public
abstract
class
BaseAdapter
extends Object
implements
ListAdapter,
SpinnerAdapter
| java.lang.Object | |
| ↳ | android.widget.BaseAdapter |
 Known Direct Subclasses
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Known Indirect Subclasses
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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).
Inherited constants |
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From
interface
android.widget.Adapter
|
Public constructors | |
|---|---|
BaseAdapter()
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Public methods | |
|---|---|
boolean
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areAllItemsEnabled()
Indicates whether all the items in this adapter are enabled. |
View
|
getDropDownView(int position, View convertView, ViewGroup parent)
Gets a |
int
|
getItemViewType(int position)
Get the type of View that will be created by |
int
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getViewTypeCount()
Returns the number of types of Views that will be created by
|
boolean
|
hasStableIds()
Indicates whether the item ids are stable across changes to the underlying data. |
boolean
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isEmpty()
|
boolean
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isEnabled(int position)
Returns true if the item at the specified position is not a separator. |
void
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notifyDataSetChanged()
Notifies the attached observers that the underlying data has been changed and any View reflecting the data set should refresh itself. |
void
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notifyDataSetInvalidated()
Notifies the attached observers that the underlying data is no longer valid or available. |
void
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registerDataSetObserver(DataSetObserver observer)
Register an observer that is called when changes happen to the data used by this adapter. |
void
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unregisterDataSetObserver(DataSetObserver observer)
Unregister an observer that has previously been registered with this
adapter via |
Inherited methods | |
|---|---|
From
class
java.lang.Object
| |
From
interface
android.widget.ListAdapter
| |
From
interface
android.widget.SpinnerAdapter
| |
From
interface
android.widget.Adapter
| |
boolean areAllItemsEnabled ()
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 | |
|---|---|
boolean |
True if all items are enabled, false otherwise. |
View getDropDownView (int position, View convertView, ViewGroup parent)
Gets a View that displays in the drop down popup
the data at the specified position in the data set.
| Parameters | |
|---|---|
position |
int:
index of the item whose view we want. |
convertView |
View:
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 |
ViewGroup:
the parent that this view will eventually be attached to |
| Returns | |
|---|---|
View |
a View corresponding to the data at the
specified position.
|
int getItemViewType (int position)
Get the type of View that will be created by getView(int, View, ViewGroup) for the specified item.
| Parameters | |
|---|---|
position |
int:
The position of the item within the adapter's data set whose view type we
want. |
| Returns | |
|---|---|
int |
An integer representing the type of View. Two views should share the same type if one
can be converted to the other in getView(int, View, ViewGroup). Note: Integers must be in the
range 0 to getViewTypeCount() - 1. IGNORE_ITEM_VIEW_TYPE can
also be returned. |
int getViewTypeCount ()
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 the adapter is set on the AdapterView.
| Returns | |
|---|---|
int |
The number of types of Views that will be created by this adapter |
boolean hasStableIds ()
Indicates whether the item ids are stable across changes to the underlying data.
| Returns | |
|---|---|
boolean |
True if the same id always refers to the same object. |
boolean isEnabled (int position)
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 |
int:
Index of the item |
| Returns | |
|---|---|
boolean |
True if the item 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. Once invoked this adapter is no longer valid and should not report further data set changes.
void registerDataSetObserver (DataSetObserver observer)
Register an observer that is called when changes happen to the data used by this adapter.
| Parameters | |
|---|---|
observer |
DataSetObserver:
the object that gets notified when the data set changes.
|
void unregisterDataSetObserver (DataSetObserver observer)
Unregister an observer that has previously been registered with this
adapter via registerDataSetObserver(DataSetObserver).
| Parameters | |
|---|---|
observer |
DataSetObserver:
the object to unregister.
|
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