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 
17 package com.android.documentsui;
18 
19 import android.os.Bundle;
20 
21 import androidx.recyclerview.selection.MutableSelection;
22 import androidx.recyclerview.selection.Selection;
23 import androidx.recyclerview.selection.SelectionTracker;
24 import androidx.recyclerview.widget.RecyclerView.AdapterDataObserver;
25 
26 import java.util.Set;
27 
28 /**
29  * A dummy SelectionTracker used by DocsSelectionHelper before a real SelectionTracker has been
30  * initialized by DirectoryFragment.
31  */
32 public class DummySelectionTracker<K> extends SelectionTracker<K> {
33 
34     @Override
addObserver(SelectionObserver observer)35     public void addObserver(SelectionObserver observer) {
36     }
37 
38     @Override
hasSelection()39     public boolean hasSelection() {
40         return false;
41     }
42 
43     @Override
getSelection()44     public Selection<K> getSelection() {
45         return new MutableSelection<K>();
46     }
47 
48     @Override
copySelection(MutableSelection<K> dest)49     public void copySelection(MutableSelection<K> dest) {
50     }
51 
52     @Override
isSelected(K key)53     public boolean isSelected(K key) {
54         return false;
55     }
56 
57     @Override
restoreSelection(Selection<K> selection)58     public void restoreSelection(Selection<K> selection) {
59     }
60 
61     @Override
clearSelection()62     public boolean clearSelection() {
63         return false;
64     }
65 
66     @Override
setItemsSelected(Iterable<K> keys, boolean selected)67     public boolean setItemsSelected(Iterable<K> keys, boolean selected) {
68         return false;
69     }
70 
71     @Override
select(K key)72     public boolean select(K key) {
73         return false;
74     }
75 
76     @Override
deselect(K key)77     public boolean deselect(K key) {
78         return false;
79     }
80 
81     @Override
getAdapterDataObserver()82     protected AdapterDataObserver getAdapterDataObserver() {
83         return null;
84     }
85 
86     @Override
startRange(int position)87     public void startRange(int position) {
88     }
89 
90     @Override
extendRange(int position)91     public void extendRange(int position) {
92     }
93 
94     @Override
endRange()95     public void endRange() {
96     }
97 
98     @Override
isRangeActive()99     public boolean isRangeActive() {
100         return false;
101     }
102 
103     @Override
anchorRange(int position)104     public void anchorRange(int position) {
105     }
106 
107     @Override
extendProvisionalRange(int position)108     public void extendProvisionalRange(int position) {
109     }
110 
111     @Override
setProvisionalSelection(Set<K> newSelection)112     public void setProvisionalSelection(Set<K> newSelection) {
113     }
114 
115     @Override
clearProvisionalSelection()116     public void clearProvisionalSelection() {
117     }
118 
119     @Override
mergeProvisionalSelection()120     public void mergeProvisionalSelection() {
121     }
122 
123     @Override
onSaveInstanceState(Bundle state)124     public void onSaveInstanceState(Bundle state) {
125     }
126 
127     @Override
onRestoreInstanceState(Bundle state)128     public void onRestoreInstanceState(Bundle state) {
129     }
130 
131 }
132