Focus and keyboard management

Imagine inspecting small objects on one removable tray. The tray marks the current work area; a directed lamp shows the object under inspection. Before lifting the tray, leave a marker beside the object where ordinary work should resume. When switching trays, deliberately move the lamp to the new work. A list of places the lamp may visit is separate from its current position.

Inspection scene	Interface relationship
Current illuminated object	Current focused element
Marked work tray	Active interaction context
Remembered return marker	A usable restoration destination
Changing the list of inspection stops	Updating sequential focus entries
Moving the lamp itself	Calling focus or handling keyboard movement

This scene is a memory aid, not a browser algorithm. A lamp cannot disable objects outside its tray: actual inertness must come from browser behavior or an implementation. A marker also survives physically when an object is removed; a disconnected DOM node cannot receive useful focus. Check the replacement destination rather than keeping a stale reference. The analogy says nothing about accessible names, speech order or a particular person's assistive technology. Inert, APG

Contrasting case: an ordinary nonmodal panel may leave surrounding controls available. Moving focus into that panel does not make it a modal. In real terms, separately track the active element, which elements accept focus, and the sequential entry points. A visible rectangle alone cannot tell you whether all three agree. Dialog

4.1 EXH-1880 and MR !2080: confirmation without losing the editing position

The local candidate page has a submit trigger, a question-list control, and a native confirmation dialog. Its initial control is Stay. The fixture opens the dialog, advances to Submit now, reverses once, and closes it. It records active-element identifiers after each operation; no elapsed duration decides the result. The return is useful because the original trigger remains connected. This example exercises entry, internal movement and return, but does not attempt programmatic background focus or press Escape. Those operations need separate evidence. Dialog

EXH-1880/MR !2080: stay > submit-now > stay > submit

4.2 Streaming: preserve a usable position during a local update

The media fixture focuses Play, then changes a separate queue paragraph from Queue empty to Two tracks queued. The button remains connected and focus stays there. This local update gives no reason to interrupt a person operating the player. A larger replacement needs a deliberate destination if it removes their current control. Deciding whether a status update needs an announcement belongs to the semantics pack; this experiment makes no claim about speech. Inspect the identity of the active element as well as the updated text, because a visible content change alone does not tell you where keyboard interaction continues. APG persistence

streaming update: play > play; queue Two tracks queued

4.3 Streaming captions: remember the internal entry point

A caption-size group starts on Small. The fixture changes both tabindex values and moves focus to Large. Tab leaves the group; reverse Tab re-enters at Large. Its keyboard indicator uses a solid outline. This checks the coordinated update, not the meaning of a selected size. Selection can remain unchanged while a person explores controls, and the group needs its own appropriate activation behavior. Production verification also needs disabled entries, removal of the current entry, reverse movement, and the relevant assistive technologies. APG roving

streaming captions: re-entry large; outline solid