XmDragContext(3X)XmDragContext(3X)NAMEXmDragContext - The DragContext widget class
SYNOPSIS
#include <Xm/DragDrop.h>
DESCRIPTION
DragContexts are special widgets used in drag and drop transactions. A
DragContext is implemented as a widget, but a client does not explic‐
itly create a DragContext widget. Instead, a client initiates a drag
and drop transaction by calling XmDragStart, and this routine initial‐
izes and returns a DragContext widget. There is a unique DragContext
for each drag operation. The toolkit frees a DragContext when a trans‐
action is complete; therefore, an application programmer should not
explicitly destroy a DragContext.
Initiator and receiver clients both use DragContexts to track the state
of a transaction. When the initiator and receiver of a transaction are
in the same client, they share the same DragContext instance. If they
are in different clients, there are two separate DragContexts. In this
case, the initiator calls XmDragStart and the toolkit provides a Drag‐
Context for the receiver client. The only resources pertinent to the
receiver are XmNexportTargets and XmNnumExportTargets. These can both
be passed as arguments to the XmDropSiteRetrieve function to obtain
information about the current drop site.
In general, in order to receive data, a drop site must share at least
one target type and operation in common with a drag source. The Drag‐
Context resource, XmNexportTargets, identifies the selection targets
for the drag source. These export targets are compared with the XmNim‐
portTargets resource list specified by a drop site. The DragContext
resource, XmNdragOperations, identifies the valid operations that can
be applied to the source data by the initiator. The drop site counter‐
part resource is XmNdropSiteOperations, which indicates a drop site's
supported operations.
A client uses DragIcon widgets to define the drag-over animation
effects associated with a given drag and drop transaction. An initiator
specifies a set of drag icons, selects a blending model, and sets fore‐
ground and background cursor colors with DragContext resources.
The type of drag-over visual used to represent a drag operation depends
on the drag protocol style. In preregister mode, the server is
grabbed, and either a cursor or a pixmap may be used as a drag-over
visual. In dynamic mode, drag-over visuals must be implemented with
the X cursor. If the resulting drag protocol style is Drop Only or
None and the XmNdragInitiatorProtocolStyle is XmDRAG_DYNAMIC or
XmDRAG_PREFER_DYNAMIC, then a dynamic visual style (cursor) is used.
Otherwise, a preregister visual style is used.
Classes
DragContext inherits behavior and resources from Core.
The class pointer is xmDragContextClass.
The class name is XmDragContext.
New Resources
The following table defines a set of widget resources used by the pro‐
grammer to specify data. The programmer can also set the resource val‐
ues 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).
XmDragContext Resource Set
Class: XmCBlendModel
Default: XmBLEND_ALL
Type: unsigned char
Access: CG
Class: XmCClientData
Default: NULL
Type: XtPointer
Access: CSG
Class: XmCConvertProc
Default: NULL
Type: XtConvertSelectionIncrProc
Access: CSG
Class: XmCCursorBackground
Default: dynamic
Type: Pixel
Access: CSG
Class: XmCCallback
Default: NULL
Type: XtCallbackList
Access: CSG
Class: XmCCallback
Default: NULL
Type: XtCallbackList
Access: C
Class: XmCDragOperations
Default: XmDROP_COPY XmDROP_MOVE
Type: unsigned char
Access: C
Class: XmCCallback
Default: NULL
Type: XtCallbackList
Access: C
Class: XmCCallback
Default: NULL
Type: XtCallbackList
Access: C
Class: XmCCallback
Default: NULL
Type: XtCallbackList
Access: C
Class: XmCCallback
Default: NULL
Type: XtCallbackList
Access: C
Class: XmCExportTargets
Default: NULL
Type: Atom *
Access: CSG
Class: XmCIncremental
Default: False
Type: Boolean
Access: CSG
Class: XmCCursorForeground
Default: dynamic
Type: Pixel
Access: CSG
