FocusDelegate.java revision 7fb763509e07f98d650efc25c91bff8b1cb239ac
163d2846409d84487d4856d3b8d18cc4684352e29Steve McKay/* 263d2846409d84487d4856d3b8d18cc4684352e29Steve McKay * Copyright 2017 The Android Open Source Project 363d2846409d84487d4856d3b8d18cc4684352e29Steve McKay * 463d2846409d84487d4856d3b8d18cc4684352e29Steve McKay * Licensed under the Apache License, Version 2.0 (the "License"); 563d2846409d84487d4856d3b8d18cc4684352e29Steve McKay * you may not use this file except in compliance with the License. 663d2846409d84487d4856d3b8d18cc4684352e29Steve McKay * You may obtain a copy of the License at 763d2846409d84487d4856d3b8d18cc4684352e29Steve McKay * 863d2846409d84487d4856d3b8d18cc4684352e29Steve McKay * http://www.apache.org/licenses/LICENSE-2.0 963d2846409d84487d4856d3b8d18cc4684352e29Steve McKay * 1063d2846409d84487d4856d3b8d18cc4684352e29Steve McKay * Unless required by applicable law or agreed to in writing, software 1163d2846409d84487d4856d3b8d18cc4684352e29Steve McKay * distributed under the License is distributed on an "AS IS" BASIS, 1263d2846409d84487d4856d3b8d18cc4684352e29Steve McKay * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 1363d2846409d84487d4856d3b8d18cc4684352e29Steve McKay * See the License for the specific language governing permissions and 1463d2846409d84487d4856d3b8d18cc4684352e29Steve McKay * limitations under the License. 1563d2846409d84487d4856d3b8d18cc4684352e29Steve McKay */ 1663d2846409d84487d4856d3b8d18cc4684352e29Steve McKay 177fb763509e07f98d650efc25c91bff8b1cb239acSteve McKaypackage androidx.widget.recyclerview.selection; 1863d2846409d84487d4856d3b8d18cc4684352e29Steve McKay 197fb763509e07f98d650efc25c91bff8b1cb239acSteve McKayimport android.support.annotation.NonNull; 2063d2846409d84487d4856d3b8d18cc4684352e29Steve McKayimport android.support.v7.widget.RecyclerView; 2163d2846409d84487d4856d3b8d18cc4684352e29Steve McKay 227fb763509e07f98d650efc25c91bff8b1cb239acSteve McKayimport androidx.widget.recyclerview.selection.ItemDetailsLookup.ItemDetails; 2363d2846409d84487d4856d3b8d18cc4684352e29Steve McKay 2463d2846409d84487d4856d3b8d18cc4684352e29Steve McKay/** 257fb763509e07f98d650efc25c91bff8b1cb239acSteve McKay * Override methods in this class to provide application specific behaviors 267fb763509e07f98d650efc25c91bff8b1cb239acSteve McKay * related to focusing item. 2763d2846409d84487d4856d3b8d18cc4684352e29Steve McKay * 287fb763509e07f98d650efc25c91bff8b1cb239acSteve McKay * @param <K> Selection key type. @see {@link StorageStrategy} for supported types. 2963d2846409d84487d4856d3b8d18cc4684352e29Steve McKay */ 307fb763509e07f98d650efc25c91bff8b1cb239acSteve McKaypublic abstract class FocusDelegate<K> { 3163d2846409d84487d4856d3b8d18cc4684352e29Steve McKay 327fb763509e07f98d650efc25c91bff8b1cb239acSteve McKay static final <K> FocusDelegate<K> dummy() { 337fb763509e07f98d650efc25c91bff8b1cb239acSteve McKay return new FocusDelegate<K>() { 3463d2846409d84487d4856d3b8d18cc4684352e29Steve McKay @Override 357fb763509e07f98d650efc25c91bff8b1cb239acSteve McKay public void focusItem(@NonNull ItemDetails<K> item) { 3663d2846409d84487d4856d3b8d18cc4684352e29Steve McKay } 3763d2846409d84487d4856d3b8d18cc4684352e29Steve McKay 3863d2846409d84487d4856d3b8d18cc4684352e29Steve McKay @Override 3963d2846409d84487d4856d3b8d18cc4684352e29Steve McKay public boolean hasFocusedItem() { 4063d2846409d84487d4856d3b8d18cc4684352e29Steve McKay return false; 4163d2846409d84487d4856d3b8d18cc4684352e29Steve McKay } 4263d2846409d84487d4856d3b8d18cc4684352e29Steve McKay 4363d2846409d84487d4856d3b8d18cc4684352e29Steve McKay @Override 4463d2846409d84487d4856d3b8d18cc4684352e29Steve McKay public int getFocusedPosition() { 4563d2846409d84487d4856d3b8d18cc4684352e29Steve McKay return RecyclerView.NO_POSITION; 4663d2846409d84487d4856d3b8d18cc4684352e29Steve McKay } 4763d2846409d84487d4856d3b8d18cc4684352e29Steve McKay 4863d2846409d84487d4856d3b8d18cc4684352e29Steve McKay @Override 4963d2846409d84487d4856d3b8d18cc4684352e29Steve McKay public void clearFocus() { 5063d2846409d84487d4856d3b8d18cc4684352e29Steve McKay } 5163d2846409d84487d4856d3b8d18cc4684352e29Steve McKay }; 5263d2846409d84487d4856d3b8d18cc4684352e29Steve McKay } 5363d2846409d84487d4856d3b8d18cc4684352e29Steve McKay 5463d2846409d84487d4856d3b8d18cc4684352e29Steve McKay /** 5563d2846409d84487d4856d3b8d18cc4684352e29Steve McKay * If environment supports focus, focus {@code item}. 5663d2846409d84487d4856d3b8d18cc4684352e29Steve McKay */ 577fb763509e07f98d650efc25c91bff8b1cb239acSteve McKay public abstract void focusItem(@NonNull ItemDetails<K> item); 5863d2846409d84487d4856d3b8d18cc4684352e29Steve McKay 5963d2846409d84487d4856d3b8d18cc4684352e29Steve McKay /** 6063d2846409d84487d4856d3b8d18cc4684352e29Steve McKay * @return true if there is a focused item. 6163d2846409d84487d4856d3b8d18cc4684352e29Steve McKay */ 6263d2846409d84487d4856d3b8d18cc4684352e29Steve McKay public abstract boolean hasFocusedItem(); 6363d2846409d84487d4856d3b8d18cc4684352e29Steve McKay 6463d2846409d84487d4856d3b8d18cc4684352e29Steve McKay /** 6563d2846409d84487d4856d3b8d18cc4684352e29Steve McKay * @return the position of the currently focused item, if any. 6663d2846409d84487d4856d3b8d18cc4684352e29Steve McKay */ 6763d2846409d84487d4856d3b8d18cc4684352e29Steve McKay public abstract int getFocusedPosition(); 6863d2846409d84487d4856d3b8d18cc4684352e29Steve McKay 6963d2846409d84487d4856d3b8d18cc4684352e29Steve McKay /** 7063d2846409d84487d4856d3b8d18cc4684352e29Steve McKay * If the environment supports focus and something is focused, unfocus it. 7163d2846409d84487d4856d3b8d18cc4684352e29Steve McKay */ 7263d2846409d84487d4856d3b8d18cc4684352e29Steve McKay public abstract void clearFocus(); 7363d2846409d84487d4856d3b8d18cc4684352e29Steve McKay} 74