NAME¶
XmDrawingArea — The DrawingArea widget class
"XmDrawingArea" "widget class" "DrawingArea"
SYNOPSIS¶
#include <Xm/DrawingA.h>
DESCRIPTION¶
DrawingArea is an empty widget that is easily adaptable to a variety of
purposes. It does no drawing and defines no behavior except for invoking
callbacks. Callbacks notify the application when graphics need to be drawn
(exposure events or widget resize) and when the widget receives input from the
keyboard or mouse.
Applications are responsible for defining appearance and behavior as needed in
response to DrawingArea callbacks.
DrawingArea is also a composite widget and subclass of
XmManager that
supports minimal geometry management for multiple widget or gadget children.
DrawingArea uses the
XmNinitialFocus resource of
XmManager to
define whether or not DrawingArea will receive focus when it is traversed to,
even if it has traversable children. If
XmNinitialFocus is NULL,
DrawingArea receives focus only if it does not have any traversable children.
If
XmNinitialFocus is not NULL, then DrawingArea receives focus when
traversed to. In the latter case, the application first needs to be able to
realize that the DrawingArea will receive focus, then, as appropriate, needs
to either call the
XmProcessTraversal function for the desired child,
or to navigate across the private DrawingArea graphics objects.
The following resources are not currently used by the DrawingArea widget:
XmNshadowThickness,
XmNtopShadowPixmap,
XmNbottomShadowPixmap,
XmNtopShadowColor, and
XmNbottomShadowColor
Data Transfer Behavior¶
DrawingArea has no widget class conversion or destination procedure. Subclasses
and the
XmNconvertCallback procedures are responsible for any
conversion of selections. Subclasses and the
XmNdestinationCallback
procedures are responsible for any data transfers to the widget.
Classes¶
DrawingArea inherits behavior and resources from the
Core,
Composite,
Constraint, and
XmManager classes.
The class pointer is
xmDrawingAreaWidgetClass.
The class name is
XmDrawingArea.
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).
XmDrawingArea Resource Set |
|
|
|
|
Name |
Class |
Type |
Default |
Access |
_ |
_ |
_ |
_ |
_ |
XmNconvertCallback |
XmCCallback |
XtCallbackList |
NULL |
C |
_ |
_ |
_ |
_ |
_ |
XmNdestinationCallback |
XmCCallback |
XtCallbackList |
NULL |
C |
_ |
_ |
_ |
_ |
_ |
XmNexposeCallback |
XmCCallback |
XtCallbackList |
NULL |
C |
_ |
_ |
_ |
_ |
_ |
XmNinputCallback |
XmCCallback |
XtCallbackList |
NULL |
C |
_ |
_ |
_ |
_ |
_ |
XmNmarginHeight |
XmCMarginHeight |
Dimension |
10 |
CSG |
_ |
_ |
_ |
_ |
_ |
XmNmarginWidth |
XmCMarginWidth |
Dimension |
10 |
CSG |
_ |
_ |
_ |
_ |
_ |
XmNresizeCallback |
XmCCallback |
XtCallbackList |
NULL |
C |
_ |
_ |
_ |
_ |
_ |
XmNresizePolicy |
XmCResizePolicy |
unsigned char |
XmRESIZE_ANY |
CSG |
_ |
_ |
_ |
_ |
_ |
- XmNconvertCallback
- Specifies a list of callbacks called when the DrawingArea is asked to
convert a selection. The type of the structure whose address is passed to
these callbacks is XmConvertCallbackStruct. The reason is
XmCR_OK.
- XmNdestinationCallback
- Specifies a list of callbacks called when the DrawingArea is the
destination of a transfer operation. The type of the structure whose
address is passed to these callbacks is
XmDestinationCallbackStruct. The reason is XmCR_OK.
- XmNexposeCallback
- Specifies the list of callbacks that is called when DrawingArea receives
an exposure event. The callback reason is XmCR_EXPOSE. The callback
structure also includes the exposure event.