Class: XmCCursorForeground
Default: dynamic
Type: Pixel
Access: CSG
Class: XmCNumExportTargets
Default: 0
Type: Cardinal
Access: CSG
Class: XmCCallback
Default: NULL
Type: XtCallbackList
Access: C
Class: XmCOperationCursorIcon
Default: dynamic
Type: Widget
Access: CSG
Class: XmCSourceCursorIcon
Default: dynamic
Type: Widget
Access: CSG
Class: XmCSourcePixmapIcon
Default: dynamic
Type: Widget
Access: CSG
Class: XmCStateCursorIcon
Default: dynamic
Type: Widget
Access: CSG
Class: XmCCallback
Default: NULL
Type: XtCallbackList
Access: C
Class: XmCCallback
Default: NULL
Type: XtCallbackList
Access: C
Class: XmCCursorForeground
Default: dynamic
Type: Pixel
Access: CSG
Specifies which combination of DragIcons are blended to produce
a drag-over visual. Blends all three DragIcons--the source,
state and operation icon. The icons are layered from top to bot‐
tom with the operation icon on top and the source icon on the
bottom. The hotspot is derived from the state icon. Blends the
state and source icons only. The hotspot is derived from the
state icon. Specifies that only the source icon is used, which
the initiator updates as required. Specifies that no drag-over
visual is generated. The client tracks the drop site status
through callback routines and updates the drag-over visuals as
necessary. Specifies the client data to be passed to the XmN‐
convertProc when it is invoked. Specifies a procedure of type
XtConvertSelectionIncrProc that converts the source data to the
format(s) requested by the receiver client. The widget argument
passed to this procedure is the DragContext widget. The selec‐
tion atom passed is _MOTIF_DROP. If XmNincremental is False,
the procedure should ignore the max_length, client_data, and
request_id arguments and should handle the conversion atomi‐
cally. Data returned by XmNconvertProc must be allocated using
XtMalloc and will be freed automatically by the toolkit after
the transfer. For additional information on selection conversion
procedures, see X Toolkit Intrinsics--C Language Interface.
Specifies the background pixel value of the cursor. Specifies
the foreground pixel value of the cursor when the state icon is
not blended. This resource defaults to the foreground color of
the widget passed to the XmDragStart function. Specifies the
list of callbacks that are called when the transaction is com‐
pleted. The type of the structure whose address is passed to
this callback is XmDragDropFinishCallbackStruct. The reason
sent by the callback is XmCR_DRAG_DROP_FINISH. Specifies the
list of callbacks that are invoked when the pointer moves. The
type of structure whose address is passed to this callback is
XmDragMotionCallbackStruct. The reason sent by the callback is
XmCR_DRAG_MOTION. Specifies the set of valid operations associ‐
ated with an initiator client for a drag transaction. This
resource is a bit mask that is formed by combining one or more
of the following values using a bitwise operation such as inclu‐
sive OR (|): XmDROP_COPY, XmDROP_LINK, XmDROP_MOVE. The value
XmDROP_NOOP for this resource indicates that no operations are
valid. For Text and TextField widgets, this resource is set to
XmDROP_COPY | XmDROP_MOVE; for List widgets, it is set to
XmDROP_COPY. Specifies the list of callbacks that are invoked
when the drop is completed. The type of the structure whose
address is passed to this callback is XmDropFinishCallback‐
Struct. The reason sent by the callback is XmCR_DROP_FINISH.
Specifies the list of callbacks that are invoked when the
pointer enters a drop site. The type of the structure whose
address is passed to this callback is XmDropSiteEnterCallback‐
Struct. The reason sent by the callback is XmCR_DROP_SITE_ENTER.
Specifies the list of callbacks that are invoked when the
pointer leaves a drop site. The type of the structure whose
address is passed to this callback is XmDropSiteLeaveCallback‐
Struct. The reason sent by the callback is XmCR_DROP_SITE_LEAVE.
