XmDisplay(3X) X11 SDE 5.4R3.00 XmDisplay(3X)
NAME
XmDisplay--The Display widget class
SYNOPSIS
#include <Xm/Display.h>
DESCRIPTION
The XmDisplay object is used by the Motif widgets to store
information that is specific to a display. It also allows the
toolkit to access certain information on widget hierarchies that
would otherwise be unavailable. Each client has one XmDisplay object
for each display it accesses.
An XmDisplay object is automatically created when the application
creates the first shell on a display (usually accomplished by a call
to XtAppInitialize or XtAppCreateShell). It is not necessary to
create an XmDisplay object by any other means. An application can
use the function XmGetXmDisplay to obtain the widget ID of the
XmDisplay object for a given display.
An application cannot supply initial values for XmDisplay resources
as arguments to a call to any function that creates widgets. The
application or user can supply initial values in a resource file.
After creating the first shell on the display, the application can
use XmGetXmDisplay to obtain the widget ID of the XmDisplay object
and then call XtSetValues to set the XmDisplay resources.
XmDisplay resources specify the drag protocol style for a client
participating in drag and drop transactions. There are two basic
protocol types, preregister and dynamic. When a preregister protocol
is used, the toolkit handles any communication between the initiator
and receiver clients, and displays the appropriate drag-over and
drag-under visual effects. A client registers its drop sites in
advance and this information is stored in a property for each top-
level window. When the drag pointer enters a top level window, the
drop site information is read by the initiator. A dynamic protocol
allows the source and destination clients to dynamically communicate
drag and drop state information between each other, and to update
their respective visuals accordingly. The toolkit provides drop site
information as the pointer passes over any given drop site. In this
mode, a receiver can supply a procedure to generate its own drag-
under effects.
Classes
Display inherits behavior and resources from Core, Composite, Shell,
WMShell, VendorShell, TopLevelShell, and ApplicationShell classes.
The class pointer is xmDisplayClass.
The class name is XmDisplay.
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
Licensed material--property of copyright holder(s) 1
XmDisplay(3X) X11 SDE 5.4R3.00 XmDisplay(3X)
values for the inherited classes to set attributes for this widget.
To reference a resource by name or by class in an .Xdefaults file,
remove the XmN or XmC prefix and use the remaining letters. To
specify one of the defined values for a resource in an .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).
XmDisplay Resource Set
Name Class Type Default Access
-------------------------------------------------------------------------------------------------------------------
XmNdefaultVirtualBindings DefaultVirtualBindings String dynamic CG
XmNdragInitiatorProtocolStyle XmCDragInitiatorProtocolStyle unsigned char XmDRAG_PREFER_RECEIVER CG
XmNdragReceiverProtocolStyle XmCDragReceiverProtocolStyle unsigned char XmDRAG_PREFER_PREREGISTER CG
XmNdefaultVirtualBindings
Specifies the default virtual bindings for the display.
Following is an example of a specification for the
defaultVirtualBindings resource in a resource file:
*defaultVirtualBindings: \
osfBackSpace : <Key>BackSpace\n\
osfInsert : <Key>InsertChar\n\ ...
osfDelete : <Key>DeleteChar
XmNdragInitiatorProtocolStyle
Specifies the drag and drop protocol requirements or
preference when the client is an initiator. The possible
values are
XmDRAG_PREREGISTER
As an initiator, this client does not use the dynamic
protocol and can only arrange visual effects with
receivers who provide preregistered information.
XmDRAG_DYNAMIC
As an initiator, this client does not make use of any
preregistered drop site information made available by
other clients, and can only arrange visual effects with
receivers who use the dynamic protocol.
XmDRAG_NONE
Specifies that drag and drop is disabled for this
client.
