XmDropTransfer(3X) UNIX System V XmDropTransfer(3X)
NAME
XmDropTransfer-The DropTransfer widget class
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
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XmDropTransfer(3X) UNIX System V XmDropTransfer(3X)
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
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XmDropTransfer(3X) UNIX System V XmDropTransfer(3X)
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
RELATED INFORMATION
Object(3X), XmDisplay(3X), XmDragContext(3X),
XmDragIcon(3X), XmDropSite(3X), XmDropTransferAdd(3X), and
XmDropTransferStart(3X).
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