VirtualKeyboard API

The {{VirtualKeyboard}} API provides authors with greater control over the visibility of the virtual keyboard (VK), and greater ability to adapt the layout of web pages when VK visibility changes.

Introduction

This section is non-normative.

The Virtual Keyboard (VK) is the on-screen keyboard used for input in scenarios where a hardware keyboard may not be available. User agents respond to the presence of the VK, without any exposure of this information to web developers in the following way: 1. Repositioning the user agent above the VK 2. Reducing the size of the layout viewport so the VK doesn't occlude it 3. Reducing the size of the visual viewport and padding the layout viewport to ensure it can be shifted above the VK This API provides a fourth option that allows the user agent to leave its layout and visual viewports unchanged and instead provide information about the intersection of the VK and layout viewport so that the author can adapt the layout of their web pages using JavaScript or CSS environment variables.

Figure showing virtual keyboard on dual screen device

Figure showing virtual keyboard on single-touch screen device

The VirtualKeyboard Interface

            partial interface Navigator {
                [SecureContext, SameObject] readonly attribute VirtualKeyboard virtualKeyboard;
            };

            [Exposed=Window, SecureContext]
            interface VirtualKeyboard : EventTarget {
                undefined show();
                undefined hide();
                readonly attribute DOMRect boundingRect;
                attribute boolean overlaysContent;
                attribute EventHandler ongeometrychange;
            };

The {{VirtualKeyboard}} object has an associated:

boundingRect

A {{DOMRect}}, initially has zero values.

overlaysContent

A boolean, initially `false`. When this attribute is set to `true`, a user agent MUST NOT resize its [=document=]'s viewport or visual viewport.

show() method

The method must follow these steps:

Let |window| be [=this=]'s [=relevant global object=]. Assert that |window| is a {{Window}} object.
If |window| does not have [=sticky activation=], abort these steps.
If the focused element is not a form control (such as the value of the [=textarea=] element), or an [=editing host=] (e.g., using contenteditable) then abort these steps.
If the {{ElementContentEditable/virtualKeyboardPolicy}} is not {{manual}} or inputMode's attribute value is none then abort these steps.
Call the system API to show the VK.
[=In parallel=], follow these steps:
1. Wait for the virtual keyboard to be shown by the system.
2. Call {{VirtualKeyboard/set the virtual keyboard bounding rect}} with the keyboard's OS reported bounding rectangle and the [=document=]'s viewport rectangle.
3. [=Fire an event=] named "geometrychange" at [=this=].

hide() method

The method must follow these steps:

Let |window| be [=this=]'s [=relevant global object=]. Assert that |window| is a {{Window}} object.
If |window| does not have [=sticky activation=], abort these steps.
If the focused element's {{ElementContentEditable/virtualKeyboardPolicy}} is not {{manual}} or inputMode's attribute value is none then abort these steps.
Call the system API to hide the VK.
[=In parallel=], follow these steps:
1. Wait for the virtual keyboard to be hidden by the system.
2. Call {{VirtualKeyboard/set the virtual keyboard bounding rect}} with the keyboard's OS reported bounding rectangle (which has all 0 values) and the [=document=]'s viewport rectangle.
3. [=Fire an event=] named "geometrychange" at [=this=].

Platform heuristics may impose additional restrictions on VK {{VirtualKeyboard/show()}} and {{VirtualKeyboard/hide()}}. e.g., on Windows the pointer type MUST be touch or pen.

A few people have expressed concerns around {{VirtualKeyboard/show()}} and {{VirtualKeyboard/hide()}} methods not being promise-based, but we believe it is a better design for web developers to use {{VirtualKeyboard/ongeometrychange}} event since it is fired when VK visibility changes, making the return values unnecessary.

{{VirtualKeyboard/overlaysContent}}

The {{VirtualKeyboard/overlaysContent}} getter steps are to return [=this=]'s {{VirtualKeyboard/overlaysContent}}.

The {{VirtualKeyboard/overlaysContent}} setter steps are to set [=this=]'s {{VirtualKeyboard/overlaysContent}} to the given value.