Specifies the list of callbacks that are invoked when a drop is
initiated. The type of the structure whose address is passed to
this callback is XmDropStartCallbackStruct. The reason sent by
the callback is XmCR_DROP_START. Specifies the list of target
atoms associated with this source. This resource identifies the
selection targets this source can be converted to. Specifies a
Boolean value that indicates whether the transfer on the initia‐
tor side uses the Xt incremental selection transfer mechanism
described in X Toolkit Intrinsics--C Language Interface. If the
value is True, the initiator uses incremental transfer; if the
value is False, the initiator uses atomic transfer. Specifies
the foreground pixel value of the cursor when the state is
invalid. This resource defaults to the value of the XmNcursor‐
Foreground resource. Specifies the foreground pixel value of
the cursor when the state is none. This resource defaults to
the value of the XmNcursorForeground resource. Specifies the
number of entries in the list of export targets. Specifies the
list of callbacks that are invoked when the drag is started and
when the user requests that a different operation be applied to
the drop. The type of the structure whose address is passed to
this callback is XmOperationChangedCallbackStruct. The reason
sent by the callback is XmCR_OPERATION_CHANGED. Specifies the
cursor icon used to designate the type of operation performed by
the drag transaction. If NULL, XmScreen resources provide
default icons for copy, link, and move operations. Specifies
the cursor icon used to represent the source when a dynamic vis‐
ual style is used. If NULL, the XmNdefaultSourceCursorIcon
resource of XmScreen provides a default cursor icon. Specifies
the pixmap icon used to represent the source when a preregister
visual style is used. The icon is used in conjunction with the
colormap of the widget passed to XmDragStart. If NULL, XmN‐
sourceCursorIcon is used. Specifies the cursor icon used to
designate the state of a drop site. If NULL, XmScreen resources
provide default icons for a valid, invalid, and no drop site
condition. Specifies the list of callbacks that are called when
the pointer enters a top-level window or root window (due to
changing screens). The type of the structure whose address is
passed to this callback is XmTopLevelEnterCallbackStruct. The
reason sent by the callback is XmCR_TOP_LEVEL_ENTER. Specifies
the list of callbacks that are called when the pointer leaves a
top level window or the root window (due to changing screens).
The type of the structure whose address is passed to this call‐
back is XmTopLevelLeaveCallbackStruct. The reason sent by the
callback is XmCR_TOP_LEVEL_LEAVE. Specifies the foreground
pixel value of the cursor designated as a valid cursor icon.
Inherited Resources
DragContext inherits behavior and resources from the following super‐
class. For a complete description of each resource, refer to the
Core(3X) man page.
Core Resource Set
Class: XmCAccelerators
Default: dynamic
Type: XtAccelerators
Access: CSG
Class: XmCSensitive
Default: dynamic
Type: Boolean
Access: G
Class: XmCBackground
Default: dynamic
Type: Pixel
Access: CSG
Class: XmCPixmap
Default: XmUNSPECIFIED_PIXMAP
Type: Pixmap
Access: CSG
Class: XmCBorderColor
Default: XtDefaultForeground
Type: Pixel
Access: CSG
Class: XmCPixmap
Default: XmUNSPECIFIED_PIXMAP
Type: Pixmap
Access: CSG
Class: XmCBorderWidth
Default: 0
Type: Dimension
Access: CSG
Class: XmCColormap
Default: dynamic
Type: Colormap
Access: CG
Class: XmCDepth
Default: dynamic
Type: int
Access: CG
Class: XmCCallback
Default: NULL
Type: XtCallbackList
Access: C
Class: XmCHeight
Default: dynamic
Type: Dimension
Access: CSG
Class: XmCInitialResourcesPersistent
Default: True
Type: Boolean
Access: C
Class: XmCMappedWhenManaged
Default: True
Type: Boolean
Access: CSG
Class: XmCScreen
Default: dynamic
Type: Screen *
Access: CG
Class: XmCSensitive
Default: True
Type: Boolean
Access: CSG
Class: XmCTranslations
Default: dynamic
Type: XtTranslations
Access: CSG
Class: XmCWidth
Default: dynamic
Type: Dimension
Access: CSG
Class: XmCPosition
Default: 0
Type: Position
Access: CSG
Class: XmCPosition
Default: 0
Type: Position
Access: CSG
Callback Information
Each of the DragContext callbacks has an associated callback structure.
A pointer to the following structure is passed to the XmNdragDropFin‐
ishCallback callback. typedef struct {
int reason;
XEvent *event;
Time timeStamp; }XmDragDropFinishCallbackStruct, *XmDragDropFin‐
ishCallback;
Indicates why the callback was invoked. Points to the XEvent that
triggered the callback. Specifies the time at which either the drag or
the drop was completed.
A pointer to the following structure is passed to callbacks for XmN‐
dragMotionCallback. typedef struct {
int reason;
XEvent *event;
Time timeStamp;
unsigned char operation;
unsigned char operations;
unsigned char dropSiteStatus;
Position x;
Position y; }XmDragMotionCallbackStruct, *XmDragMotionCallback;
Indicates why the callback was invoked. Points to the XEvent that
triggered the callback. Specifies the timestamp of the logical event.
Identifies an operation.
If the toolkit has just called a DropSite's XmNdragProc, the
toolkit initializes operation to the value of the operation mem‐
ber of the XmDragProcCallbackStruct at the time the DropSite's
XmNdragProc returns.
