Screen Readers don't announce dropdown is collapsed/expanded

[jswiderski]

Type of report

Bug

Provide detailed reproduction steps (if any)

1. Open CKEditor with Screen Reader other than JAWS enabled
2. Press Alt+F10 to move focus to toolbar
3. Keep Pressing Tab until you reach Styles, Font, Format or Size dropdown and press Enter once you do that.

Expected result

Screen Reader should announce that dropdown is collapsed and once Enter is pressed, it should announce the it has been expanded.

Actual result

Except for JAWS which informs about dropdown navigation in its own way, nothing happens.
It looks like the link element of button dropdown is missing the aria-expanded attribute.

Other details

• Browser: Any
• OS: Any
• CKEditor version: 4.14.0
• Installed CKEditor plugins: N/A

---

By adding below code in line https://github.com/ckeditor/ckeditor4/blob/major/plugins/richcombo/plugin.js#L382 there is an improvement:

var linkEl = el.getElementsByTag( 'a' ).getItem( 0 );
	if( linkEl )
		linkEl.setAttribute( 'aria-expanded', state == CKEDITOR.TRISTATE_ON );	

ChromeVox and NVDA - announce list is collapsed/expanded
Narrator - only announced the list is collapsed
JAWS ignores the attribute but announced how to navigate through dropdown in its own way.

[jacekbogdanski]

Closed in #4148