-
- The default bit gravity for Manager windows is NorthWestGravity.
This may cause the XmNexposeCallback procedures not to be invoked
when the DrawingArea window is made smaller.
- XmNinputCallback
- Specifies the list of callbacks that is called when the DrawingArea
receives a keyboard or mouse event (key or button, up or down). The
callback reason is XmCR_INPUT. The callback structure also includes
the input event.
- XmNmarginHeight
- Specifies the minimum spacing in pixels between the top or bottom edge of
DrawingArea and any child widget.
- XmNmarginWidth
- Specifies the minimum spacing in pixels between the left or right edge of
DrawingArea and any child widget.
- XmNresizeCallback
- Specifies the list of callbacks that is called when the DrawingArea is
resized. The callback reason is XmCR_RESIZE.
- XmNresizePolicy
- Controls the policy for resizing DrawingArea widgets. Possible values
include XmRESIZE_NONE (fixed size), XmRESIZE_ANY (shrink or
grow as needed), and XmRESIZE_GROW (grow only).
Inherited Resources¶
DrawingArea inherits behavior and resources from the following superclasses. For
a complete description of each resource, refer to the reference page for that
superclass.
XmManager Resource Set |
|
|
|
|
Name |
Class |
Type |
Default |
Access |
_ |
_ |
_ |
_ |
_ |
XmNbottomShadowColor |
XmCBottomShadowColor |
Pixel |
dynamic |
CSG |
_ |
_ |
_ |
_ |
_ |
XmNbottomShadowPixmap |
XmCBottomShadowPixmap |
Pixmap |
XmUNSPECIFIED_PIXMAP |
CSG |
_ |
_ |
_ |
_ |
_ |
XmNforeground |
XmCForeground |
Pixel |
dynamic |
CSG |
_ |
_ |
_ |
_ |
_ |
XmNhelpCallback |
XmCCallback |
XtCallbackList |
NULL |
C |
_ |
_ |
_ |
_ |
_ |
XmNhighlightColor |
XmCHighlightColor |
Pixel |
dynamic |
CSG |
_ |
_ |
_ |
_ |
_ |
XmNhighlightPixmap |
XmCHighlightPixmap |
Pixmap |
dynamic |
CSG |
_ |
_ |
_ |
_ |
_ |
XmNinitialFocus |
XmCInitialFocus |
Widget |
NULL |
CSG |
_ |
_ |
_ |
_ |
_ |
XmNlayoutDirection |
XmCLayoutDirection |
XmDirection |
dynamic |
CG |
_ |
_ |
_ |
_ |
_ |
XmNnavigationType |
XmCNavigationType |
XmNavigationType |
XmTAB_GROUP |
CSG |
_ |
_ |
_ |
_ |
_ |
XmNpopupHandlerCallback |
XmCCallback |
XtCallbackList |
NULL |
C |
_ |
_ |
_ |
_ |
_ |
XmNshadowThickness |
XmCShadowThickness |
Dimension |
0 |
CSG |
_ |
_ |
_ |
_ |
_ |
XmNstringDirection |
XmCStringDirection |
XmStringDirection |
dynamic |
CG |
_ |
_ |
_ |
_ |
_ |
XmNtopShadowColor |
XmCTopShadowColor |
Pixel |
dynamic |
CSG |
_ |
_ |
_ |
_ |
_ |
XmNtopShadowPixmap |
XmCTopShadowPixmap |
Pixmap |
dynamic |
CSG |
_ |
_ |
_ |
_ |
_ |
XmNtraversalOn |