If the toolkit has not called an XmNdragProc and the pointer is
within an active drop site, the toolkit initializes operation by
selecting an operation from the bitwise AND of the initial value
of the operations member and the value of the DropSite's XmN‐
dropSiteOperations resource. The toolkit searches this set first
for XmDROP_MOVE, then for XmDROP_COPY, then for XmDROP_LINK, and
initializes operation to the first operation it finds in the
set. If the toolkit finds none of these operations in the set,
it initializes operation to XmDROP_NOOP.
If the toolkit has not called an XmNdragProc and the pointer is
not within an active drop site, the toolkit initializes opera‐
tion by selecting an operation from the initial value of the
operations member. The toolkit searches this set first for
XmDROP_MOVE, then for XmDROP_COPY, then for XmDROP_LINK, and
initializes operation to the first operation it finds in the
set. If the toolkit finds none of these operations in the set,
it initializes operation to XmDROP_NOOP. Indicates the set of
operations supported for the source data.
If the toolkit has just called a DropSite's XmNdragProc, the
toolkit initializes operations to the bitwise AND of the Drop‐
Site's XmNdropOperations and the value of the operations member
of the XmDragProcCallbackStruct at the time the DropSite's XmN‐
dragProc returns. If the resulting set of operations is empty,
the toolkit initializes operations to XmDROP_NOOP.
If the toolkit has not called an XmNdragProc and the user does
not select an operation (by pressing a modifier key), the tool‐
kit initializes operations to the value of the DragContext's
XmNdragOperations resource.
If the toolkit has not called an XmNdragProc and the user does
select an operation, the toolkit initializes operations to the
bitwise AND of the corresponding operation and the value of the
DragContext's XmNdragOperations resource. If the resulting set
of operations is empty, the toolkit initializes operations to
XmDROP_NOOP. Indicates whether or not a drop site is valid.
If the toolkit has just called a DropSite's XmNdragProc, the
toolkit initializes dropSiteStatus to the value of the drop‐
SiteStatus member of the XmDragProcCallbackStruct at the time
the DropSite's XmNdragProc returns.
If the toolkit has not called an XmNdragProc, it initializes
dropSiteStatus as follows: the toolkit initializes dropSiteSta‐
tus to XmNO_DROP_SITE if the pointer is over an inactive drop
site or is not over a drop site. The toolkit initializes drop‐
SiteStatus to XmDROP_SITE_VALID if all the following conditions
are met: The pointer is over an active drop site. The DragCon‐
text's XmNexportTargets and the DropSite's XmNimportTargets are
compatible. The initial value of the operation member is not
XmDROP_NOOP.
Otherwise, the toolkit initializes dropSiteStatus to
XmDROP_SITE_INVALID.
A pointer to the following structure is passed for the XmNdropFinish‐
Callback callback: typedef struct {
int reason;
XEvent *event;
Time timeStamp;
unsigned char operation;
unsigned char operations;
unsigned char dropSiteStatus;
unsigned char dropAction;
unsigned char completionStatus; }XmDropFinishCallbackStruct,
*XmDropFinishCallback;
Indicates why the callback was invoked. Points to the XEvent that
triggered the callback. Specifies the time at which the drop was com‐
pleted. Identifies an operation.
If the pointer is over an active drop site when the drop begins,
the toolkit initializes operation to the value of the operation
member of the XmDropProcCallbackStruct at the time the Drop‐
Site's XmNdropProc returns.
If the pointer is not over an active drop site when the drop
begins, the toolkit initializes operation by selecting an opera‐
tion from the initial value of the operations member. The tool‐
kit searches this set first for XmDROP_MOVE, then for
XmDROP_COPY, then for XmDROP_LINK, and initializes operation to
the first operation it finds in the set. If it finds none of
these operations in the set, it initializes operation to
XmDROP_NOOP. Indicates the set of operations supported for the
source data.
If the pointer is over an active drop site when the drop begins,
the toolkit initializes operations to the bitwise AND of the
DropSite's XmNdropOperations and the value of the operations
member of the XmDropProcCallbackStruct at the time the Drop‐
Site's XmNdropProc returns. If the resulting set of operations
is empty, the toolkit initializes operations to XmDROP_NOOP.
