API Reference

Class List

pc.Keyboard

Extends: pc.EventHandler

A Keyboard device bound to an Element. Allows you to detect the state of the key presses. Note, Keyboard object must be attached to an Element before it can detect any key presses.

var keyboard = new pc.Keyboard(window); // attach keyboard listeners to the window

Summary

Methods

attach

Attach the keyboard event handlers to an Element.

detach

Detach the keyboard event handlers from the element it is attached to.

isPressed

Return true if the key is currently down.

wasPressed

Returns true if the key was pressed since the last update.

wasReleased

Returns true if the key was released since the last update.

Events

keydown

Event fired when a key is pressed.

keyup

Event fired when a key is released.

Inherited

Methods

fire

Fire an event, all additional arguments are passed on to the event listener.

hasEvent

Test if there are any handlers bound to an event name.

off

Detach an event handler from an event.

on

Attach an event handler to an event.

once

Attach an event handler to an event.

Details

Constructor

Keyboard([element], [options])

Create a new Keyboard object.

var keyboard = new pc.Keyboard(window); // attach keyboard listeners to the window

Parameters

elementElement, Window

Element to attach Keyboard to. Note that elements like <div> can't accept focus by default. To use keyboard events on an element like this it must have a value of 'tabindex' e.g. tabindex="0". For more details: http://www.w3.org/WAI/GL/WCAG20/WD-WCAG20-TECHS/SCR29.html.

optionsobject

Optional options object.

options.preventDefaultboolean

Call preventDefault() in key event handlers. This stops the default action of the event occurring. e.g. Ctrl+T will not open a new browser tab

options.stopPropagationboolean

Call stopPropagation() in key event handlers. This stops the event bubbling up the DOM so no parent handlers will be notified of the event

Methods

attach(element)

Attach the keyboard event handlers to an Element.

Parameters

elementElement

The element to listen for keyboard events on.

detach()

Detach the keyboard event handlers from the element it is attached to.

isPressed(key)

Return true if the key is currently down.

Parameters

keynumber

The keyCode of the key to test. See the pc.KEY_* constants.

Returns

boolean

True if the key was pressed, false if not.

wasPressed(key)

Returns true if the key was pressed since the last update.

Parameters

keynumber

The keyCode of the key to test. See the pc.KEY_* constants.

Returns

boolean

True if the key was pressed.

wasReleased(key)

Returns true if the key was released since the last update.

Parameters

keynumber

The keyCode of the key to test. See the pc.KEY_* constants.

Returns

boolean

True if the key was pressed.

Events

keydown

Event fired when a key is pressed.

var onKeyDown = function (e) {
    if (e.key === pc.KEY_SPACE) {
        // space key pressed
    }
    e.event.preventDefault(); // Use original browser event to prevent browser action.
};
app.keyboard.on("keydown", onKeyDown, this);

Parameters

eventpc.KeyboardEvent

The Keyboard event object. Note, this event is only valid for the current callback.

keyup

Event fired when a key is released.

var onKeyUp = function (e) {
    if (e.key === pc.KEY_SPACE) {
        // space key released
    }
    e.event.preventDefault(); // Use original browser event to prevent browser action.
};
app.keyboard.on("keyup", onKeyUp, this);

Parameters

eventpc.KeyboardEvent

The Keyboard event object. Note, this event is only valid for the current callback.

Inherited

Methods

fire(name, [arg1], [arg2], [arg3], [arg4], [arg5], [arg6], [arg7], [arg8])

Fire an event, all additional arguments are passed on to the event listener.

obj.fire('test', 'This is the message');

Parameters

nameobject

Name of event to fire.

arg1*

First argument that is passed to the event handler.

arg2*

Second argument that is passed to the event handler.

arg3*

Third argument that is passed to the event handler.

arg4*

Fourth argument that is passed to the event handler.

arg5*

Fifth argument that is passed to the event handler.

arg6*

Sixth argument that is passed to the event handler.

arg7*

Seventh argument that is passed to the event handler.

arg8*

Eighth argument that is passed to the event handler.

Returns

pc.EventHandler

Self for chaining.

hasEvent(name)

Test if there are any handlers bound to an event name.

obj.on('test', function () { }); // bind an event to 'test'
obj.hasEvent('test'); // returns true
obj.hasEvent('hello'); // returns false

Parameters

namestring

The name of the event to test.

Returns

boolean

True if the object has handlers bound to the specified event name.

off([name], [callback], [scope])

Detach an event handler from an event. If callback is not provided then all callbacks are unbound from the event, if scope is not provided then all events with the callback will be unbound.

var handler = function () {
};
obj.on('test', handler);

obj.off(); // Removes all events
obj.off('test'); // Removes all events called 'test'
obj.off('test', handler); // Removes all handler functions, called 'test'
obj.off('test', handler, this); // Removes all hander functions, called 'test' with scope this

Parameters

namestring

Name of the event to unbind.

callbackpc.callbacks.HandleEvent

Function to be unbound.

scopeobject

Scope that was used as the this when the event is fired.

Returns

pc.EventHandler

Self for chaining.

on(name, callback, [scope])

Attach an event handler to an event.

obj.on('test', function (a, b) {
    console.log(a + b);
});
obj.fire('test', 1, 2); // prints 3 to the console

Parameters

namestring

Name of the event to bind the callback to.

callbackpc.callbacks.HandleEvent

Function that is called when event is fired. Note the callback is limited to 8 arguments.

scopeobject

Object to use as 'this' when the event is fired, defaults to current this.

Returns

pc.EventHandler

Self for chaining.

once(name, callback, [scope])

Attach an event handler to an event. This handler will be removed after being fired once.

obj.once('test', function (a, b) {
    console.log(a + b);
});
obj.fire('test', 1, 2); // prints 3 to the console
obj.fire('test', 1, 2); // not going to get handled

Parameters

namestring

Name of the event to bind the callback to.

callbackpc.callbacks.HandleEvent

Function that is called when event is fired. Note the callback is limited to 8 arguments.

scopeobject

Object to use as 'this' when the event is fired, defaults to current this.

Returns

pc.EventHandler

Self for chaining.