Expanding Keyboard Reference

Copyright 2019 Moddable Tech, Inc.
Revised: July 2, 2019

The vertical and horizontal expanding keyboard modules implement touch screen keyboards for use with Piu on Moddable One and Moddable Two products. The keys automatically expand when tapped, eliminating the need for a stylus. Both keyboards implement the same API.

• Source code: vertical/keyboard.js horizontal/keyboard.js
• Relevant Examples: vertical-expanding-keyboard horizontal-expanding-keyboard

The keyboards are designed to fit a 240 x 320 screen. The vertical keyboard height is 185 pixels. The horizontal keyboard height is 164 pixels and designed to run in a landscape orientation. Both orientations fill the application screen width.

Key presses trigger events that can be captured in the application's behavior. The style (font and weight) of the keyboard's text are defined by a Style object supplied by the caller. This allows the use of Style templates.

A KeyboardField container and associated behavior are additionally provided to facilitate integrating the keyboard into apps. This container displays the keys pressed along with a blinking I-beam cursor. The KeyboardField height should be tall enough to fit the I-beam cursor, which is outset from the field text.

Keyboard Module Exports

Export	Type	Description
VerticalExpandingKeyboard	constructor	Constructor used to create vertical expanding keyboard instances.
HorizontalExpandingKeyboard	constructor	Constructor used to create horizontal expanding keyboard instances.

import {VerticalExpandingKeyboard} from "keyboard";
import {HorizontalExpandingKeyboard} from "keyboard";

KeyboardField Module Exports

Export	Type	Description
KeyboardField	constructor	Constructor used to create keyboard field instances.

import {KeyboardField} from "common/keyboard";

Keyboard Objects

Constructor Description

VerticalExpandingKeyboard(behaviorData, dictionary)

HorizontalExpandingKeyboard(behaviorData, dictionary)

Argument	Type	Description
behaviorData	*	A parameter that is passed into the onCreate function of the keyboard's behavior. This may be any type of object, including null or a dictionary with arbitrary parameters.
dictionary	object	An object with properties to configure the resulting keyboard. Only parameters specified in the Dictionary section below will have an effect; other parameters will be ignored.

Returns a VerticalExpandingKeyboard or HorizontalExpandingKeyboard Container instance.

const KeyboardStyle = Style.template({ font:"18px Roboto", color:"black" });
let keyboard = new VerticalExpandingKeyboard(null, { Style:KeyboardStyle, target:this.data["FIELD"] });

Dictionary

Parameter	Type	Default Value	Description
Style	style	n/a	Required. A Piu Style object that will be used for the text on keys.
target	object	n/a	Required. A Piu Container object that will receive the onKeyUp event.
doTransition	boolean	false	Whether or not to transition in the keyboard when it is first displayed and transition out when dismissed.

Triggered Events

onKeyboardOK(container, text)

Argument	Type	Description
container	object	The behavior's Container object
text	string	The complete string entered into the field

The keyboard bubbles this event when the OK button is pressed.

onKeyboardRowsContracted(container)

Argument	Type	Description
container	object	The behavior's Container object

The keyboard bubbles this event when it is done horizontally contracting the keyboard rows back to the unzoomed view.

onKeyboardRowsExpanded(container)

Argument	Type	Description
container	object	The behavior's Container object

The keyboard bubbles this event when it is done horizontally expanding the keyboard rows to the zoomed view.

onKeyboardTransitionFinished(container, out)

Argument	Type	Description
container	object	The behavior's Container object
out	boolean	Set true when the keyboard transitions out of view, false when the keyboard transitions into view

The keyboard bubbles this event when it is done transitioning on and off the screen. The onKeyboardTransitionFinished function will usually be implemented and triggered in the calling application's behavior.

onKeyUp(container, key)

Argument	Type	Description
container	object	The behavior's Container object
key	string	The string value of the key that was pressed (e.g., 'a', '3', '$'). It can also be \b for backspace or \r for the submit button.

The keyboard bubbles the onKeyUp event when a key is released. The onKeyUp function will usually be implemented and triggered in the calling application's behavior.

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KeyboardField Object

Constructor Description

KeyboardField(behaviorData, dictionary)

Argument	Type	Description
behaviorData	*	A parameter that is passed into the onCreate function of the keyboard field's behavior. This may be any type of object, including null or a dictionary with arbitrary parameters.
dictionary	object	An object with properties to configure the resulting keyboard field. Only parameters specified in the Dictionary section below will have an effect; other parameters will be ignored.

Returns a KeyboardField Container instance.

const FieldStyle = Style.template({ font: "20px Open Sans", color: "black", horizontal:"left", vertical:"middle" });
let keyboardField = new KeyboardField(null, { Style:FieldStyle });

Dictionary

Parameter	Type	Default Value	Description
Style	style	n/a	Required. A Piu Style object that will be used for the keyboard entry text.
password	boolean	false	Set true to enable password mode. The password mode hides each character displayed after a short delay.

Triggered Events

onKeyboardOK(container, text)

Argument	Type	Description
container	object	The behavior's Container object
text	string	The complete string entered into the field

The keyboard bubbles this event when the OK button is pressed.