| /* |
| * Copyright (C) 2007 The Android Open Source Project |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| package android.widget; |
| |
| import android.database.DataSetObservable; |
| import android.database.DataSetObserver; |
| import android.view.View; |
| import android.view.ViewGroup; |
| |
| /** |
| * Common base class of common implementation for an {@link Adapter} that can be |
| * used in both {@link ListView} (by implementing the specialized |
| * {@link ListAdapter} interface) and {@link Spinner} (by implementing the |
| * specialized {@link SpinnerAdapter} interface). |
| */ |
| public abstract class BaseAdapter implements ListAdapter, SpinnerAdapter { |
| private final DataSetObservable mDataSetObservable = new DataSetObservable(); |
| |
| public boolean hasStableIds() { |
| return false; |
| } |
| |
| public void registerDataSetObserver(DataSetObserver observer) { |
| mDataSetObservable.registerObserver(observer); |
| } |
| |
| public void unregisterDataSetObserver(DataSetObserver observer) { |
| mDataSetObservable.unregisterObserver(observer); |
| } |
| |
| /** |
| * Notifies the attached observers that the underlying data has been changed |
| * and any View reflecting the data set should refresh itself. |
| */ |
| public void notifyDataSetChanged() { |
| mDataSetObservable.notifyChanged(); |
| } |
| |
| /** |
| * Notifies the attached observers that the underlying data is no longer valid |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 Once invoked this adapter is no longer valid and should |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 notifyDataSetInvalidated() { |
| mDataSetObservable.notifyInvalidated(); |
| } |
| |
| public boolean areAllItemsEnabled() { |
| return true; |
| } |
| |
| public boolean isEnabled(int position) { |
| return true; |
| } |
| |
| public View getDropDownView(int position, View convertView, ViewGroup parent) { |
| return getView(position, convertView, parent); |
| } |
| |
| public int getItemViewType(int position) { |
| return 0; |
| } |
| |
| public int getViewTypeCount() { |
| return 1; |
| } |
| |
| public boolean isEmpty() { |
| return getCount() == 0; |
| } |
| } |