Key

Use Key to construct keys, bind callbacks, access their properties, and enable or disable them. You can have multiple handlers for a single key combination, however only one can be enabled at a time.

info

Enabling a key combination that has been exclusively registered by another app will fail. macOS gives exclusivity to the first app that requests the key combination.

See Keys for a list available keys for binding.

Interface

class Key implements Identifiable

  static int on(String key, Array<String> modifiers, Function callback)
  static void once(String key, Array<String> modifiers, Function callback)
  static void off(int identifier)

  property String key
  property Array<String> modifiers

  constructor Key Key(String key, Array<String> modifiers, Function callback)
  boolean isEnabled()
  boolean enable()
  boolean disable()

end

Static Methods

• on(String key, Array<String> modifiers, Function callback) constructs a managed handler for a key and returns the identifier for the handler, for arguments see new Key(...)
• once(String key, Array<String> modifiers, Function callback) constructs a managed handler for a key that is by default only triggered one time and then disabled, for more control you can explicitly return false from the callback function and the handler will not be disabled until you return something else, for arguments see new Key(...)
• off(int identifier) disables the managed handler for a key with the given identifier

Instance Properties

• key read-only property for the key character in lower case or case sensitive special key
• modifiers read-only property for the key modifiers in lower case

Constructor

• new Key(String key, Array<String> modifiers, Function callback) constructs and binds the key character with the specified modifiers (can be an empty list) to a callback function and returns the handler, you must keep a reference to the handler in order for your callback to get called, you can have multiple handlers for a single key combination, only one can be enabled at a time, any previous handler for the same key combination will automatically be disabled, the callback function receives its handler as the first argument and as the second argument a boolean that indicates if the key was repeated (key combination is held down)

Instance Methods

• isEnabled() returns true if the key handler is enabled, by default true
• enable() enables the key handler, any previous handler for the same key combination will automatically be disabled, returns true if successful
• disable() disables the key handler, returns true if successful

Example

// Bind “Control + Shift + Q” to a callback function
const identifier = Key.on('q', ['control', 'shift'], () => {
  console.log('Key combination pressed.');
});

// Disable the handler and release the key combination
Key.off(identifier);