<p>Each <span>control group owner object</span> can also act as the <dfn data-x="dialog group

manager">manager</dfn> of a <dfn>dialog group</dfn>.</p>

<p>Each <code>dialog</code> element that has an <code data-x="attr-dialog-open">open</code>

attribute specified and that is <span>being rendered</span> (i.e. that is a <span>control group

owner object</span>) and is not <span>expressly inert</span>

belongs to the <span>dialog group</span> whose <span data-x="dialog group manager">manager</span> is

the <code>dialog</code> element's nearest ancestor <span>control group owner object</span>.</p>

<p>If no <code>dialog</code> element has a particular <span>control group owner object</span> as

its nearest ancestor <span>control group owner object</span>, then that <span>control group owner

object</span> has no <span>dialog group</span>.</p>

<p>Each <span>dialog group</span> can have a <code>dialog</code> designated as the <dfn>focused

dialog of the dialog group</dfn>. Which <code>dialog</code> is so designated changes over time,

based on algorithms in this specification.</p>

<p>Elements in <span data-x="dialog group">dialog groups</span> are ordered in <span>tree

order</span>.</p>

<hr>

<p>If <var>candidate</var> has a <span>dialog group</span> with a designated

<span>focused dialog of the dialog group</span>, then let <var>candidate</var> be the

designated <span>focused dialog of the dialog group</span>, and redo this step.</p>

<p>Otherwise, if <var>candidate</var> has a non-empty <span>control group</span>, and the

<p>If <var>current object</var> is a <code>dialog</code> object in a <span>dialog group</span>,

let <var>current object</var> be that <span>dialog group</span>'s <span data-x="dialog group

manager">manager</span>, and return to the step labeled <i>loop</i>.</p>

<p>Otherwise, if <var>current object</var> is a <span>focusable area</span>, let <var>current

<p>If <var>new focus target</var> is a <span>control group owner object</span> that is

not a <span>focusable area</span>, but does have a <span>dialog group</span>, and that <span>dialog group</span>

has a designated <span data-x="focused dialog of the dialog group">focused dialog</span>, then

let <var>new focus target</var> be the <span>focused dialog of the dialog

group</span>, and redo this step.</p>

<p>Otherwise, if <var>new focus target</var> is a <span>control group owner

<p>If <var>old focus target</var> is a <code>dialog</code> in a <span>dialog group</span>, and

the <span>dialog group manager</span> has a non-empty <span>control group</span>, then let

<var>new focus target</var> be the designated <span data-x="focused area of the control

group">focused area of that focus group</span>.</p>

<p>Otherwise, if <var>old focus target</var> is a <span>focusable area</span>, then let <var>new

<p>When a <span>dialog group</span> is formed, if the <span>dialog group manager</span> has an empty

<span>control group</span>, the first non-<span>inert</span> <code>dialog</code> in the <span>dialog

group</span>, if any, or else the first <code>dialog</code> in the <span>dialog group</span> regardless of

<span data-x="inert">inertness</span>, must be designated the <span>focused dialog of the dialog

group</span>.</p>

<p><dfn>Focus fixup rule one</dfn>: When the designated <span data-x="focused area of the control

<p><dfn>Focus fixup rule two</dfn>: When a <span>dialog group</span> has no designated <span>focused

dialog of the dialog group</span>, and its <span>dialog group manager</span>'s <span>control

group</span> changes from being non-empty to being empty, the first non-<span>inert</span>

<code>dialog</code> in the <span>dialog group</span>, if any, or else the first <code>dialog</code> in

the <span>dialog group</span> regardless of <span data-x="inert">inertness</span>, must be designated

the <span>focused dialog of the dialog group</span>.</p>

<p><dfn>Focus fixup rule three</dfn>: When the designated <span data-x="focused dialog of the

dialog group">focused dialog of a dialog group</span> is removed from that <span>dialog

group</span> in some way (e.g. it stops <span>being rendered</span>, it loses its <code

data-x="attr-dialog-open">open</code> attribute, it becomes <span>expressly inert</span>, etc),

and there is still a <span>dialog group</span> (because the <code>dialog</code> in question was

not the last <code>dialog</code> in that <span>dialog group</span>): if the <span>dialog

group</span>'s <span data-x="dialog group manager">manager</span>'s <span>control group</span> is

non-empty, let there be no designated <span>focused dialog of the dialog group</span> any more;

otherwise (in the case that the <span>control group</span> is empty), designate the first

non-<span>inert</span> <code>dialog</code> in the <span>dialog group</span> to be the

