C++ GraphComponentPtr::parentChanging方法代码示例

void GraphComponent::removeChildInternal( GraphComponentPtr child, bool emitParentChanged )
{
	if( emitParentChanged )
	{
		child->parentChanging( 0 );
	}
	ChildContainer::iterator it = std::find( m_children.begin(), m_children.end(), child );
	if( it == m_children.end() || child->m_parent != this )
	{
		// the public removeChild() method protects against this case, but it's still possible to 
		// arrive here if an Action (which has a direct binding to removeChildInternal) is being replayed
		// from the undo queue, and just prior to that something called the public removeChild() method.
		// this can occur if a slot calls removeChild() from a signal triggered during the replay of the
		// undo queue. the onus is on such slots to not reperform their work when ScriptNode::currentActionStage()
		// is Action::Redo - instead they should rely on the fact that their actions will have been
		// recorded and replayed automatically.
		throw Exception( boost::str( boost::format( "GraphComponent::removeChildInternal : \"%s\" is not a child of \"%s\"." ) % child->fullName() % fullName() ) );
	}
	m_children.erase( it );
	child->m_parent = 0;
	childRemovedSignal()( this, child.get() );
	if( emitParentChanged )
	{	
		child->parentChangedSignal()( child.get(), this );
	}
}

void GraphComponent::addChildInternal( GraphComponentPtr child )
{
	child->parentChanging( this );
	GraphComponent *previousParent = child->m_parent;
	if( previousParent )
	{
		// remove the child from the previous parent, but don't emit parentChangedSignal.
		// this prevents a parent changed signal with new parent 0 followed by a parent
		// changed signal with the new parent.
		previousParent->removeChildInternal( child, false );
	}
	m_children.push_back( child );
	child->m_parent = this;
	child->setName( child->m_name.value() ); // to force uniqueness
	childAddedSignal()( this, child.get() );
	child->parentChangedSignal()( child.get(), previousParent );
}

void GraphComponent::addChildInternal( GraphComponentPtr child, size_t index )
{
	child->parentChanging( this );
	GraphComponent *previousParent = child->m_parent;
	if( previousParent )
	{
		// remove the child from the previous parent, but don't emit parentChangedSignal.
		// this prevents a parent changed signal with new parent null followed by a parent
		// changed signal with the new parent.
		previousParent->removeChildInternal( child, false );
	}

	m_children.insert( m_children.begin() + min( index, m_children.size() ), child );
	child->m_parent = this;
	child->setName( child->m_name.value() ); // to force uniqueness
	Signals::emitLazily( m_signals.get(), &Signals::childAddedSignal, this, child.get() );
	child->parentChanged( previousParent );
	Signals::emitLazily( child->m_signals.get(), &Signals::parentChangedSignal, child.get(), previousParent );
}