Primary Selection

Description

Each collection maintains its own selection. A selection need not contain any elements, in which case it is said to be an empty selection. At any time, there is one selection called the primary selection, which is the last selection explicitly started by the user.

Clicking BSelect or BSelect only moves the primary selection to a collection when it results in making a selection that is not empty. When BSelect is clicked, an implementation can move the primary selection to the component even if the resulting selection is empty. Dragging BSelect, BSelect, or BSelect must move the primary selection to the component if a button release during the pointer motion could have potentially selected any element.

A selection is said to be persistent if it is highlighted even when it is not the primary selection.

Persistent

There are two variants of persistent selections: persistent always, in which the current selection is always highlighted, and persistent on focus, in which the current selection is only highlighted when it is the primary selection or when the collection has the keyboard focus. In either case, stronger highlighting should be used when the current selection is also the primary selection. When focus is in the collection, can be used to promote the current selection to the primary selection.

Nonpersistent

The collection only highlights a primary selection. When the primary selection is lost to another collection, the current selection is set to empty. When focus is in the collection, and it does not have the primary selection, can be used to restore the previous selection and make it the primary selection.

Collections that are never editable (such as noneditable Lists) should always use persistent selections. Collections that are editable can either use persistent or nonpersistent selections.

Primary transfer can be invoked by clicking BTransfer or through standard keyboard bindings. There are three primary transfer operations:

Primary Copy

In an editable collection, BTransfer Click, BTransfer Click, [Copy], and must copy the primary selection to the insertion position, as defined in Transfer Models. (Note that the insertion position is usually different for mouse and keyboard operations.)

Primary Move

In an editable collection, BTransfer Click, [Cut], and must move the primary selection to the insertion position, as defined in Transfer Models. (Note that the insertion position is usually different for mouse and keyboard operations.)

Primary Link

In an editable collection, BTransfer Click must place a link to the primary selection at the insertion position, as defined in Transfer Models.

Related Information

See Selection Actions and Transfer Models for more information about the primary selection.