1/*
2 * Copyright (C) 2014 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 android.support.v4.view;
18
19import android.os.Build;
20import android.view.LayoutInflater;
21
22/**
23 * Helper for accessing features in {@link android.view.LayoutInflater}
24 * introduced after API level 4 in a backwards compatible fashion.
25 */
26public final class LayoutInflaterCompat {
27
28    interface LayoutInflaterCompatImpl {
29        public void setFactory(LayoutInflater layoutInflater, LayoutInflaterFactory factory);
30        public LayoutInflaterFactory getFactory(LayoutInflater layoutInflater);
31    }
32
33    static class LayoutInflaterCompatImplBase implements LayoutInflaterCompatImpl {
34        @Override
35        public void setFactory(LayoutInflater layoutInflater, LayoutInflaterFactory factory) {
36            LayoutInflaterCompatBase.setFactory(layoutInflater, factory);
37        }
38
39        @Override
40        public LayoutInflaterFactory getFactory(LayoutInflater layoutInflater) {
41            return LayoutInflaterCompatBase.getFactory(layoutInflater);
42        }
43    }
44
45    static class LayoutInflaterCompatImplV11 extends LayoutInflaterCompatImplBase {
46        @Override
47        public void setFactory(LayoutInflater layoutInflater, LayoutInflaterFactory factory) {
48            LayoutInflaterCompatHC.setFactory(layoutInflater, factory);
49        }
50    }
51
52    static class LayoutInflaterCompatImplV21 extends LayoutInflaterCompatImplV11 {
53        @Override
54        public void setFactory(LayoutInflater layoutInflater, LayoutInflaterFactory factory) {
55            LayoutInflaterCompatLollipop.setFactory(layoutInflater, factory);
56        }
57    }
58
59    static final LayoutInflaterCompatImpl IMPL;
60    static {
61        final int version = Build.VERSION.SDK_INT;
62        if (version >= 21) {
63            IMPL = new LayoutInflaterCompatImplV21();
64        } else if (version >= 11) {
65            IMPL = new LayoutInflaterCompatImplV11();
66        } else {
67            IMPL = new LayoutInflaterCompatImplBase();
68        }
69    }
70
71    /*
72     * Hide the constructor.
73     */
74    private LayoutInflaterCompat() {
75    }
76
77    /**
78     * Attach a custom Factory interface for creating views while using
79     * this LayoutInflater. This must not be null, and can only be set once;
80     * after setting, you can not change the factory.
81     *
82     * @see LayoutInflater#setFactory(android.view.LayoutInflater.Factory)
83     */
84    public static void setFactory(LayoutInflater inflater, LayoutInflaterFactory factory) {
85        IMPL.setFactory(inflater, factory);
86    }
87
88    /**
89     * Return the current {@link LayoutInflaterFactory} (or null). This is
90     * called on each element name. If the factory returns a View, add that
91     * to the hierarchy. If it returns null, proceed to call onCreateView(name).
92     *
93     * @return The {@link LayoutInflaterFactory} associated with the
94     * {@link LayoutInflater}. Will be {@code null} if the inflater does not
95     * have a {@link LayoutInflaterFactory} but a raw {@link LayoutInflater.Factory}.
96     * @see LayoutInflater#getFactory()
97     */
98    public static LayoutInflaterFactory getFactory(LayoutInflater inflater) {
99        return IMPL.getFactory(inflater);
100    }
101
102}
103