private bool TryGetParentGroupFromItemHelper( object item, out CollectionViewGroup collectionViewGroup )
{
//This helper method is used to simplify previous code flow of the TryGetParentGroupFromItem method.
collectionViewGroup = null;
//-----------------------------------------------
//1 - First check is to see of the item is a CVG.
//-----------------------------------------------
CollectionViewGroup groupItem = item as CollectionViewGroup;
if( groupItem != null )
{
Group group = this.GetGroupFromCollectionViewGroup( groupItem );
if( group != null )
{
GroupGeneratorNode groupGeneratorNode = group.GeneratorNode;
if( groupGeneratorNode.Parent == null )
{
//no parent for speficied item.
return true;
}
//if the nodeHelper was able to locate the content, use the nodeHelper's CurrentNode as the node for the item.
collectionViewGroup = ( ( GroupGeneratorNode )groupGeneratorNode.Parent ).CollectionViewGroup;
return true;
}
//item is a CVG, but is not present in the generator!
return false;
}
//-----------------------------------------------
//2 - Second check is to see if the item is already in the generated list
//-----------------------------------------------
//item might be in the "generated" list... much quicker to find-out if it is!
//note: if the item belongs to a detail, then it will be excluded from the "fast" algo.
int itemGenPosIndex = this.FindFirstGeneratedIndexForLocalItem( item );
if( itemGenPosIndex != -1 )
{
//item was generated and was not from a DetailGeneratorNode
if( m_genPosToNode[ itemGenPosIndex ].Parent == null )
{
//no parent for speficied item.
return true;
}
collectionViewGroup = ( ( GroupGeneratorNode )m_genPosToNode[ itemGenPosIndex ].Parent ).CollectionViewGroup;
return true;
}
//-----------------------------------------------
//3 - Third check is to check of the item is a GroupHeaderFooterItem
//-----------------------------------------------
if( item.GetType() == typeof( GroupHeaderFooterItem ) )
{
GroupHeaderFooterItem groupHeaderFooterItem = ( GroupHeaderFooterItem )item;
CollectionViewGroup parentGroup = groupHeaderFooterItem.Group;
if( this.GetGroupFromCollectionViewGroup( parentGroup ) != null )
{
//since the goal is the find the parentGroup from the item passed (which is a GroupHeader or GroupFooter), then the Group
//is what I am looking for.
collectionViewGroup = parentGroup;
return true;
}
//Item was a GroupHeaderFooterItem but was not part of the genreator!
return false;
}
//-----------------------------------------------
//4 - Final Check
//-----------------------------------------------
//if the item was not generated, then try to find the item as is within the generator's content
GeneratorNodeHelper finalNodeHelper = new GeneratorNodeHelper( m_startNode, 0, 0 );
if( finalNodeHelper.AbsoluteFindItem( item ) )
{
//item was not generated but was part of this generator
if( finalNodeHelper.CurrentNode.Parent == null )
{
//no parent for speficied item.
return true;
}
collectionViewGroup = ( ( GroupGeneratorNode )finalNodeHelper.CurrentNode.Parent ).CollectionViewGroup;
return true;
}
else
{
return false;
}
//Default function behavior, if nobody else returned, then the function did not work as intended... as each "block" is supposed to return a value...
throw new DataGridInternalException();
}