| /* |
| * Copyright 2017 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 androidx.recyclerview.selection; |
| |
| import static android.support.annotation.RestrictTo.Scope.LIBRARY_GROUP; |
| |
| import android.support.annotation.RestrictTo; |
| import android.support.v7.widget.RecyclerView; |
| |
| import androidx.recyclerview.selection.ItemDetailsLookup.ItemDetails; |
| |
| /** |
| * Override methods in this class to connect specialized behaviors of the selection |
| * code to the application environment. |
| * |
| * @param <K> Selection key type. Usually String or Long. |
| * |
| * @hide |
| */ |
| @RestrictTo(LIBRARY_GROUP) |
| public abstract class FocusCallbacks<K> { |
| |
| static final <K> FocusCallbacks<K> dummy() { |
| return new FocusCallbacks<K>() { |
| @Override |
| public void focusItem(ItemDetails<K> item) { |
| } |
| |
| @Override |
| public boolean hasFocusedItem() { |
| return false; |
| } |
| |
| @Override |
| public int getFocusedPosition() { |
| return RecyclerView.NO_POSITION; |
| } |
| |
| @Override |
| public void clearFocus() { |
| } |
| }; |
| } |
| |
| /** |
| * If environment supports focus, focus {@code item}. |
| */ |
| public abstract void focusItem(ItemDetails<K> item); |
| |
| /** |
| * @return true if there is a focused item. |
| */ |
| public abstract boolean hasFocusedItem(); |
| |
| /** |
| * @return the position of the currently focused item, if any. |
| */ |
| public abstract int getFocusedPosition(); |
| |
| /** |
| * If the environment supports focus and something is focused, unfocus it. |
| */ |
| public abstract void clearFocus(); |
| } |