Function

Summary

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

Signature

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 function drop-object-collection-index returns 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 these two values 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.

Example

For an example illustrating the use of drag and drop in a choice, see
examples/capi/choice/drag-and-drop.lisp

See also

drop-object-collection-item