ViewConfigurationCompat.java revision f185f104c4786740765e549d535f9ba1052f96cc 
1/*
2 * Copyright (C) 2011 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.view.ViewConfiguration;
20
21/**
22 * Helper for accessing features in {@link ViewConfiguration}
23 * introduced after API level 4 in a backwards compatible fashion.
24 */
25public final class ViewConfigurationCompat {
26    /**
27     * Interface for the full API.
28     */
29    interface ViewConfigurationVersionImpl {
30        boolean hasPermanentMenuKey(ViewConfiguration config);
31    }
32
33    /**
34     * Interface implementation that doesn't use anything about v4 APIs.
35     */
36    static class BaseViewConfigurationVersionImpl implements ViewConfigurationVersionImpl {
37        @Override
38        public boolean hasPermanentMenuKey(ViewConfiguration config) {
39            // Pre-HC devices will always have a menu button
40            return true;
41        }
42    }
43
44    /**
45     * Interface implementation for devices with at least v11 APIs.
46     */
47    static class HoneycombViewConfigurationVersionImpl extends BaseViewConfigurationVersionImpl {
48        @Override
49        public boolean hasPermanentMenuKey(ViewConfiguration config) {
50            // There is no way to check on Honeycomb so we assume false
51            return false;
52        }
53    }
54
55    /**
56     * Interface implementation for devices with at least v14 APIs.
57     */
58    static class IcsViewConfigurationVersionImpl extends HoneycombViewConfigurationVersionImpl {
59        @Override
60        public boolean hasPermanentMenuKey(ViewConfiguration config) {
61            return ViewConfigurationCompatICS.hasPermanentMenuKey(config);
62        }
63    }
64
65    /**
66     * Select the correct implementation to use for the current platform.
67     */
68    static final ViewConfigurationVersionImpl IMPL;
69    static {
70        if (android.os.Build.VERSION.SDK_INT >= 14) {
71            IMPL = new IcsViewConfigurationVersionImpl();
72        } else if (android.os.Build.VERSION.SDK_INT >= 11) {
73            IMPL = new HoneycombViewConfigurationVersionImpl();
74        } else {
75            IMPL = new BaseViewConfigurationVersionImpl();
76        }
77    }
78
79    // -------------------------------------------------------------------
80
81    /**
82     * Call {@link ViewConfiguration#getScaledPagingTouchSlop()}.
83     *
84     * @deprecated Call {@link ViewConfiguration#getScaledPagingTouchSlop()} directly.
85     */
86    @Deprecated
87    public static int getScaledPagingTouchSlop(ViewConfiguration config) {
88        return config.getScaledPagingTouchSlop();
89    }
90
91    /**
92     * Report if the device has a permanent menu key available to the user, in a backwards
93     * compatible way.
94     */
95    public static boolean hasPermanentMenuKey(ViewConfiguration config) {
96        return IMPL.hasPermanentMenuKey(config);
97    }
98
99    private ViewConfigurationCompat() {}
100}
101