com.google.gwt.view.client

Class AbstractDataProvider<T>

java.lang.Object

com.google.gwt.view.client.AbstractDataProvider<T>

Type Parameters:

T - the data type of records in the list

All Implemented Interfaces:

ProvidesKey<T>

Direct Known Subclasses:

AsyncDataProvider, ListDataProvider

public abstract class AbstractDataProvider<T>
extends java.lang.Object
implements ProvidesKey<T>

A base implementation of a data source for HasData implementations.

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	AbstractDataProvider() Construct an AbstractDataProvider without a key provider.
protected	AbstractDataProvider(ProvidesKey<T> keyProvider) Construct an AbstractDataProvider with a given key provider.

Method Summary

Modifier and Type	Method and Description
void	addDataDisplay(HasData<T> display) Adds a data display to this adapter.
java.util.Set<HasData<T>>	getDataDisplays() Get the set of displays currently assigned to this adapter.
java.lang.Object	getKey(T item) Get the key for a list item.
ProvidesKey<T>	getKeyProvider() Get the ProvidesKey that provides keys for list items.
Range[]	getRanges() Get the current ranges of all displays.
protected abstract void	onRangeChanged(HasData<T> display) Called when a display changes its range of interest.
void	removeDataDisplay(HasData<T> display) Remove the given data display.
protected void	updateRowCount(int count, boolean exact) Inform the displays of the total number of items that are available.
protected void	updateRowData(HasData<T> display, int start, java.util.List<T> values) Informs a single display of new data.
protected void	updateRowData(int start, java.util.List<T> values) Inform the displays of the new data.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

AbstractDataProvider

protected AbstractDataProvider()

Construct an AbstractDataProvider without a key provider.

AbstractDataProvider

protected AbstractDataProvider(ProvidesKey<T> keyProvider)

Construct an AbstractDataProvider with a given key provider.

Parameters:

keyProvider - a ProvidesKey object

Method Detail

addDataDisplay

public void addDataDisplay(HasData<T> display)

Adds a data display to this adapter. The current range of interest of the display will be populated with data.

Parameters:

display - a HasData.

getDataDisplays

public java.util.Set<HasData<T>> getDataDisplays()

Get the set of displays currently assigned to this adapter.

Returns:

the set of HasData

getKey

public java.lang.Object getKey(T item)

Get the key for a list item. The default implementation returns the item itself.

Specified by:

getKey in interface ProvidesKey<T>

Parameters:

item - the list item

Returns:

the key that represents the item

getKeyProvider

public ProvidesKey<T> getKeyProvider()

Get the ProvidesKey that provides keys for list items.

Returns:

the ProvidesKey

getRanges

public Range[] getRanges()

Get the current ranges of all displays.

Returns:

the ranges

removeDataDisplay

public void removeDataDisplay(HasData<T> display)

Remove the given data display.

Parameters:

display - a HasData instance

Throws:

java.lang.IllegalStateException - if the display is not present

onRangeChanged

protected abstract void onRangeChanged(HasData<T> display)

Called when a display changes its range of interest.

Parameters:

display - the display whose range has changed

updateRowCount

protected void updateRowCount(int count,
                              boolean exact)

Inform the displays of the total number of items that are available.

Parameters:

count - the new total row count

exact - true if the count is exact, false if it is an estimate

updateRowData

protected void updateRowData(int start,
                             java.util.List<T> values)

Inform the displays of the new data.

Parameters:

start - the start index

values - the data values

updateRowData

protected void updateRowData(HasData<T> display,
                             int start,
                             java.util.List<T> values)

Informs a single display of new data.

Parameters:

display - the display to be updated

start - the start index

values - the data values