CompatibilityInfo.java revision 2f5e6b2d31f445a4e9faf3a7ace94f9ef6948336 
1/*
2 * Copyright (C) 2006 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.content.res;
18
19import android.content.pm.ApplicationInfo;
20import android.util.DisplayMetrics;
21import android.view.Gravity;
22
23/**
24 * CompatibilityInfo class keeps the information about compatibility mode that the application is
25 * running under.
26 *
27 *  {@hide}
28 */
29public class CompatibilityInfo {
30    /** default compatibility info object for compatible applications */
31    public static final CompatibilityInfo DEFAULT_COMPATIBILITY_INFO = new CompatibilityInfo();
32
33    /**
34     * The default width of the screen in portrait mode.
35     */
36    public static final int DEFAULT_PORTRAIT_WIDTH = 320;
37
38    /**
39     * The default height of the screen in portrait mode.
40     */
41    public static final int DEFAULT_PORTRAIT_HEIGHT = 480;
42
43    /**
44     * Application's scale.
45     */
46    public final float mApplicationScale;
47
48    /**
49     * Application's inverted scale.
50     */
51    public final float mApplicationInvertedScale;
52
53    /**
54     *
55     * A boolean flag to indicates that the application can expand over the original size.
56     */
57    public final boolean mExpandable;
58
59    /**
60     * A boolean flag to tell if the application needs scaling (when mApplicationScale != 1.0f)
61     */
62    public final boolean mScalingRequired;
63
64    public CompatibilityInfo(ApplicationInfo appInfo) {
65        // A temp workaround to fix rotation issue.
66        // mExpandable = appInfo.expandable;
67        mExpandable = true;
68        float packageDensityScale = -1.0f;
69        if (appInfo.supportsDensities != null) {
70            int minDiff = Integer.MAX_VALUE;
71            for (int density : appInfo.supportsDensities) {
72                int tmpDiff = Math.abs(DisplayMetrics.DEVICE_DENSITY - density);
73                if (tmpDiff == 0) {
74                    packageDensityScale = 1.0f;
75                    break;
76                }
77                // prefer higher density (appScale>1.0), unless that's only option.
78                if (tmpDiff < minDiff && packageDensityScale < 1.0f) {
79                    packageDensityScale = DisplayMetrics.DEVICE_DENSITY / (float) density;
80                    minDiff = tmpDiff;
81                }
82            }
83        }
84        if (packageDensityScale > 0.0f) {
85            mApplicationScale = packageDensityScale;
86        } else {
87            mApplicationScale = DisplayMetrics.DEVICE_DENSITY / (float) DisplayMetrics.DEFAULT_DENSITY;
88        }
89        mApplicationInvertedScale = 1.0f / mApplicationScale;
90        mScalingRequired = mApplicationScale != 1.0f;
91    }
92
93    private CompatibilityInfo() {
94        mApplicationScale = mApplicationInvertedScale = 1.0f;
95        mExpandable = true;
96        mScalingRequired = false;
97    }
98
99    @Override
100    public String toString() {
101        return "CompatibilityInfo{scale=" + mApplicationScale +
102                ", expandable=" + mExpandable + "}";
103    }
104}
105