XmDRAG_DROP_ONLY
As an initiator, this client does not use either the
preregistered drop site information or the dynamic
protocol. It supports dragging, and any time the cursor
is over a client that supports drag and drop, valid
Licensed material--property of copyright holder(s) 2
XmDisplay(3X) X11 SDE 5.4R3.00 XmDisplay(3X)
feedback is provided. There are no other visual
effects.
XmDRAG_PREFER_DYNAMIC
As an initiator, this client can support both the
preregister and dynamic protocols, but prefers to use
dynamic protocols whenever possible in order to provide
high-quality drag-under feedback.
XmDRAG_PREFER_PREREGISTER
As an initiator, this client can support both the
preregister and dynamic protocols, but prefers to use
the preregister protocol whenever possible in order to
accommodate performance needs or to provide consistent
drag-over feedback.
XmDRAG_PREFER_RECEIVER
Indicates that this client can support both preregister
and dynamic protocols, but will defer to the preference
of the receiver client. This value is valid only for
the XmNdragInitiatorProtocolStyle resource, and is its
default value.
XmNdragReceiverProtocolStyle
Specifies the drag and drop protocol requirements or
preference when this client is a receiver. The values are
XmDRAG_PREREGISTER
As a receiver, this client preregisters drop site
information and does not use the dynamic protocol. It
can only arrange visual effects with initiators who make
use of the preregistered information.
XmDRAG_DYNAMIC
As a receiver, this client uses the dynamic protocol and
does not preregister drop site information. It can only
arrange visual effects with initiators who use the
dynamic protocol.
XmDRAG_NONE
Specifies that drag and drop is disabled for this
client.
XmDRAG_DROP_ONLY
As a receiver, this client neither uses the dynamic
protocol nor preregisters drop site information. It
supports dropping, and when dragging over this client,
valid feedback is always provided, but there are no
other visual effects.
XmDRAG_PREFER_DYNAMIC
As a receiver, this client can support both the
Licensed material--property of copyright holder(s) 3
XmDisplay(3X) X11 SDE 5.4R3.00 XmDisplay(3X)
preregister and dynamic protocols, but prefers to use
dynamic protocol whenever possible in order to provide
high-quality drag-under feedback.
XmDRAG_PREFER_PREREGISTER
As a receiver, this client can support both the
preregister and dynamic protocols, but prefers to use
the preregister protocol whenever possible in order to
accommodate performance needs.
The actual protocol used between an initiator and a
receiver is based on the protocol style of the receiver and
initiator. The decision matrix is as follows:
Drag Receiver Protocol Style
Drag Initiator ----------------------------------------------------------------
Protocol Style Preregister Prefer Preregister Prefer Dynamic Dynamic
-----------------------------------------------------------------------------------
Preregister Preregister Preregister Preregister Drop Only
-----------------------------------------------------------------------------------
Prefer Preregister Preregister Preregister Preregister Dynamic
-----------------------------------------------------------------------------------
Prefer Receiver Preregister Preregister Dynamic Dynamic
-----------------------------------------------------------------------------------
Prefer Dynamic Preregister Dynamic Dynamic Dynamic
-----------------------------------------------------------------------------------
Dynamic Drop Only Dynamic Dynamic Dynamic
The value XmDRAG_NONE does not appear in the above matrix.
When specified for either the initiator or receiver side,
XmDRAG_NONE implies that drag and drop transactions are not
supported. A value of XmDRAG_DROP_ONLY (Drop Only) results
when an initiator and receiver cannot compromise protocol
styles, that is, one client requires dynamic mode while the
other can only support preregister mode, or if either
explicitly has specified XmDRAG_DROP_ONLY.
Inherited Resources
All of the superclass resources inherited by XmDisplay are designated
N/A (not applicable).
RELATED INFORMATION
ApplicationShell(3X), Composite(3X), Core(3X), TopLevelShell(3X),
VendorShell(3X), WMShell(3X), XmGetXmDisplay(3X), and XmScreen(3X).
Licensed material--property of copyright holder(s) 4