DeviceUtils.java revision f2477e01787aa58f445919b809d89e252beef54f 
1// Copyright (c) 2012 The Chromium Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style license that can be
3// found in the LICENSE file.
4
5package org.chromium.content.browser;
6
7import android.content.Context;
8import android.content.pm.PackageManager;
9
10import org.chromium.base.CommandLine;
11import org.chromium.content.common.ContentSwitches;
12
13/**
14 * A utility class that has helper methods for device configuration.
15 */
16public class DeviceUtils {
17
18    /**
19     * The minimum width that would classify the device as a tablet.
20     */
21    private static final int MINIMUM_TABLET_WIDTH_DP = 600;
22
23    private static Boolean sIsTv = null;
24    private static Boolean sIsTablet = null;
25
26    /**
27     * @param context Android's context
28     * @return        Whether the app is should treat the device as a tablet for layout.
29     */
30    public static boolean isTablet(Context context) {
31        if (sIsTablet == null) {
32            if (isTv(context)) {
33                sIsTablet = true;
34                return sIsTablet;
35            }
36            int minimumScreenWidthDp = context.getResources().getConfiguration().
37                    smallestScreenWidthDp;
38            sIsTablet = minimumScreenWidthDp >= MINIMUM_TABLET_WIDTH_DP;
39        }
40        return sIsTablet;
41    }
42
43    /**
44     * Checks if the device should be treated as TV. Note that this should be
45     * invoked before {@link #isTablet(Context)} to get the correct result
46     * since they are not orthogonal.
47     *
48     * @param context Android context
49     * @return {@code true} if the device should be treated as TV.
50     */
51    public static boolean isTv(Context context) {
52        if (sIsTv == null) {
53            PackageManager manager = context.getPackageManager();
54            if (manager != null) {
55                sIsTv = manager.hasSystemFeature(PackageManager.FEATURE_TELEVISION);
56                return sIsTv;
57            }
58            sIsTv = false;
59        }
60        return sIsTv;
61    }
62
63    /**
64     * Appends the switch specifying which user agent should be used for this device.
65     * @param context The context for the caller activity.
66     */
67    public static void addDeviceSpecificUserAgentSwitch(Context context) {
68        if (isTablet(context)) {
69            CommandLine.getInstance().appendSwitch(ContentSwitches.TABLET_UI);
70        } else {
71            CommandLine.getInstance().appendSwitch(ContentSwitches.USE_MOBILE_UA);
72        }
73    }
74}
75