1. 6ユーザーとの対話処理
    1. 6.1 The hidden attribute
    2. 6.2 Page visibility
      1. 6.2.1 The VisibilityStateEntry interface
    3. 6.3 Inert subtrees
      1. 6.3.1 Modal dialogs and inert subtrees
      2. 6.3.2 The inert attribute
    4. 6.4 Tracking user activation
      1. 6.4.1 Data model
      2. 6.4.2 Processing model
      3. 6.4.3 APIs gated by user activation
      4. 6.4.4 The UserActivation interface
      5. 6.4.5 User agent automation
    5. 6.5 Activation behavior of elements
      1. 6.5.1 The ToggleEvent interface
    6. 6.6 Focus
      1. 6.6.1 Introduction
      2. 6.6.2 Data model
      3. 6.6.3 The tabindex attribute
      4. 6.6.4 Processing model
      5. 6.6.5 Sequential focus navigation
      6. 6.6.6 Focus management APIs
      7. 6.6.7 The autofocus attribute
    7. 6.7 Assigning keyboard shortcuts
      1. 6.7.1 Introduction
      2. 6.7.2 The accesskey attribute
      3. 6.7.3 Processing model
    8. 6.8 Editing
      1. 6.8.1 Making document regions editable: The contenteditable content attribute
      2. 6.8.2 Making entire documents editable: the designMode getter and setter
      3. 6.8.3 Best practices for in-page editors
      4. 6.8.4 Editing APIs
      5. 6.8.5 Spelling and grammar checking
      6. 6.8.6 Writing suggestions
      7. 6.8.7 Autocapitalization
      8. 6.8.8 Autocorrection
      9. 6.8.9 Input modalities: the inputmode attribute
      10. 6.8.10 Input modalities: the enterkeyhint attribute
    9. 6.9 Find-in-page
      1. 6.9.1 Introduction
      2. 6.9.2 Interaction with details and hidden=until-found
      3. 6.9.3 Interaction with selection
    10. 6.10 Close requests and close watchers
      1. 6.10.1 Close requests
      2. 6.10.2 Close watcher infrastructure
      3. 6.10.3 The CloseWatcher interface

6 User interaction

6.1 The hidden attribute

Global_attributes/hidden

Support in one engine only.

FirefoxNoSafariNoChrome102+
OperaNoEdge102+
Edge (Legacy)?Internet ExplorerNo
Firefox Android?Safari iOS?Chrome Android?WebView Android?Samsung Internet?Opera Android?

Global_attributes/hidden

Support in all current engines.

Firefox4+Safari5.1+Chrome10+
Opera?Edge79+
Edge (Legacy)12+Internet Explorer11
Firefox Android?Safari iOS?Chrome Android?WebView Android4+Samsung Internet?Opera Android?

すべてのHTML要素hiddenコンテンツ属性設定を持ってもよい。The hidden attribute is an enumerated attribute with the following keywords and states:

キーワード状態概要
hiddenhiddenWill not be rendered.
(the empty string)
until-foundhidden until foundWill not be rendered, but content inside will be accessible to find-in-page and fragment navigation.

The attribute's missing value default is the not hidden state, and its invalid value default is the hidden state.

When an element has the hidden attribute in the hidden state, it indicates that the element is not yet, or is no longer, directly relevant to the page's current state, or that it is being used to declare content to be reused by other parts of the page as opposed to being directly accessed by the user. User agents should not render elements that are in the hidden state. この要件は、スタイルレイヤーを通して間接的に実装されてもよい。For example, a web browser could implement these requirements using the rules suggested in the Rendering section.

When an element has the hidden attribute in the hidden until found state, it indicates that the element is hidden like the hidden state but the content inside the element will be accessible to find-in-page and fragment navigation. When these features attempt to scroll to a target which is in the element's subtree, the user agent will remove the hidden attribute in order to reveal the content before scrolling to it. In addition to removing the hidden attribute, an event named beforematch is also fired on the element before the hidden attribute is removed.

Web browsers will use 'content-visibility: hidden' instead of 'display: none' when the hidden attribute is in the hidden until found state, as specified in the Rendering section.

この属性は通常CSSを使用して実装されているため、CSSを使用して上書きすることもできる。For instance, a rule that applies 'display: block' to all elements will cancel the effects of the hidden state. したがって著者は、期待通りに属性がスタイル付けされていることを確認し、そのスタイルシートを書く際に注意する必要がある。In addition, legacy user agents which don't support the hidden until found state will have 'display: none' instead of 'content-visibility: hidden', so authors are encouraged to make sure that their style sheets don't change the 'display' or 'content-visibility' properties of hidden until found elements.

Since elements with the hidden attribute in the hidden until found state use 'content-visibility: hidden' instead of 'display: none', there are two caveats of the hidden until found state that make it different from the hidden state:

  1. The element needs to be affected by layout containment in order to be revealed by find-in-page. This means that if the element in the hidden until found state has a 'display' value of 'none', 'contents', or 'inline', then the element will not be revealed by find-in-page.

  2. The element will still have a generated box when in the hidden until found state, which means that borders, margin, and padding will still be rendered around the element.

In the following skeletal example, the attribute is used to hide the web game's main screen until the user logs in:

  <h1>The Example Game</h1>
  <section id="login">
   <h2>Login</h2>
   <form>
    ...
    <!-- calls login() once the user's credentials have been checked -->
   </form>
   <script>
    function login() {
      // switch screens
      document.getElementById('login').hidden = true;
      document.getElementById('game').hidden = false;
    }
   </script>
  </section>
  <section id="game" hidden>
   ...
  </section>

hidden属性は、別のプレゼンテーションに合法的に示すことができたコンテンツを隠すために使用されてはならない。たとえば、タブ付きインターフェイスは単にオーバーフロープレゼンテーションの一種であるため、タブ付きダイアログでパネルを隠すためにhiddenを使用することは誤りである。―それはスクロールバーをもつ1つの大きなページ内のすべてのフォームコントロールを示すのと同様である。ちょうど1つのプレゼンテーションからコンテンツを非表示にするためにこの属性を使用することも同様に誤りである。―何かがhiddenとマークされる場合、それは、たとえばスクリーンリーダーなどを含む、すべてのプレゼンテーションから隠されている。

自身がhiddenでない要素は、hiddenである要素へハイパーリンクされてはならない。自身がhiddenでないlabelおよびoutput要素のfor属性も同様に、hiddenである要素を参照してはならない。どちらの場合も、このような参照はユーザーの混乱を引き起こすだろう。

しかし、要素およびスクリプトは、他のコンテキストでhiddenである要素を参照してもよい。

たとえば、hidden属性でマークされたセクションにリンクするhref属性を使用するのは誤りだろう。コンテンツが適切または関連しない場合、それにリンクする理由はない。

しかし、自身がhiddenである説明を参照するために、ARIA aria-describedby属性を使用することは構わない。While hiding the descriptions implies that they are not useful alone, they could be written in such a way that they are useful in the specific context of being referenced from the elements that they describe.

同様に、hidden属性を持つcanvas要素は、オフスクリーンバッファとしてスクリプト化されたグラフィックスエンジンによって使用されるかもしれず、フォームコントロールは、form属性を使用する隠しform要素を参照するかもしれない。

hidden属性によって非表示にされたセクション内の要素は依然としてアクティブである。たとえば、そのようなセクションでのスクリプトやフォームコントロールは、依然として実行および送信する。それらのプレゼンテーションのみがユーザーに変更される。

HTMLElement/hidden

Support in all current engines.

Firefox4+Safari5.1+Chrome6+
Opera11.6+Edge79+
Edge (Legacy)12+Internet Explorer11
Firefox Android?Safari iOS?Chrome Android?WebView Android3+Samsung Internet?Opera Android12+

The hidden getter steps are:

  1. If the hidden attribute is in the hidden until found state, then return "until-found".

  2. If the hidden attribute is set, then return true.

  3. Return false.

The hidden setter steps are:

  1. If the given value is a string that is an ASCII case-insensitive match for "until-found", then set the hidden attribute to "until-found".

  2. Otherwise, if the given value is false, then remove the hidden attribute.

  3. Otherwise, if the given value is the empty string, then remove the hidden attribute.

  4. Otherwise, if the given value is null, then remove the hidden attribute.

  5. Otherwise, if the given value is 0, then remove the hidden attribute.

  6. Otherwise, if the given value is NaN, then remove the hidden attribute.

  7. Otherwise, set the hidden attribute to the empty string.

The ancestor hidden-until-found revealing algorithm is to run the following steps on currentNode:

  1. While currentNode has a parent node within the flat tree:

    1. If currentNode has the hidden attribute in the hidden until found state, then:

      1. Fire an event named beforematch at currentNode.

      2. Remove the hidden attribute from currentNode.

    2. Set currentNode to the parent node of currentNode within the flat tree.

6.2 Page visibility

A traversable navigable's system visibility state, including its initial value upon creation, is determined by the user agent. It represents, for example, whether the browser window is minimized, a browser tab is currently in the background, or a system element such as a task switcher obscures the page.

When a user-agent determines that the system visibility state for traversable navigable traversable has changed to newState, it must run the following steps:

  1. Let navigables be the inclusive descendant navigables of traversable's active document.

  2. For each navigable of navigables in what order?:

    1. Let document be navigable's active document.

    2. Queue a global task on the user interaction task source given document's relevant global object to update the visibility state of document with newState.

A Document has a visibility state, which is either "hidden" or "visible", initially set to "hidden".

Document/visibilityState

Support in all current engines.

Firefox18+Safari7+Chrome33+
Opera20+Edge79+
Edge (Legacy)12+Internet Explorer10+
Firefox Android?Safari iOS?Chrome Android?WebView Android4.4.3+Samsung Internet?Opera Android20+

The visibilityState getter steps are to return this's visibility state.

Document/hidden

Support in all current engines.

Firefox18+Safari7+Chrome33+
Opera12.1+Edge79+
Edge (Legacy)12+Internet Explorer10+
Firefox Android?Safari iOS?Chrome Android?WebView Android4.4.3+Samsung Internet?Opera Android12.1+

The hidden getter steps are to return true if this's visibility state is "hidden", otherwise false.

To update the visibility state of Document document to visibilityState:

  1. If document's visibility state equals visibilityState, then return.

  2. Set document's visibility state to visibilityState.

  3. Queue a new VisibilityStateEntry whose visibility state is visibilityState and whose timestamp is the current high resolution time given document's relevant global object.

  4. Run the screen orientation change steps with document. [SCREENORIENTATION]

  5. Run the view transition page visibility change steps with document.

  6. Run any page visibility change steps which may be defined in other specifications, with visibility state and document.

    It would be better if specification authors sent a pull request to add calls from here into their specifications directly, instead of using the page visibility change steps hook, to ensure well-defined cross-specification call order. As of the time of this writing the following specifications are known to have page visibility change steps, which will be run in an unspecified order: Device Posture API and Web NFC. [DEVICEPOSTURE] [WEBNFC]

  7. Fire an event named visibilitychange at document, with its bubbles attribute initialized to true.

6.2.1 The VisibilityStateEntry interface

VisibilityStateEntry

Support in one engine only.

FirefoxNoSafariNoChrome115+
Opera?Edge115+
Edge (Legacy)?Internet ExplorerNo
Firefox Android?Safari iOS?Chrome Android?WebView Android?Samsung Internet?Opera Android?

The VisibilityStateEntry interface exposes visibility changes to the document, from the moment the document becomes active.

For example, this allows JavaScript code in the page to examine correlation between visibility changes and paint timing:
function wasHiddenBeforeFirstContentfulPaint() {
    const fcpEntry = performance.getEntriesByName("first-contentful-paint")[0];
    const visibilityStateEntries = performance.getEntriesByType("visibility-state");
    return visibilityStateEntries.some(e =>
                                            e.startTime < fcpEntry.startTime &&
                                            e.name === "hidden");
}

Since hiding a page can cause throttling of rendering and other user-agent operations, it is common to use visibility changes as an indication that such throttling has occurred. However, other things could also cause throttling in different browsers, such as long periods of inactivity.

[Exposed=(Window)]
interface VisibilityStateEntry : PerformanceEntry {
  readonly attribute DOMString name;                 // shadows inherited name
  readonly attribute DOMString entryType;            // shadows inherited entryType
  readonly attribute DOMHighResTimeStamp startTime;  // shadows inherited startTime
  readonly attribute unsigned long duration;         // shadows inherited duration
};

The VisibilityStateEntry has an associated DOMHighResTimeStamp timestamp.

The VisibilityStateEntry has an associated "visible" or "hidden" visibility state.

The name getter steps are to return this's visibility state.

The entryType getter steps are to return "visibility-state".

The startTime getter steps are to return this's timestamp.

The duration getter steps are to return zero.

6.3 Inert subtrees

See also inert for an explanation of the attribute of the same name.

A node (in particular elements and text nodes) can be inert. When a node is inert:

Inert nodes generally cannot be focused, and user agents do not expose the inert nodes to accessibility APIs or assistive technologies. Inert nodes that are commands will become inoperable to users, in the manner described above.

User agents may allow the user to override the restrictions on find-in-page and text selection, however.

By default, a node is not inert.

A Document document is blocked by a modal dialog subject if subject is the topmost dialog element in document's top layer. While document is so blocked, every node that is connected to document, with the exception of the subject element and its flat tree descendants, must become inert.

subject can additionally become inert via the inert attribute, but only if specified on subject itself (i.e., subject escapes inertness of ancestors); subject's flat tree descendants can become inert in a similar fashion.

dialog要素のshowModal()メソッドは、dialog要素をノード文書最上位レイヤー追加することによって、このメカニズムをトリガーさせる。

6.3.2 The inert attribute

Global_attributes/inert

Support in all current engines.

Firefox112+Safari15.5+Chrome102+
Opera?Edge102+
Edge (Legacy)?Internet ExplorerNo
Firefox Android?Safari iOS?Chrome Android?WebView Android?Samsung Internet?Opera Android?

The inert attribute is a boolean attribute that indicates, by its presence, that the element and all its flat tree descendants which don't otherwise escape inertness (such as modal dialogs) are to be made inert by the user agent.

