com.whitestein.lsps.vaadin.ui.components.table.dataset

Interface IDataset

All Known Implementing Classes:

DataDataset, GenericDataset, GroupingDataset, InMemoryDatasetFilter, QueryDataset, TypeDataset

public interface IDataset

Provides data for UITable. By default does not perform any sorting nor filtering unless setSort(SortSpec) or setFilter(java.util.Set) is called.

Author:

mvy

Method Summary

Modifier and Type	Method and Description
Type	getItemType() Returns the type of data returned by the load functions.
boolean	isFilterSupported(Filter filter) True if given filter criterion is supported.
boolean	isSortSupported(ISort criterion) True if given sort criterion is supported.
List<Object>	load(int startIndex, int count) Load batch of items, mostly records or simple types.
void	setFilter(Set<Filter> filters) Sets the new filtering criteria.
void	setSort(SortSpec sort) Sets the new sorting criteria.
int	size() Gets number of items available through this query.

Method Detail

size

int size()

Gets number of items available through this query.

Returns:

Number of items. Only count items which pass filters.

load

List<Object> load(int startIndex,
                  int count)

Load batch of items, mostly records or simple types. The items must be sorted and filtered accordingly, as stated by last call to setSort(SortSpec) and/or setFilter(java.util.Set) respectively.

Parameters:

startIndex - Starting index of the item list, must be 0 or greater.

count - Count of the items to be retrieved, must be 0 or greater.

Returns:

List of items, mostly RecordHolders. Should never fail with out of bounds exception - if the startIndex or count is out of bounds, the item is simply not returned. The list may or may not be mutable.

setSort

void setSort(SortSpec sort)

Sets the new sorting criteria. This class should sort based on concrete implementations of ISort and must ignore sort criteria classes of unknown/unsupported types. Next call to load(int, int) must return sorted filtered data.

Parameters:

sort - the sorting criteria, not null.

setFilter

void setFilter(Set<Filter> filters)

Sets the new filtering criteria. This class should filter based on concrete implementations of ISort and must ignore filter criteria classes of unknown/unsupported types. Next call to load(int, int) must return properly filtered data.

Parameters:

filters - the filtering criteria, not null, may be empty. Silently ignore unsupported filters.

isSortSupported

boolean isSortSupported(ISort criterion)

True if given sort criterion is supported.

Parameters:

criterion - the criterion, not null.

Returns:

true if given sort criterion is supported, false if not.

isFilterSupported

boolean isFilterSupported(Filter filter)

True if given filter criterion is supported.

Parameters:

filter - the filter, not null.

Returns:

true if given filter is supported, false if not.

getItemType

Type getItemType()

Returns the type of data returned by the load functions. Returns Object if the type cannot be guessed.

Returns:

the type, never null.