Inspired by bug 72932. A dropdown UI element by design is for picking a single item. We should not mislead users into thinking otherwise. 1. View - Toolbars - Form controls 2. Draw a List Box and configure it 3. Right-click - Control 4. Play around with the options Dropdown and Multiselection
The bug report does not give a sufficiently convincing rationale for reducing the number of values that can be chosen from a drop-down list to just one value. To make a comparison with HTML, the select element has always allowed developers to enable the selection of multiple values (by adding the attribute "multiple"): https://www.w3.org/TR/html52/sec-forms.html#elementdef-select Moreover, the ODF 1.3 specification (released in June 2021) does not express a limitation either. Subchapter "13.5.13 <form:listbox>" of Part 3 says: The <form:listbox> element defines an input control that allows a user to select one or more items from a list. It is an alternative representation for a group of radio buttons. (Note that the last sentence contradicts the first; if more than value can be selected, the listbox is an alternative representation of a "group" of check boxes.) The more cogent argument would be that selecting more than one value from a single list box is not user friendly for most users and even more difficult for keyboard-only users. See for example the Stack Overflow question "Many people don't know how to multi-select items in a HTML <select> control, so…?" https://stackoverflow.com/q/204075/6002174 (The answers can be ignored in the context of this bug.) The usability of multiselect drop-downs is sufficiently bad to require instructions for users near the drop-down list.
(In reply to Christophe Strobbe from comment #1) > The bug report does not give a sufficiently convincing rationale for > reducing the number of values that can be chosen from a drop-down list to > just one value. > > To make a comparison with HTML, the select element has always allowed > developers to enable the selection of multiple values (by adding the > attribute "multiple"): > https://www.w3.org/TR/html52/sec-forms.html#elementdef-select https://developer.mozilla.org/en-US/docs/Web/HTML/Element/select#attr-multiple "This Boolean attribute indicates that multiple options can be selected in the list. If it is not specified, then only one option can be selected at a time. When multiple is specified, most browsers will show a scrolling list box instead of a single line dropdown." So the browser implementations are in line with the listbox & dropdown differences of LibreOffice's form elements. (In reply to Christophe Strobbe from comment #1) > Moreover, the ODF 1.3 specification (released in June 2021) does not express > a limitation either. Subchapter "13.5.13 <form:listbox>" of Part 3 says: > > The <form:listbox> element defines an input control that allows a user to > select one or more items from a list. It is an alternative representation > for a group of radio buttons. Right, as said in bug 72932 comment 22, multiselection for listboxes works fine.