void GraphComponent::removeChild( GraphComponentPtr child )
{
if( child->m_parent!=this )
{
throw Exception( "Object is not a child." );
}
if( refCount() )
{
// someone is pointing to us, so we may have a ScriptNode ancestor and we should do things
// in an undoable way.
Action::enact(
this,
// ok to bind raw pointers to this, because enact() guarantees
// the lifetime of the subject.
boost::bind( &GraphComponent::removeChildInternal, this, child, true ),
boost::bind( &GraphComponent::addChildInternal, this, child, child->index() )
);
}
else
{
// we have no references to us - chances are we're in construction still. adding ourselves to an
// undo queue is impossible, and creating temporary smart pointers to ourselves (as above) will
// cause our destruction before construction completes. just do the work directly.
removeChildInternal( child, true );
}
}
void GraphComponent::addChild( GraphComponentPtr child )
{
if( child->m_parent==this )
{
return;
}
throwIfChildRejected( child.get() );
if( refCount() )
{
// someone is pointing to us, so we may have a ScriptNode ancestor and we should do things
// in an undoable way. figure out what our undo function should be - it varies based on what
// the previous parent was.
Action::Function undoFn;
if( child->m_parent )
{
if( child->m_parent->isInstanceOf( (IECore::TypeId)ScriptNodeTypeId ) )
{
// use raw pointer to avoid circular reference between script and undo queue
undoFn = boost::bind( &GraphComponent::addChildInternal, child->m_parent, child, child->index() );
}
else
{
// use smart pointer to ensure parent remains alive, even if something unscrupulous
// messes it with non-undoable actions that aren't stored in the undo queue.
undoFn = boost::bind( &GraphComponent::addChildInternal, GraphComponentPtr( child->m_parent ), child, child->index() );
}
}
else
{
// no previous parent.
undoFn = boost::bind( &GraphComponent::removeChildInternal, this, child, true );
}
Action::enact(
this,
// ok to use raw pointer for this - lifetime of subject guaranteed.
boost::bind( &GraphComponent::addChildInternal, this, child, m_children.size() ),
undoFn
);
}
else
{
// we have no references to us - chances are we're in construction still. adding ourselves to an
// undo queue is impossible, and creating temporary smart pointers to ourselves (as above) will
// cause our destruction before construction completes. just do the work directly.
addChildInternal( child, m_children.size() );
}
}
