KeyboardState Component

src/controls/keyboard.js#L3-L30

Handles valid key related events and key states for the entity.

Note: This is an internally used component, automatically included in the KeyboardSystem.

Events

KeyDown [Data = {KeyboardEvent}]
when a key is pressed
KeyUp [Data = {KeyboardEvent}]
when a key is released

The standard Crafty KeyboardEvent object:

// event name of key event
e.eventName

// Normalized keyCode number according to `Crafty.keys`
e.key

// Original keyboard event, containing additional native properties
e.originalEvent

In addition to binding to these events, the current state (pressed/released) of a key can also be queried using the .isKeyDown method.

Methods

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.isKeyDown()

src/controls/keyboard.js#L40-L65
public Boolean isKeyDown(String keyName)
keyName

Name of the key to check. See Crafty.keys.

[Returns]

The pressed state of the key

public Boolean isKeyDown(Number keyCode)
keyCode

Key code in Crafty.keys.

[Returns]

The pressed state of the key

Determine if a certain key is currently down.

Example

ent.bind('UpdateFrame', function() {
  if (Crafty.s('Keyboard').isKeyDown('SPACE'))
    this.y--;
});
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.resetKeyDown()

src/controls/keyboard.js#L73-L86
public this .resetKeyDown()

Reset all currently pressed keys. Triggers appropriate "KeyUp" events.

This method is called internally, but may be useful when running Crafty in headless mode.

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.triggerKey()

src/controls/keyboard.js#L102-L131
public this triggerKey(String eventName, Object eventData)
eventName

Name of the key event to trigger ("KeyDown" or "KeyUp")

eventData

The key event to trigger

Try to trigger a key event on this entity and persist the key state. This method prevents inconsistent key state. e.g. If this entity didn't receive a "KeyDown" previously, it won't fire a "KeyUp" event.

This method is called internally, but may be useful when running Crafty in headless mode.

Example

var wasTriggered = false;

ent.requires('KeyboardState')
   .bind('KeyUp', function(evt) {
      wasTriggered = true;
   })
   .triggerKey('KeyUp', { key: Crafty.keys.RIGHT_ARROW });

Crafty.log(wasTriggered); // prints false

See Also