1 /*
2  * Copyright (C) 2015 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 
17 package android.support.v7.widget.helper;
18 
19 import android.graphics.Canvas;
20 import android.support.v7.widget.RecyclerView;
21 import android.view.View;
22 
23 /**
24  * Utility class for {@link ItemTouchHelper} which handles item transformations for different
25  * API versions.
26  * <p/>
27  * This class has methods that map to {@link ItemTouchHelper.Callback}'s drawing methods. Default
28  * implementations in {@link ItemTouchHelper.Callback} call these methods with
29  * {@link RecyclerView.ViewHolder#itemView} and {@link ItemTouchUIUtil} makes necessary changes
30  * on the View depending on the API level. You can access the instance of {@link ItemTouchUIUtil}
31  * via {@link ItemTouchHelper.Callback#getDefaultUIUtil()} and call its methods with the children
32  * of ViewHolder that you want to apply default effects.
33  *
34  * @see ItemTouchHelper.Callback#getDefaultUIUtil()
35  */
36 public interface ItemTouchUIUtil {
37 
38     /**
39      * The default implementation for {@link ItemTouchHelper.Callback#onChildDraw(Canvas,
40      * RecyclerView, RecyclerView.ViewHolder, float, float, int, boolean)}
41      */
onDraw(Canvas c, RecyclerView recyclerView, View view, float dX, float dY, int actionState, boolean isCurrentlyActive)42     void onDraw(Canvas c, RecyclerView recyclerView, View view,
43             float dX, float dY, int actionState, boolean isCurrentlyActive);
44 
45     /**
46      * The default implementation for {@link ItemTouchHelper.Callback#onChildDrawOver(Canvas,
47      * RecyclerView, RecyclerView.ViewHolder, float, float, int, boolean)}
48      */
onDrawOver(Canvas c, RecyclerView recyclerView, View view, float dX, float dY, int actionState, boolean isCurrentlyActive)49     void onDrawOver(Canvas c, RecyclerView recyclerView, View view,
50             float dX, float dY, int actionState, boolean isCurrentlyActive);
51 
52     /**
53      * The default implementation for {@link ItemTouchHelper.Callback#clearView(RecyclerView,
54      * RecyclerView.ViewHolder)}
55      */
clearView(View view)56     void clearView(View view);
57 
58     /**
59      * The default implementation for {@link ItemTouchHelper.Callback#onSelectedChanged(
60      * RecyclerView.ViewHolder, int)}
61      */
onSelected(View view)62     void onSelected(View view);
63 }
64 
65