android.widget
Class BaseAdapter

java.lang.Object
  android.widget.BaseAdapter

All Implemented Interfaces:

Adapter, ListAdapter, SpinnerAdapter

Direct Known Subclasses:

ArrayAdapter, CursorAdapter, ExpandableListConnector, PreferenceGroupAdapter, SimpleAdapter

public abstract class BaseAdapter
extends Object
implements ListAdapter, SpinnerAdapter

Common base class of common implementation for an Adapter that can be used in both ListView (by implementing the specialized ListAdapter interface} and Spinner (by implementing the specialized SpinnerAdapter interface.

Field Summary

Fields inherited from interface android.widget.Adapter

IGNORE_ITEM_VIEW_TYPE, NO_SELECTION

Constructor Summary

BaseAdapter()

Method Summary

boolean	areAllItemsEnabled() Are all items in this ListAdapter enabled? If yes it means all items are selectable and clickable.
View	getDropDownView(int position, View convertView, ViewGroup parent) Get a View that displays in the drop down popup the data at the specified position in the data set.
int	getItemViewType(int position) Get the type of View that will be created by Adapter.getView(int, android.view.View, android.view.ViewGroup) for the specified item.
int	getViewTypeCount() Returns the number of types of Views that will be created by Adapter.getView(int, android.view.View, android.view.ViewGroup).
boolean	hasStableIds() Indicated whether the item ids are stable across changes to the underlying data.
boolean	isEmpty()
boolean	isEnabled(int position) Returns true if the item at the specified position is not a separator.
void	notifyDataSetChanged()
void	notifyDataSetInvalidated()
void	registerDataSetObserver(DataSetObserver observer) Register an observer that is called when changes happen to the data used by this adapter.
void	unregisterDataSetObserver(DataSetObserver observer) Unregister an observer that has previously been registered with this adapter via Adapter.registerDataSetObserver(android.database.DataSetObserver).

Methods inherited from class java.lang.Object

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

Methods inherited from interface android.widget.Adapter

getCount, getItem, getItemId, getView

Constructor Detail

BaseAdapter

public BaseAdapter()

Method Detail

hasStableIds

public boolean hasStableIds()

Description copied from interface: Adapter

Indicated whether the item ids are stable across changes to the underlying data.

Specified by:

hasStableIds in interface Adapter

Returns:

True if the same id always refers to the same object.

registerDataSetObserver

public void registerDataSetObserver(DataSetObserver observer)

Description copied from interface: Adapter

Register an observer that is called when changes happen to the data used by this adapter.

Specified by:

registerDataSetObserver in interface Adapter

Parameters:

observer - the object that gets notified when the data set changes.

unregisterDataSetObserver

public void unregisterDataSetObserver(DataSetObserver observer)

Description copied from interface: Adapter

Unregister an observer that has previously been registered with this adapter via Adapter.registerDataSetObserver(android.database.DataSetObserver).

Specified by:

unregisterDataSetObserver in interface Adapter

Parameters:

observer - the object to unregister.

notifyDataSetChanged

public void notifyDataSetChanged()

notifyDataSetInvalidated

public void notifyDataSetInvalidated()

areAllItemsEnabled

public boolean areAllItemsEnabled()

Description copied from interface: ListAdapter

Are all items in this ListAdapter enabled? If yes it means all items are selectable and clickable.

Specified by:

areAllItemsEnabled in interface ListAdapter

Returns:

True if all items are enabled

isEnabled

public boolean isEnabled(int position)

Description copied from interface: ListAdapter

Returns true if the item at the specified position is not a separator. (A separator is a non-selectable, non-clickable item).

Specified by:

isEnabled in interface ListAdapter

Parameters:

position - Index of the item

Returns:

True if the item is not a separator

getDropDownView

public View getDropDownView(int position,
                            View convertView,
                            ViewGroup parent)

Description copied from interface: SpinnerAdapter

Get a View that displays in the drop down popup the data at the specified position in the data set.

Specified by:

getDropDownView in interface SpinnerAdapter

Parameters:

position - index of the item whose view we want.

convertView - the old view to reuse, if possible. Note: You should check that this view is non-null and of an appropriate type before using. If it is not possible to convert this view to display the correct data, this method can create a new view.

parent - the parent that this view will eventually be attached to

Returns:

a View corresponding to the data at the specified position.

getItemViewType

public int getItemViewType(int position)

Description copied from interface: Adapter

Get the type of View that will be created by Adapter.getView(int, android.view.View, android.view.ViewGroup) for the specified item.

Specified by:

getItemViewType in interface Adapter

Parameters:

position - The position of the item within the adapter's data set whose view type we want.

Returns:

An integer representing the type of View. Two views should share the same type if one can be converted to the other in Adapter.getView(int, android.view.View, android.view.ViewGroup). Note: Integers must be in the range 0 to Adapter.getViewTypeCount() - 1. Adapter.IGNORE_ITEM_VIEW_TYPE can also be returned.

See Also:

IGNORE_ITEM_VIEW_TYPE

getViewTypeCount

public int getViewTypeCount()

Description copied from interface: Adapter

Returns the number of types of Views that will be created by Adapter.getView(int, android.view.View, android.view.ViewGroup). Each type represents a set of views that can be converted in Adapter.getView(int, android.view.View, android.view.ViewGroup). If the adapter always returns the same type of View for all items, this method should return 1.

This method will only be called when when the adapter is set on the the AdapterView.

Specified by:

getViewTypeCount in interface Adapter

Returns:

The number of types of Views that will be created by this adapter

isEmpty

public boolean isEmpty()

Specified by:

isEmpty in interface Adapter

Returns:

true if this adapter doesn't contain any data. This is used to determine whether the empty view should be displayed. A typical implementation will return getCount() == 0 but since getCount() includes the headers and footers, specialized adapters might want a different behavior.