EV3Key

java.lang.Object
- ev3dev.sensors.EV3Key

```
public class EV3Key
extends java.lang.Object
```
Implementation of the Key interface for EV3. The easiest way to get an instance of this class is to use one of the static constants of the Button class.

Nested Class Summary

Nested Classes
Modifier and Type Class and Description

(package private) static class EV3Key.KeyType

Nested Classes
Modifier and Type	Class and Description
`(package private) static class`	`EV3Key.KeyType`

Field Summary

Fields
Modifier and Type	Field and Description
`static int`	`BUTTON_ALL`
`static int`	`BUTTON_BACKSPACE`
`static int`	`BUTTON_DOWN`
`static int`	`BUTTON_ENTER`
`static int`	`BUTTON_ESCAPE`
`static int`	`BUTTON_LEFT`
`static int`	`BUTTON_RIGHT`
`static int`	`BUTTON_UP`
`private static int`	`EVENT_BUFFER_LEN`
`private static int`	`KEY_ID_INDEX`
`private static int`	`KEY_STATE_INDEX`
`private static byte`	`keyBits`
`private static java.lang.Thread`	`keyEventReader`
`private static java.util.Map<EV3Key.KeyType,java.util.Set<KeyListener>>`	`keyListeners`
`private EV3Key.KeyType`	`keyType`
`private static Logger`	`log`
`(package private) static byte`	`STATE_KEY_DOWN`
`(package private) static byte`	`STATE_KEY_UP`
`private static java.lang.String`	`SYSTEM_EVENT_PATH`

Constructor Summary

Constructors
Constructor and Description

EV3Key(EV3Key.KeyType keyType)
Create an Instance of EV3Key.

EV3Key(int id)
Create an Instance of EV3Key by the numeric key ID.

Constructors
Constructor and Description
`EV3Key(EV3Key.KeyType keyType)` Create an Instance of EV3Key.
`EV3Key(int id)` Create an Instance of EV3Key by the numeric key ID.

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`void`	`addKeyListener(KeyListener keyListener)` Adds a listener for this key's 'pressed' and 'released' events.
`private static void`	`broadcastToListeners(EV3Key.KeyType keyType, java.util.function.BiConsumer<KeyListener,Key> notificationMethod)`
`boolean`	`equals(java.lang.Object obj)`
`int`	`getId()` Returns the ID of this key.
`java.lang.String`	`getName()` Returns the name of this key.
`int`	`hashCode()`
`boolean`	`isDown()` A non-blocking check of whether this key is currently pressed.
`boolean`	`isUp()` A non-blocking check of whether this key is currently released.
`(package private) static void`	`processKeyEvent(byte keyId, byte keyState)`
`void`	`removeKeyListener(KeyListener keyListener)` Removes the given key event listener.
`void`	`simulateEvent(int i)`
`java.lang.String`	`toString()`
`void`	`waitForPress()` A blocking call that will return once this key gets pressed.
`void`	`waitForPressAndRelease()` A blocking call that will first wait for this key being pressed and then it waits for this key being released.

Methods inherited from class java.lang.Object
clone, finalize, getClass, notify, notifyAll, wait, wait, wait

- Field Detail
  - log
```
private static final Logger log
```
  - BUTTON_UP
```
public static final int BUTTON_UP
```
    See Also:
    
    Constant Field Values
  - BUTTON_DOWN
```
public static final int BUTTON_DOWN
```
    See Also:
    
    Constant Field Values
  - BUTTON_LEFT
```
public static final int BUTTON_LEFT
```
    See Also:
    
    Constant Field Values
  - BUTTON_RIGHT
```
public static final int BUTTON_RIGHT
```
    See Also:
    
    Constant Field Values
  - BUTTON_ENTER
```
public static final int BUTTON_ENTER
```
    See Also:
    
    Constant Field Values
  - BUTTON_BACKSPACE
```
public static final int BUTTON_BACKSPACE
```
    See Also:
    
    Constant Field Values
  - BUTTON_ESCAPE
```
public static final int BUTTON_ESCAPE
```
    See Also:
    
    Constant Field Values
  - BUTTON_ALL
```
public static final int BUTTON_ALL
```
    See Also:
    
    Constant Field Values
  - STATE_KEY_DOWN
```
static final byte STATE_KEY_DOWN
```
    See Also:
    
    Constant Field Values
  - STATE_KEY_UP
```
static final byte STATE_KEY_UP
```
    See Also:
    
