Package icyllis.modernui.widget

Interface Adapter

All Known Subinterfaces:
ListAdapter, SpinnerAdapter, WrapperListAdapter
All Known Implementing Classes:
ArrayAdapter, BaseAdapter, HeaderViewListAdapter, MenuAdapter
public interface Adapter
An Adapter object acts as a bridge between an AdapterView and the underlying data for that view. The Adapter provides access to the data items. The Adapter is also responsible for making a View for each item in the data set.
See Also:

  • Field Details

  • Method Details

    • registerDataSetObserver

      void registerDataSetObserver(@NonNull DataSetObserver observer)
      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.

    • unregisterDataSetObserver

      void unregisterDataSetObserver(@NonNull DataSetObserver observer)
      Unregister an observer that has previously been registered with this adapter via registerDataSetObserver(icyllis.modernui.util.DataSetObserver).
      Parameters:
      observer - the object to unregister.

    • getCount

      int getCount()
      How many items are in the data set represented by this Adapter.
      Returns:
      Count of items.

    • getItem

      Object getItem(int position)
      Get the data item associated with the specified position in the data set.
      Parameters:
      position - Position of the item whose data we want within the adapter's data set.
      Returns:
      The data at the specified position, may be null.

    • getItemId

      long getItemId(int position)
      Get the row id associated with the specified position in the list.
      Parameters:
      position - The position of the item within the adapter's data set whose row id we want.
      Returns:
      The id of the item at the specified position.

    • hasStableIds

      boolean hasStableIds()
      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.

    • getView

      View getView(int position, @Nullable View convertView, @NonNull ViewGroup parent)
      Get a View that displays the data at the specified position in the data set. You can create a View manually.

      This method should not return null unless the item count is zero.

      Parameters:
      position - The position of the item within the adapter's data set 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. Heterogeneous lists can specify their number of view types, so that this View is always of the right type (see getViewTypeCount() and getItemViewType(int)).
      parent - The parent that this view will eventually be attached to
      Returns:
      A View corresponding to the data at the specified position.

    • getItemViewType

      int getItemViewType(int position)
      Get the type of View that will be created by getView(int, icyllis.modernui.view.View, icyllis.modernui.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:
      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, icyllis.modernui.view.View, icyllis.modernui.view.ViewGroup). Note: Integers must be in the range 0 to getViewTypeCount() - 1. IGNORE_ITEM_VIEW_TYPE can also be returned.
      See Also:

    • getViewTypeCount

      int getViewTypeCount()

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

    • isEmpty

      boolean isEmpty()
      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.