An inert subtree should not contain any content or controls which are critical to understanding or using aspects of the page which are not in the inert state. Content in an inert subtree will not be perceivable by all users, or interactive. Authors should not specify elements as inert unless the content they represent are also visually obscured in some way. In most cases, authors should not specify the inert attribute on individual form controls. In these instances, the disabled attribute is probably more appropriate.

The following example shows how to mark partially loaded content, visually obscured by a "loading" message, as inert.

<section aria-labelledby=s1>
  <h3 id=s1>Population by City</h3>
  <div class=container>
    <div class=loading><p>Loading...</p></div>
    <div inert>
      <form>
        <fieldset>
          <legend>Date range</legend>
          <div>
            <label for=start>Start</label>
            <input type=date id=start>
          </div>
          <div>
            <label for=end>End</label>
            <input type=date id=end>
          </div>
          <div>
            <button>Apply</button>
          </div>
        </fieldset>
      </form>
      <table>
        <caption>From 20-- to 20--</caption>
        <thead>
          <tr>
            <th>City</th>
            <th>State</th>
            <th>20-- Population</th>
            <th>20-- Population</th>
            <th>Percentage change</th>
          </tr>
        </thead>
        <tbody>
          <!-- ... -->
        </tbody>
      </table>
    </div>
  </div>
</section>
Screenshot of Population by City content with an overlaid loading message which visually obscures the form controls and data table which have not fully rendered, and thus are in the inert state.

The "loading" overlay obscures the inert content, making it visually apparent that the inert content is not presently accessible. Notice that the heading and "loading" text are not descendants of the element with the inert attribute. This will ensure this text is accessible to all users, while the inert content cannot be interacted with by anyone.

By default, there is no persistent visual indication of an element or its subtree being inert. Appropriate visual styles for such content is often context-dependent. For instance, an inert off-screen navigation panel would not require a default style, as its off-screen position visually obscures the content. Similarly, a modal dialog element's backdrop will serve as the means to visually obscure the inert content of the web page, rather than styling the inert content specifically.

However, for many other situations authors are strongly encouraged to clearly mark what parts of their document are active and which are inert, to avoid user confusion. In particular, it is worth remembering that not all users can see all parts of a page at once; for example, users of screen readers, users on small devices or with magnifiers, and even users using particularly small windows might not be able to see the active part of a page and might get frustrated if inert sections are not obviously inert.

HTMLElement/inert

Support in all current engines.

Firefox112+Safari15.5+Chrome102+
Opera?Edge102+
Edge (Legacy)?Internet ExplorerNo
Firefox Android?Safari iOS?Chrome Android?WebView Android?Samsung Internet?Opera Android?

The inert IDL attribute must reflect the content attribute of the same name.

6.4 Tracking user activation

To prevent abuse of certain APIs that could be annoying to users (e.g., opening popups or vibrating phones), user agents allow these APIs only when the user is actively interacting with the web page or has interacted with the page at least once. This "active interaction" state is maintained through the mechanisms defined in this section.

6.4.1 Data model

For the purpose of tracking user activation, each Window W has two relevant values:

A user agent also defines a transient activation duration, which is a constant number indicating how long a user activation is available for certain user activation-gated APIs (e.g., for opening popups).

The transient activation duration is expected be at most a few seconds, so that the user can possibly perceive the link between an interaction with the page and the page calling the activation-gated API.

We then have the following boolean user activation states for W:

Sticky activation

When the current high resolution time given W is greater than or equal to the last activation timestamp in W, W is said to have sticky activation.

This is W's historical activation state, indicating whether the user has ever interacted in W. It starts false, then changes to true (and never changes back to false) when W gets the very first activation notification.

Transient activation

When the current high resolution time given W is greater than or equal to the last activation timestamp in W, and less than the last activation timestamp in W plus the transient activation duration, then W is said to have transient activation.

This is W's current activation state, indicating whether the user has interacted in W recently. This starts with a false value, and remains true for a limited time after every activation notification W gets.

The transient activation state is considered expired if it becomes false because the transient activation duration time has elapsed since the last user activation. Note that it can become false even before the expiry time through an activation consumption.

History-action activation

When the last history-action activation timestamp of W is not equal to the last activation timestamp of W, then W is said to have history-action activation.

This is a special variant of user activation, used to allow access to certain session history APIs which, if used too frequently, would make it harder for the user to traverse back using browser UI. It starts with a false value, and becomes true whenever the user interacts with W, but is reset to false through history-action activation consumption. This ensures such APIs cannot be used multiple times in a row without an intervening user activation. But unlike transient activation, there is no time limit within which such APIs must be used.

The last activation timestamp and last history-action activation timestamp are retained even after the Document changes its fully active status (e.g., after navigating away from a Document, or navigating to a cached Document). This means sticky activation state spans multiple navigations as long as the same Document gets reused. For the transient activation state, the original expiry time remains unchanged (i.e., the state still expires within the transient activation duration limit from the original activation triggering input event). It is important to consider this when deciding whether to base certain things off sticky activation or transient activation.

6.4.2 Processing model

When a user interaction causes firing of an activation triggering input event in a Document document, the user agent must perform the following activation notification steps before dispatching the event:

  1. Assert: document is fully active.

  2. Let windows be « document's relevant global object ».

  3. Extend windows with the active window of each of document's ancestor navigables.

  4. Extend windows with the active window of each of document's descendant navigables, filtered to include only those navigables whose active document's origin is same origin with document's origin.

  5. For each window in windows:

    1. Set window's last activation timestamp to the current high resolution time.

    2. Notify the close watcher manager about user activation given window.

An activation triggering input event is any event whose isTrusted attribute is true and whose type is one of:

Activation consuming APIs defined in this and other specifications can consume user activation by performing the following steps, given a Window W:

  1. If W's navigable is null, then return.

  2. Let top be W's navigable's top-level traversable.

  3. Let navigables be the inclusive descendant navigables of top's active document.

  4. Let windows be the list of Window objects constructed by taking the active window of each item in navigables.

  5. For each window in windows, if window's last activation timestamp is not positive infinity, then set window's last activation timestamp to negative infinity.

History-action activation-consuming APIs can consume history-action user activation by performing the following steps, given a Window W:

  1. If W's navigable is null, then return.

  2. Let top be W's navigable's top-level traversable.

  3. Let navigables be the inclusive descendant navigables of top's active document.

  4. Let windows be the list of Window objects constructed by taking the active window of each item in navigables.

  5. For each window in windows, set window's last history-action activation timestamp to window's last activation timestamp.

Note the asymmetry in the sets of browsing contexts in the page that are affected by an activation notification vs an activation consumption: an activation consumption changes (to false) the transient activation states for all browsing contexts in the page, but an activation notification changes (to true) the states for a subset of those browsing contexts. The exhaustive nature of consumption here is deliberate: it prevents malicious sites from making multiple calls to an activation consuming API from a single user activation (possibly by exploiting a deep hierarchy of iframes).

6.4.3 APIs gated by user activation

APIs that are dependent on user activation are classified into different levels:

Sticky activation-gated APIs

These APIs require the sticky activation state to be true, so they are blocked until the very first user activation.

Transient activation-gated APIs

These APIs require the transient activation state to be true, but they don't consume it, so multiple calls are allowed per user activation until the transient state expires.

Transient activation-consuming APIs

These APIs require the transient activation state to be true, and they consume user activation in each call to prevent multiple calls per user activation.

History-action activation-consuming APIs

These APIs require the history-action activation state to be true, and they consume history-action user activation in each call to prevent multiple calls per user activation.

6.4.4 The UserActivation interface

UserActivation

FirefoxNoSafari16.4+Chrome72+
Opera?Edge79+
Edge (Legacy)?Internet ExplorerNo
Firefox Android?Safari iOS?Chrome Android?WebView Android?Samsung Internet?Opera Android?

Each Window has an associated UserActivation, which is a UserActivation object. Upon creation of the Window object, its associated UserActivation must be set to a new UserActivation object created in the Window object's relevant realm.

[Exposed=Window]
interface UserActivation {
  readonly attribute boolean hasBeenActive;
  readonly attribute boolean isActive;
};

partial interface Navigator {
  [SameObject] readonly attribute UserActivation userActivation;
};
navigator.userActivation.hasBeenActive

Returns whether the window has sticky activation.

navigator.userActivation.isActive

Returns whether the window has transient activation.

Navigator/userActivation

FirefoxNoSafari16.4+Chrome72+
Opera?Edge79+
Edge (Legacy)?Internet ExplorerNo
Firefox Android?Safari iOS?Chrome Android?WebView Android?Samsung Internet?Opera Android?

The userActivation getter steps are to return this's relevant global object's associated UserActivation.

UserActivation/hasBeenActive

FirefoxNoSafari16.4+Chrome72+
Opera?Edge79+
Edge (Legacy)?Internet ExplorerNo
Firefox Android?Safari iOS?Chrome Android?WebView Android?Samsung Internet?Opera Android?

The hasBeenActive getter steps are to return true if this's relevant global object has sticky activation, and false otherwise.

UserActivation/hasBeenActive

FirefoxNoSafari16.4+Chrome72+
Opera?Edge79+
Edge (Legacy)?Internet ExplorerNo
Firefox Android?Safari iOS?Chrome Android?WebView Android?Samsung Internet?Opera Android?

The isActive getter steps are to return true if this's relevant global object has transient activation, and false otherwise.

6.4.5 User agent automation

For the purposes of user-agent automation and application testing, this specification defines the following extension command for the Web Driver specification. It is optional for a user agent to support the following extension command. [WEBDRIVER]

HTTP MethodURI Template
`POST`/session/{session id}/window/consume-user-activation

The remote end steps are:

  1. Let window be current browsing context's active window.

  2. Let consume be true if window has transient activation; otherwise false.

  3. If consume is true, then consume user activation of window.

  4. Return success with data consume.

6.5 Activation behavior of elements

HTMLの特定の要素は、ユーザーがアクティブにすることができることを意味する、アクティベーション動作を持つ。これは、常にclickイベントによって発生する。

The user agent should allow the user to manually trigger elements that have an activation behavior, for instance using keyboard or voice input, or through mouse clicks. When the user triggers an element with a defined activation behavior in a manner other than clicking it, the default action of the interaction event must be to fire a click event at the element.

element.click()

HTMLElement/click

Support in all current engines.

Firefox3+Safari6+Chrome9+
Opera10.5+Edge79+
Edge (Legacy)12+Internet Explorer5.5+
Firefox Android4+Safari iOS?Chrome Android?WebView Android4.4+Samsung Internet1.0+Opera Android11+

あたかも要素をクリックされたかのように動作する。

Each element has an associated click in progress flag, which is initially unset.

The click() method must run the following steps:

  1. If this element is a form control that is disabled, then return.

  2. If this element's click in progress flag is set, then return.

  3. Set this element's click in progress flag.

  4. Fire a synthetic pointer event named click at this element, with the not trusted flag set.

  5. Unset this element's click in progress flag.

6.5.1 The ToggleEvent interface

ToggleEvent/ToggleEvent

Support in all current engines.

Firefox🔰 114+Safari17+Chrome114+
Opera?Edge114+
Edge (Legacy)?Internet ExplorerNo
Firefox Android?Safari iOS?Chrome Android?WebView Android?Samsung Internet?Opera Android?

ToggleEvent

Support in all current engines.

Firefox🔰 114+Safari17+Chrome114+
Opera?Edge114+
Edge (Legacy)?Internet ExplorerNo
Firefox Android?Safari iOS?Chrome Android?WebView Android?Samsung Internet?Opera Android?
[Exposed=Window]
interface ToggleEvent : Event {
  constructor(DOMString type, optional ToggleEventInit eventInitDict = {});
  readonly attribute DOMString oldState;
  readonly attribute DOMString newState;
};

dictionary ToggleEventInit : EventInit {
  DOMString oldState = "";
  DOMString newState = "";
};
event.oldState

Set to "closed" when transitioning from closed to open, or set to "open" when transitioning from open to closed.

event.newState

Set to "open" when transitioning from closed to open, or set to "closed" when transitioning from open to closed.

ToggleEvent/oldState

Support in all current engines.

Firefox🔰 114+Safari17+Chrome114+
Opera?Edge114+
Edge (Legacy)?Internet ExplorerNo
Firefox Android?Safari iOS?Chrome Android?WebView Android?Samsung Internet?Opera Android?

ToggleEvent/newState

Support in all current engines.

Firefox🔰 114+Safari17+Chrome114+
Opera?Edge114+
Edge (Legacy)?Internet ExplorerNo
Firefox Android?Safari iOS?Chrome Android?WebView Android?Samsung Internet?Opera Android?

The oldState and newState attributes must return the values they are initialized to.

A toggle task tracker is a struct which has:

task
A task which fires a ToggleEvent.
old state
A string which represents the task's event's value for the oldState attribute.

6.6 Focus

6.6.1 Introduction

この節は非規範的である。

HTMLユーザーインターフェイスは典型的に、フォームコントロール、スクロール可能領域、リンク、ダイアログボックス、ブラウザータブなど、複数のインタラクティブウィジットから成る。これらウィジェットは、他(たとえば、リンク、フォームコントロール)を含むもの(たとえば、ブラウザータブ、ダイアログボックス)をもつ、階層構造を形成する。

キーボードを使用するインターフェイスと情報交換する場合、アクティブなウィジェットから、フォーカスされると呼ばれる、インタラクティブなウィジェットの階層構造を通して、キー入力はシステムから流れる。

グラフィカル環境で動作するブラウザータブにおいて動作するHTMLアプリケーションを考えてみる。このアプリケーションが、いくつかのテキストコントロールおよびリンクをもつページを持ち、それ自身がテキストコントロールとボタンを持った、モーダルダイアログを表示していると想定する。

このシナリオにおいて、その子の間でHTMLアプリケーションを含むブラウザータブを持つだろう、フォーカス可能なウィジェットの階層構造は、ブラウザーウィンドウを含むかもしれない。タブ自身は、ダイアログと同様に、その子として、様々なリンクおよびテキストコントロールを持つだろう。ダイアログ自身は、その子として、テキストコントロールおよびボタンを持つだろう。

If the widget with focus in this example was the text control in the dialog box, then key input would be channeled from the graphical system to ① the web browser, then to ② the tab, then to ③ the dialog, and finally to ④ the text control.