If the pointer is not over an active drop site when the drop
begins and if the user does not select an operation (by pressing
a modifier key), the toolkit initializes operations to the value
of the DragContext's XmNdragOperations resource.
If the pointer is not over an active drop site when the drop
begins and if the user does select an operation, the toolkit
initializes operations to the bitwise AND of the corresponding
operation and the value of the DragContext's XmNdragOperations
resource. If the resulting set of operations is empty, the tool‐
kit initializes operations to XmDROP_NOOP. Indicates whether or
not a drop site is valid.
If the pointer is over an active drop site when the drop begins,
the toolkit initializes dropSiteStatus to the value of the drop‐
SiteStatus member of the XmDropProcCallbackStruct at the time
the DropSite's XmNdropProc returns.
If the pointer is not over an active drop site when the drop
begins, the toolkit initializes dropSiteStatus to
XmNO_DROP_SITE. Identifies the drop action. The values are:
XmDROP, XmDROP_CANCEL, XmDROP_HELP, and XmDROP_INTERRUPT. The
value XmDROP_INTERRUPT is currently unsupported; if specified,
it will be interpreted as an XmDROP_CANCEL. An IN/OUT member
that indicates the status of the drop action. After the last
callback procedure has returned, the final value of this member
determines what visual transition effects will be applied. There
are two values: The drop was successful. The drop was unsuc‐
cessful.
A pointer to the following structure is passed to callbacks for XmN‐
dropSiteEnterCallback: typedef struct {
int reason;
XEvent *event;
Time timeStamp;
unsigned char operation;
unsigned char operations;
unsigned char dropSiteStatus;
Position x;
Position y; }XmDropSiteEnterCallbackStruct, *XmDropSiteEnter‐
Callback;
Indicates why the callback was invoked. Points to the XEvent that
triggered the callback. Specifies the time the crossing event
occurred. Identifies an operation.
If the toolkit has just called a DropSite's XmNdragProc, the
toolkit initializes operation to the value of the operation mem‐
ber of the XmDragProcCallbackStruct at the time the DropSite's
XmNdragProc returns.
If the toolkit has not called an XmNdragProc, it initializes
operation by selecting an operation from the bitwise AND of the
initial value of the operations member and the value of the
DropSite's XmNdropSiteOperations resource. The toolkit searches
this set first for XmDROP_MOVE, then for XmDROP_COPY, then for
XmDROP_LINK, and initializes operation to the first operation it
finds in the set. If the toolkit finds none of these operations
in the set, it initializes operation to XmDROP_NOOP. Indicates
the set of operations supported for the source data.
If the toolkit has just called a DropSite's XmNdragProc, the
toolkit initializes operations to the bitwise AND of the Drop‐
Site's XmNdropOperations and the value of the operations member
of the XmDragProcCallbackStruct at the time the DropSite's XmN‐
dragProc returns. If the resulting set of operations is empty,
the toolkit initializes operations to XmDROP_NOOP.
If the toolkit has not called an XmNdragProc and the user does
not select an operation (by pressing a modifier key), the tool‐
kit initializes operations to the value of the DragContext's
XmNdragOperations resource.
If the toolkit has not called an XmNdragProc and the user does
select an operation, the toolkit initializes operations to the
bitwise AND of the corresponding operation and the value of the
DragContext's XmNdragOperations resource. If the resulting set
of operations is empty, the toolkit initializes operations to
XmDROP_NOOP. Indicates whether or not a drop site is valid.
If the toolkit has just called a DropSite's XmNdragProc, the
toolkit initializes dropSiteStatus to the value of the drop‐
SiteStatus member of the XmDragProcCallbackStruct at the time
the DropSite's XmNdragProc returns.
If the toolkit has not called an XmNdragProc, it initializes
dropSiteStatus as follows: the toolkit initializes dropSiteSta‐
tus to XmDROP_SITE_VALID if the DragContext's XmNexportTargets
and the DropSite's XmNimportTargets are compatible and if the
initial value of the operation member is not XmDROP_NOOP. Other‐
wise, the toolkit initializes dropSiteStatus to
XmDROP_SITE_INVALID. Indicates the x-coordinate of the pointer
in root window coordinates. Indicates the y-coordinate of the
pointer in root window coordinates.
A pointer to the following structure is passed to callbacks for XmN‐
dropSiteLeaveCallback. typedef struct {
int reason;
XEvent *event;
Time timeStamp; }XmDropSiteLeaveCallbackStruct, *XmDropSiteLeave‐
Callback;
Indicates why the callback was invoked. Points to the XEvent that
triggered the callback. Specifies the timestamp of the logical event.
