1/*
2 * Copyright 2017 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 com.example.android.supportv7.widget.selection.simple;
18
19import static androidx.core.util.Preconditions.checkArgument;
20
21import android.content.Context;
22import android.util.Log;
23import android.view.LayoutInflater;
24import android.view.View;
25import android.view.ViewGroup;
26import android.widget.LinearLayout;
27
28import androidx.recyclerview.selection.ItemKeyProvider;
29import androidx.recyclerview.selection.SelectionTracker;
30import androidx.recyclerview.widget.RecyclerView;
31
32import com.example.android.supportv7.Cheeses;
33import com.example.android.supportv7.R;
34
35final class SimpleSelectionDemoAdapter extends RecyclerView.Adapter<DemoHolder> {
36
37    private static final String TAG = "SelectionDemos";
38    private final Context mContext;
39    private final ItemKeyProvider<Long> mKeyProvider;
40
41    // This should be replaced at "bind" time with a real test that
42    // asks SelectionTracker.
43    private SelectionTest mSelTest;
44
45    SimpleSelectionDemoAdapter(Context context, ItemKeyProvider<Long> keyProvider) {
46        mContext = context;
47        mKeyProvider = keyProvider;
48        mSelTest = new SelectionTest() {
49            @Override
50            public boolean isSelected(Long id) {
51                throw new IllegalStateException(
52                        "Adapter must be initialized with SelectionTracker.");
53            }
54        };
55    }
56
57    // Glue together SelectionTracker and the adapter.
58    public void bindSelectionHelper(final SelectionTracker<Long> selectionTracker) {
59        checkArgument(selectionTracker != null);
60        mSelTest = new SelectionTest() {
61            @Override
62            public boolean isSelected(Long id) {
63                return selectionTracker.isSelected(id);
64            }
65        };
66    }
67
68    void loadData() {
69        onDataReady();
70    }
71
72    private void onDataReady() {
73        notifyDataSetChanged();
74    }
75
76    @Override
77    public int getItemCount() {
78        return Cheeses.sCheeseStrings.length;
79    }
80
81    @Override
82    public long getItemId(int position) {
83        return position;
84    }
85
86    @Override
87    public void onBindViewHolder(DemoHolder holder, int position) {
88        Long key = getItemId(position);
89        Log.v(TAG, "Just before rendering item position=" + position + ", key=" + key);
90        holder.update(Cheeses.sCheeseStrings[position], mSelTest.isSelected(key));
91    }
92
93    @Override
94    public DemoHolder onCreateViewHolder(ViewGroup parent, int viewType) {
95        LinearLayout layout = inflateLayout(mContext, parent, R.layout.selection_demo_list_item);
96        return new DemoHolder(layout);
97    }
98
99    @SuppressWarnings("TypeParameterUnusedInFormals")  // Convenience to avoid clumsy cast.
100    private static <V extends View> V inflateLayout(
101            Context context, ViewGroup parent, int layout) {
102
103        return (V) LayoutInflater.from(context).inflate(layout, parent, false);
104    }
105
106    private interface SelectionTest {
107        boolean isSelected(Long id);
108    }
109}
110