キーボードイベントは、常にこのフォーカスされた要素で対象にされる。

6.6.2 Data model

A top-level traversable has system focus when it can receive keyboard input channeled from the operating system, possibly targeted at one of its active document's descendant navigables.

A top-level traversable has user attention when its system visibility state is "visible", and it either has system focus or user agent widgets directly related to it can receive keyboard input channeled from the operating system.

User attention is lost when a browser window loses focus, whereas system focus might also be lost to other system widgets in the browser window such as a location bar.

A Document d is a fully active descendant of a top-level traversable with user attention when d is fully active and d's node navigable's top-level traversable has user attention.

The term focusable area is used to refer to regions of the interface that can further become the target of such keyboard input. フォーカス可能領域は、要素、要素の一部、またはユーザーエージェントによって処理される他の領域となることができる。

フォーカス可能領域は、DOMでフォーカス可能領域の位置を表すNodeオブジェクトである、DOMアンカーを持つ。(フォーカス可能領域Node自身である場合、それはそれ自身のDOM anchorである。)フォーカス可能領域を表すために他のDOMオブジェクトが存在しない場合、DOMアンカーは、フォーカス可能領域に適するようないくつかのAPIで使用される。

以下のテーブルは、どのオブジェクトがフォーカス可能領域となることができるかを説明する。左の列におけるセルは、フォーカス可能領域となることができるオブジェクトを説明する。右の列におけるセルは、この要素に対するDOMアンカーを説明する。(両方の列をまたぐセルは、非規範的な例である。)

Focusable areaDOM anchor
Elements that meet all the following criteria: 要素自身。

iframe, dialog, <input type=text>, sometimes <a href=""> (depending on platform conventions).

The shapes of area elements in an image map associated with an img element that is being rendered and is not inert.img要素

次の例において、それぞれ画像の、area要素は2つの形状を作成する。最初の形状のDOMアンカーは、最初のimg要素であり、2つめの形状のDOM anchorは、2つめのimg要素である。

<map id=wallmap><area alt="Enter Door" coords="10,10,100,200" href="door.html"></map>
...
<img src="images/innerwall.jpeg" alt="There is a white wall here, with a door." usemap="#wallmap">
...
<img src="images/outerwall.jpeg" alt="There is a red wall here, with a door." usemap="#wallmap">
The user-agent provided subwidgets of elements that are being rendered and are not actually disabled or inert.フォーカス可能領域がサブウィジェットとなる要素。

The controls in the user interface for a video element, the up and down buttons in a spin-control version of <input type=number>, the part of a details element's rendering that enables the element to be opened or closed using keyboard input.

The scrollable regions of elements that are being rendered and are not inert.スクロール可能な領域のスクロールが作成されたボックスに対する要素

CSS 'overflow'プロパティの'scroll'値が典型的にスクロール可能領域を作成する。

The viewport of a Document that has a non-null browsing context and is not inert.ビューポートが作成されたDocument

iframeのコンテンツ。

Any other element or part of an element determined by the user agent to be a focusable area, especially to aid with accessibility or to better match platform conventions.要素。

A user agent could make all list item bullets sequentially focusable, so that a user can more easily navigate lists.

Similarly, a user agent could make all elements with title attributes sequentially focusable, so that their advisory information can be accessed.

A navigable container (e.g. an iframe) is a focusable area, but key events routed to a navigable container get immediately routed to its content navigable's active document. Similarly, in sequential focus navigation a navigable container essentially acts merely as a placeholder for its content navigable's active document.


One focusable area in each Document is designated the focused area of the document. どのコントロールがそのように呼ばれるかは時間とともに変化し、この仕様におけるアルゴリズムに基づく。

Even if a document is not fully active and not shown to the user, it can still have a focused area of the document. If a document's fully active state changes, its focused area of the document will stay the same.

The currently focused area of a top-level traversable traversable is the focusable area-or-null returned by this algorithm:

  1. If traversable does not have system focus, then return null.

  2. Let candidate be traversable's active document.

  3. While candidate's focused area is a navigable container with a non-null content navigable: set candidate to the active document of that navigable container's content navigable.

  4. If candidate's focused area is non-null, set candidate to candidate's focused area.

  5. candidateを返す。

The current focus chain of a top-level traversable traversable is the focus chain of the currently focused area of traversable, if traversable is non-null, or an empty list otherwise.

An element that is the DOM anchor of a focusable area is said to gain focus when that focusable area becomes the currently focused area of a top-level traversable. When an element is the DOM anchor of a focusable area of the currently focused area of a top-level traversable, it is focused.

The focus chain of a focusable area subject is the ordered list constructed as follows:

  1. Let output be an empty list.

  2. Let currentObject be subject.

  3. While true:

    1. Append currentObject to output.

    2. If currentObject is an area element's shape, then append that area element to output.

      Otherwise, if currentObject's DOM anchor is an element that is not currentObject itself, then append currentObject's DOM anchor to output.

    3. If currentObject is a focusable area, then set currentObject to currentObject's DOM anchor's node document.

      Otherwise, if currentObject is a Document whose node navigable's parent is non-null, then set currentObject to currentObject's node navigable's parent.

      Otherwise, break.

  4. Return output.

    The chain starts with subject and (if subject is or can be the currently focused area of a top-level traversable) continues up the focus hierarchy up to the Document of the top-level traversable.

All elements that are focusable areas are said to be focusable.

There are two special types of focusability for focusable areas:

Elements which are not focusable are not focusable areas, and thus not sequentially focusable and not click focusable.

Being focusable is a statement about whether an element can be focused programmatically, e.g. via the focus() method or autofocus attribute. In contrast, sequentially focusable and click focusable govern how the user agent responds to user interaction: respectively, to sequential focus navigation and as activation behavior.

The user agent might determine that an element is not sequentially focusable even if it is focusable and is included in its Document's sequential focus navigation order, according to user preferences. For example, macOS users can set the user agent to skip non-form control elements, or can skip links when doing sequential focus navigation with just the Tab key (as opposed to using both the Option and Tab keys).

Similarly, the user agent might determine that an element is not click focusable even if it is focusable. For example, in some user agents, clicking on a non-editable form control does not focus it, i.e. the user agent has determined that such controls are not click focusable.

Thus, an element can be focusable, but neither sequentially focusable nor click focusable. For example, in some user agents, a non-editable form-control with a negative-integer tabindex value would not be focusable via user interaction, only via programmatic APIs.

When a user activates a click focusable focusable area, the user agent must run the focusing steps on the focusable area with focus trigger set to "click".

Note that focusing is not an activation behavior, i.e. calling the click() method on an element or dispatching a synthetic click event on it won't cause the element to get focused.


A node is a focus navigation scope owner if it is a Document, a shadow host, a slot, or an element in the popover showing state which also has a popover invoker set.

Each focus navigation scope owner has a focus navigation scope, which is a list of elements. Its contents are determined as follows:

Every element element has an associated focus navigation owner, which is either null or a focus navigation scope owner. It is determined by the following algorithm:

  1. If element's parent is null, then return null.

  2. If element's parent is a shadow host, then return element's assigned slot.

  3. If element's parent is a shadow root, then return the parent's host.

  4. If element's parent is the document element, then return the parent's node document.

  5. If element is in the popover showing state and has a popover invoker set, then return element.

  6. Return element's parent's associated focus navigation owner.

Then, the contents of a given focus navigation scope owner owner's focus navigation scope are all elements whose associated focus navigation owner is owner.

The order of elements within a focus navigation scope does not impact any of the algorithms in this specification. Ordering only becomes important for the tabindex-ordered focus navigation scope and flattened tabindex-ordered focus navigation scope concepts defined below.

A tabindex-ordered focus navigation scope is a list of focusable areas and focus navigation scope owners. Every focus navigation scope owner owner has tabindex-ordered focus navigation scope, whose contents are determined as follows:

The order within a tabindex-ordered focus navigation scope is determined by each element's tabindex value, as described in the section below.

The rules there do not give a precise ordering, as they are composed mostly of "should" statements and relative orderings.

A flattened tabindex-ordered focus navigation scope is a list of focusable areas. Every focus navigation scope owner owner owns a distinct flattened tabindex-ordered focus navigation scope, whose contents are determined by the following algorithm:

  1. Let result be a clone of owner's tabindex-ordered focus navigation scope.

  2. For each item of result:

    1. If item is not a focus navigation scope owner, then continue.

    2. If item is not a focusable area, then replace item with all of the items in item's flattened tabindex-ordered focus navigation scope.

    3. Otherwise, insert the contents of item's flattened tabindex-ordered focus navigation scope after item.

6.6.3 The tabindex attribute

Global_attributes/tabindex

Support in all current engines.

Firefox1.5+Safari4+Chrome1+
Opera?Edge79+
Edge (Legacy)12+Internet ExplorerYes
Firefox Android?Safari iOS?Chrome Android?WebView Android?Samsung Internet?Opera Android?

The tabindex content attribute allows authors to make an element and regions that have the element as its DOM anchor be focusable areas, allow or prevent them from being sequentially focusable, and determine their relative ordering for sequential focus navigation.

The name "tab index" comes from the common use of the Tab key to navigate through the focusable elements. The term "tabbing" refers to moving forward through sequentially focusable focusable areas.

tabindex属性が指定される場合、妥当な整数である値を持たなければならない。Positive numbers specify the relative position of the element's focusable areas in the sequential focus navigation order, and negative numbers indicate that the control is not sequentially focusable.

0または-1以外の値を使用している場合、開発者は、これが正しく行うために複雑になるよう、自身のtabindex属性に対して用心すべきである。

The following provides a non-normative summary of the behaviors of the possible tabindex attribute values. The below processing model gives the more precise rules.

omitted (or non-integer values)
The user agent will decide whether the element is focusable, and if it is, whether it is sequentially focusable or click focusable (or both).
−1 (or other negative integer values)
Causes the element to be focusable, and indicates that the author would prefer the element to be click focusable but not sequentially focusable. The user agent might ignore this preference for click and sequential focusability, e.g., for specific element types according to platform conventions, or for keyboard-only users.
0
Causes the element to be focusable, and indicates that the author would prefer the element to be both click focusable and sequentially focusable. The user agent might ignore this preference for click and sequential focusability.
positive integer values
Behaves the same as 0, but in addition creates a relative ordering within a tabindex-ordered focus navigation scope, so that elements with higher tabindex attribute value come later.

Note that the tabindex attribute cannot be used to make an element non-focusable. The only way a page author can do that is by disabling the element, or making it inert.


The tabindex value of an element is the value of its tabindex attribute, parsed using the rules for parsing integers. If parsing fails or the attribute is not specified, then the tabindex value is null.

The tabindex value of a focusable area is the tabindex value of its DOM anchor.

The tabindex value of an element must be interpreted as follows:

If the value is null

The user agent should follow platform conventions to determine if the element should be considered as a focusable area and if so, whether the element and any focusable areas that have the element as their DOM anchor are sequentially focusable, and if so, what their relative position in their tabindex-ordered focus navigation scope is to be. If the element is a focus navigation scope owner, it must be included in its tabindex-ordered focus navigation scope even if it is not a focusable area.

The relative ordering within a tabindex-ordered focus navigation scope for elements and focusable areas that belong to the same focus navigation scope and whose tabindex value is null should be in shadow-including tree order.

Modulo platform conventions, it is suggested that the following elements should be considered as focusable areas and be sequentially focusable:

If the value is a negative integer

The user agent must consider the element as a focusable area, but should omit the element from any tabindex-ordered focus navigation scope.

One valid reason to ignore the requirement that sequential focus navigation not allow the author to lead to the element would be if the user's only mechanism for moving the focus is sequential focus navigation. For instance, a keyboard-only user would be unable to click on a text control with a negative tabindex, so that user's user agent would be well justified in allowing the user to tab to the control regardless.

If the value is a zero

The user agent must allow the element to be considered as a focusable area and should allow the element and any focusable areas that have the element as their DOM anchor to be sequentially focusable.

The relative ordering within a tabindex-ordered focus navigation scope for elements and focusable areas that belong to the same focus navigation scope and whose tabindex value is zero should be in shadow-including tree order.

If the value is greater than zero

The user agent must allow the element to be considered as a focusable area and should allow the element and any focusable areas that have the element as their DOM anchor to be sequentially focusable, and should place the element — referenced as candidate below — and the aforementioned focusable areas in the tabindex-ordered focus navigation scope where the element is a part of so that, relative to other elements and focusable areas that belong to the same focus navigation scope, they are:

HTMLElement/tabIndex

Support in all current engines.

Firefox1+Safari3.1+Chrome1+
Opera12.1+Edge79+
Edge (Legacy)18Internet Explorer🔰 5.5+
Firefox Android?Safari iOS?Chrome Android?WebView Android?Samsung Internet?Opera Android12.1+

The tabIndex IDL attribute must reflect the value of the tabindex content attribute. The default value is 0 if the element is an a, area, button, frame, iframe, input, object, select, textarea, or SVG a element, or is a summary element that is a summary for its parent details. The default value is −1 otherwise.

The varying default value based on element type is a historical artifact.

6.6.4 Processing model

To get the focusable area for a focus target that is either an element that is not a focusable area, or is a navigable, given an optional string focus trigger (default "other"), run the first matching set of steps from the following list:

If focus target is an area element with one or more shapes that are focusable areas

Return the shape corresponding to the first img element in tree order that uses the image map to which the area element belongs.

If focus target is an element with one or more scrollable regions that are focusable areas

Return the element's first scrollable region, according to a pre-order, depth-first traversal of the flat tree. [CSSSCOPING]

If focus target is the document element of its Document

Return the Document's viewport.

If focus target is a navigable

Return the navigable's active document.

If focus target is a navigable container with a non-null content navigable

Return the navigable container's content navigable's active document.

If focus target is a shadow host whose shadow root's delegates focus is true
  1. Let focusedElement be the currently focused area of a top-level traversable's DOM anchor.

  2. If focus target is a shadow-including inclusive ancestor of focusedElement, then return focusedElement.

  3. Return the focus delegate for focus target given focus trigger.

For sequential focusability, the handling of shadow hosts and delegates focus is done when constructing the sequential focus navigation order. That is, the focusing steps will never be called on such shadow hosts as part of sequential focus navigation.

