1/*
2 * Copyright 2018 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17package androidx.recyclerview.widget;
18
19import android.graphics.Canvas;
20import android.view.View;
21
22/**
23 * Utility class for {@link ItemTouchHelper} which handles item transformations for different
24 * API versions.
25 * <p/>
26 * This class has methods that map to {@link ItemTouchHelper.Callback}'s drawing methods. Default
27 * implementations in {@link ItemTouchHelper.Callback} call these methods with
28 * {@link RecyclerView.ViewHolder#itemView} and {@link ItemTouchUIUtil} makes necessary changes
29 * on the View depending on the API level. You can access the instance of {@link ItemTouchUIUtil}
30 * via {@link ItemTouchHelper.Callback#getDefaultUIUtil()} and call its methods with the children
31 * of ViewHolder that you want to apply default effects.
32 *
33 * @see ItemTouchHelper.Callback#getDefaultUIUtil()
34 */
35public interface ItemTouchUIUtil {
36
37    /**
38     * The default implementation for {@link ItemTouchHelper.Callback#onChildDraw(Canvas,
39     * RecyclerView, RecyclerView.ViewHolder, float, float, int, boolean)}
40     */
41    void onDraw(Canvas c, RecyclerView recyclerView, View view,
42            float dX, float dY, int actionState, boolean isCurrentlyActive);
43
44    /**
45     * The default implementation for {@link ItemTouchHelper.Callback#onChildDrawOver(Canvas,
46     * RecyclerView, RecyclerView.ViewHolder, float, float, int, boolean)}
47     */
48    void onDrawOver(Canvas c, RecyclerView recyclerView, View view,
49            float dX, float dY, int actionState, boolean isCurrentlyActive);
50
51    /**
52     * The default implementation for {@link ItemTouchHelper.Callback#clearView(RecyclerView,
53     * RecyclerView.ViewHolder)}
54     */
55    void clearView(View view);
56
57    /**
58     * The default implementation for {@link ItemTouchHelper.Callback#onSelectedChanged(
59     * RecyclerView.ViewHolder, int)}
60     */
61    void onSelected(View view);
62}
63
64