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Android APIs
public abstract class

BaseAdapter

extends Object
implements ListAdapter SpinnerAdapter
java.lang.Object
   ↳ android.widget.BaseAdapter
Known Direct Subclasses
Known Indirect Subclasses

Class Overview

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).

Summary

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Inherited Constants
From interface android.widget.Adapter
Public Constructors
BaseAdapter()
Public Methods
boolean areAllItemsEnabled()
Indicates whether all the items in this adapter are enabled.
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 getView(int, View, ViewGroup) for the specified item.
int getViewTypeCount()

Returns the number of types of Views that will be created by getView(int, View, ViewGroup).

boolean hasStableIds()
Indicates 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()
Notifies the attached observers that the underlying data has been changed and any View reflecting the data set should refresh itself.
void notifyDataSetInvalidated()
Notifies the attached observers that the underlying data is no longer valid or available.
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 registerDataSetObserver(DataSetObserver).
[Expand]
Inherited Methods
From class java.lang.Object
From interface android.widget.Adapter
From interface android.widget.ListAdapter
From interface android.widget.SpinnerAdapter

Public Constructors

public BaseAdapter ()

Added in API level 1

Public Methods

public boolean areAllItemsEnabled ()

Added in API level 1

Indicates whether all the items in this adapter are enabled. If the value returned by this method changes over time, there is no guarantee it will take effect. If true, it means all items are selectable and clickable (there is no separator.)

Returns
  • True if all items are enabled, false otherwise.

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

Added in API level 1

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

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.

public int getItemViewType (int position)

Added in API level 1

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

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

public int getViewTypeCount ()

Added in API level 1

Returns the number of types of Views that will be created by getView(int, View, ViewGroup). Each type represents a set of views that can be converted in getView(int, 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.

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

public boolean hasStableIds ()

Added in API level 1

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

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

public boolean isEmpty ()

Added in API level 1

public boolean isEnabled (int position)

Added in API level 1

Returns true if the item at the specified position is not a separator. (A separator is a non-selectable, non-clickable item). The result is unspecified if position is invalid. An ArrayIndexOutOfBoundsException should be thrown in that case for fast failure.

Parameters
position Index of the item
Returns
  • True if the item is not a separator

public void notifyDataSetChanged ()

Added in API level 1

Notifies the attached observers that the underlying data has been changed and any View reflecting the data set should refresh itself.

public void notifyDataSetInvalidated ()

Added in API level 1

Notifies the attached observers that the underlying data is no longer valid or available. Once invoked this adapter is no longer valid and should not report further data set changes.

public void registerDataSetObserver (DataSetObserver observer)

Added in API level 1

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

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

public void unregisterDataSetObserver (DataSetObserver observer)

Added in API level 1

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

Parameters
observer the object to unregister.