そうでなければ

Return null.

The focus delegate for a focusTarget, given an optional string focusTrigger (default "other"), is given by the following steps:

  1. If focusTarget is a shadow host and its shadow root's delegates focus is false, then return null.

  2. Let whereToLook be focusTarget.

  3. If whereToLook is a shadow host, then set whereToLook to whereToLook's shadow root.

  4. Let autofocusDelegate be the autofocus delegate for whereToLook given focusTrigger.

  5. If autofocusDelegate is not null, then return autofocusDelegate.

  6. For each descendant of whereToLook's descendants, in tree order:

    1. Let focusableArea be null.

    2. If focusTarget is a dialog element and descendant is sequentially focusable, then set focusableArea to descendant.

    3. Otherwise, if focusTarget is not a dialog and descendant is a focusable area, set focusableArea to descendant.

    4. Otherwise, set focusableArea to the result of getting the focusable area for descendant given focusTrigger.

      This step can end up recursing, i.e., the get the focusable area steps might return the focus delegate of descendant.

    5. If focusableArea is not null, then return focusableArea.

    It's important that we are not looking at the shadow-including descendants here, but instead only at the descendants. Shadow hosts are instead handled by the recursive case mentioned above.

  7. Return null.

The above algorithm essentially returns the first suitable focusable area where the path between its DOM anchor and focusTarget delegates focus at any shadow tree boundaries.

The autofocus delegate for a focus target given a focus trigger is given by the following steps:

  1. For each descendant descendant of focus target, in tree order:

    1. If descendant does not have an autofocus content attribute, then continue.

    2. Let focusable area be descendant, if descendant is a focusable area; otherwise let focusable area be the result of getting the focusable area for descendant given focus trigger.

    3. If focusable area is null, then continue.

    4. If focusable area is not click focusable and focus trigger is "click", then continue.

    5. Return focusable area.

  2. Return null.

The focusing steps for an object new focus target that is either a focusable area, or an element that is not a focusable area, or a navigable, are as follows. They can optionally be run with a fallback target and a string focus trigger.

  1. If new focus target is not a focusable area, then set new focus target to the result of getting the focusable area for new focus target, given focus trigger if it was passed.

  2. If new focus target is null, then:

    1. If no fallback target was specified, then return.

    2. Otherwise, set new focus target to the fallback target.

  3. If new focus target is a navigable container with non-null content navigable, then set new focus target to the content navigable's active document.

  4. If new focus target is a focusable area and its DOM anchor is inert, then return.

  5. If new focus target is the currently focused area of a top-level traversable, then return.

  6. Let old chain be the current focus chain of the top-level traversable in which new focus target finds itself.

  7. Let new chain be the focus chain of new focus target.

  8. Run the focus update steps with old chain, new chain, and new focus target respectively.

User agents must immediately run the focusing steps for a focusable area or navigable candidate whenever the user attempts to move the focus to candidate.

The unfocusing steps for an object old focus target that is either a focusable area or an element that is not a focusable area are as follows:

  1. If old focus target is a shadow host whose shadow root's delegates focus is true, and old focus target's shadow root is a shadow-including inclusive ancestor of the currently focused area of a top-level traversable's DOM anchor, then set old focus target to that currently focused area of a top-level traversable.

  2. If old focus target is inert, then return.

  3. If old focus target is an area element and one of its shapes is the currently focused area of a top-level traversable, or, if old focus target is an element with one or more scrollable regions, and one of them is the currently focused area of a top-level traversable, then let old focus target be that currently focused area of a top-level traversable.

  4. Let old chain be the current focus chain of the top-level traversable in which old focus target finds itself.

  5. If old focus target is not one of the entries in old chain, then return.

  6. If old focus target is not a focusable area, then return.

  7. Let topDocument be old chain's last entry.

  8. If topDocument's node navigable has system focus, then run the focusing steps for topDocument's viewport.

    Otherwise, apply any relevant platform-specific conventions for removing system focus from topDocument's node navigable, and run the focus update steps given old chain, an empty list, and null.

The unfocusing steps do not always result in the focus changing, even when applied to the currently focused area of a top-level traversable. For example, if the currently focused area of a top-level traversable is a viewport, then it will usually keep its focus regardless until another focusable area is explicitly focused with the focusing steps.


The focus update steps, given an old chain, a new chain, and a new focus target respectively, are as follows:

  1. If the last entry in old chain and the last entry in new chain are the same, pop the last entry from old chain and the last entry from new chain and redo this step.

  2. For each entry entry in old chain, in order, run these substeps:

    1. If entry is an input element, and the change event applies to the element, and the element does not have a defined activation behavior, and the user has changed the element's value or its list of selected files while the control was focused without committing that change (such that it is different to what it was when the control was first focused), then:

      1. Set entry's user validity to true.

      2. Fire an event named change at the element, with the bubbles attribute initialized to true.

    2. If entry is an element, let blur event target be entry.

      If entry is a Document object, let blur event target be that Document object's relevant global object.

      Otherwise, let blur event target be null.

    3. If entry is the last entry in old chain, and entry is an Element, and the last entry in new chain is also an Element, then let related blur target be the last entry in new chain. Otherwise, let related blur target be null.

    4. If blur event target is not null, fire a focus event named blur at blur event target, with related blur target as the related target.

      In some cases, e.g., if entry is an area element's shape, a scrollable region, or a viewport, no event is fired.

  3. Apply any relevant platform-specific conventions for focusing new focus target. (For example, some platforms select the contents of a text control when that control is focused.)

  4. For each entry entry in new chain, in reverse order, run these substeps:

    1. If entry is a focusable area, and the focused area of the document is not entry:

      1. Set document's relevant global object's navigation API's focus changed during ongoing navigation to true.

      2. Designate entry as the focused area of the document.

    2. If entry is an element, let focus event target be entry.

      If entry is a Document object, let focus event target be that Document object's relevant global object.

      Otherwise, let focus event target be null.

    3. If entry is the last entry in new chain, and entry is an Element, and the last entry in old chain is also an Element, then let related focus target be the last entry in old chain. Otherwise, let related focus target be null.

    4. If focus event target is not null, fire a focus event named focus at focus event target, with related focus target as the related target.

      In some cases, e.g. if entry is an area element's shape, a scrollable region, or a viewport, no event is fired.

To fire a focus event named e at an element t with a given related target r, fire an event named e at t, using FocusEvent, with the relatedTarget attribute initialized to r, the view attribute initialized to t's node document's relevant global object, and the composed flag set.


When a key event is to be routed in a top-level traversable, the user agent must run the following steps:

  1. Let target area be the currently focused area of the top-level traversable.

  2. Assert: target area is not null, since key events are only routed to top-level traversables that have system focus. Therefore, target area is a focusable area.

  3. Let target node be target area's DOM anchor.

  4. If target node is a Document that has a body element, then let target node be the body element of that Document.

    Otherwise, if target node is a Document object that has a non-null document element, then let target node be that document element.

  5. If target node is not inert, then:

    1. Let canHandle be the result of dispatching the key event at target node.

    2. If canHandle is true, then let target area handle the key event. This might include firing a click event at target node.


The has focus steps, given a Document object target, are as follows:

  1. If target's node navigable's top-level traversable does not have system focus, then return false.

  2. Let candidate be target's node navigable's top-level traversable's active document.

  3. While true:

    1. If candidate is target, then return true.

    2. If the focused area of candidate is a navigable container with a non-null content navigable, then set candidate to the active document of that navigable container's content navigable.

    3. Otherwise, return false.

6.6.5 Sequential focus navigation

Each Document has a sequential focus navigation order, which orders some or all of the focusable areas in the Document relative to each other. Its contents and ordering are given by the flattened tabindex-ordered focus navigation scope of the Document.

Per the rules defining the flattened tabindex-ordered focus navigation scope, the ordering is not necessarily related to the tree order of the Document.

If a focusable area is omitted from the sequential focus navigation order of its Document, then it is unreachable via sequential focus navigation.

There can also be a sequential focus navigation starting point. It is initially unset. The user agent may set it when the user indicates that it should be moved.

For example, the user agent could set it to the position of the user's click if the user clicks on the document contents.

User agents are required to set the sequential focus navigation starting point to the target element when navigating to a fragment.

A sequential focus direction is one of two possible values: "forward", or "backward". They are used in the below algorithms to describe the direction in which sequential focus travels at the user's request.

A selection mechanism is one of two possible values: "DOM", or "sequential". They are used to describe how the sequential navigation search algorithm finds the focusable area it returns.

When the user requests that focus move from the currently focused area of a top-level traversable to the next or previous focusable area (e.g., as the default action of pressing the tab key), or when the user requests that focus sequentially move to a top-level traversable in the first place (e.g., from the browser's location bar), the user agent must use the following algorithm:

  1. Let starting point be the currently focused area of a top-level traversable, if the user requested to move focus sequentially from there, or else the top-level traversable itself, if the user instead requested to move focus from outside the top-level traversable.

  2. If there is a sequential focus navigation starting point defined and it is inside starting point, then let starting point be the sequential focus navigation starting point instead.

  3. Let direction be "forward" if the user requested the next control, and "backward" if the user requested the previous control.

    Typically, pressing tab requests the next control, and pressing shift + tab requests the previous control.

  4. Loop: Let selection mechanism be "sequential" if starting point is a navigable or if starting point is in its Document's sequential focus navigation order.

    Otherwise, starting point is not in its Document's sequential focus navigation order; let selection mechanism be "DOM".

  5. Let candidate be the result of running the sequential navigation search algorithm with starting point, direction, and selection mechanism.

  6. If candidate is not null, then run the focusing steps for candidate and return.

  7. Otherwise, unset the sequential focus navigation starting point.

  8. If starting point is a top-level traversable, or a focusable area in the top-level traversable, the user agent should transfer focus to its own controls appropriately (if any), honouring direction, and then return.

    For example, if direction is backward, then the last sequentially focusable control before the browser's rendering area would be the control to focus.

    If the user agent has no sequentially focusable controls — a kiosk-mode browser, for instance — then the user agent may instead restart these steps with the starting point being the top-level traversable itself.

  9. Otherwise, starting point is a focusable area in a child navigable. Set starting point to that child navigable's parent and return to the step labeled loop.

The sequential navigation search algorithm, given a focusable area starting point, sequential focus direction direction, and selection mechanism selection mechanism, consists of the following steps. They return a focusable area-or-null.

  1. Pick the appropriate cell from the following table, and follow the instructions in that cell.

    The appropriate cell is the one that is from the column whose header describes direction and from the first row whose header describes starting point and selection mechanism.

    direction is "forward"direction is "backward"
    starting point is a navigableLet candidate be the first suitable sequentially focusable area in starting point's active document, if any; or else nullLet candidate be the last suitable sequentially focusable area in starting point's active document, if any; or else null
    selection mechanism is "DOM"

    Let candidate be the suitable sequentially focusable area, that appears nearest after starting point in starting point's Document, in shadow-including tree order, if any; or else null

    In this case, starting point does not necessarily belong to its Document's sequential focus navigation order, so we'll select the suitable item from that list that comes after starting point in shadow-including tree order.

    Let candidate be the suitable sequentially focusable area, that appears nearest before starting point in starting point's Document, in shadow-including tree order, if any; or else null
    selection mechanism is "sequential"Let candidate be the first suitable sequentially focusable area after starting point, in starting point's Document's sequential focus navigation order, if any; or else nullLet candidate be the last suitable sequentially focusable area before starting point, in starting point's Document's sequential focus navigation order, if any; or else null

    A suitable sequentially focusable area is a focusable area whose DOM anchor is not inert and is sequentially focusable.

  2. If candidate is a navigable container with a non-null content navigable, then:

    1. Let recursive candidate be the result of running the sequential navigation search algorithm with candidate's content navigable, direction, and "sequential".

    2. If recursive candidate is null, then return the result of running the sequential navigation search algorithm with candidate, direction, and selection mechanism.

    3. Otherwise, set candidate to recursive candidate.

  3. candidateを返す。

6.6.6 Focus management APIs

dictionary FocusOptions {
  boolean preventScroll = false;
  boolean focusVisible;
};
documentOrShadowRoot.activeElement

Document/activeElement

Support in all current engines.

Firefox3+Safari4+Chrome2+
Opera12.1+Edge79+
Edge (Legacy)12+Internet Explorer6+
Firefox Android?Safari iOS?Chrome Android?WebView Android37+Samsung Internet?Opera Android12.1+

ShadowRoot/activeElement

Support in all current engines.

Firefox63+Safari10+Chrome53+
Opera?Edge79+
Edge (Legacy)?Internet ExplorerNo
Firefox Android?Safari iOS?Chrome Android?WebView Android?Samsung Internet?Opera Android?

キーイベントが送られるまたは送る文書における最も深い要素を返す。大まかに言って、これは文書における被フォーカス要素である。

For the purposes of this API, when a child navigable is focused, its container is focused within its parent's active document. For example, if the user moves the focus to a text control in an iframe, the iframe is the element returned by the activeElement API in the iframe's node document.

Similarly, when the focused element is in a different node tree than documentOrShadowRoot, the element returned will be the host that's located in the same node tree as documentOrShadowRoot if documentOrShadowRoot is a shadow-including inclusive ancestor of the focused element, and null if not.

document.hasFocus()

Document/hasFocus

Support in all current engines.

Firefox3+Safari4+Chrome2+
Opera?Edge79+
Edge (Legacy)12+Internet Explorer5.5+
Firefox Android?Safari iOS?Chrome Android?WebView Android37+Samsung Internet?Opera Android?

キーイベントが文書を通してまたは文書に向かって送られる場合にtrueを返し、そうでなければfalseを返す。大まかに言って、これは文書、この内側でネストされた文書、被フォーカスに対応する。

window.focus()

Window/focus

Support in all current engines.

Firefox1+Safari1+Chrome1+
Opera12.1+Edge79+
Edge (Legacy)12+Internet Explorer4+
Firefox Android?Safari iOS?Chrome Android18+WebView Android?Samsung Internet?Opera Android12.1+

Moves the focus to the window's navigable, if any.

element.focus([ { preventScroll: true } ])

HTMLElement/focus

Support in all current engines.

