QNode Class

(Qt3DCore::QNode)

QNode is the base class of all Qt3D node classes used to build a Qt3D scene. More...

Properties

  • 1 property inherited from QObject

Public Functions

QNode(QNode *parent = Q_NULLPTR)
virtual ~QNode()
bool blockNotifications(bool block)
QNodeList childrenNodes() const
const QNodeId id() const
bool isEnabled() const
bool notificationsBlocked() const
QNode *parentNode() const
  • 31 public functions inherited from QObject

Public Slots

void setEnabled(bool isEnabled)
virtual void setParent(QNode *parent)
  • 1 public slot inherited from QObject

Signals

void enabledChanged(bool enabled)
void parentChanged(QObject *parent)

Protected Functions

void cleanup()
virtual void copy(const QNode *ref)
virtual void sceneChangeEvent(const QSceneChangePtr &change)
  • 9 protected functions inherited from QObject

Static Protected Members

QNode *clone(QNode *node)
typedef QNodeList
typedef QNodePtr

Additional Inherited Members

  • 11 static public members inherited from QObject

Detailed Description

QNode is the base class of all Qt3D node classes used to build a Qt3D scene.

The owernship of QNode is determined by the QObject parent/child relationship between nodes. By itself, a QNode has no visual appearance and no particular meaning, it is there as a way of building a node based tree structure.

The parent of a QNode instance can only be another QNode instance.

Each QNode instance has a unique id that allows it to be recognizable from other instances.

When properties are defined on a QNode subclass, their NOTIFY signal will automatically generate notifications that the Qt3D backend aspects will receive.

When subclassing QNode, make sure to call QNode::cleanup() from your subclass's destructor to ensure proper notification to backend aspects. Faiure to do so will result in crashes when one of your QNode subclass instance is eventually destroyed.

See also QEntity and QComponent.

Property Documentation

enabled : bool

Access functions:

bool isEnabled() const
void setEnabled(bool isEnabled)

Notifier signal:

void enabledChanged(bool enabled)

parent : Qt3DCore::QNode *

Access functions:

QNode *parentNode() const
virtual void setParent(QNode *parent)

Notifier signal:

void parentChanged(QObject *parent)

Member Function Documentation

QNode::QNode(QNode *parent = Q_NULLPTR)

Creates a new QNode instance with parent parent.

Note: The backend aspects will be notified that a QNode instance is part of the scene only if it has a parent; unless this is the root node of the Qt3D scene.

See also setParent().

[virtual] QNode::~QNode()

Destroys the instance of QNode. The destructor is virtual.

bool QNode::blockNotifications(bool block)

If block is true, property change notifications sent by this object to aspects are blocked. If block is false, no such blocking will occur.

The return value is the previous value of notificationsBlocked().

Note that the other notification types will be sent even if the notifications for this object have been blocked.

See also notificationsBlocked().

QNodeList QNode::childrenNodes() const

Returns a list filled with the QNode children of the current QNode instance.

[protected] void QNode::cleanup()

This methods can only be called once and takes care of notyfing the backend aspects that the current Qt3DCore::QNode instance is about to be destroyed.

Note: It must be called by the destructor of every class subclassing QNode that is clonable (using the QT3D_CLONEABLE macro).

[static protected] QNode *QNode::clone(QNode *node)

Returns a clone of node. All the children of node are cloned as well.

Note: This is the only way to create two nodes with the same id.

[virtual protected] void QNode::copy(const QNode *ref)

Copies all the attributes from ref to the current Qt3DCore::QNode instance.

Note: When subclassing QNode, you should reimplement this method and always call the copy method on the base class. This will ensure that when cloned, the QNode is properly initialized.

const QNodeId QNode::id() const

Returns the id that uniquely identifies the QNode instance.

bool QNode::isEnabled() const

Returns whether the QNode is enabled or not.

Note: Getter function for property enabled.

bool QNode::notificationsBlocked() const

Returns true if aspect notifications are blocked; otherwise returns false. By default, notifications are not blocked.

See also blockNotifications().

QNode *QNode::parentNode() const

Returns the immediate QNode parent, or null if the node has no parent.

Note: Getter function for property parent.

[virtual protected] void QNode::sceneChangeEvent(const QSceneChangePtr &change)

[slot] void QNode::setEnabled(bool isEnabled)

Set the QNode to enabled if isEnabled is true. By default a QNode is always enabled.

Note: the interpretation of what enabled means is aspect-dependent. Even if enabled is set to false, some aspects may still consider the node in some manner. This is documented on a class by class basis.

Note: Setter function for property enabled.

See also isEnabled().

[virtual slot] void QNode::setParent(QNode *parent)

Sets the parent node of the current QNode instance to parent. Setting the parent will notify the backend aspects about current QNode instance's parent change.

Note: if parent happens to be null, this will actually notify that the current QNode instance was removed from the scene.

Note: Setter function for property parent.

Related Non-Members

typedef Qt3DCore::QNodeList

List of QNode pointers.

typedef Qt3DCore::QNodePtr

A shared pointer for QNode.

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