XmCTraversalOn |
Boolean |
True |
CSG |
_ |
_ |
_ |
_ |
_ |
XmNunitType |
XmCUnitType |
unsigned char |
dynamic |
CSG |
_ |
_ |
_ |
_ |
_ |
XmNuserData |
XmCUserData |
XtPointer |
NULL |
CSG |
_ |
_ |
_ |
_ |
_ |
Composite Resource Set |
|
|
|
|
Name |
Class |
Type |
Default |
Access |
_ |
_ |
_ |
_ |
_ |
XmNchildren |
XmCReadOnly |
WidgetList |
NULL |
G |
_ |
_ |
_ |
_ |
_ |
XmNinsertPosition |
XmCInsertPosition |
XtOrderProc |
NULL |
CSG |
_ |
_ |
_ |
_ |
_ |
XmNnumChildren |
XmCReadOnly |
Cardinal |
0 |
G |
_ |
_ |
_ |
_ |
_ |
Core Resource Set |
|
|
|
|
Name |
Class |
Type |
Default |
Access |
_ |
_ |
_ |
_ |
_ |
XmNaccelerators |
XmCAccelerators |
XtAccelerators |
dynamic |
CSG |
_ |
_ |
_ |
_ |
_ |
XmNancestorSensitive |
XmCSensitive |
Boolean |
dynamic |
G |
_ |
_ |
_ |
_ |
_ |
XmNbackground |
XmCBackground |
Pixel |
dynamic |
CSG |
_ |
_ |
_ |
_ |
_ |
XmNbackgroundPixmap |
XmCPixmap |
Pixmap |
XmUNSPECIFIED_PIXMAP |
CSG |
_ |
_ |
_ |
_ |
_ |
XmNborderColor |
XmCBorderColor |
Pixel |
XtDefaultForeground |
CSG |
_ |
_ |
_ |
_ |
_ |
XmNborderPixmap |
XmCPixmap |
Pixmap |
XmUNSPECIFIED_PIXMAP |
CSG |
_ |
_ |
_ |
_ |
_ |
XmNborderWidth |
XmCBorderWidth |
Dimension |
0 |
CSG |
_ |
_ |
_ |
_ |
_ |
XmNcolormap |
XmCColormap |
Colormap |
dynamic |
CG |
_ |
_ |
_ |
_ |
_ |
XmNdepth |
XmCDepth |
int |
dynamic |
CG |
_ |
_ |
_ |
_ |
_ |
XmNdestroyCallback |
XmCCallback |
XtCallbackList |
NULL |
C |
_ |
_ |
_ |
_ |
_ |
XmNheight |
XmCHeight |
Dimension |
dynamic |
CSG |
_ |
_ |
_ |
_ |
_ |
XmNinitialResourcesPersistent |
XmCInitialResourcesPersistent |
Boolean |
True |
C |
_ |
_ |
_ |
_ |
_ |
XmNmappedWhenManaged |
XmCMappedWhenManaged |
Boolean |
True |
CSG |
_ |
_ |
_ |
_ |
_ |
XmNscreen |
XmCScreen |
Screen * |
dynamic |
CG |
_ |
_ |
_ |
_ |
_ |
XmNsensitive |
XmCSensitive |
Boolean |
True |
CSG |
_ |
_ |
_ |
_ |
_ |
XmNtranslations |
XmCTranslations |
XtTranslations |
dynamic |
CSG |
_ |
_ |
_ |
_ |
_ |
XmNwidth |
XmCWidth |
Dimension |
dynamic |
CSG |
_ |
_ |
_ |
_ |
_ |
XmNx |
XmCPosition |
Position |
0 |
CSG |
_ |
_ |
_ |
_ |
_ |
XmNy |
XmCPosition |
Position |
0 |
CSG |
_ |
_ |
_ |
_ |
_ |
A pointer to the following structure is passed to the
XmNexposeCallback,
XmNinputCallback, and
XmNresizeCallback procedures:
typedef struct
{
int reason;
XEvent * event;
Window window;
} XmDrawingAreaCallbackStruct;
- reason
- Indicates why the callback was invoked.
- event
- Points to the XEvent that triggered the callback. This is NULL for
the XmNresizeCallback.
- window
- Is set to the widget window.