Firefox1.5+Safari3+Chrome1+
Opera8+Edge79+
Edge (Legacy)12+Internet Explorer5.5+
Firefox Android?Safari iOS1+Chrome Android?WebView Android?Samsung Internet?Opera Android10.1+

フォーカスを要素に移動する。

If the element is a navigable container, moves the focus to its content navigable instead.

デフォルトでは、このメソッドはまた要素をビューにスクロールする。Providing the preventScroll option and setting it to true prevents this behavior.

element.blur()

HTMLElement/blur

Support in all current engines.

Firefox1.5+Safari3+Chrome1+
Opera8+Edge79+
Edge (Legacy)12+Internet Explorer5.5+
Firefox Android?Safari iOS1+Chrome Android?WebView Android?Samsung Internet?Opera Android10.1+

フォーカスをビューポートに移動する。このメソッドの使用は奨められない。ビューポートにフォーカスしたい場合、Document文書要素上のfocus()メソッドを呼び出す。

見苦しいフォーカスリングを発見する場合、フォーカスリングを非表示にするためにこの方法を使用してはならない。Instead, use the :focus-visible pseudo-class to override the 'outline' property, and provide a different way to show what element is focused. 代替フォーカススタイルが利用可能にならないか、ページが主にキーボードを使用してページをナビゲートする人に対して著しく使用可能にならないか、ページをナビゲートするのに役立つフォーカスアウトラインを使う人の刺客を減少させないかどうかに注意する。

For example, to hide the outline from textarea elements and instead use a yellow background to indicate focus, you could use:

textarea:focus-visible { outline: none; background: yellow; color: black; }

The activeElement attribute's getter must run these steps:

  1. Let candidate be the DOM anchor of the focused area of this DocumentOrShadowRoot's node document.

  2. Set candidate to the result of retargeting candidate against this DocumentOrShadowRoot.

  3. If candidate's root is not this DocumentOrShadowRoot, then return null.

  4. If candidate is not a Document object, then return candidate.

  5. If candidate has a body element, then return that body element.

  6. If candidate's document element is non-null, then return that document element.

  7. Return null.

The hasFocus() method on the Document object, when invoked, must return the result of running the has focus steps with the Document object as the argument.

The focus() method, when invoked, must run these steps:

  1. Let current be this Window object's navigable.

  2. If current is null, then return.

  3. Run the focusing steps with current.

  4. If current is a top-level traversable, user agents are encouraged to trigger some sort of notification to indicate to the user that the page is attempting to gain focus.

Window/blur

Support in all current engines.

Firefox1+Safari1+Chrome1+
Opera12.1+Edge79+
Edge (Legacy)12+Internet Explorer4+
Firefox Android?Safari iOS?Chrome Android?WebView Android?Samsung Internet?Opera Android12.1+

The blur() method steps are to do nothing.

Historically, the focus() and blur() methods actually affected the system-level focus of the system widget (e.g., tab or window) that contained the navigable, but hostile sites widely abuse this behavior to the user's detriment.

The focus(options) method on elements, when invoked, must run the following steps:

  1. If the element is marked as locked for focus, then return.

  2. Mark the element as locked for focus.

  3. Run the focusing steps for the element.

  4. If the value of the focusVisible dictionary member of options is true, or is not present but in an implementation-defined way the user agent determines it would be best to do so, then indicate focus.

  5. If the value of the preventScroll dictionary member of options is false, then scroll the element into view given "auto", "center", and "center".

  6. Unmark the element as locked for focus.

The blur() method, when invoked, should run the unfocusing steps for the element on which the method was called. User agents may selectively or uniformly ignore calls to this method for usability reasons.

For example, if the blur() method is unwisely being used to remove the focus ring for aesthetics reasons, the page would become unusable by keyboard users. Ignoring calls to this method would thus allow keyboard users to interact with the page.

6.6.7 The autofocus attribute

The autofocus content attribute allows the author to indicate that an element is to be focused as soon as the page is loaded, allowing the user to just start typing without having to manually focus the main element.

When the autofocus attribute is specified on an element inside dialog elements or HTML elements whose popover attribute is set, then it will be focused when the dialog or popover becomes shown.

autofocus属性は真偽属性である。

To find the nearest ancestor autofocus scoping root element given an Element element:

  1. If element is a dialog element, then return element.

  2. If element's popover attribute is not in the no popover state, then return element.

  3. Let ancestor be element.

  4. While ancestor has a parent element:

    1. Set ancestor to ancestor's parent element.

    2. If ancestor is a dialog element, then return ancestor.

    3. If ancestor's popover attribute is not in the no popover state, then return ancestor.

  5. Return ancestor.

両方がautofocus属性を指定される同じ直近の祖先オートフォーカス範囲のルート要素をもつ2つの要素が存在してはならない。

Each Document has an autofocus candidates list, initially empty.

Each Document has an autofocus processed flag boolean, initially false.

When an element with the autofocus attribute specified is inserted into a document, run the following steps:

  1. If the user has indicated (for example, by starting to type in a form control) that they do not wish focus to be changed, then optionally return.

  2. Let target be the element's node document.

  3. If target is not fully active, then return.

  4. If target's active sandboxing flag set has the sandboxed automatic features browsing context flag, then return.

  5. For each ancestorNavigable of target's ancestor navigables: if ancestorNavigable's active document's origin is not same origin with target's origin, then return.

  6. Let topDocument be target's node navigable's top-level traversable's active document.

  7. If topDocument's autofocus processed flag is false, then remove the element from topDocument's autofocus candidates, and append the element to topDocument's autofocus candidates.

We do not check if an element is a focusable area before storing it in the autofocus candidates list, because even if it is not a focusable area when it is inserted, it could become one by the time flush autofocus candidates sees it.

To flush autofocus candidates for a document topDocument, run these steps:

  1. If topDocument's autofocus processed flag is true, then return.

  2. Let candidates be topDocument's autofocus candidates.

  3. If candidates is empty, then return.

  4. If topDocument's focused area is not topDocument itself, or topDocument has non-null target element, then:

    1. Empty candidates.

    2. Set topDocument's autofocus processed flag to true.

    3. Return.

  5. While candidates is not empty:

    1. Let element be candidates[0].

    2. Let doc be element's node document.

    3. If doc is not fully active, then remove element from candidates, and continue.

    4. If doc's node navigable's top-level traversable is not the same as topDocument's node navigable, then remove element from candidates, and continue.

    5. If doc's script-blocking style sheet set is not empty, then return.

      In this case, element is the currently-best candidate, but doc is not ready for autofocusing. We'll try again next time flush autofocus candidates is called.

    6. Remove element from candidates.

    7. Let inclusiveAncestorDocuments be a list consisting of the active document of doc's inclusive ancestor navigables.

    8. If any Document in inclusiveAncestorDocuments has non-null target element, then continue.

    9. Let target be element.

    10. If target is not a focusable area, then set target to the result of getting the focusable area for target.

      Autofocus candidates can contain elements which are not focusable areas. In addition to the special cases handled in the get the focusable area algorithm, this can happen because a non-focusable area element with an autofocus attribute was inserted into a document and it never became focusable, or because the element was focusable but its status changed while it was stored in autofocus candidates.

    11. If target is not null, then:

      1. Empty candidates.

      2. Set topDocument's autofocus processed flag to true.

      3. Run the focusing steps for target.

This handles the automatic focusing during document load. The show() and showModal() methods of dialog elements also processes the autofocus attribute.

Focusing the element does not imply that the user agent has to focus the browser window if it has lost focus.

Global_attributes/autofocus

Support in one engine only.

Firefox🔰 1+Safari🔰 4+Chrome79+
Opera66+Edge79+
Edge (Legacy)NoInternet Explorer🔰 10+
Firefox Android?Safari iOS?Chrome Android?WebView Android79+Samsung Internet?Opera Android57+

autofocus IDL属性は、同じ名前のコンテンツ属性を反映しなければならない。

次の断片において、文書が読み込まれるとき、テキストコントロールにフォーカスされる。

<input maxlength="256" name="q" value="" autofocus>
<input type="submit" value="Search">

The autofocus attribute applies to all elements, not just to form controls. This allows examples such as the following:

<div contenteditable autofocus>Edit <strong>me!</strong><div>

6.7 Assigning keyboard shortcuts

6.7.1 Introduction

この節は非規範的である。

アクティブまたはフォーカスさせることができる各要素はaccesskey属性を使用して、それをアクティブにするための単一のキーの組み合わせを割り当てることができる。

正確なショートカットは、ユーザーエージェントによって決定され、ユーザーのキーボードに関する情報に基づき、どのキーボードショートカットが既にプラットフォーム上に存在し、他にどのようなショートカットがページ上で指定され、ガイドとしてaccesskey属性に提供された情報を使用する。

関連するキーボードショートカットが多種多様な入力デバイスで利用可能であることを確実にするために、著者はaccesskey属性で多数の選択肢を提供できる。

各選択肢は、文字または数字のような、単一の文字で構成される。

ユーザーエージェントは、キーボードショートカットの一覧をユーザーに提供できるが、著者は行うことも推奨される。accessKeyLabel IDL属性は、ユーザーエージェントによって割り当てられた実際のキーの組み合わせを表す文字列を返す。

この例において、著者はショートカットキーを使用して呼び出すことができるボタンを提供してきた。フルキーボードをサポートするために、著者は可能なキーとして"C"を提供している。To support devices equipped only with numeric keypads, the author has provided "1" as another possible key.

<input type=button value=Collect onclick="collect()"
       accesskey="C 1" id=c>

ショートカットキーが何であるかをユーザーに伝えるために、著者は明示的にボタンのラベルにキーの組み合わせを追加するために選択しているここでのこのスクリプトを持つ。

function addShortcutKeyLabel(button) {
  if (button.accessKeyLabel != '')
    button.value += ' (' + button.accessKeyLabel + ')';
}
addShortcutKeyLabel(document.getElementById('c'));

異なるプラットフォーム上のブラウザーは、たとえ同じキーの組み合わせであっても、そのプラットフォーム上で普及している規則に基づいて異なるラベルを表示する。たとえば、キーの組み合わせが、Controlキー、Shiftキー、および文字Cである場合、Macのブラウザーが"^⇧C"を表示するかもしれない一方で、Windowsのブラウザーは"Ctrl+Shift+C"を表示するかもしれない。一方でEmacsのブラウザーは単に"C-C"を表示するかもしれない。同様に、キーの組み合わせがAltキーとEscキーである場合、Windowsは"Alt+Esc"を使用するかもしれず、Macは"⌥⎋"を使用するかもしれず、Emacsのブラウザーは、"M-ESC"または"ESC ESC"を使用するかもしれない。

したがって、一般に、accessKeyLabel IDL属性から返された値を解析しようとするのは賢明ではない。

6.7.2 The accesskey attribute

Global_attributes/accesskey

Support in all current engines.

Firefox1+Safari4+Chrome1+
Opera?Edge79+
Edge (Legacy)12+Internet ExplorerYes
Firefox Android?Safari iOS?Chrome Android?WebView Android?Samsung Internet?Opera Android?

すべてのHTML要素は、accesskeyコンテンツ属性の設定を持ってもよい。accesskey属性値は、要素をアクティブまたはフォーカスするキーボードショートカットを作成するためのガイドとして、ユーザーエージェントによって使用される。

If specified, the value must be an ordered set of unique space-separated tokens none of which are identical to another token and each of which must be exactly one code point in length.

次の例において、サイトを熟知するキーボードユーザーがより迅速に関連するページに移動できるよう、さまざまなリンクがアクセスキーとともに与えられる:

<nav>
 <p>
  <a title="Consortium Activities" accesskey="A" href="/Consortium/activities">Activities</a> |
  <a title="Technical Reports and Recommendations" accesskey="T" href="/TR/">Technical Reports</a> |
  <a title="Alphabetical Site Index" accesskey="S" href="/Consortium/siteindex">Site Index</a> |
  <a title="About This Site" accesskey="B" href="/Consortium/">About Consortium</a> |
  <a title="Contact Consortium" accesskey="C" href="/Consortium/contact">Contact</a>
 </p>
</nav>

次の例において、検索フィールドは2つの可能なアクセスキー、"s"と"0"(この順番で)が与えられる。A user agent on a device with a full keyboard might pick Ctrl + Alt + S as the shortcut key, while a user agent on a small device with just a numeric keypad might pick just the plain unadorned key 0:

<form action="/search">
 <label>Search: <input type="search" name="q" accesskey="s 0"></label>
 <input type="submit">
</form>

次の例において、ボタンは説明可能なアクセスキーを持つ。このスクリプトは次に、ユーザーエージェントが選択したキーの組み合わせを通知するためにボタンのラベルの更新を試みる。

<input type=submit accesskey="N @ 1" value="Compose">
...
<script>
 function labelButton(button) {
   if (button.accessKeyLabel)
     button.value += ' (' + button.accessKeyLabel + ')';
 }
 var inputs = document.getElementsByTagName('input');
 for (var i = 0; i < inputs.length; i += 1) {
   if (inputs[i].type == "submit")
     labelButton(inputs[i]);
 }
</script>

あるユーザーエージェントにおいて、ボタンのラベルは"Compose(⌘N)"になるかもしれない。別のものにおいて、これは"Compose(Alt+⇧+1)"になるかもしれない。ユーザーエージェントがキーを割り当てない場合、単に"Compose"になる。正確な文字列は割り当てられるアクセスキーが何であるか、およびどのようにユーザーエージェントがそのキーの組み合わせを表すかに依存する。

6.7.3 Processing model

An element's assigned access key is a key combination derived from the element's accesskey content attribute. Initially, an element must not have an assigned access key.

Whenever an element's accesskey attribute is set, changed, or removed, the user agent must update the element's assigned access key by running the following steps:

  1. If the element has no accesskey attribute, then skip to the fallback step below.

  2. Otherwise, split the attribute's value on ASCII whitespace, and let keys be the resulting tokens.

  3. For each value in keys in turn, in the order the tokens appeared in the attribute's value, run the following substeps:

    1. If the value is not a string exactly one code point in length, then skip the remainder of these steps for this value.

    2. If the value does not correspond to a key on the system's keyboard, then skip the remainder of these steps for this value.

