feat(ui5-li-custom): improve accessibility announcements

[IlianaB]

related to #7729

[ui5-webcomponents-bot]

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[aborjinik]

why don't we reuse this? We could externalize it from the table.
https://github.com/UI5/webcomponents/blob/main/packages/main/src/TableCustomAnnouncement.ts#L55

[IlianaB]

why don't we reuse this? We could externalize it from the table. https://github.com/UI5/webcomponents/blob/main/packages/main/src/TableCustomAnnouncement.ts#L55

We discussed with the team: we could use an externalized logic for extracting accessibility descriptions. The only concern - currently there is a specific table-related logic. Can it be separated from the externalized method for processing the accessibility info?

[aborjinik]

Actually, I do not see any table-specific logic here. But if such logic exists, it should go into the options (we should probably use the second parameter of getAccessibilityDescription for options anyway).

1. data-ui5-table-acc-text (we could generalize this to data-ui5-acc-text) can be used for native elements (or web components) to provide (or override) accessibility information.
2. If there is nothing inside the custom list item, I think it would be acceptable to announce it as "Empty".
3. If we cannot retrieve the accessibility information of an element and the default accessibility logic does not return any text, but the element is tabbable (for example, a simple native <input> element), we should not announce it as empty. Instead we announce something like "contains control", so the user knows that F2 can be used to jump into it for more details.

As mentioned I do not see those as table-specific.

[IlianaB]

Actually, I do not see any table-specific logic here. But if such logic exists, it should go into the options (we should probably use the second parameter of getAccessibilityDescription for options anyway).

1. data-ui5-table-acc-text (we could generalize this to data-ui5-acc-text) can be used for native elements (or web components) to provide (or override) accessibility information.
2. If there is nothing inside the custom list item, I think it would be acceptable to announce it as "Empty".
3. If we cannot retrieve the accessibility information of an element and the default accessibility logic does not return any text, but the element is tabbable (for example, a simple native <input> element), we should not announce it as empty. Instead we announce something like "contains control", so the user knows that F2 can be used to jump into it for more details.

As mentioned I do not see those as table-specific.

Thanks for explanations @aborjinik . Let us know when it’s ready for use. We’ll try to adapt. If any questions or difficulties arise, we’ll contact you. :)