{{VirtualKeyboard/boundingRect}}

The attribute reports the intersection of the VK with the [=document=]'s viewport in client coordinates. Call {{VirtualKeyboard/set the virtual keyboard bounding rect}}.

set the virtual keyboard bounding rect

To set the virtual keyboard bounding rect, with |osk| (a DOMRect representing the on-screen keyboard rectangle), and |lv| (a DOMRect representing the [=document=]'s viewport rectangle) as inputs, run the following steps:

Let |osk| be the on-screen keyboard rectangle that is the result of running the algorithm in {{VirtualKeyboard/show()}} or {{VirtualKeyboard/hide()}} on [=this=].
Let |lv| be the [=document=]'s viewport that is the result of running the algorithm in {{VirtualKeyboard/show()}} or {{VirtualKeyboard/hide()}} on [=this=].
Map |osk| to the coordinate space of |lv|.
Let |bounds| be a {{DOMRect}} object.
Update |bounds| by intersecting |lv| with the |osk|.
Map |bounds| to the coordinate space of |lv|.
Return |bounds|.

The {{VirtualKeyboard/boundingRect}} getter steps are to return [=this=]'s {{VirtualKeyboard/boundingRect}}.

ongeometrychange

The event is dispatched when the intersection of the VK and the [=document=]'s viewport changes, e.g., in response to the VK being shown or hidden or the browser window being repositioned.

Extensions to the ElementContentEditable mixin

            partial interface ElementContentEditable {
                [CEReactions] attribute DOMString virtualKeyboardPolicy;
           };

Add handling of input and textarea.

The virtualKeyboardPolicy is an enumerated attribute whose keywords are the string, auto, and manual. The IDL attribute must reflect the respective content attributes of the same name. When specified on an element that is a contenteditable host, auto causes the corresponding editable element to automatically show the VK when it is focused or tapped & manual decouples focus and tap on the editable element from changes in the VK’s current state - the VK remains as it was.
The change in setting of any {{ElementContentEditable/virtualKeyboardPolicy}} attribute value, negates currently defined behavior, unless it is a change from auto to empty string or vice versa.

Specify timing relative to events like focus.

When auto enumerated attribute is set, the VK is handled by the browser.
When manual enumerated attribute is set, it prevents the default handling of the VK in a browser and needs to be handled by the script.
When empty string enumerated attribute is set, the VK is handled by the browser.

Name	Value
keyboard-inset-top	length
keyboard-inset-right	length
keyboard-inset-bottom	length
keyboard-inset-left	length
keyboard-inset-width	length
keyboard-inset-height	length

Examples

Example with usage of VK control APIs.

                        
                        <div contenteditable virtualkeyboardpolicy="manual" inputmode="text"
                        style="height:50px;width:300px;border:1px solid black;"data-formula="12+30">42</div>
                        <script>
                            let div = document.querySelector("div")
                            div.addEventListener("focusout", handleFocusOut)
                            div.addEventListener("dblclick", handleDblClick)

                            function handleFocusOut() {
                                let formula = parseIntoFormula(div.firstChild.data)
                                div.setAttribute("data-formula", formula)
                                div.firstChild.data = evaluateFormula(formula)
                            }

                            function handleDblClick(e) {
                                div.firstChild.data = div.getAttribute("data-formula")

                                if (e.pointerType == "touch") {
                                    navigator.virtualKeyboard.show()
                                }
                            }

                            function parseIntoFormula(text) {
                                return "12+30"
                            }

                            function evaluateFormula(formula) {
                                return "42"
                            }

                            function handleSuccessfulShow() {
                                // handle success of VK shown
                            }

                            function handleFailedShow() {
                                // handle failure of VK shown
                            }
                        </script>

Examples with usage of overlaysContent and geometry event as a result of VK showing.

                        
                            <meta name="viewport" content="width=device-width, initial-scale=1">
                            <style>
                                body {
                                    display: grid;
                                    margin: 8px;
                                    height: calc(100vh - 16px);
                                    grid-template:
                                    "messages"  1fr
                                    "input"     auto
                                    "keyboard"  env(keyboard-inset-height, 0px);
                                }
                                input[type=text]::placeholder {
                                    color: #444;
                                }
                                input[type=text] {
                                    padding: 10px;
                                    font-size: 24px;
                                    border: 4px solid black;
                                    border-radius: 4px;
                                    background-color: #86DBF6;
                                    justify-self: center;
                                }
                            </style>
                            <div id="messages">...</div>
                            <input type="text" placeholder="type...">
                            <script>
                                if ("virtualKeyboard" in navigator) {
                                    navigator.virtualKeyboard.overlaysContent = true
                                }
                            </script>

