jQuery Continuous Key Press Handler

A jQuery based Javascript class that handles all key presses. Offers a continuous key press event on multiple keys at a custom refresh rate. Allows the setting of a different callback function for press and release of key.

Requires

jQuery

Defaults

Continuous key press: false

Refresh rate: 30 per second

Usage

Instantiate the controller by assigning it to a variable. Good practice is to use the same variable name as the object. It is only neccesary to instantiate the KeyController object once.

var KeyController = new KeyController();

Assign functions to keys by calling the add() method from the handler. This method can be called multiple times for different keys.

KeyController.add({
  key, // which key to assign following functions to
  down: function(){}, // function to run when key is pressed down, and the function that is run if continuous key press event is set
  up: function(){}, // function to run when key is released
  continuous, // boolean to toggle continuous key press. optional. default value: true
  rate // number of times per second to fire the down event whilst key is held down. optional. default value: 30
}); 

Pass the callback functions to the respective arguments. Assign them to a key. Toggle whether the down() function will run continuously, and if so, set the refresh rate.

In this example, the message "key has been pressed" will appear in the console 10 times a second whilst the user is holding down the "A" key. On release, the message "key has been released" will appear.

KeyController.add({
  key: '65',
  down: function(){
    console.log('key has been pressed');
  },
  up: function(){
    console.log('key has been released');
  },
  continuous: true,
  rate: 10
}); 

Full example

Below is a small example that continually prints a message in the console whilst the "A" key is pressed and held down, and then prints a last message when the "A" key has been released. Also it prints one message in the console when the "D" key is pressed, and then prints a message when the "D" key has been released.

var KeyController = new KeyController();

KeyController.add({
  key: '65',
  down: function(){
    console.log('The A key has been pressed and this message will keep printing to the console at a rate of 10 per second.');
  },
  up: function(){
    console.log('The A key has been released, the messages will now stop.');
  },
  continuous: true,
  rate: 10
}); 

KeyController.add({
  key: '68',
  down: function(){
    console.log('The D key has been pressed.');
  },
  up: function(){
    console.log('The D key has been released.');
  },
  continuous: false
});