Method _handleArrowNavigation

packages/main/src/Select.ts:862–888

(e: KeyboardEvent)

	}

	_handleArrowNavigation(e: KeyboardEvent) {
		e.preventDefault();

		if (this.readonly) {
			return;
		}

		let nextIndex = -1;
		const currentIndex = this._selectedIndex;
		const isDownKey = isDown(e);

		if (isDownKey) {
			nextIndex = this._getNextOptionIndex();
		} else {
			nextIndex = this._getPreviousOptionIndex();
		}

		this._changeSelectedItem(this._selectedIndex, nextIndex);

		if (currentIndex !== this._selectedIndex) {
			// Announce new item even if picker is opened.
			// The aria-activedescendents attribute can't be used,
			// because listitem elements are in different shadow dom
			this.itemSelectionAnnounce();
			this._scrollSelectedItem();
		}
	}

	_changeSelectedItem(oldIndex: number, newIndex: number) {
		const options: Array<IOption> = this.options;