A pointer to the following structure is passed for the XmNdropStart‐
Callback callback: typedef struct {
int reason;
XEvent *event;
Time timeStamp;
unsigned char operation;
unsigned char operations;
unsigned char dropSiteStatus;
unsigned char dropAction;
Position x;
Position y; }XmDropStartCallbackStruct, *XmDropStartCallback;
Indicates why the callback was invoked. Points to the XEvent that
triggered the callback. Specifies the time at which the drag was com‐
pleted. Identifies an operation.
If the pointer is over an active drop site when the drop begins,
the toolkit initializes operation to the value of the operation
member of the XmDropProcCallbackStruct at the time the Drop‐
Site's XmNdropProc returns.
If the pointer is not over an active drop site when the drop
begins, the toolkit initializes operation by selecting an opera‐
tion from the initial value of the operations member. The tool‐
kit searches this set first for XmDROP_MOVE, then for
XmDROP_COPY, then for XmDROP_LINK, and initializes operation to
the first operation it finds in the set. If it finds none of
these operations in the set, it initializes operation to
XmDROP_NOOP. Indicates the set of operations supported for the
source data.
If the pointer is over an active drop site when the drop begins,
the toolkit initializes operations to the bitwise AND of the
DropSite's XmNdropOperations and the value of the operations
member of the XmDropProcCallbackStruct at the time the Drop‐
Site's XmNdropProc returns. If the resulting set of operations
is empty, the toolkit initializes operations to XmDROP_NOOP.
If the pointer is not over an active drop site when the drop
begins and if the user does not select an operation (by pressing
a modifier key), the toolkit initializes operations to the value
of the DragContext's XmNdragOperations resource.
If the pointer is not over an active drop site when the drop
begins and if the user does select an operation, the toolkit
initializes operations to the bitwise AND of the corresponding
operation and the value of the DragContext's XmNdragOperations
resource. If the resulting set of operations is empty, the tool‐
kit initializes operations to XmDROP_NOOP. Indicates whether or
not a drop site is valid.
If the pointer is over an active drop site when the drop begins,
the toolkit initializes dropSiteStatus to the value of the drop‐
SiteStatus member of the XmDropProcCallbackStruct at the time
the DropSite's XmNdropProc returns.
If the pointer is not over an active drop site when the drop
begins, the toolkit initializes dropSiteStatus to
XmNO_DROP_SITE. An IN/OUT member that identifies the drop
action. The values are XmDROP, XmDROP_CANCEL, XmDROP_HELP, and
XmDROP_INTERRUPT. The value of dropAction can be modified to
change the action actually initiated. The value XmDROP_INTERRUPT
is currently unsupported; if specified, it will be interpreted
as a XmDROP_CANCEL. Indicates the x-coordinate of the pointer
in root window coordinates. Indicates the y-coordinate of the
pointer in root window coordinates.
A pointer to the following structure is passed to the XmNopera‐
tionChangedCallback callback: typedef struct {
int reason;
XEvent *event;
Time timeStamp;
unsigned char operation;
unsigned char operations;
unsigned char dropSiteStatus; }XmOperationChangedCallbackStruct,
*XmOperationChangedCallback;
Indicates why the callback was invoked. Points to the XEvent that
triggered the callback. Specifies the time at which the crossing event
occurred. Identifies an operation.
If the toolkit has just called a DropSite's XmNdragProc, the
toolkit initializes operation to the value of the operation mem‐
ber of the XmDragProcCallbackStruct at the time the DropSite's
XmNdragProc returns.
If the toolkit has not called an XmNdragProc and the pointer is
within an active drop site, the toolkit initializes operation by
selecting an operation from the bitwise AND of the initial value
of the operations member and the value of the DropSite's XmN‐
dropSiteOperations resource. The toolkit searches this set first
for XmDROP_MOVE, then for XmDROP_COPY, then for XmDROP_LINK, and
initializes operation to the first operation it finds in the
set. If the toolkit finds none of these operations in the set,
it initializes operation to XmDROP_NOOP.
