[Accessibility] ui5-input / ui5-date-picker do not expose aria-readonly; read-only state is not conveyed to AT

Bug Description

Summary

The inner <input> rendered by Input sets the native HTML readonly attribute but never aria-readonly. On a bare textbox that would suffice, but Input/DatePicker decorate the same element with composite-widget semantics (role, aria-haspopup, aria-roledescription), and in that context screen readers (verified JAWS/NVDA, de-DE) announce the role/popup but drop the read-only state.

Select renders aria-readonly explicitly and is announced correctly, so on the same read-only form ui5-select reads as read-only while ui5-date-picker does not.

Steps to reproduce

<ui5-select readonly>              <!-- state announced (has aria-readonly) -->
  <ui5-option selected>Personal goals</ui5-option>
</ui5-select>
<ui5-date-picker readonly value="2026-01-01"></ui5-date-picker>  <!-- NOT announced -->
<ui5-input readonly value="hello"></ui5-input>                    <!-- NOT announced -->

Navigate with a screen reader; inspect the shadow inner <input>: readonly present, aria-readonly absent.

Observed (de-DE): ui5-select → "… Listenfeld … Die Auswahl ändern Sie mit den Pfeiltasten" ✅; ui5-date-picker → "Datumseingabe · Hat Popup · …", no read-only state ❌.

Expected

Read-only ui5-input/ui5-date-picker expose aria-readonly="true" on the focusable inner input, consistent with ui5-select.

Root cause (@ui5/webcomponents@2.26.0)

src/InputTemplate.tsx (inner <input>) sets native readonly but none of its 9 aria-* attributes is aria-readonly:

readonly={this._readonly}                              // line 35 — native attr only
aria-haspopup={this.accInfo.ariaHasPopup}              // line 44
aria-roledescription={this.accInfo.ariaRoledescription}// line 46
aria-required={this.required}                          // line 50
// no aria-readonly

Input.accInfo / DatePicker.accInfo expose no read-only key, so there is nothing to bind (DatePicker even adds aria-haspopup="grid" — the semantics that suppress the native readonly announcement). The signal exists but is used only for behavior: get _readonly() { return this.readonly && !this.disabled; }.

Contrast — src/SelectTemplate.tsx: role="combobox" (line 30) + aria-readonly={this.readonly} (line 38).

Emitter matrix (grep -l aria-readonly dist/*Template.js): CheckBox, MonthPicker, RatingIndicator, Select, Switch, Tokenizer, YearPicker, YearRangePicker emit it; Input and DatePicker (and all Input-based controls: DateTimePicker, DateRangePicker, ComboBox, MultiInput, …) emit 0.

Identical in 2.25.0 and current latest 2.26.0 — not fixed by upgrade.

Suggested fix

Emit aria-readonly from Input so all Input-derived components inherit it:

1. Add "ariaReadonly": this._readonly || undefined to Input.accInfo (and DatePicker.accInfo if overridden).
2. Bind aria-readonly={this.accInfo.ariaReadonly} on the inner input in InputTemplate.tsx.

Environment

@ui5/webcomponents 2.25.0 & 2.26.0 · Chromium/Edge · Windows · JAWS/NVDA de-DE · affects ui5-input, ui5-date-picker and other Input-based controls.

Organization

SF

• I’m not disclosing any internal or sensitive information.