A pointer to the following structure is passed to the
XmNconvertCallback
procedures:
typedef struct
{
int reason;
XEvent * event;
Atom selection;
Atom target;
XtPointer source_data;
XtPointer location_data;
int flags;
XtPointer parm;
int parm_format;
unsigned long parm_length;
int status;
XtPointer value;
Atom type;
int format;
unsigned long length;
} XmConvertCallbackStruct;
- reason
- Indicates why the callback was invoked.
- event
- Points to the XEvent that triggered the callback. It can be
NULL.
- selection
- Indicates the selection for which conversion is being requested. Possible
values are CLIPBOARD, PRIMARY, SECONDARY, and
_MOTIF_DROP.
- target
- Indicates the conversion target.
- source_data
- Contains information about the selection source. When the selection is
_MOTIF_DROP, source_data is the DragContext. Otherwise, it
is NULL.
- location_data
- Contains information about the location of data to be converted. If the
value is NULL, the data to be transferred consists of the widget's current
selection.
- flags
- Indicates the status of the conversion. Following are the possible
values:
- XmCONVERTING_NONE
- This flag is currently unused.
- XmCONVERTING_PARTIAL
- The target widget was able to be converted, but some data was lost.
- XmCONVERTING_SAME
- The conversion target is the source of the data to be transferred.
- XmCONVERTING_TRANSACT
- This flag is currently unused.
- parm
- Contains parameter data for this target. If no parameter data exists, the
value is NULL.
-
- When selection is CLIPBOARD and target is
_MOTIF_CLIPBOARD_TARGETS or
_MOTIF_DEFERRED_CLIPBOARD_TARGETS, the value is the requested
operation ( XmCOPY, XmMOVE, or XmLINK).
- parm_format
- Specifies whether the data in parm should be viewed as a list of
char, short, or long quantities. Possible values are
0 (when parm is NULL), 8 (when the data in parm should be
viewed as a list of chars), 16 (when the data in parm should
be viewed as a list of shorts), or 32 (when the data in parm
should be viewed as a list of longs). Note that parm_format
symbolizes a data type, not the number of bits in each list element. For
example, on some machines, a parm_format of 32 means that the data
in parm should be viewed as a list of 64-bit quantities, not 32-bit
quantities.
- parm_length
- Specifies the number of elements of data in parm, where each
element has the size specified by parm_format. When parm is
NULL, the value is 0.
- status
- An IN/OUT member that specifies the status of the conversion. The initial
value is XmCONVERT_DEFAULT. The callback procedure can set this
member to one of the following values:
- XmCONVERT_DEFAULT
- This value means that the widget class conversion procedure, if any, is
called after the callback procedures return. If the widget class
conversion procedure produces any data, it overwrites the data provided by
the callback procedures in the value member.
- XmCONVERT_MERGE
- This value means that the widget class conversion procedure, if any, is
called after the callback procedures return. If the widget class
conversion procedure produces any data, it appends its data to the data
provided by the callback procedures in the value member. This value
is intended for use with targets that result in lists of data, such as
TARGETS.
- XmCONVERT_DONE
- This value means that the callback procedure has successfully finished the
conversion. The widget class conversion procedure, if any, is not called
after the callback procedures return.
- XmCONVERT_REFUSE
- This value means that the callback procedure has terminated the conversion
process without completing the requested conversion. The widget class
conversion procedure, if any, is not called after the callback procedures
return.
- value
- An IN/OUT parameter that contains any data that the callback procedure
produces as a result of the conversion. The initial value is NULL. If the
callback procedure sets this member, it must ensure that the type,
format, and length members correspond to the data in
value. The callback procedure is responsible for allocating, but
not for freeing, memory when it sets this member.
- type
- An IN/OUT parameter that indicates the type of the data in the
value member. The initial value is INTEGER.
- format
- An IN/OUT parameter that specifies whether the data in value should
be viewed as a list of char, short, or long
quantities. The initial value is 8. The callback procedure can set this
member to 8 (for a list of char), 16 (for a list of short),
or 32 (for a list of long).
- length
- An IN/OUT member that specifies the number of elements of data in
value, where each element has the size symbolized by format.