If the toolkit has not called an XmNdragProc and the pointer is
not within an active drop site, the toolkit initializes opera‐
tion by selecting an operation from the initial value of the
operations member. The toolkit searches this set first for
XmDROP_MOVE, then for XmDROP_COPY, then for XmDROP_LINK, and
initializes operation to the first operation it finds in the
set. If the toolkit finds none of these operations in the set,
it initializes operation to XmDROP_NOOP. Indicates the set of
operations supported for the source data.
If the toolkit has just called a DropSite's XmNdragProc, the
toolkit initializes operations to the bitwise AND of the Drop‐
Site's XmNdropOperations and the value of the operations member
of the XmDragProcCallbackStruct at the time the DropSite's XmN‐
dragProc returns. If the resulting set of operations is empty,
the toolkit initializes operations to XmDROP_NOOP.
If the toolkit has not called an XmNdragProc and the user does
not select an operation (by pressing a modifier key), the tool‐
kit initializes operations to the value of the DragContext's
XmNdragOperations resource.
If the toolkit has not called an XmNdragProc and the user does
select an operation, the toolkit initializes operations to the
bitwise AND of the corresponding operation and the value of the
DragContext's XmNdragOperations resource. If the resulting set
of operations is empty, the toolkit initializes operations to
XmDROP_NOOP. Indicates whether or not a drop site is valid.
If the toolkit has just called a DropSite's XmNdragProc, the
toolkit initializes dropSiteStatus to the value of the drop‐
SiteStatus member of the XmDragProcCallbackStruct at the time
the DropSite's XmNdragProc returns.
If the toolkit has not called an XmNdragProc, it initializes
dropSiteStatus as follows: the toolkit initializes dropSiteSta‐
tus to XmNO_DROP_SITE if the pointer is over an inactive drop
site or is not over a drop site. The toolkit initializes drop‐
SiteStatus to XmDROP_SITE_VALID if all the following conditions
are met: The pointer is over an active drop site The DragCon‐
text's XmNexportTargets and the DropSite's XmNimportTargets are
compatible The initial value of the operation member is not
XmDROP_NOOP
Otherwise, the toolkit initializes dropSiteStatus to
XmDROP_SITE_INVALID.
A pointer to the following structure is passed to callbacks for XmNto‐
pLevelEnterCallback: typedef struct {
int reason;
XEvent *event;
Time timestamp;
Screen screen;
Window window;
Position x;
Position y;
unsigned char dragProtocolStyle; }XmTopLevelEnterCallbackStruct,
*XmTopLevelEnterCallback;
Indicates why the callback was invoked. Points to the XEvent that
triggered the callback. Specifies the timestamp of the logical event.
Specifies the screen associated with the top-level window or root win‐
dow being entered. Specifies the ID of the top-level window or root
window being entered. Indicates the x-coordinate of the pointer in
root window coordinates. Indicates the y-coordinate of the pointer in
root window coordinates. Specifies the protocol style adopted by the
initiator. The values are XmDRAG_DROP_ONLY, XmDRAG_DYNAMIC,
XmDRAG_NONE, and XmDRAG_PREREGISTER.
A pointer to the following structure is passed to callbacks for XmNto‐
pLevelLeaveCallback: typedef struct {
int reason;
XEvent *event;
Time timestamp;
Screen screen;
Window window; }XmTopLevelLeaveCallbackStruct, *XmTopLevelLeave‐
Callback;
Indicates why the callback was invoked. Points to the XEvent that
triggered the callback. Specifies the timestamp of the logical event.
Specifies a screen associated with the top-level window or root window
being left. Specifies the ID of the top-level window or root window
being left.
Translations
The XmDragContext translations are listed below. These translations may
not directly correspond to a translation table. BDrag Motion: DragMo‐
tion() BDrag Release: FinishDrag() KCancel: CancelDrag() KHelp:
HelpDrag()
Action Routines
The XmDragContext action routines are described below: Cancels the drag
operation and frees the associated DragContext. Drags the selected
data as the pointer is moved. Finishes the drag operation and starts
the drop operation. Initiates a conditional drop that enables the
receiver to provide help information to the user. The user can cancel
or continue the drop operation in response to this information.
Virtual Bindings
The bindings for virtual keys are vendor specific. For information
about bindings for virtual buttons and keys, see VirtualBindings(3X).
SEE ALSOCore(3X), XmDisplay(3X), XmDragCancel(3X), XmDragIcon(3X),
XmDragStart(3X), XmDropSite(3X), XmDropTransfer(3X), XmScreen(3X)XmDragContext(3X)