    3. (This is a tracking vector.) If the user agent can find a mix of zero or more modifier keys that, combined with the key that corresponds to the value given in the attribute, can be used as the access key, then the user agent may assign that combination of keys as the element's assigned access key and return.

  4. Fallback: Optionally, the user agent may assign a key combination of its choosing as the element's assigned access key and then return.

  5. If this step is reached, the element has no assigned access key.

Once a user agent has selected and assigned an access key for an element, the user agent should not change the element's assigned access key unless the accesskey content attribute is changed or the element is moved to another Document.

When the user presses the key combination corresponding to the assigned access key for an element, if the element defines a command, the command's Hidden State facet is false (visible), the command's Disabled State facet is also false (enabled), the element is in a document that has a non-null browsing context, and neither the element nor any of its ancestors has a hidden attribute specified, then the user agent must trigger the Action of the command.

User agents might expose elements that have an accesskey attribute in other ways as well, e.g. in a menu displayed in response to a specific key combination.


HTMLElement/accessKey

Support in all current engines.

Firefox5+Safari6+Chrome17+
Opera12.1+Edge79+
Edge (Legacy)12+Internet Explorer5.5+
Firefox Android?Safari iOS?Chrome Android?WebView Android?Samsung Internet?Opera Android12.1+

The accessKey IDL attribute must reflect the accesskey content attribute.

HTMLElement/accessKeyLabel

Firefox8+Safari14+ChromeNo
Opera?EdgeNo
Edge (Legacy)?Internet ExplorerNo
Firefox Android?Safari iOS?Chrome Android?WebView Android?Samsung Internet?Opera Android?

The accessKeyLabel IDL attribute must return a string that represents the element's assigned access key, if any. If the element does not have one, then the IDL attribute must return the empty string.

6.8 Editing

6.8.1 Making document regions editable: The contenteditable content attribute

HTMLElement/contentEditable

Support in all current engines.

Firefox3+Safari3+Chrome1+
Opera9+Edge79+
Edge (Legacy)12+Internet Explorer5.5+
Firefox Android?Safari iOS1+Chrome Android?WebView Android?Samsung Internet?Opera Android10.1+
interface mixin ElementContentEditable {
  [CEReactions] attribute DOMString contentEditable;
  [CEReactions] attribute DOMString enterKeyHint;
  readonly attribute boolean isContentEditable;
  [CEReactions] attribute DOMString inputMode;
};

Global_attributes/contenteditable

Support in all current engines.

Firefox3+Safari4+Chrome1+
Opera9+Edge79+
Edge (Legacy)12+Internet Explorer5.5+
Firefox Android?Safari iOS?Chrome Android?WebView Android?Samsung Internet?Opera Android?

The contenteditable content attribute is an enumerated attribute with the following keywords and states:

キーワード状態概要
truetrueThe element is editable.
(the empty string)
falsefalseThe element is not editable.
plaintext-onlyplaintext-onlyOnly the element's raw text content is editable; rich formatting is disabled.

The attribute's missing value default and invalid value default are both the inherit state. The inherit state indicates that the element is editable (or not) based on the parent element's state.

たとえば、ユーザーがHTMLを使用する記事を書くことが期待される、新しい記事を公開するためにformおよびtextareaを持つページを考えてみる:

<form method=POST>
 <fieldset>
  <legend>New article</legend>
  <textarea name=article>&lt;p>Hello world.&lt;/p></textarea>
 </fieldset>
 <p><button>Publish</button></p>
</form>

スクリプトを有効にする場合、textarea要素は、contenteditable属性を使用して、代わりにリッチテキストコントロールに置き換えることができる:

<form method=POST>
 <fieldset>
  <legend>New article</legend>
  <textarea id=textarea name=article>&lt;p>Hello world.&lt;/p></textarea>
  <div id=div style="white-space: pre-wrap" hidden><p>Hello world.</p></div>
  <script>
   let textarea = document.getElementById("textarea");
   let div = document.getElementById("div");
   textarea.hidden = true;
   div.hidden = false;
   div.contentEditable = "true";
   div.oninput = (e) => {
     textarea.value = div.innerHTML;
   };
  </script>
 </fieldset>
 <p><button>Publish</button></p>
</form>

たとえば挿入リンクを挿入する機能は、document.execCommand()APIを使用する、またはSelectionAPIおよび他のDOM APIを使用して実装することができる。[EXECCOMMAND] [SELECTION] [DOM]

contenteditable属性はまた、大きな効果を使用することができる:

<!doctype html>
<html lang=en>
<title>Live CSS editing!</title>
<style style=white-space:pre contenteditable>
html { margin:.2em; font-size:2em; color:lime; background:purple }
head, title, style { display:block }
body { display:none }
</style>
element.contentEditable [ = value ]

Returns "true", "plaintext-only", "false", or "inherit", based on the state of the contenteditable attribute.

その状態を変更する設定が可能である。

新しい値がこれらの文字列のいずれかでない場合、"SyntaxError" DOMExceptionを投げる。

element.isContentEditable

HTMLElement/isContentEditable

Support in all current engines.

Firefox4+Safari3+Chrome1+
Opera12.1+Edge79+
Edge (Legacy)12+Internet Explorer5.5+
Firefox Android?Safari iOS1+Chrome Android?WebView Android?Samsung Internet?Opera Android12.1+

要素が編集可能な場合にtrueを返す。そうでなければfalseを返す。

The contentEditable IDL attribute, on getting, must return the string "true" if the content attribute is set to the true state, "plaintext-only" if the content attribute is set to the plaintext-only state, "false" if the content attribute is set to the false state, and "inherit" otherwise. On setting, if the new value is an ASCII case-insensitive match for the string "inherit" then the content attribute must be removed, if the new value is an ASCII case-insensitive match for the string "true" then the content attribute must be set to the string "true", if the new value is an ASCII case-insensitive match for the string "plaintext-only" then the content attribute must be set to the string "plaintext-only", if the new value is an ASCII case-insensitive match for the string "false" then the content attribute must be set to the string "false", and otherwise the attribute setter must throw a "SyntaxError" DOMException.

The isContentEditable IDL attribute, on getting, must return true if the element is either an editing host or editable, and false otherwise.

6.8.2 Making entire documents editable: the designMode getter and setter

document.designMode [ = value ]

Document/designMode

Support in all current engines.

Firefox1+Safari1.2+Chrome1+
Opera9+Edge79+
Edge (Legacy)12+Internet Explorer4+
Firefox Android?Safari iOS?Chrome Android?WebView Android?Samsung Internet?Opera Android10.1+

文書が編集可能である場合に"on"を返し、ない場合に"off"を返す。

文書の現在の状態を変更する設定が可能である。これは、文書をフォーカスし、その文書で文書の選択をリセットする。

Document objects have an associated design mode enabled, which is a boolean. 最初はfalseである。

The designMode getter steps are to return "on" if this's design mode enabled is true; otherwise "off".

The designMode setter steps are:

  1. Let value be the given value, converted to ASCII lowercase.

  2. If value is "on" and this's design mode enabled is false, then:

    1. Set this's design mode enabled to true.

    2. Reset this's active range's start and end boundary points to be at the start of this.

    3. Run the focusing steps for this's document element, if non-null.

  3. If value is "off", then set this's design mode enabled to false.

6.8.3 Best practices for in-page editors

著者は、もともと値'pre-wrap'へこれら編集のメカニズムを介して作成された編集ホストおよびマークアップ上の'white-space'プロパティを設定することを奨める。デフォルトのHTML空白処理は、あまりWYSIWYG編集に向かず、そして'white-space'がデフォルト値のままである場合、いくつかのコーナーの場合において、行の折り返しは正しく動作しない。

デフォルト'normal'値が代わりに使用される場合に発生する問題の例として、単語の間に2つのスペース(ここでは"␣"によって表される)とともに、"yellow␣␣ball"と入力したユーザーの場合を考える。'white-space'のデフォルト値('normal')のための場所での編集規則ともに、結果のマークアップは、"yellow&nbsp; ball"または"yellow &nbsp;ball"のいずれかで構成される。すなわち、2つの単語間の非開票スペースに加えて、通常スペースが存在する。'white-space'に対する'normal'値は共に相殺するために隣接する通常スペースを必要とするため、これは必要である。

前者の場合において、たとえ行の末尾で"yellow"単独で一致するとしても、"yellow⍽"は次の行("⍽"は非改行スペースを表すためにここで使用されている)に折り返す。後者の場合において、行の先頭に包まれる場合、"⍽ball"は非改行スペース由来の可視インデントを持つだろう。

しかし、'white-space'が'pre-wrap'に設定される場合、編集規則は、代わりに単に単語間に2つの通常のスペースを置き、2つの単語が行末で分割されるべきであり、スペースはレンダリングから削除されてきれいになる。

6.8.4 Editing APIs

An editing host is either an HTML element with its contenteditable attribute in the true state or plaintext-only state, or a child HTML element of a Document whose design mode enabled is true.

The definition of the terms active range, editing host of, and editable, the user interface requirements of elements that are editing hosts or editable, the execCommand(), queryCommandEnabled(), queryCommandIndeterm(), queryCommandState(), queryCommandSupported(), and queryCommandValue() methods, text selections, and the delete the selection algorithm are defined in execCommand. [EXECCOMMAND]

6.8.5 Spelling and grammar checking

User agents can support the checking of spelling and grammar of editable text, either in form controls (such as the value of textarea elements), or in elements in an editing host (e.g. using contenteditable).

For each element, user agents must establish a default behavior, either through defaults or through preferences expressed by the user. There are three possible default behaviors for each element:

true-by-default
The element will be checked for spelling and grammar if its contents are editable and spellchecking is not explicitly disabled through the spellcheck attribute.
false-by-default
The element will never be checked for spelling and grammar unless spellchecking is explicitly enabled through the spellcheck attribute.
inherit-by-default
The element's default behavior is the same as its parent element's. Elements that have no parent element cannot have this as their default behavior.

Global_attributes/spellcheck

Support in all current engines.

FirefoxYesSafariYesChrome9+
OperaYesEdge79+
Edge (Legacy)12+Internet Explorer11
Firefox Android57+Safari iOS9.3+Chrome Android47+WebView Android?Samsung Internet?Opera Android37+

The spellcheck attribute is an enumerated attribute with the following keywords and states:

キーワード状態概要
truetrueSpelling and grammar will be checked.
(the empty string)
falsefalseSpelling and grammar will not be checked.

The attribute's missing value default and invalid value default are both the default state. The default state indicates that the element is to act according to a default behavior, possibly based on the parent element's own spellcheck state, as defined below.


element.spellcheck [ = value ]

要素がスペルや文法チェックを持つ場合はtrueを返す。そうでなければfalseを返す。

デフォルトを上書きしてspellcheckコンテンツ属性を設定するための、設定が可能である。

The spellcheck IDL attribute, on getting, must return true if the element's spellcheck content attribute is in the true state, or if the element's spellcheck content attribute is in the default state and the element's default behavior is true-by-default, or if the element's spellcheck content attribute is in the default state and the element's default behavior is inherit-by-default and the element's parent element's spellcheck IDL attribute would return true; otherwise, if none of those conditions applies, then the attribute must instead return false.

The spellcheck IDL attribute is not affected by user preferences that override the spellcheck content attribute, and therefore might not reflect the actual spellchecking state.

On setting, if the new value is true, then the element's spellcheck content attribute must be set to "true", otherwise it must be set to "false".


User agents should only consider the following pieces of text as checkable for the purposes of this feature:

For text that is part of a Text node, the element with which the text is associated is the element that is the immediate parent of the first character of the word, sentence, or other piece of text. For text in attributes, it is the attribute's element. For the values of input and textarea elements, it is the element itself.

To determine if a word, sentence, or other piece of text in an applicable element (as defined above) is to have spelling- and grammar-checking enabled, the UA must use the following algorithm:

  1. If the user has disabled the checking for this text, then the checking is disabled.
  2. Otherwise, if the user has forced the checking for this text to always be enabled, then the checking is enabled.
  3. Otherwise, if the element with which the text is associated has a spellcheck content attribute, then: if that attribute is in the true state, then checking is enabled; otherwise, if that attribute is in the false state, then checking is disabled.
  4. Otherwise, if there is an ancestor element with a spellcheck content attribute that is not in the default state, then: if the nearest such ancestor's spellcheck content attribute is in the true state, then checking is enabled; otherwise, checking is disabled.
  5. Otherwise, if the element's default behavior is true-by-default, then checking is enabled.
  6. Otherwise, if the element's default behavior is false-by-default, then checking is disabled.
  7. Otherwise, if the element's parent element has its checking enabled, then checking is enabled.
  8. Otherwise, checking is disabled.

If the checking is enabled for a word/sentence/text, the user agent should indicate spelling and grammar errors in that text. User agents should take into account the other semantics given in the document when suggesting spelling and grammar corrections. User agents may use the language of the element to determine what spelling and grammar rules to use, or may use the user's preferred language settings. UAs should use input element attributes such as pattern to ensure that the resulting value is valid, where possible.

If checking is disabled, the user agent should not indicate spelling or grammar errors for that text.

The element with ID "a" in the following example would be the one used to determine if the word "Hello" is checked for spelling errors. In this example, it would not be.

<div contenteditable="true">
 <span spellcheck="false" id="a">Hell</span><em>o!</em>
</div>

The element with ID "b" in the following example would have checking enabled (the leading space character in the attribute's value on the input element causes the attribute to be ignored, so the ancestor's value is used instead, regardless of the default).

<p spellcheck="true">
 <label>Name: <input spellcheck=" false" id="b"></label>
</p>

この仕様は、スペルや文法チェッカーに対するユーザーインターフェイスを定義しない。ユーザーエージェントはオンデマンドチェックを提供するかもしれず、チェックが有効である間に連続的なチェックを実行するかもしれず、または他のインターフェイスを使用するかもしれない。

6.8.6 Writing suggestions

User agents offer writing suggestions as users type into editable regions, either in form controls (e.g., the textarea element) or in elements in an editing host.

The writingsuggestions content attribute is an enumerated attribute with the following keywords and states:

キーワード状態概要
truetrueWriting suggestions should be offered on this element.
(the empty string)
falsefalseWriting suggestions should not be offered on this element.

