OnChildViewHolderSelectedListener.java
/*
* Copyright 2021 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.leanback.widget;
import android.annotation.SuppressLint;
import androidx.annotation.NonNull;
import androidx.annotation.Nullable;
import androidx.leanback.widget.ItemAlignmentFacet.ItemAlignmentDef;
import androidx.recyclerview.widget.RecyclerView;
/**
* Interface for receiving notification when a child of this ViewGroup has been selected.
* There are two methods:
* <ul>
* <li>
* {link {@link #onChildViewHolderSelected(RecyclerView, RecyclerView.ViewHolder, int, int)}}
* is called when the view holder is about to be selected. The listener could change size
* of the view holder in this callback.
* </li>
* <li>
* {link {@link #onChildViewHolderSelectedAndPositioned(RecyclerView, RecyclerView.ViewHolder,
* int, int)} is called when view holder has been selected and laid out in RecyclerView.
* </li>
* </ul>
*/
@SuppressLint("ListenerInterface")
public abstract class OnChildViewHolderSelectedListener {
/**
* Callback method to be invoked when a child of this ViewGroup has been selected. Listener
* might change the size of the child and the position of the child is not finalized. To get
* the final layout position of child, override {@link #onChildViewHolderSelectedAndPositioned(
*RecyclerView, RecyclerView.ViewHolder, int, int)}.
*
* @param parent The RecyclerView where the selection happened.
* @param child The ViewHolder within the RecyclerView that is selected, or null if no
* view is selected.
* @param position The position of the view in the adapter, or NO_POSITION
* if no view is selected.
* @param subposition The index of which {@link ItemAlignmentDef} being used,
* 0 if there is no ItemAlignmentDef defined for the item.
*/
public void onChildViewHolderSelected(@NonNull RecyclerView parent,
@Nullable RecyclerView.ViewHolder child,
int position, int subposition) {
}
/**
* Callback method to be invoked when a child of this ViewGroup has been selected and
* positioned.
*
* @param parent The RecyclerView where the selection happened.
* @param child The ViewHolder within the RecyclerView that is selected, or null if no
* view is selected.
* @param position The position of the view in the adapter, or NO_POSITION
* if no view is selected.
* @param subposition The index of which {@link ItemAlignmentDef} being used,
* 0 if there is no ItemAlignmentDef defined for the item.
*/
public void onChildViewHolderSelectedAndPositioned(@NonNull RecyclerView parent,
@Nullable RecyclerView.ViewHolder child, int position, int subposition) {
}
}