1 /*
2  * Copyright (C) 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 
17 package com.android.dialer.speeddial.draghelper;
18 
19 import android.content.Context;
20 import android.graphics.Canvas;
21 import android.support.annotation.NonNull;
22 import android.support.annotation.Nullable;
23 import android.support.v7.widget.RecyclerView;
24 import android.support.v7.widget.RecyclerView.ViewHolder;
25 import android.support.v7.widget.helper.ItemTouchHelper;
26 import com.android.dialer.logging.DialerImpression;
27 import com.android.dialer.logging.Logger;
28 
29 /** {@link ItemTouchHelper} for Speed Dial favorite contacts. */
30 public class SpeedDialItemTouchHelperCallback extends ItemTouchHelper.Callback {
31 
32   private final ItemTouchHelperAdapter adapter;
33   private final Context context;
34 
35   // When dragged item is in removeView, onMove() and onChildDraw() are called in turn. This
36   // behavior changes when dragged item entering/leaving removeView. The boolean field
37   // movedOverRemoveView is for onMove() and onChildDraw() to flip.
38   private boolean movedOverRemoveView;
39   private boolean inRemoveView;
40 
SpeedDialItemTouchHelperCallback(Context context, ItemTouchHelperAdapter adapter)41   public SpeedDialItemTouchHelperCallback(Context context, ItemTouchHelperAdapter adapter) {
42     this.context = context;
43     this.adapter = adapter;
44   }
45 
46   @Override
isLongPressDragEnabled()47   public boolean isLongPressDragEnabled() {
48     // We'll manually call ItemTouchHelper#startDrag
49     return false;
50   }
51 
52   @Override
isItemViewSwipeEnabled()53   public boolean isItemViewSwipeEnabled() {
54     // We don't want to enable swiping
55     return false;
56   }
57 
58   @Override
canDropOver( @onNull RecyclerView recyclerView, @NonNull ViewHolder current, @NonNull ViewHolder target)59   public boolean canDropOver(
60       @NonNull RecyclerView recyclerView, @NonNull ViewHolder current, @NonNull ViewHolder target) {
61     return adapter.canDropOver(target);
62   }
63 
64   @Override
getMovementFlags(@onNull RecyclerView recyclerView, @NonNull ViewHolder viewHolder)65   public int getMovementFlags(@NonNull RecyclerView recyclerView, @NonNull ViewHolder viewHolder) {
66     if (!adapter.canDropOver(viewHolder)) {
67       return makeMovementFlags(0, 0);
68     }
69 
70     int dragFlags =
71         ItemTouchHelper.UP | ItemTouchHelper.DOWN | ItemTouchHelper.START | ItemTouchHelper.END;
72     return makeMovementFlags(dragFlags, /* swipeFlags */ 0);
73   }
74 
75   @Override
onMove( @onNull RecyclerView recyclerView, @NonNull ViewHolder viewHolder, @NonNull ViewHolder target)76   public boolean onMove(
77       @NonNull RecyclerView recyclerView,
78       @NonNull ViewHolder viewHolder,
79       @NonNull ViewHolder target) {
80     if (target.getItemViewType() == 0) { // 0 for RowType.REMOVE_VIEW
81       movedOverRemoveView = true;
82       if (!inRemoveView) {
83         // onMove() first called
84         adapter.enterRemoveView();
85         inRemoveView = true;
86       }
87       return false;
88     } else if (inRemoveView) {
89       // Move out of removeView fast
90       inRemoveView = false;
91       movedOverRemoveView = false;
92       adapter.leaveRemoveView();
93     }
94     adapter.onItemMove(viewHolder.getAdapterPosition(), target.getAdapterPosition());
95     return true;
96   }
97 
98   @Override
onMoved( @onNull RecyclerView recyclerView, @NonNull ViewHolder viewHolder, int fromPos, @NonNull ViewHolder viewHolder1, int toPos, int x, int y)99   public void onMoved(
100       @NonNull RecyclerView recyclerView,
101       @NonNull ViewHolder viewHolder,
102       int fromPos,
103       @NonNull ViewHolder viewHolder1,
104       int toPos,
105       int x,
106       int y) {
107     Logger.get(context)
108         .logImpression(DialerImpression.Type.FAVORITE_MOVE_FAVORITE_BY_DRAG_AND_DROP);
109     super.onMoved(recyclerView, viewHolder, fromPos, viewHolder1, toPos, x, y);
110   }
111 
112   @Override
onChildDraw( @onNull Canvas canvas, @NonNull RecyclerView recyclerView, @NonNull ViewHolder viewHolder, float dx, float dy, int i, boolean isCurrentlyActive)113   public void onChildDraw(
114       @NonNull Canvas canvas,
115       @NonNull RecyclerView recyclerView,
116       @NonNull ViewHolder viewHolder,
117       float dx,
118       float dy,
119       int i,
120       boolean isCurrentlyActive) {
121     if (inRemoveView) {
122       if (!isCurrentlyActive) {
123         // View animating back to its original state, which means drop in this case
124         inRemoveView = false;
125         adapter.dropOnRemoveView(viewHolder);
126       }
127       if (!movedOverRemoveView) {
128         // when the view is over a droppable target, onMove() will be called before onChildDraw()
129         // thus if onMove() is not called, it is not over a droppable target.
130         inRemoveView = false;
131         adapter.leaveRemoveView();
132       }
133     }
134     movedOverRemoveView = false;
135     super.onChildDraw(canvas, recyclerView, viewHolder, dx, dy, i, isCurrentlyActive);
136   }
137 
138   @Override
onSelectedChanged(@ullable ViewHolder viewHolder, int actionState)139   public void onSelectedChanged(@Nullable ViewHolder viewHolder, int actionState) {
140     super.onSelectedChanged(viewHolder, actionState);
141     adapter.onSelectedChanged(viewHolder, actionState);
142   }
143 
144   @Override
onSwiped(@onNull ViewHolder viewHolder, int direction)145   public void onSwiped(@NonNull ViewHolder viewHolder, int direction) {
146     // No-op since we don't support swiping
147   }
148 
149   /** RecyclerView adapters interested in drag and drop should implement this interface. */
150   public interface ItemTouchHelperAdapter {
151 
onItemMove(int fromPosition, int toPosition)152     void onItemMove(int fromPosition, int toPosition);
153 
canDropOver(ViewHolder target)154     boolean canDropOver(ViewHolder target);
155 
onSelectedChanged(@ullable ViewHolder viewHolder, int actionState)156     void onSelectedChanged(@Nullable ViewHolder viewHolder, int actionState);
157 
enterRemoveView()158     void enterRemoveView();
159 
leaveRemoveView()160     void leaveRemoveView();
161 
dropOnRemoveView(ViewHolder fromViewHolder)162     void dropOnRemoveView(ViewHolder fromViewHolder);
163   }
164 }
165