The attribute's missing value default is the default state. The default state indicates that the element is to act according to a default behavior, possibly based on the parent element's own writingsuggestions state, as defined below.

The attribute's invalid value default is the true state.

element.writingSuggestions [ = value ]

Returns "true" if the user agent is to offer writing suggestions under the scope of the element; otherwise, returns "false".

Can be set, to override the default and set the writingsuggestions content attribute.

The computed writing suggestions value of a given element is determined by running the following steps:

  1. If element's writingsuggestions content attribute is in the false state, return "false".

  2. If element's writingsuggestions content attribute is in the default state, element has a parent element, and the computed writing suggestions value of element's parent element is "false", then return "false".

  3. Return "true".

The writingSuggestions getter steps are:

  1. Return this's computed writing suggestions value.

The writingSuggestions IDL attribute is not affected by user preferences that override the writingsuggestions content attribute, and therefore might not reflect the actual writing suggestions state.

The writingSuggestions setter steps are:

  1. Set this's writingsuggestions content attribute to the given value.


User agents should only offer suggestions within an element's scope if the result of running the following algorithm given element returns true:

  1. If the user has disabled writing suggestions, then return false.

  2. If none of the following conditions are true:

    then return false.

  3. If element has an inclusive ancestor with a writingsuggestions content attribute that's not in the default and the nearest such ancestor's writingsuggestions content attribute is in the false state, then return false.

  4. Otherwise, return true.

This specification does not define the user interface for writing suggestions. A user agent could offer on-demand suggestions, continuous suggestions as the user types, inline suggestions, autofill-like suggestions in a popup, or could use other interfaces.

6.8.7 Autocapitalization

モバイルデバイス上の仮想キーボードや音声入力など、テキストを入力するいくつかの方法では、文の最初の文字を自動的に大文字にすることでユーザーを支援することがある(この規則で言語でテキストを構成する場合)。自動大文字化を実装する仮想キーボードは、自動大文字にすべき文字を入力しようとするとき、大文字の文字を表示するように自動的に切り替えるかもしれない(ただし、ユーザーはその文字を小文字に切り替え可能である)。例えば音声入力など、他の入力の種類は、ユーザーが最初に介入するオプションを与えないような方法で自動大文字化を行ってもよい。autocapitalize属性は、著者がそのような振る舞いを制御するのを可能にする。

典型的に実装されるように、autocapitalize属性は、物理キーボードで入力するときの動作に影響しない。(この理由のために、場合によっては自動大文字化の動作を上書きしたり、最初の入力の後にテキストを編集することをユーザーの能力と同様に、属性をいかなる種類の入力検証にも当てにしてはならない。

The autocapitalize attribute can be used on an editing host to control autocapitalization behavior for the hosted editable region, on an input or textarea element to control the behavior for inputting text into that element, or on a form element to control the default behavior for all autocapitalize-and-autocorrect inheriting elements associated with the form element.

The autocapitalize attribute never causes autocapitalization to be enabled for input elements whose type attribute is in one of the URL, Email, or Password states. (This behavior is included in the used autocapitalization hint algorithm below.)

自動大文字化処理モデルは、以下のように定義される5つの自動大文字化ヒントの中から選択することに基づく:

default

The user agent and input method should make their own determination of whether or not to enable autocapitalization.

none

自動大文字化は適用されるべきではない(すべての文字は小文字をデフォルトにすべきである)。

sentences

各文の最初の文字は大文字をデフォルトにすべきである。他のすべての文字は小文字をデフォルトにすべきである。

words

各単語の最初の文字は大文字をデフォルトにすべきである。他のすべての文字は小文字をデフォルトにすべきである。

characters

全ての文字は大文字をデフォルトにすべきである。

Global_attributes/autocapitalize

Support in all current engines.

Firefox111+SafariNoChrome43+
Opera?Edge79+
Edge (Legacy)?Internet Explorer?
Firefox Android?Safari iOS5+Chrome Android?WebView Android?Samsung Internet?Opera Android?

autocapitalize属性は、状態が可能な自動大文字ヒントである列挙属性である。属性の状態で指定された自動大文字化ヒントは、ユーザーエージェントの動作を通知する、使用済みの自動大文字化ヒントを形成するための他の考慮事項と組み合わされる。この属性のキーワードと状態マッピングは次のとおり:

キーワード状態
offnone
none
onsentences
sentences
wordswords
characterscharacters

The attribute's missing value default is the default state, and its invalid value default is the sentences state.

element.autocapitalize [ = value ]

要素の現在の自動大文字化状態を返す。設定されていない場合は空文字列を返す。form要素から状態を継承するinput要素とtextarea要素の場合、これはform要素の自動大文字化状態を返すが、編集可能領域の要素の場合、これは(この要素が実際に編集ホストでない限り)編集ホストの自動大文字化状態を返さないことに注意すること。

autocapitalizeコンテンツ属性を設定する(そしてそれによって要素の自動大文字化動作を変化させる)ことで、設定が可能である。

To compute the own autocapitalization hint of an element element, run the following steps:

  1. If the autocapitalize content attribute is present on element, and its value is not the empty string, return the state of the attribute.

  2. If element is an autocapitalize-and-autocorrect inheriting element and has a non-null form owner, return the own autocapitalization hint of element's form owner.

  3. Return default.

The autocapitalize getter steps are to:

  1. Let state be the own autocapitalization hint of this.

  2. If state is default, then return the empty string.

  3. If state is none, then return "none".

  4. If state is sentences, then return "sentences".

  5. Return the keyword value corresponding to state.

The autocapitalize setter steps are to set the autocapitalize content attribute to the given value.


User agents that support customizable autocapitalization behavior for a text input method and wish to allow web developers to control this functionality should, during text input into an element, compute the used autocapitalization hint for the element. This will be an autocapitalization hint that describes the recommended autocapitalization behavior for text input into the element.

User agents or input methods may choose to ignore or override the used autocapitalization hint in certain circumstances.

The used autocapitalization hint for an element element is computed using the following algorithm:

  1. If element is an input element whose type attribute is in one of the URL, Email, or Password states, then return default.

  2. If element is an input element or a textarea element, then return element's own autocapitalization hint.

  3. If element is an editing host or an editable element, then return the own autocapitalization hint of the editing host of element.

  4. Assert: this step is never reached, since text input only occurs in elements that meet one of the above criteria.

6.8.8 Autocorrection

Some methods of entering text assist users by automatically correcting misspelled words while typing, a process also known as autocorrection. User agents can support autocorrection of editable text, either in form controls (such as the value of textarea elements), or in elements in an editing host (e.g., using contenteditable). Autocorrection may be accompanied by user interfaces indicating that text is about to be autocorrected or has been autocorrected, and is commonly performed when inserting punctuation characters, spaces, or new paragraphs after misspelled words. The autocorrect attribute allows authors to control such behavior.

The autocorrect attribute can be used on an editing host to control autocorrection behavior for the hosted editable region, on an input or textarea element to control the behavior when inserting text into that element, or on a form element to control the default behavior for all autocapitalize-and-autocorrect inheriting elements associated with the form element.

The autocorrect attribute never causes autocorrection to be enabled for input elements whose type attribute is in one of the URL, E-mail, or Password states. (This behavior is included in the used autocorrection state algorithm below.)

The autocorrect attribute is an enumerated attribute with the following keywords and states:

キーワード状態概要
ononThe user agent is permitted to automatically correct spelling errors while the user types. Whether spelling is automatically corrected while typing left is for the user agent to decide, and may depend on the element as well as the user's preferences.
(the empty string)
offoffThe user agent is not allowed to automatically correct spelling while the user types.

The attribute's invalid value default and missing value default are both the on state.

The autocorrect getter steps are: return true if the element's used autocorrection state is on and false if the element's used autocorrection state is off. The setter steps are: if the given value is true, then the element's autocorrect attribute must be set to "on"; otherwise it must be set to "off".

To compute the used autocorrection state of an element element, run these steps:

  1. If element is an input element whose type attribute is in one of the URL, E-mail, or Password states, then return off.

  2. If the autocorrect content attribute is present on element, then return the state of the attribute.

  3. If element is an autocapitalize-and-autocorrect inheriting element and has a non-null form owner, then return the state of element's form owner's autocorrect attribute.

  4. Return on.

element . autocorrect

Returns the autocorrection behavior of the element. Note that for autocapitalize-and-autocorrect inheriting elements that inherit their state from a form element, this will return the autocorrection behavior of the form element, but for an element in an editable region, this will not return the autocorrection behavior of the editing host (unless this element is, in fact, the editing host).

element . autocorrect = value

Updates the autocorrect content attribute (and thereby changes the autocorrection behavior of the element).

The input element in the following example would not allow autocorrection, since it does not have an autocorrect content attribute and therefore inherits from the form element, which has an attribute of "off". However, the textarea element would allow autocorrection, since it has an autocorrect content attribute with a value of "on".

<form autocorrect="off">
 <input type="search">
 <textarea autocorrect="on"></textarea>
</form>

6.8.9 Input modalities: the inputmode attribute

ユーザーエージェントは、フォームコントロール(textarea要素の値など)で、または編集ホストcontenteditableなど)における要素でinputmode属性をサポートすることができる。

Global_attributes/inputmode

Support in all current engines.

Firefox95+SafariNoChrome66+
Opera?Edge79+
Edge (Legacy)?Internet ExplorerNo
Firefox Android79+Safari iOS12.2+Chrome Android?WebView Android?Samsung Internet?Opera Android?

inputmodeコンテンツ属性は、ユーザーがコンテンツを入力する際に最も参考になる入力メカニズムの種類を指定する列挙属性である。

キーワード説明
noneユーザーエージェントは仮想キーボードを表示すべきではない。このキーワードは、独自のキーボードコントロールをレンダリングするコンテンツに役立つ。
textユーザーエージェントは、ユーザーのロケールでテキスト入力が可能な仮想キーボードを表示すべきである。
telユーザーエージェントは、電話番号入力が可能な仮想キーボードを表示すべきであある。これは、数字0〜9、"#"文字、および"*"文字のキーを含むべきである。一部のロケールで、これはまた、アルファベットのニーモニックラベル(たとえば、米国で、"2"キーはまた、歴史的に文字A、B、およびCで標識されている)を含むことができる。
urlユーザーエージェントは、"/"と"."文字、"www"や".com"のようなドメイン名の中で見つかった文字列を簡単に入力するための、URLの入力を補助するためのキーとともに、ユーザーのロケールでテキスト入力が可能な仮想キーボードを表示すべきである。
emailThe user agent should display a virtual keyboard capable of text input in the user's locale, with keys for aiding in the input of email addresses, such as that for the "@" character and the "." character.
numericユーザーエージェントは、数字入力が可能な仮想キーボードを表示すべきであある。このキーワードは、PIN入力に便利である。
decimalユーザーエージェントは、小数入力が可能な仮想キーボードを表示すべきであある。ロケールの数値キーおよびフォーマットセパレーターを表示すべきである。
searchユーザーエージェントは、検索に最適化された仮想キーボードを表示すべきである。

HTMLElement/inputMode

Support in all current engines.

Firefox95+Safari12.1+Chrome66+
Opera?Edge79+
Edge (Legacy)?Internet ExplorerNo
Firefox Android79+Safari iOS?Chrome Android?WebView Android?Samsung Internet?Opera Android?

The inputMode IDL attribute must reflect the inputmode content attribute, limited to only known values.

When inputmode is unspecified (or is in a state not supported by the user agent), the user agent should determine the default virtual keyboard to be shown. Contextual information such as the input type or pattern attributes should be used to determine which type of virtual keyboard should be presented to the user.

6.8.10 Input modalities: the enterkeyhint attribute

ユーザーエージェントは、フォームコントロール(textarea要素の値など)で、または編集ホストcontenteditableなど)における要素でenterkeyhint属性をサポートすることができる。

Global_attributes/enterkeyhint

Support in all current engines.

Firefox94+Safari13.1+Chrome77+
Opera66+Edge79+
Edge (Legacy)?Internet ExplorerNo
Firefox Android?Safari iOS?Chrome Android?WebView Android?Samsung Internet?Opera Android57+

enterkeyhintコンテンツ属性は、仮想キーボードのEnterキーに表示するアクションラベル(またはアイコン)を指定する列挙属性である。これにより、ユーザーにとってより役立つようにするために、著者はEnterキーの表示をカスタマイズを可能にする。

キーワード説明
enterユーザーエージェントは、典型的には新しい行を挿入する、操作'enter'の合図を提示すべきである。
doneThe user agent should present a cue for the operation 'done', typically meaning there is nothing more to input and the input method editor (IME) will be closed.
goユーザーエージェントは、典型的にはユーザーがタイプしたテキストのターゲットにユーザーを連れて行くことを意味する、操作'go'の合図を提示すべきである。
nextユーザーエージェントは、典型的にはテキストを受け付ける次のフィールドにユーザーを連れて行く、操作'next'の合図を提示すべきである。
previousユーザーエージェントは、典型的にはテキストを受け入れる前のフィールドにユーザーを連れて行く、操作'previous'の合図を提示すべきである。
searchユーザーエージェントは、典型的にはユーザーがタイプしたテキストの検索の結果にユーザーを連れて行く、操作「検索」の合図を提示すべきである。
sendユーザーエージェントは、典型的にはテキストをそのテキストのターゲットに配信する、操作'send'の合図を提示すべきである。

HTMLElement/enterKeyHint

Support in all current engines.

Firefox94+Safari13.1+Chrome77+
Opera?Edge79+
Edge (Legacy)?Internet ExplorerNo
Firefox Android?Safari iOS?Chrome Android?WebView Android?Samsung Internet?Opera Android?

The enterKeyHint IDL attribute must reflect the enterkeyhint content attribute, limited to only known values.

When enterkeyhint is unspecified (or is in a state not supported by the user agent), the user agent should determine the default action label (or icon) to present. Contextual information such as the inputmode, type, or pattern attributes should be used to determine which action label (or icon) to present on the virtual keyboard.

6.9 Find-in-page

6.9.1 Introduction

This section defines find-in-page — a common user-agent mechanism which allows users to search through the contents of the page for particular information.

