/hybridgroup/gobot/blob/master/platforms/keyboard/README.md
+*/
+package keyboard

platforms/keyboard/keyboard.go

@@ -0,0 +1,156 @@
+package keyboard
+
+import (
+	"os"
+	"os/exec"
+)
+
+type bytes [3]byte
+
+type KeyEvent struct {
+	Bytes bytes
+	Key   int
+	Char  string
+}
+
+const (
+	Tilde = iota + 96
+	A
+	B
+	C
+	D
+	E
+	F
+	G
+	H
+	I
+	J
+	K
+	L
+	M
+	N
+	O
+	P
+	Q
+	R
+	S
+	T
+	U
+	V
+	W
+	X
+	Y
+	Z
+)
+
+const (
+	Escape   = 27
+	Spacebar = 32
+)
+
+const (
+	Zero = iota + 48
+	One
+	Two
+	Three
+	Four
+	Five
+	Six
+	Seven
+	Eight
+	Nine
+)
+
+const (
+	ArrowUp = iota + 65
+	ArrowDown
+	ArrowRight
+	ArrowLeft
+)
+
+// used to hold the original stty state
+var originalState string
+
+func Parse(input bytes) KeyEvent {
+	var event = KeyEvent{Bytes: input, Char: string(input[:])}
+
+	var code byte
+
+	// basic input codes
+	if input[1] == 0 && input[2] == 0 {
+		code = input[0]
+
+		// space bar
+		if code == Spacebar {
+			event.Key = Spacebar
+		}
+
+		// vanilla escape
+		if code == Escape {
+			event.Key = Escape
+		}
+
+		// number keys
+		if code >= 48 && code <= 57 {
+			event.Key = int(code)
+		}
+
+		// alphabet
+		if code >= 97 && code <= 122 {
+			event.Key = int(code)
+		}
+
+		return event
+	}
+
+	// arrow keys
+	if input[0] == Escape && input[1] == 91 {
+		code = input[2]
+
+		if code >= 65 && code <= 68 {
+			event.Key = int(code)
+			return event
+		}
+	}
+
+	return event
+}
+
+// fetches original state, sets up TTY for raw (unbuffered) input
+func configure() (err error) {
+	state, err := stty("-g")
+	if err != nil {
+		return err
+	}
+
+	originalState = state
+
+	// -echo: terminal doesn't echo typed characters back to the terminal
+	// -icanon: terminal doesn't interpret special characters (like backspace)
+	if _, err := stty("-echo", "-icanon"); err != nil {
+		return err
+	}
+
+	return
+}
+
+// restores the TTY to the original state
+func restore() (errs []error) {
+	if _, err := stty(originalState); err != nil {
+		return []error{err}
+	}
+
+	return
+}
+
+func stty(args ...string) (string, error) {
+	cmd := exec.Command("stty", args...)
+	cmd.Stdin = os.Stdin
+
+	out, err := cmd.Output()
+	if err != nil {
+		return "", err
+	}
+
+	return string(out), nil
+}

platforms/keyboard/keyboard_driver.go

@@ -0,0 +1,81 @@
+package keyboard
+
+import (
+	"log"
+	"os"
+
+	"github.com/hybridgroup/gobot"
+)
+
+var _ gobot.Driver = (*KeyboardDriver)(nil)
+
+type KeyboardDriver struct {
+	name    string
+	connect func(*KeyboardDriver) (err error)
+	listen  func(*KeyboardDriver)
+	stdin   *os.File
+	gobot.Eventer
+}
+
+func NewKeyboardDriver(name string) *KeyboardDriver {
+	k := &KeyboardDriver{
+		name: name,
+		connect: func(k *KeyboardDriver) (err error) {
+			if err := configure(); err != nil {
+				return err
+			}
+
+			k.stdin = os.Stdin
+			return
+		},
+		listen: func(k *KeyboardDriver) {
+			ctrlc := bytes{3}
+
+			for {
+				var keybuf bytes
+				k.stdin.Read(keybuf[0:3])
+
+				if keybuf == ctrlc {
+					proc, err := os.FindProcess(os.Getpid())
+					if err != nil {
+						log.Fatal(err)
+					}
+
+					proc.Signal(os.Interrupt)
+					break
+				}
+
+				gobot.Publish(k.Event("key"), Parse(keybuf))
+
+			}
+		},
+		Eventer: gobot.NewEventer(),
+	}
+
+	k.AddEvent("key")
+
+	return k
+}
+
+func (k *KeyboardDriver) Name() string                 { return k.name }
+func (k *KeyboardDriver) Connection() gobot.Connection { return nil }
+
+// Start initializes keyboard by grabbing key events as they come in and
+// publishing a key event
+func (k *KeyboardDriver) Start() (errs []error) {
+	if err := k.connect(k); err != nil {
+		return []error{err}
+	}
+
+	go k.listen(k)
+
+	return
+}
+
+// Halt stops camera driver
+func (k *KeyboardDriver) Halt() (errs []error) {
+	if originalState != "" {
+		return restore()
+	}
+	return
+}