NAME¶
XmDropTransfer — The DropTransfer widget class
"XmDropSite" "widget class" "DropTransfer"
SYNOPSIS¶
#include <Xm/DragDrop.h>
DESCRIPTION¶
DropTransfer provides a set of resources that identifies the procedures and
associated information required by the toolkit in order to process and
complete a drop transaction. Clients should not explicitly create a
DropTransfer widget. Instead, a client initiates a transfer by calling
XmDropTransferStart, which initializes and returns a DropTransfer
widget. If this function is called within an
XmNdropProc callback, the
actual transfers are initiated after the callback returns. Even if no data
needs to be transferred,
XmDropTransferStart needs to be called
(typically with no arguments, or just setting
XmNtransferStatus) to
finish the drag and drop transaction.
The
XmNdropTransfers resource specifies a transfer list that describes
the requested target types for the source data. A transfer list is an array of
XmDropTransferEntryRec structures, each of which identifies a target
type. The transfer list is analogous to the MULTIPLE selections capability
defined in the
Inter-Client Communication Conventions Manual (ICCCM).
The DropTransfer resource,
XmNtransferProc, specifies a transfer
procedure of type XtSelectionCallbackProc that delivers the requested
selection data. This procedure operates in conjunction with the underlying Xt
selection capabilities and is called for each target in the transfer list.
Additional target types can be requested after a transfer is initiated by
calling the
XmDropTransferAdd function.
Structures¶
An
XmDropTransferEntry is a pointer to the following structure of type
XmDropTransferEntryRec, which identifies a selection target associated
with a given drop transaction:
typedef struct
{
XtPointer client_data;
Atom target;
} XmDropTransferEntryRec, *XmDropTransferEntry;
- client_data
- Specifies any additional information required by this selection
target
- target
- Specifies a selection target associated with the drop operation
Classes¶
DropTransfer inherits behavior and a resource from
Object.
The class pointer is
xmDropTransferObjectClass.
The class name is
XmDropTransfer.
New Resources¶
The following table defines a set of widget resources used by the programmer to
specify data. The programmer can also set the resource values for the
inherited classes to set attributes for this widget. To reference a resource
by name or by class in a
.Xdefaults file, remove the
XmN or
XmC prefix and use the remaining letters. To specify one of the defined
values for a resource in a
.Xdefaults file, remove the
Xm prefix
and use the remaining letters (in either lowercase or uppercase, but include
any underscores between words). The codes in the access column indicate if the
given resource can be set at creation time (C), set by using
XtSetValues (S), retrieved by using
XtGetValues (G), or is not
applicable (N/A).
XmDropTransfer Resource Set |
|
|
|
|
Name |
Class |
Type |
Default |
Access |
_ |
_ |
_ |
_ |
_ |
XmNdropTransfers |
XmCDropTransfers |
XmDropTransferEntryRec * |
NULL |
CG |
_ |
_ |
_ |
_ |
_ |
XmNincremental |
XmCIncremental |
Boolean |
False |
CSG |
_ |
_ |
_ |
_ |
_ |
XmNnumDropTransfers |
XmCNumDropTransfers |
Cardinal |
0 |
CSG |
_ |
_ |
_ |
_ |
_ |
XmNtransferProc |
XmCTransferProc |
XtSelectionCallbackProc |
NULL |
CSG |
_ |
_ |
_ |
_ |
_ |
XmNtransferStatus |
XmCTransferStatus |
unsigned char |
XmTRANSFER_SUCCESS |
CSG |
_ |
_ |
_ |
_ |
_ |
- XmNdropTransfers
- Specifies the address of an array of drop transfer entry records. The drop
transfer is complete when all the entries in the list have been
processed.
- XmNincremental
- Specifies a Boolean value that indicates whether the transfer on the
receiver side uses the Xt incremental selection transfer mechanism
described in X Toolkit Intrinsics—C Language Interface. If
the value is True, the receiver uses incremental transfer; if the value is
False, the receiver uses atomic transfer.
- XmNnumDropTransfers
- Specifies the number of entries in XmNdropTransfers. If this
resource is set to 0 at any time, the transfer is considered complete. The
value of XmNtransferStatus determines the completion handshaking
process.
- XmNtransferProc
- Specifies a procedure of type XtSelectionCallbackProc that delivers
the requested selection values. The widget argument passed to this
procedure is the DropTransfer widget. The selection atom passed is
_MOTIF_DROP. For additional information on selection callback procedures,
see X Toolkit Intrinsics—C Language Interface.
- XmNtransferStatus
- Specifies the current status of the drop transfer. The client updates this
value when the transfer ends and communicates the value to the initiator.
The possible values are
- XmTRANSFER_SUCCESS
- The transfer succeeded.
- XmTRANSFER_FAILURE
- The transfer failed.
Inherited Resources¶
DropTransfer inherits behavior and a resource from
Object. For a complete
description of this resource, refer to the
Object reference page.
Object Resource Set |
|
|
|
|
Name |
Class |
Type |
Default |
Access |
_ |
_ |
_ |
_ |
_ |
XmNdestroyCallback |
XmCCallback |
XtCallbackList |
NULL |
C |
_ |
_ |
_ |
_ |
_ |
Object(3),
XmDisplay(3),
XmDragContext(3),
XmDragIcon(3),
XmDropSite(3),
XmDropTransferAdd(3), and
XmDropTransferStart(3).