NAME

Composite widget class − fundamental widget with children. 

SYNOPSIS

Public Headers:<X11/StringDefs.h>
<X11/Composite.h>

Private Header:<X11/CompositeP.h>

Class Name:Composite

Class Hierarchy:Core → Composite

Class Pointer:compositeWidgetClass

Instantiation:Composite is an Intrinsics meta-class, and is not normally instantiated. 

Functions/Macros:XtIsComposite()

DESCRIPTION

Composite is the superclass of all classes that can have children.  It defines methods for geometry management of those children. 

NEW RESOURCES

Composite defines the following resources:

XtNchildren
List of widget’s children.

XtNinsertPosition
Points to an XtOrderProc() function which is to be called to determine the position at which each child should be inserted into the XtNchildren array. 

XtNnumChildren
Length of the array in XtNchildren. 

INHERITED RESOURCES

Composite inherits the following resources.  The resources are listed alphabetically, along with the superclass that defines them. 

CLASS STRUCTURE

The composite class structure is defined as follows: typedef struct {  XtGeometryHandler geometry_manager; /∗ geometry manager for children ∗/  XtWidgetProc change_managed; /∗ change managed state of child ∗/  XtWidgetProc insert_child; /∗ physically add child to parent ∗/  XtWidgetProc delete_child; /∗ physically remove child ∗/  XPointer extension; /∗ pointer to extension record ∗/ } CompositeClassPart;
 
typedef struct { CoreClassPart core_class;  CompositeClassPart composite_class; } CompositeClassRec, ∗CompositeWidgetClass; The fields of this class structure have the following meanings:

geometry_manager()
The geometry_manager() method called when a child widget requests a new size or location.  See the reference page in Section 4.  Use XtInheritGeometryManager to inherit the geometry_manager() method of the superclass. 

change_managed()
The change_managed() method called when a child or children become managed or unmanaged.  See the reference page in Section 4.  Use XtInheritChangeManaged to inherit the change_managed() method of the superclass. 

insert_child()
The insert_child() method called to add a child to the widgets children instance array.  See the reference page in Section 4.  Use XtInheritInsertChild to inherit the insert_child() method of the superclass. 

delete_child()
The delete_child() method called to add a child to the widgets children instance array.  See the reference page in Section 4.  Use XtInheritDeleteChild to inherit the delete_child() method of the superclass. 

extension
A linked list of extension records, or NULL.  There is currently one extension defined for Composite which allows the class to specify whether it accepts non-widget children.  See below. 

EXTENSION STRUCTURE

There is one extension defined for the Composite class.  The extension structure is shown below; the record_type field should be NULLQUARK, and the version field should be XtCompositeExtensionVersion.  The accepts_objects field should be True if the class should accept non-widget objects as children, or False if it should not accept them.  typedef struct {  XtPointer next_extension;    /∗ next record is linked list, or NULL ∗/  XrmQuark record_type;        /∗ NULLQUARK ∗/  long version;                /∗ XtCompositeExtensionVersion ∗/  Cardinal record_size;        /∗ use sizeof() ∗/  Boolean accepts_objects; } CompositeClassExtensionRec, ∗CompositeClassExtension;

INSTANCE STRUCTURE

The composite instance structure contains at least the following fields (which need not be in this order): typedef struct {  WidgetList  children; /∗ array of ALL widget children ∗/  Cardinal    num_children; /∗ total number of widget children ∗/  Cardinal    num_slots; /∗ number of slots in children array ∗/  XtOrderProc insert_position; /∗ compute position of new child ∗/ } CompositePart;
 
typedef struct { CorePart core;  CompositePart composite; } CompositeRec, ∗CompositeWidget;

SEE ALSO

XtManageChildrenUNIX SYSTEM V/68,
XtOrderProcUNIX SYSTEM V/88,
CoreUNIX SYSTEM V/68 and V/88 Release 4,
change_managedUNIX SYSTEM V/68 and V/88 Release 4, delete_childUNIX SYSTEM V/68 and V/88 Release 4, geometry_managerUNIX SYSTEM V/68 and V/88 Release 4, insert_childUNIX SYSTEM V/68 and V/88 Release 4.