drop-object-collection-index

drop-object-collection-index Accessor

Summary

Gets the index and relative place in the collection that an object is being dropped over.

Package

capi

Signatures

drop-object-collection-index drop-object => index, placement

(setf (drop-object-collection-index drop-object) (values new-index new-placement))

Arguments

`drop-object`⇩	A `drop-object`, as passed to the `drop-callback`.
`new-index`⇩	An integer.
`new-placement`⇩	One of `:above`, `:item` or `:below`.

Values

`index`⇩	An integer.
`placement`⇩	One of `:above`, `:item` or `:below`.

Description

The accessor drop-object-collection-index accesses the index and place relative to that index within the collection that the object drop-object is being dropped over. This information is only meaningful when the pane is an instance of list-panel or tree-view.

The returned value index is the position in the collection (see get-collection-item or choice-selection). The returned value placement indicates whether the user is dropping above, on or below the item at index.

There is also a setf expander that can be called with the values new-index and new-placement within the :drag stage of the operation, to adjust where the user will be allowed to drop the object.

Notes

drop-object-collection-index should only be called within a drop-callback. It is not supported on X11/Motif. See simple-pane for information about drop callbacks.

Examples

For an example illustrating the use of drag and drop in a choice, see:

(example-edit-file "capi/choice/drag-and-drop")