<span>focused dialog of the dialog group</span>, or, if they are all <span>inert</span>, designate

the first <code>dialog</code> in the <span>dialog group</span> to be the <span>focused dialog of

the dialog group</span> regardless of <span data-x="inert">inertness</span>.</p>

<p>When the <span>currently focused area of a top-level browsing context</span> was a <span>focusable

area</span> but stops being a <span>focusable area</span>, or when it was a <code>dialog</code> in a

<span>dialog group</span> and stops being part of that <span>dialog group</span>, or when it

starts being <span>inert</span>, the user agent must run the following steps:</p>

<ol> <!-- this is basically a special-cased version of the focusing steps -->

<li><p>Let <var>old focus target</var> be whatever the <span data-x="currently focused

area of a top-level browsing context">currently focused area of the top-level browsing

context</span> was immediately before this algorithm became applicable (e.g. before the element

was disabled, or the dialog was closed, or whatever caused this algorithm to run).</p></li>

<li><p>Let <var>old chain</var> be the <span>focus chain</span> of the <span

data-x="currently focused area of a top-level browsing context">currently focused area of the

top-level browsing context</span> at the same time.</p></li>

<li><p>Make sure that the changes implied by the focus fixup rules <span data-x="focus fixup rule

one">one</span>, <span data-x="focus fixup rule two">two</span>, and <span data-x="focus fixup

rule three">three</span> above are applied.</p></li>

<li><p>Let <var>new focus target</var> be the <span>currently focused area of a

top-level browsing context</span>.</p></li>

<li><p>If <var>old focus target</var> and <var>new focus target</var> are the

same, return.</p></li>

<li><p>Let <var>new chain</var> be the <span>focus chain</span> of <var>new

focus target</var>.</p></li>

<li><p>Run the <span>focus update steps</span> with <var>old chain</var>, <var>new chain</var>, and <var>new focus target</var> respectively.</p></li>

</ol>

<li><p>If <var>entry</var> is a <code>dialog</code> element: let <var>entry</var> be the

designated <span data-x="focused dialog of the dialog group">focused dialog of its dialog

group</span>.</p></li>

<span>focused area of the control group</span>. If its <span>control group</span>'s <span

data-x="control group owner object">owner object</span> is also a <span>dialog group

manager</span>, then let there be no designated <span data-x="focused dialog of the dialog

group">focused dialog</span> in that <span>dialog group</span>.</p>

<p>If <var>candidate</var> has a <span>dialog group</span> with a designated <span>focused

dialog of the dialog group</span>, then let <var>candidate</var> be the designated

<span>focused dialog of the dialog group</span>, and redo this step.</p>

<p>Otherwise, if <var>candidate</var> has a non-empty <span>control group</span>, and the

<td>Let <var>candidate</var> be the first <span>suitable sequentially focusable area</span> in <var>starting point</var>'s <span>active document</span>'s <span>primary control group</span>, if any; or else null

<td>Let <var>candidate</var> be the last <span>suitable sequentially focusable area</span> in <var>starting point</var>'s <span>active document</span>'s <span>primary control group</span>, if any; or else null

<p>The <dfn>primary control group</dfn> of a <span>control group owner object</span> <var>X</var> is the <span>control group</span> of <var>X</var> if <var>X</var> has no <span>dialog group</span> or if its <span>dialog group</span> has no

designated <span>focused dialog of the dialog group</span>, otherwise, it is the <span>primary

control group</span> of <var>X</var>'s <span>dialog group</span>'s designated

<span>focused dialog of the dialog group</span>.</p>

<li><p>While <var>candidate</var> has a <span>dialog group</span> with a designated

<span>focused dialog of the dialog group</span>, set <var>candidate</var> to the

designated <span>focused dialog of the dialog group</span>.</p></li>