Access to the find-in-page feature is provided via a find-in-page interface. This is a user-agent provided user interface, which allows the user to specify input and the parameters of the search. This interface can appear as a result of a shortcut or a menu selection.

A combination of text input and settings in the find-in-page interface represents the user query. This typically includes the text that the user wants to search for, as well as optional settings (e.g., the ability to restrict the search to whole words only).

The user-agent processes page contents for a given query, and identifies zero or more matches, which are content ranges that satisfy the user query.

One of the matches is identified to the user as the active match. It is highlighted and scrolled into view. The user can navigate through the matches by advancing the active match using the find-in-page interface.

Issue #3539 tracks standardizing how find-in-page underlies the currently-unspecified window.find() API.

6.9.2 Interaction with details and hidden=until-found

When find-in-page begins searching for matches, all details elements in the page which do not have their open attribute set should have the skipped contents of their second slot become accessible, without modifying the open attribute, in order to make find-in-page able to search through it. Similarly, all HTML elements with the hidden attribute in the hidden until found state should have their skipped contents become accessible without modifying the hidden attribute in order to make find-in-page able to search through them. After find-in-page finishes searching for matches, the details elements and the elements with the hidden attribute in the hidden until found state should have their contents become skipped again. This entire process must happen synchronously (and so is not observable to users or to author code). [CSSCONTAIN]

When find-in-page chooses a new active match, perform the following steps:

  1. Let node be the first node in the active match.

  2. Queue a global task on the user interaction task source given node's relevant global object to run the following steps:

    1. Run the ancestor details revealing algorithm on node.

    2. Run the ancestor hidden-until-found revealing algorithm on node.

(This is a tracking vector.) When find-in-page auto-expands a details element like this, it will fire a toggle event. As with the separate scroll event that find-in-page fires, this event could be used by the page to discover what the user is typing into the find-in-page dialog. If the page creates a tiny scrollable area with the current search term and every possible next character the user could type separated by a gap, and observes which one the browser scrolls to, it can add that character to the search term and update the scrollable area to incrementally build the search term. By wrapping each possible next match in a closed details element, the page could listen to toggle events instead of scroll events. This attack could be addressed for both events by not acting on every character the user types into the find-in-page dialog.

6.9.3 Interaction with selection

The find-in-page process is invoked in the context of a document, and may have an effect on the selection of that document. Specifically, the range that defines the active match can dictate the current selection. These selection updates, however, can happen at different times during the find-in-page process (e.g. upon the find-in-page interface dismissal or upon a change in the active match range).

6.10 Close requests and close watchers

6.10.1 Close requests

In an implementation-defined (and likely device-specific) manner, a user can send a close request to the user agent. This indicates that the user wishes to close something that is currently being shown on the screen, such as a popover, menu, dialog, picker, or display mode.

Some example close requests are:

Whenever the user agent receives a potential close request targeted at a Document document, it must queue a global task on the user interaction task source given document's relevant global object to perform the following close request steps:

  1. If document's fullscreen element is not null, then:

    1. Fully exit fullscreen given document's node navigable's top-level traversable's active document.

    2. Return.

    This does not fire any relevant event, such as keydown; it only causes fullscreenchange to be eventually fired.

  2. Optionally, skip to the step labeled alternative processing.

    For example, if the user agent detects user frustration at repeated close request interception by the current web page, it might take this path.

  3. Fire any relevant events, per UI Events or other relevant specifications. [UIEVENTS]

    An example of a relevant event in the UI Events model would be the keydown event that UI Events suggests firing when the user presses the Esc key on their keyboard. On most platforms with keyboards, this is treated as a close request, and so would trigger these close request steps.

    An example of relevant events that are outside of the model given in UI Events would be assistive technology synthesizing an Esc keydown event when the user sends a close request by using a dismiss gesture.

  4. Let event be null if no such events are fired, or the Event object representing one of the fired events otherwise. If multiple events are fired, which one is chosen is implementation-defined.

  5. If event is not null, and its canceled flag is set, then return.

  6. If document is not fully active, then return.

    This step is necessary because, if event is not null, then an event listener might have caused document to no longer be fully active.

  7. Let closedSomething be the result of processing close watchers on document's relevant global object.

  8. If closedSomething is true, then return.

  9. Alternative processing: Otherwise, there was nothing watching for a close request. The user agent may instead interpret this interaction as some other action, instead of interpreting it as a close request.

On platforms where pressing the Esc key is interpreted as a close request, the user agent must interpret the key being pressed down as the close request, instead of the key being released. Thus, in the above algorithm, the "relevant events" that are fired must be the single keydown event.

On platforms where Esc is the close request, the user agent will first fire an appropriately-initialized keydown event. If the web developer cancels the event by calling preventDefault(), then nothing further happens. But if the event fires without being canceled, then the user agent proceeds to process close watchers.

On platforms where a back button is a potential close request, no event is involved, so when the back button is pressed, the user agent proceeds directly to process close watchers. If there is an active close watcher, then that will get triggered. If there is not, then the user agent can interpret the back button press in another way, for example as a request to traverse the history by a delta of −1.

6.10.2 Close watcher infrastructure

Each Window has a close watcher manager, which is a struct with the following items:

Most of the complexity of the close watcher manager comes from anti-abuse protections designed to prevent developers from disabling users' history traversal abilities, for platforms where a close request's fallback action is the main mechanism of history traversal. In particular:

The grouping of close watchers is designed so that if multiple close watchers are created without history-action activation, they are grouped together, so that a user-triggered close request will close all of the close watchers in a group. This ensures that web developers can't intercept an unlimited number of close requests by creating close watchers; instead they can create a number equal to at most 1 + the number of times the user activates the page.

The next user interaction allows a new group boolean encourages web developers to create close watchers in a way that is tied to individual user activations. Without it, each user activation would increase the allowed number of groups, even if the web developer isn't "using" those user activations to create close watchers. In short:

This protection is not important for upholding our desired invariant of creating at most (1 + the number of times the user activates the page) groups. A determined abuser will just create one close watcher per user interaction, "banking" them for future abuse. But this system causes more predictable behavior for the normal case, and encourages non-abusive developers to create close watchers directly in response to user interactions.

To notify the close watcher manager about user activation given a Window window:

  1. Let manager be window's close watcher manager.

  2. If manager's next user interaction allows a new group is true, then increment manager's allowed number of groups.

  3. Set manager's next user interaction allows a new group to false.


A close watcher is a struct with the following items:

A close watcher closeWatcher is active if closeWatcher's window's close watcher manager contains any list which contains closeWatcher.


To establish a close watcher given a Window window, a list of steps cancelAction, and a list of steps closeAction:

  1. Assert: window's associated Document is fully active.

  2. Let closeWatcher be a new close watcher, with

    window
    window
    cancel action
    cancelAction
    close action
    closeAction
    is running cancel action
    false
  3. Let manager be window's close watcher manager.

  4. If manager's groups's size is less than manager's allowed number of groups, then append « closeWatcher » to manager's groups.

  5. Otherwise:

    1. Assert: manager's groups's size is at least 1 in this branch, since manager's allowed number of groups is always at least 1.

    2. Append closeWatcher to manager's groups's last item.

  6. Set manager's next user interaction allows a new group to true.

  7. Return closeWatcher.

To request to close a close watcher closeWatcher:

  1. If closeWatcher is not active, then return true.

  2. If closeWatcher's is running cancel action is true, then return true.

  3. Let window be closeWatcher's window.

  4. If window's associated Document is not fully active, then return true.

  5. Let canPreventClose be true if window's close watcher manager's groups's size is less than window's close watcher manager's allowed number of groups, and window has history-action activation; otherwise false.

  6. Set closeWatcher's is running cancel action to true.

  7. Let shouldContinue be the result of running closeWatcher's cancel action given canPreventClose.

  8. Set closeWatcher's is running cancel action to false.

  9. If shouldContinue is false, then:

    1. Assert: canPreventClose is true.

    2. Consume history-action user activation given window.

    3. Return false.

    Note that since these substeps consume history-action user activation, requesting to close a close watcher twice without any intervening user activation will result in canPreventClose being false the second time.

  10. Close closeWatcher.

  11. Return true.

To close a close watcher closeWatcher:

  1. If closeWatcher is not active, then return.

  2. If closeWatcher's window's associated Document is not fully active, then return.

  3. Destroy closeWatcher.

  4. Run closeWatcher's close action.

To destroy a close watcher closeWatcher:

  1. Let manager be closeWatcher's window's close watcher manager.

  2. For each group of manager's groups: remove closeWatcher from group.

  3. Remove any item from manager's groups that is empty.


To process close watchers given a Window window:

  1. Let processedACloseWatcher be false.

  2. If window's close watcher manager's groups is not empty:

    1. Let group be the last item in window's close watcher manager's groups.

    2. For each closeWatcher of group, in reverse order:

      1. Set processedACloseWatcher to true.

      2. Let shouldProceed be the result of requesting to close closeWatcher.

      3. If shouldProceed is false, then break.

  3. If window's close watcher manager's allowed number of groups is greater than 1, decrement it by 1.

  4. Return processedACloseWatcher.

6.10.3 The CloseWatcher interface

[Exposed=Window]
interface CloseWatcher : EventTarget {
  constructor(optional CloseWatcherOptions options = {});

  undefined requestClose();
  undefined close();
  undefined destroy();

  attribute EventHandler oncancel;
  attribute EventHandler onclose;
};

dictionary CloseWatcherOptions {
  AbortSignal signal;
};
watcher = new CloseWatcher()
watcher = new CloseWatcher({ signal })

Creates a new CloseWatcher instance.

If the signal option is provided, then watcher can be destroyed (as if by watcher.destroy()) by aborting the given AbortSignal.

If any close watcher is already active, and the Window does not have history-action activation, then the resulting CloseWatcher will be closed together with that already-active close watcher in response to any close request. (This already-active close watcher does not necessarily have to be a CloseWatcher object; it could be a modal dialog element, or a popover generated by an element with the popover attribute.)

watcher.requestClose()

Acts as if a close request was sent targeting watcher, by first firing a cancel event, and if that event is not canceled with preventDefault(), proceeding to fire a close event before deactivating the close watcher as if watcher.destroy() was called.

This is a helper utility that can be used to consolidate cancelation and closing logic into the cancel and close event handlers, by having all non-close request closing affordances call this method.

watcher.close()

Immediately fires the close event, and then deactivates the close watcher as if watcher.destroy() was called.

This is a helper utility that can be used trigger the closing logic into the close event handler, skipping any logic in the cancel event handler.

watcher.destroy()

Deactivates watcher, so that it will no longer receive close events and so that new independent CloseWatcher instances can be constructed.

This is intended to be called if the relevant UI element is torn down in some other way than being closed.

Each CloseWatcher instance has an internal close watcher, which is a close watcher.

The new CloseWatcher(options) constructor steps are:

  1. If this's relevant global object's associated Document is not fully active, then throw an "InvalidStateError" DOMException.

  2. Let closeWatcher be the result of establishing a close watcher given this's relevant global object, with:

  3. If options["signal"] exists, then:

    1. If options["signal"] is aborted, then destroy closeWatcher.

    2. Add the following steps to options["signal"]:

      1. Destroy closeWatcher.

  4. Set this's internal close watcher to closeWatcher.

The requestClose() method steps are to request to close this's internal close watcher.

The close() method steps are to close this's internal close watcher.

The destroy() method steps are to destroy this's internal close watcher.

The following are the event handlers (and their corresponding event handler event types) that must be supported, as event handler IDL attributes, by all objects implementing the CloseWatcher interface:

Event handlerEvent handler event type
oncancelcancel
oncloseclose

If one wanted to implement a custom picker control, which closed itself on a user-provided close request as well as when a close button is pressed, the following code shows how one would use the CloseWatcher API to process close requests:

const watcher = new CloseWatcher();
const picker = setUpAndShowPickerDOMElement();

let chosenValue = null;

watcher.onclose = () => {
  chosenValue = picker.querySelector('input').value;
  picker.remove();
};

picker.querySelector('.close-button').onclick = () => watcher.requestClose();

Note how the logic to gather the chosen value is centralized in the CloseWatcher object's close event handler, with the click event handler for the close button delegating to that logic by calling requestClose().

The cancel event on CloseWatcher objects can be used to prevent the close event from firing, and the CloseWatcher from being destroying. A typical use case is as follows:

watcher.oncancel = async (e) => {
  if (hasUnsavedData && e.cancelable) {
    e.preventDefault();

    const userReallyWantsToClose = await askForConfirmation("Are you sure you want to close?");
    if (userReallyWantsToClose) {
      hasUnsavedData = false;
      watcher.close();
    }
  }
};

For abuse prevention purposes, this event is only cancelable if the page has history-action activation, which will be lost after any given close request. This ensures that if the user sends a close request twice in a row without any intervening user activation, the request definitely succeeds; the second request ignores any cancel event handler's attempt to call preventDefault() and proceeds to close the CloseWatcher.

Combined, the above two examples show how requestClose() and close() differ. Because we used requestClose() in the click event handler for the close button, clicking that button will trigger the CloseWatcher's cancel event, and thus potentially ask the user for confirmation if there is unsaved data. If we had used close(), then this check would be skipped. Sometimes that is appropriate, but usually requestClose() is the better option for user-triggered close requests.

In addition to the user activation restrictions for cancel events, there is a more subtle form of user activation gating for CloseWatcher construction. If one creates more than one CloseWatcher without user activation, then the newly-created one will get grouped together with the most-recently-created close watcher, so that a single close request will close them both:

window.onload = () => {
  // This will work as normal: it is the first close watcher created without user activation.
  (new CloseWatcher()).onclose = () => { /* ... */ };
};

button1.onclick = () => {
  // This will work as normal: the button click counts as user activation.
  (new CloseWatcher()).onclose = () => { /* ... */ };
};

button2.onclick = () => {
  // These will be grouped together, and both will close in response to a single close request.
  (new CloseWatcher()).onclose = () => { /* ... */ };
  (new CloseWatcher()).onclose = () => { /* ... */ };
};

This means that calling destroy(), close(), or requestClose() properly is important. Doing so is the only way to get back the "free" ungrouped close watcher slot. Such close watchers created without user activation are useful for cases like session inactivity timeout dialogs or urgent notifications of server-triggered events, which are not generated in response to user activation.