Newton Developer Technical Information: Newton Programmer's Guide: 2.1 OS Addendum /

Chapter 11 - Miscellaneous / Reference

Functions and Methods / Views

DragAndDrop

view:DragAndDrop(unit, dragBounds, pinBounds, copy, dragInfo)

Starts the drag and drop process, returning when the dragged item(s) is dropped into a view or into the clipboard; it is usually called from a ViewClickScript.

unit

The stroke unit received by the ViewClickScript method.

dragBounds

The bounds of the item to be dragged, in global coordinates. The image enclosed by the bounds is used by the clipboard.

pinBounds

A bounds frame or nil. The bounds to use when constraining the object within the app area. If you pass nil, the drag object's bounds, dragBounds, are used. If the object being dragged is almost the size of the app area, you may want to specify a smaller bounds frame than dragBounds, otherwise the object may not appear to move far enough. If you specify a bounds frame larger that dragBounds, the object cannot be dragged near the edge of the app area.

copy

Nil or non-nil, indicating whether to drag a copy or the original items. Specify non-nil to drag a copy, nil to move the original items.

dragInfo

An array of frames (one frame per dragged item). Each frame has the following slots:

types An array of symbols of the types to which an item can be converted.

dragRef Any valid NewtonScript object. This value is passed to your other methods, such as your ViewGetDropDataScript.

label An optional string used when the drop is to the clipboard; it is used as the clipboard label. If this slot is missing and the item has a 'text type, the text data is used as the label; otherwise a default label is used.

minDragDistance An integer, the minimum distance in pixels that the user must drag the object before it moves. The default is 4.

return value

This method returns one of the following integers:

kDragNot = 0 The item was not dragged at all.

kDragged = 1 The item was dragged, but was rejected by the destination.

kDragNDropped = 2 The item was dropped into another view.

DISCUSSION

The *DragAndDrop method sends several messages to both the source view (the view from which *DragAndDrop was sent) and the destination view (the view that will receive the items). If you want other views to be able to accept data, these views must implement all of the destination methods. If you have more than one view that can receive a drop, it is easier if you make one drop-aware proto and use it for your other views.

SEE ALSO

For further information see "Dragging and Dropping with Views" (page 3-40) in Newton Programmer's Guide.

COMPATIBILTY

The dragInfo argument's minDragDistance slot is ignored in Newton operating systems prior to Newton 2.1.