XmDisplay(3) - FreeBSD Ports 15.1.quarterly Manual Pages

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XmDisplay(3) Library Functions Manual XmDisplay(3)

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 in-
formation 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 XtAppIni-
tialize or XtAppCreateShell). It is not necessary to create an XmDisplay
object by any other means. An application can use the function XmGetXmDis-
play to obtain the widget ID of the XmDisplay object for a given display.

An application cannot supply initial values for XmDisplay resources as ar-
guments 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 ob-
tain 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 partici-
pating in drag and drop transactions. The two basic protocol types are pre-
register and dynamic. When a preregister protocol is used, the toolkit han-
dles any communication between the initiator and receiver clients and dis-
plays 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 communi-
cate drag and drop state information between each other, and to update
their respective visuals accordingly. The toolkit provides drop site infor-
mation as the pointer passes over any given drop site. In this mode, a re-
ceiver 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 program-
mer 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 re-
maining letters (in either lowercase or uppercase, but include any under-
scores 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), re-
trieved by using XtGetValues (G), or is not applicable (N/A).

XmNdefaultButtonEmphasis
Specifies whether to change the look of the PushButton widget and
gadget that have the XmNshowAsDefault resource set. When the
PushButton is the default, it has an etched out button which is
enclosed with another etched in border. The XmNdefaultButtonEm-
phasis has the follow possible values, which affect the location
cursor:

XmINTERNAL_HIGHLIGHT
Causes the location cursor to appear in between the two
etched borders to minimize the space required.

XmEXTERNAL_HIGHLIGHT
Causes the PushButton to draw the location cursor out-
side the second border.

XmNdefaultVirtualBindings
Specifies the default virtual bindings for the display. Follow-
ing is an example of a specification for the defaultVirtualBind-
ings resource in a resource file:

*defaultVirtualBindings: \
osfBackSpace: <Key>BackSpace \n\
osfInsert: <Key>InsertChar \n\
osfDelete: <Key>DeleteChar \n\
...
osfLeft: <Key>left, Ctrl<Key>H

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 re-
ceivers 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 pro-
tocol. It supports dragging, and any time the cursor is
over a client that supports drag and drop, valid feed-
back is provided. There are no other visual effects.

XmDRAG_PREFER_DYNAMIC
As an initiator, this client can support both the pre-
register and dynamic protocols, but prefers to use dy-
namic protocols whenever possible in order to provide
high-quality drag-under feedback.

XmDRAG_PREFER_PREREGISTER
As an initiator, this client can support both the pre-
register and dynamic protocols, but prefers to use the
preregister protocol whenever possible in order to ac-
commodate 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 in-
formation 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 prereg-
ister and dynamic protocols, but prefers to use the dy-
namic protocol whenever possible in order to provide
high-quality drag-under feedback.

XmDRAG_PREFER_PREREGISTER
As a receiver, this client can support both the prereg-
ister and dynamic protocols, but prefers to use the
preregister protocol whenever possible in order to ac-
commodate performance needs.

The default value of this resource is dependent on the capabili-
ties of the display. If the display supports the shape extension,
allowing the dynamic protocol to use arbitrarily sized drag cur-
sors, the default of this resource is XmDRAG_PREFER_DYNAMIC, oth-
erwise the default is XmDRAG_PREFER_PREREGISTER.

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 described in the following table.
+----------------+----------------------------------------------+
| Drag Initiator | | | | |
| | Drag Receiver Protocol Style | | | |
+----------------+------------------------------+---+---+-------+
+----------------+------------------------------+---+---+-------+
+----------------+------------------------------+---+---+-------+
+----------------+------------------------------+---+---+-------+
+----------------+------------------------------+---+---+-------+
+----------------+------------------------------+---+---+-------+
+----------------+------------------------------+---+---+-------+

The value XmDRAG_NONE does not appear in the matrix. When speci-
fied for either the initiator or receiver side, XmDRAG_NONE im-
plies that drag and drop transactions are not supported. A value
of XmDRAG_DROP_ONLY (Drop Only) results when an initiator and re-
ceiver cannot compromise protocol styles, that is, one client re-
quires dynamic mode while the other can only support preregister
mode, or if either explicitly has specified XmDRAG_DROP_ONLY.

XmNdragStartCallback
Specifies the list of callbacks that are invoked when the Xm-
DragStart function is called. The type of structure whose address
is passed to this callback is XmDragStartCallbackStruct. The
callback reason is XmCR_DRAG_START.

XmNenableBtn1Transfer
Specifies if selection and transfer actions are integrated on
Btn1 and extend actions are activated on Btn2. This resource can
take the following values:

XmOFF Disables integration and selection activation on Btn1.

XmBUTTON2_TRANSFER
Enables integration and selection activation on Btn1
and transfer on Btn2.

XmBUTTON2_ADJUST
Enables integration and selection activation on Btn1
and adjust on Btn2.

This resource affects the actions of Text, TextField, List, and
Container.

XmNenableButtonTab
Specifies if the action for the <Tab> key (KNextField and KPre-
vField actions) is to be modified. A value of True modifies the
key to move as an arrow key until the boundary of a tab group is
reached. Then, at the boundary of the tab group, KNextField and
KPrevField will move to the next or previous tab group, respec-
tively. A value of False does not cause modification.

XmNenableDragIcon
Specifies which set of icons are to be used for system default
cursors during drag and drop operations. A value of False speci-
fies that earlier versions of Motif release icons are used, a
value of True specifies that alternate icons are used. This re-
source affects both the 16x16 and the 32x32 icons that the system
defaults for each of the Screen objects associated with this dis-
play.