The initial value is 0.
A pointer to the following callback structure is passed to the
XmNdestinationCallback procedures:
typedef struct
{
int reason;
XEvent * event;
Atom selection;
XtEnum operation;
int flags;
XtPointer transfer_id;
XtPointer destination_data;
XtPointer location_data;
Time time;
} XmDestinationCallbackStruct;
- reason
- Indicates why the callback was invoked.
- event
- Points to the XEvent that triggered the callback. It can be
NULL.
- selection
- Indicates the selection for which data transfer is being requested.
Possible values are CLIPBOARD, PRIMARY, SECONDARY,
and _MOTIF_DROP.
- operation
- Indicates the type of transfer operation requested.
- •
- When the selection is PRIMARY, possible values are XmMOVE,
XmCOPY, and XmLINK.
- •
- When the selection is SECONDARY or CLIPBOARD, possible
values are XmCOPY and XmLINK.
- •
- When the selection is _MOTIF_DROP, possible values are
XmMOVE, XmCOPY, XmLINK, and XmOTHER. A value
of XmOTHER means that the callback procedure must get further
information from the XmDropProcCallbackStruct in the
destination_data member.
- flags
- Indicates whether or not the destination widget is also the source of the
data to be transferred. Following are the possible values:
- XmCONVERTING_NONE
- The destination widget is not the source of the data to be
transferred.
- XmCONVERTING_SAME
- The destination widget is the source of the data to be transferred.
- transfer_id
- Serves as a unique ID to identify the transfer transaction.
- destination_data
- Contains information about the destination. When the selection is
_MOTIF_DROP, the callback procedures are called by the drop site's
XmNdropProc, and destination_data is a pointer to the
XmDropProcCallbackStruct passed to the XmNdropProc
procedure. When the selection is SECONDARY, destination_data
is an Atom representing a target recommmended by the selection owner for
use in converting the selection. Otherwise, destination_data is
NULL.
- location_data
- Contains information about the location where data is to be transferred.
The value is always NULL when the selection is SECONDARY or
CLIPBOARD. If the value is NULL, the data is to be inserted at the
widget's cursor position. location_data is only valid for the
duration of a transfer. Once XmTransferDone procedures start to be
called, location_data will no longer be stable.
- time
- Indicates the time when the transfer operation began.
Translations¶
XmDrawingArea inherits translations from XmManager. Before calling the XmManager
actions, all events in the inherited translations except
<BtnMotion>,
<EnterWindow>,
<LeaveWindow>,
<FocusIn>, and
<FocusOut> also call the DrawingAreaInput() action.
XmDrawingArea has the following additional translations. The following key names
are listed in the X standard key event translation table syntax. This format
is the one used by Motif to specify the widget actions corresponding to a
given key. A brief overview of the format is provided under
VirtualBindings(3). For a complete description of the format, please
refer to the X Toolkit Instrinsics Documentation.
- <BtnDown>:
- DrawingAreaInput()
- <BtnUp>:
- DrawingAreaInput()
- <KeyDown>:
- DrawingAreaInput() ManagerGadgetKeyInput()
- <KeyUp>:
- DrawingAreaInput()
Action Routines¶
The
XmDrawingArea action routines are
- DrawingAreaInput():
- Unless the event takes place in a gadget, calls the callbacks for
XmNinputCallback
- ManagerGadgetKeyInput():
- Causes the current gadget to process a keyboard event
Additional Behavior¶
The XmDrawingArea widget has the following additional behavior:
- <Expose>:
- Calls the callbacks for XmNexposeCallback
- <Widget Resize>:
- Calls the callbacks for XmNresizeCallback
Virtual Bindings¶
The bindings for virtual keys are vendor specific. For information about
bindings for virtual buttons and keys, see
VirtualBindings(3).
Composite(3),
Constraint(3),
Core(3),
XmCreateDrawingArea(3),
XmManager(3),
XmVaCreateDrawingArea(3), and
XmVaCreateManagedDrawingArea(3).