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

attachAttach the keyboard event handlers to an Element
detachDetach the keyboard event handlers from the element it is attached to.
isPressedReturn true if the key is currently down.
wasPressedReturns true if the key was pressed since the last update.
wasReleasedReturns true if the key was released since the last update.

Events

keydownEvent fired when a key is pressed.
keyupEvent fired when a key is released.

Inherited

Methods

fireFire an event, all additional arguments are passed on to the event listener
hasEventTest if there are any handlers bound to an event name
offDetach an event handler from an event.
onAttach an event handler to an event
onceAttach 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, WindowElement 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
optionsObjectOptional options object.
options.preventDefaultBooleanCall 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.stopPropagationBooleanCall 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

elementElementThe 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

keyNumberThe 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

keyNumberThe 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

keyNumberThe 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.KeyboardEventThe 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.KeyboardEventThe 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

nameObjectName 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

nameStringThe 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

nameStringName of the event to unbind
callbackpc.callbacks.HandleEventFunction to be unbound.
scopeObjectScope 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

nameStringName of the event to bind the callback to
callbackpc.callbacks.HandleEventFunction that is called when event is fired. Note the callback is limited to 8 arguments.
scopeObjectObject 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

nameStringName of the event to bind the callback to
callbackpc.callbacks.HandleEventFunction that is called when event is fired. Note the callback is limited to 8 arguments.
scopeObjectObject to use as 'this' when the event is fired, defaults to current this

Returns

pc.EventHandler Self for chaining.