XmNenableEtchedInMenu
Specifies the shadowing of the button widgets and gadgets in
menus when the control is activated. A value of True causes the
selected menu to be drawn with the shadow etched in; this shadow
style is consistent with the selected appearance of other button
widgets outside of menus. A value of False causes the selected
menu to be draw with the shadow etched out. This resource affects
the actions of PushButton, ToggleButton, and CascadeButton wid-
gets and gadgets when they are children of Menu.

When this resource is set, the background of a button in a menu
uses the XmNselectColor (derived from the XmNselectPixel) when
armed as a default. A PushButton uses the XmNarmColor if it is
defined. A ToggleButton uses the XmNselectColor if XmNindicatorOn
is False and XmNfillOnSelect is True.

XmNenableToggleColor
Specifies how to determine the default value of the XmNselect-
Color resource of ToggleButton and ToggleButtonGadget. A value
of True causes the default value of XmNselectColor to be set to
the value of XmNhighlightColor. A value of False causes the de-
fault value of XmNselectColor to be set to the value of XmNback-
ground. This resource only affects the appearance of ToggleBut-
ton widgets and gadgets that are in XmONE_OF_MANY or
XmONE_OF_MANY_ROUND mode. In addition, XmNenableToggleColor only
influences the default value of XmNselectColor. That is, if the
user or application sets a value for XmNselectColor, then XmNen-
ableToggleColor is ignored.

XmNenableToggleVisual
Specifies the visual appearance of the ToggleButton widget and/or
gadget. This resource affects the default value of the ToggleBut-
ton[Gadget] XmNindicatorType and XmNindicatorOn resources. When
the ToggleButton is in a RadioBox, a value of True causes the
XmONE_OF_MANY_ROUND (a shadowed circle) to be the default. Oth-
erwise, when this resource is True, the ToggleButton XmNindica-
torOn resource causes a default of XmN_OF_MANY, which will be a
shadowed square with a check mark (check box).

A value of False causes the following:

XmONE_OF_MANY
Is a shadowed diamond.

XmN_OF_MANY
Is a shadowed square.

XmNenableUnselectableDrag
Specifies whether or not it is possible to drag from Label and
Scale. A value of True enables the drag; a value of False dis-
ables it.

XmNenableWarp
Specifies if an application is allowed to warp the pointer from
the user. A value of True enables warping, a value of False does
not.

XmNmotifVersion
Specifies the current version of Motif that the current implemen-
tation is supposed to behave like. By default, this resource gets
its value from release values in Xm.h.

XmNnoFontCallback
This callback is called whenever a rendition attempts to load a
font or fontset and fails. This can happen on creation if the
font is specified as XmLOAD_IMMEDIATE or when an attempt is made
to render an XmString using a font specified as XmLOAD_DEFERRED.
An application can have this callback attempt to remedy this
problem by calling XmRenditionUpdate on the input rendition to
provide a font for the widget to use. This may be done by either
providing an an alternative font name to be loaded using the XmN-
fontName and XmNfontType resources or with an already loaded font
using the XmNfont resource. The callback reason is XmCR_NO_FONT.
This callback uses the XmDisplayCallbackStruct structure.

XmNnoRenditionCallback
This callback is called whenever an attempt is made to render a
segment with a RENDITION tag which does not match any renditions
in a given render table. The callback reason is XmCR_NO_RENDI-
TION. This callback uses the XmDisplayCallbackStruct structure.

An application can have this callback attempt to remedy this
problem by creating a new rendition with the given tag and adding
it to render_table.

The XmNnoRenditionCallback should deallocate the render table
passed in in the render_table field of the callback structure.
Note that the table will automatically be deallocated if the Xm-
RenderTableAddRenditions function is called on it. The callback
should NOT deallocate the modified render table that is passed
back to Motif in the render_table field. If the application
wishes to manipulate this render table further, it should make a
copy with the XmRenderTableCopy function before returning from
the callback.

XmNuserData
Specifies a client data pointer for applications. An internally
unused resource.

Inherited Resources
All of the superclass resources inherited by XmDisplay are designated N/A
(not applicable).

Callback Information
A pointer to the following structure is passed to the XmNdragStartCallback
callback:

typedef struct
{
int reason;
XEvent *event;
Widget timeStamp;
Boolean doit;
}XmDragStartCallbackStruct;

reason Indicates why the callback was invoked

event Points to the XEvent that triggered the callback

widget Indicates the ID of the widget from which the drag was initiated.

doit Is an IN/OUT member that allows the callback to determine whether
to continue with the drag or cancel. Setting doit to False will
cancel the drag. The default value is NULL.

A pointer to the following structure is passed to the XmNnoFontCallback and
XmNnoRenditionCallback callbacks:

typedef struct
{
int reason;
XEvent *event;
XmRendition rendition;
char *font_name;
XmRenderTable render_table;
XmStringTag tag;
}XmDisplayCallbackStruct;

reason Indicates why the callback was invoked.

event Points to the XEvent that triggered the callback. It can be NULL.

rendition Specifies the rendition with the missing font.

font_name Specifies the name of the font or font set which could not be
loaded.

render_table
Specifies the render table with the missing rendition.

tag Specifies the tag of the missing rendition.

RELATED
ApplicationShell(3), Composite(3), Core(3), TopLevelShell(3), Vendor-
Shell(3), WMShell(3), XmGetXmDisplay(3), and XmScreen(3).

XmDisplay(3)

NAME | SYNOPSIS | DESCRIPTION | RELATED

Want to link to this manual page? Use this URL:
<https://man.freebsd.org/cgi/man.cgi?query=XmDisplay&sektion=3&manpath=FreeBSD+Ports+15.1.quarterly>

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