The figure and markup below are a representation of a canvas-based spreadsheet that repositions the active cell when the VK is shown. The `geometrychange` event triggers a paint request for the canvas. The painting code can then use the `boundingRect` property to render the active cell in the proper location. Figure showing virtual keyboard on single-touch screen device

                            
                                <meta name="viewport" content="width=device-width, initial-scale=1">
                                <style>
                                    body {
                                        display: grid;
                                        margin: 0;
                                        height: 100vh;
                                        grid-template:
                                        "controls" min-content
                                        "cells"    1fr;
                                    }
                                    #controls {
                                        height: 100px;
                                        background-color: #139CFF;
                                    }
                                    canvas {
                                        justify-self: stretch;
                                        align-self: stretch;
                                    }
                                </style>
                                <div id="controls">...</div>
                                <canvas></canvas>
                                <script type="module">
                                    navigator.virtualKeyboard.overlaysContent = true

                                    navigator.virtualKeyboard.addEventListener("geometrychange", () => {
                                        // Request the canvas be repainted so it can reposition
                                        // the active cell above the virtual keyboard.
                                        requestAnimationFrame(paintCanvas)
                                    })

                                    paintCanvas() {
                                        let keyboardRect = navigator.virtualKeyboard.boundingRect
                                        // Use keyboard rect in omitted code below to paint cells in the
                                        // proper position accounting for the keyboard rect along with
                                        // any panning of the cell area that the user may have performed.
                                    }
                                </script>

The figure below represents a map application that presents a map on one window segment and search results on another. Using the proposal for Window Segments and media queries, the search box shown will increase its bottom margin to remain visible whenever the virtual keyboard appears on the left side of the foldable device. Figure showing virtual keyboard on single-touch screen device

Figure showing virtual keyboard on single-touch screen device

                            
                                <meta name="viewport" content="width=device-width, initial-scale=1">
                                <style>
                                    @media (spanning: single-fold-vertical) {
                                        body {
                                            display: grid;
                                            margin: 0;
                                            height: 100vh;
                                            grid-template-columns: env(fold-left) calc(100vw - env(fold-right));
                                            grid-column-gap: calc(env(fold-right) - env(fold-left));
                                        }
                                        .map {
                                            grid-column: 1;
                                            grid-row: 1;
                                        }
                                        .search-box {
                                        /* overlay into same grid column as the map */
                                            grid-column: 1;
                                            grid-row: 1;

                                            /* position the search box at the bottom of the cell, centered */
                                            align-self: end;

                                            /* margin when keyboard not showing on left screen */
                                            margin: 20px;

                                            /* give it a little style */
                                            padding: 10px;
                                            font-size: 24px;
                                            border: 4px solid black;
                                            border-radius: 4px;
                                            background-color: #86DBF6;
                                        }
                                        .locations-list {
                                            grid-column: 2;
                                            grid-row: 1;
                                        }

                                        @media (env(keyboard-inset-right) <= env(fold-left)) {
                                        /* keyboard is on the left screen, adjust search box */
                                            .search-box {
                                                margin-bottom: calc(20px + env(keyboard-inset-height));
                                            }
                                        }
                                    }
                                </style>
                                <div class="map">...</div>
                                <input class="search-box" type="search" placeholder="search...">
                                <div class="locations-list">...</div>
                                <script type="module">
                                    navigator.virtualKeyboard.overlaysContent = true
                                </script>

Introduction

The VirtualKeyboard Interface

Extensions to the ElementContentEditable mixin

Virtual Keyboard Visibility Change CSS environment variables.

Keyboard inset variables

Examples

Example with usage of VK control APIs.

Examples with usage of overlaysContent and geometry event as a result of VK showing.

Privacy and Security Considerations

{{VirtualKeyboard/hide()}} and {{VirtualKeyboard/show()}} methods

{{VirtualKeyboard/boundingRect}}, {{VirtualKeyboard/overlaysContent}} and {{VirtualKeyboard/ongeometrychange}} attributes

Contributors