H3D::X3DBindableNode Class Reference
[Abstract nodes.]

X3DBindableNode is the abstract base type for all bindable children nodes, including Background, TextureBackground, Fog, NavigationInfo, Viewpoint and DeviceInfo. More...

#include <X3DBindableNode.h>

Inheritance diagram for H3D::X3DBindableNode:

List of all members.

Public Types
typedef std::deque< X3DBindableNode * >	StackType
typedef map< string, StackType >	StackMapType
Public Member Functions
	X3DBindableNode (const string &_bindable_stack_name, Inst< SFSetBind > _set_bind=0, Inst< SFNode > _metadata=0, Inst< SFTime > _bindTime=0, Inst< SFBool > _isBound=0)
	Constructor.
virtual	~X3DBindableNode ()
	Destructor.
virtual void	toStackTop ()
	Move this instance to the stack top.
virtual void	removeFromStack ()
	Remove the bindable node from the stack.
bool	isStackTop ()
	Is this node at the top of the stack.
Static Public Member Functions
static X3DBindableNode *	getActive (const string &bindable_stack_name)
	Returns the active bindable instance, i.e.
static const StackType &	getStack (const string &bindable_stack_name)
	Get the stack for a given name.
Public Attributes
auto_ptr< SFSetBind >	set_bind
	Input field to bind or unbind the node.
auto_ptr< SFTime >	bindTime
	The bindTime field is the time at which the Viewpoint node is bound or unbound.
auto_ptr< SFBool >	isBound
	Output field telling if this node is bound or not.
Static Public Attributes
static H3DNodeDatabase	database
	The H3DNodedatabase for this node.
Protected Attributes
string	bindable_stack_name
Static Protected Attributes
static StackMapType	stack
	The bindable stack.
Classes
struct	SFSetBind
	The SFSetBind field calls toStackTop() and removeFromStack() on the X3DBindableNode it is in depending on the value that it is set to. More...

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Detailed Description

X3DBindableNode is the abstract base type for all bindable children nodes, including Background, TextureBackground, Fog, NavigationInfo, Viewpoint and DeviceInfo.

These nodes have the unique behaviour that only one of each type can be bound (i.e., affect the user's experience) at any instant in time. The browser shall maintain an independent, separate stack for each type of bindable node. Each of these nodes includes a set_bind inputOnly field and an isBound outputOnly field. The set_bind inputOnly field is used to move a given node to and from its respective top of stack. A TRUE value sent to the set_bind inputOnly field moves the node to the top of the stack; sending a FALSE value removes it from the stack. The isBound event is output when a given node is:

• moved to the top of the stack;
• removed from the top of the stack;
• pushed down from the top of the stack by another node being placed on top.

That is, isBound events are sent when a given node becomes, or ceases to be, the active node. The node at the top of the stack (the most recently bound node) is the active node for its type and is used by the browser to set the world state. If the stack is empty (i.e., either the X3D file has no bindable nodes for a given type or the stack has been popped until empty), the default field values for that node type are used to set world state. The results are undefined if a multiply instanced (DEF/USE) bindable node is bound.

The following rules describe the behaviour of the binding stack for a node of type <bindable node>="">:

• During read, the first encountered <bindable node>=""> is bound by pushing it to the top of the <bindable node>=""> stack. The first encountered <bindable node>=""> sends an isBound TRUE event.
• When a set_bind TRUE event is received by a <bindable node>="">,
  1. If it is not on the top of the stack: the current top of stack node sends an isBound FALSE event. The new node is moved to the top of the stack and becomes the currently bound <bindable node>="">. The new <bindable node>=""> (top of stack) sends an isBound TRUE event.
  2. If the node is already at the top of the stack, this event has no effect.
• When a set_bind FALSE event is received by a <bindable node>=""> in the stack, it is removed from the stack. If it was on the top of the stack,
  1. it sends an isBound FALSE event.
  2. the next node in the stack becomes the currently bound <bindable node>=""> (i.e., pop) and issues an isBound TRUE event.
• If a set_bind FALSE event is received by a node not in the stack, the event is ignored and isBound events are not sent.
• When a node replaces another node at the top of the stack, the isBound TRUE and FALSE output events from the two nodes are sent simultaneously (i.e., with identical timestamps).
• If a bound node is deleted, it behaves as if it received a set_bind FALSE event (see f above).

The results are undefined if a bindable node is bound and is the child of an LOD, Switch, or any node or prototype that disables its children.

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Member Function Documentation

static X3DBindableNode* H3D::X3DBindableNode::getActive (  const string &  bindable_stack_name  )  [inline, static]

Returns the active bindable instance, i.e. the instance on the top of the bindable stack.

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Member Data Documentation

auto_ptr< SFTime > H3D::X3DBindableNode::bindTime

The bindTime field is the time at which the Viewpoint node is bound or unbound. Access type: outputOnly

auto_ptr< SFBool > H3D::X3DBindableNode::isBound

Output field telling if this node is bound or not. Access type: outputOnly

auto_ptr< SFSetBind > H3D::X3DBindableNode::set_bind

Input field to bind or unbind the node. Access type: inputOnly Valid range: TRUE or FALSE

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