Engine.UIListElementProvider

/**
 * Provides an interface for providing a UIList with a collection of data through the UIListElement interface
 *
 * Copyright 1998-2011 Epic Games, Inc. All Rights Reserved.
 */
interface UIListElementProvider
	native(UIPrivate);

cpptext
{
	/**
	 * Retrieves the list of all data tags contained by this element provider which correspond to list element data.
	 *
	 * @return	the list of tags supported by this element provider which correspond to list element data.
	 */
	virtual TArray<FName> GetElementProviderTags()=0;

	/**
	 * Returns the number of list elements associated with the data tag specified.
	 *
	 * @param	FieldName	the name of the property to get the element count for.  guaranteed to be one of the values returned
	 *						from GetElementProviderTags.
	 *
	 * @return	the total number of elements that are required to fully represent the data specified.
	 */
	virtual INT GetElementCount( FName FieldName )=0;

	/**
	 * Retrieves the list elements associated with the data tag specified.
	 *
	 * @param	FieldName		the name of the property to get the element count for.  guaranteed to be one of the values returned
	 *							from GetElementProviderTags.
	 * @param	out_Elements	will be filled with the elements associated with the data specified by DataTag.
	 *
	 * @return	TRUE if this data store contains a list element data provider matching the tag specified.
	 */
	virtual UBOOL GetListElements( FName FieldName, TArray<INT>& out_Elements )=0;

	/**
	 * Determines whether a member of a collection should be considered "enabled" by subscribed lists.  Disabled elements will still be displayed in the list
	 * but will be drawn using the disabled state.
	 *
	 * @param	FieldName			the name of the collection data field that CollectionIndex indexes into.
	 * @param	CollectionIndex		the index into the data field collection indicated by FieldName to check
	 *
	 * @return	TRUE if FieldName doesn't correspond to a valid collection data field, CollectionIndex is an invalid index for that collection,
	 *			or the item is actually enabled; FALSE only if the item was successfully resolved into a data field value, but should be considered disabled.
	 */
	virtual UBOOL IsElementEnabled( FName FieldName, INT CollectionIndex ) { return TRUE; }

	/**
	 * Retrieves a UIListElementCellProvider for the specified data tag that can provide the list with the available cells for this list element.
	 * Used by the UI editor to know which cells are available for binding to individual list cells.
	 *
	 * @param	FieldName		the tag of the list element data field that we want the schema for.
	 *
	 * @return	a pointer to some instance of the data provider for the tag specified.  only used for enumerating the available
	 *			cell bindings, so doesn't need to actually contain any data (i.e. can be the CDO for the data provider class, for example)
	 */
	virtual TScriptInterface<class IUIListElementCellProvider> GetElementCellSchemaProvider( FName FieldName )=0;

	/**
	 * Retrieves a UIListElementCellProvider for the specified data tag that can provide the list with the values for the cells
	 * of the list element indicated by CellValueProvider.DataSourceIndex
	 *
	 * @param	FieldName		the tag of the list element data field that we want the values for
	 * @param	ListIndex		the list index for the element to get values for
	 *
	 * @return	a pointer to an instance of the data provider that contains the value for the data field and list index specified
	 */
	virtual TScriptInterface<class IUIListElementCellProvider> GetElementCellValueProvider( FName FieldName, INT ListIndex )=0;
}

DefaultProperties
{

}