    Constant Field Values
  - SYSTEM_EVENT_PATH
```
private static final java.lang.String SYSTEM_EVENT_PATH
```
    See Also:
    
    Constant Field Values
  - EVENT_BUFFER_LEN
```
private static final int EVENT_BUFFER_LEN
```
    See Also:
    
    Constant Field Values
  - KEY_ID_INDEX
```
private static final int KEY_ID_INDEX
```
    See Also:
    
    Constant Field Values
  - KEY_STATE_INDEX
```
private static final int KEY_STATE_INDEX
```
    See Also:
    
    Constant Field Values
  - keyBits
```
private static byte keyBits
```
  - keyListeners
```
private static java.util.Map<EV3Key.KeyType,java.util.Set<KeyListener>> keyListeners
```
  - keyEventReader
```
private static final java.lang.Thread keyEventReader
```
  - keyType
```
private EV3Key.KeyType keyType
```
- Constructor Detail
  - EV3Key
```
public EV3Key(EV3Key.KeyType keyType)
```
    Create an Instance of EV3Key.
    
    Parameters:
    
    keyType -
  - EV3Key
```
public EV3Key(int id)
```
    Create an Instance of EV3Key by the numeric key ID.
    
    Parameters:
    
    id -
- Method Detail
  - getId
```
public int getId()
```
    Returns the ID of this key.
    
    Returns:
    
    one of the BUTTON_* constants
  - isDown
```
public boolean isDown()
```
    A non-blocking check of whether this key is currently pressed. This is
    
    Returns:
    
    true for pressed, false otherwise
  - isUp
```
public boolean isUp()
```
    A non-blocking check of whether this key is currently released.
    
    Returns:
    
    true for released, false otherwise
  - waitForPress
```
public void waitForPress()
```
    A blocking call that will return once this key gets pressed. This method returns immediately if this key is pressed already.
  - waitForPressAndRelease
```
public void waitForPressAndRelease()
```
    A blocking call that will first wait for this key being pressed and then it waits for this key being released. Unlike waitForPress(), this method will always block because this key cannot be already pressed and released at the same time. At the least, this key will be pressed so this method will only wait for it to be released.
  - addKeyListener
```
public void addKeyListener(KeyListener keyListener)
```
    Adds a listener for this key's 'pressed' and 'released' events. If this is the Button.ALL key, the listener will be getting notifications for any key events.
    
    Parameters:
    
    keyListener -
  - removeKeyListener
```
public void removeKeyListener(KeyListener keyListener)
```
    Removes the given key event listener.
    
    Parameters:
    
    keyListener -
  - simulateEvent
```
public void simulateEvent(int i)
```
  - getName
```
public java.lang.String getName()
```
    Returns the name of this key.
    
    Returns:
    
    e.g. "LEFT" or "ENTER"
  - equals
```
public boolean equals(java.lang.Object obj)
```
    Overrides:
    
    equals in class java.lang.Object
    
    Parameters:
    
    obj -
    
    Returns:
    
    true if the obj is an instance of Key and if the button IDs are the same.
  - hashCode
```
public int hashCode()
```
    Overrides:
    
    hashCode in class java.lang.Object
    
    Returns:
    
    the button ID based hash code
  - toString
```
public java.lang.String toString()
```
    Overrides:
    
    toString in class java.lang.Object
  - processKeyEvent
```
static void processKeyEvent(byte keyId,
                            byte keyState)
```
  - broadcastToListeners
```
private static void broadcastToListeners(EV3Key.KeyType keyType,
                                         java.util.function.BiConsumer<KeyListener,Key> notificationMethod)
```

Class EV3Key

Nested Class Summary

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

log

BUTTON_UP

BUTTON_DOWN

BUTTON_LEFT

BUTTON_RIGHT

BUTTON_ENTER

BUTTON_BACKSPACE

BUTTON_ESCAPE

BUTTON_ALL

STATE_KEY_DOWN

STATE_KEY_UP

SYSTEM_EVENT_PATH

EVENT_BUFFER_LEN

KEY_ID_INDEX

KEY_STATE_INDEX

keyBits

keyListeners

keyEventReader

keyType

Constructor Detail

EV3Key

EV3Key

Method Detail

getId

isDown

isUp

waitForPress

waitForPressAndRelease

addKeyListener

removeKeyListener

simulateEvent

getName

equals

hashCode

toString

processKeyEvent

broadcastToListeners