modo.keyListener

The keyListener object is no creatable element, but attaches itself to the modo core. Once enabled with modo.keyListener.enable(), it observes any keystroke made and emits events according to it.

Its possible to submit a scope to the keyListener, to make it possible to forward key events to only a single element temporarily.

Heads up: This is not a element constructor!

About event scopes

With event scopes, we introduced a pattern that is not used in BackboneJS. We added the scopes to the keyListener element, because it may be necessary to override captured keys in different states of your application.

Example: You listen for multiple global hotkeys or keystrokes inside your application. When a certain dialog is displayed, you want to mute the global hotkeys for the time the dialog is open.

Doing this with event scopes is easy: just set the scope when opening the dialog and all global key-events won't be triggered anymore. Release the scope after the dialog has been closed and all keystrokes are available again.

Properties

keymapObject

The keymap object stores the relations between key names in human language and and javascript keycodes. The keymap object contains keymaps for different languages, since keyboard layouts differ from country to country. The keymap is picked through navigator.language.

lastKeyString

Contains the last pressed key.

isScopedBoolean

Contains information about if the keyListener currently runs in scoped mode or not.

Methods

enable()

Enables the keyListener. It won't listen for, or capture keyboard events before this method is called. Calling it multiple times has no effect. So you may call it from every application module that needs the keyListener.

disable()

This method disables the keyListener. No more keyboard events will be triggered until enable() is called again.

isPressed(key)

Returns true, when the given key is currently pressed. key can either be the keys name, or its index.

setScope(scope)

Will shift the current event scope to the submitted namespace. Can be called multiple times - if a later scope is being released, the scope switches back to the previous state until no more scopes are active.

releaseScope(scope)

Removes a scope from the scopes list. If it was the last submitted scope, the scope pointer will switch back to the previously submitted scope.

onScoped(scope, eventName, callback, [context])

Wrapper method for the "on" method, to bind to scoped events. Read more about Backbone.Events.on()

offScoped(scope, eventName, callback, context)

Wrapper method for the "off" method, to unbind scoped events. Read more about Backbone.Events.off()

Events

stroke

Will be triggered when a key-stroke (combination of keys) has been pressed.

The stroke name is created like this:

[ctrl+][shift[+]][alt]+keyName

So for example: ctrl+u or alt+f or even ctrl+shift+z.

[keyname]

You can listen to specific keys directly, like so:

modo.keyListener.on('u', function(e){});

The event will be triggered, when the specified key has been pressed.

Special key names are: backspace, tab, enter, shift, ctrl, alt, pause, capslock, escape, space, pageup, pagedown, end, home, left, up, right, down, insert, delete, f1-f12, numlock, scrolllock

keyPress

This event is triggered on every key press. The name of the pressed key is submitted as an event attribute.