DisplayAdjustmentUtils.java revision 6437518061fc8718590e0272ed17ea64710d2299 
1/*
2 * Copyright (C) 2013 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.android.server.accessibility;
18
19import android.content.ContentResolver;
20import android.content.Context;
21import android.opengl.Matrix;
22import android.os.IBinder;
23import android.os.Parcel;
24import android.os.RemoteException;
25import android.os.ServiceManager;
26import android.provider.Settings;
27import android.util.Slog;
28import android.view.accessibility.AccessibilityManager;
29
30/**
31 * Utility methods for performing accessibility display adjustments.
32 */
33class DisplayAdjustmentUtils {
34    private static final String LOG_TAG = DisplayAdjustmentUtils.class.getSimpleName();
35
36    /** Matrix and offset used for converting color to gray-scale. */
37    private static final float[] GRAYSCALE_MATRIX = new float[] {
38        .2126f, .2126f, .2126f, 0,
39        .7152f, .7152f, .7152f, 0,
40        .0722f, .0722f, .0722f, 0,
41             0,      0,      0, 1
42    };
43
44    /**
45     * Matrix and offset used for luminance inversion. Represents a transform
46     * from RGB to YIQ color space, rotation around the Y axis by 180 degrees,
47     * transform back to RGB color space, and subtraction from 1. The last row
48     * represents a non-multiplied addition, see surfaceflinger's ProgramCache
49     * for full implementation details.
50     */
51    private static final float[] INVERSION_MATRIX_VALUE_ONLY = new float[] {
52        0.402f, -0.598f, -0.599f, 0,
53       -1.174f, -0.174f, -1.175f, 0,
54       -0.228f, -0.228f,  0.772f, 0,
55             1,       1,       1, 1
56    };
57
58    /** Default inversion mode for display color correction. */
59    private static final int DEFAULT_DISPLAY_DALTONIZER =
60            AccessibilityManager.DALTONIZER_CORRECT_DEUTERANOMALY;
61
62    /**
63     * Returns whether the specified user with has any display color
64     * adjustments.
65     */
66    public static boolean hasAdjustments(Context context, int userId) {
67        final ContentResolver cr = context.getContentResolver();
68
69        if (Settings.Secure.getIntForUser(cr,
70                Settings.Secure.ACCESSIBILITY_DISPLAY_INVERSION_ENABLED, 0, userId) != 0) {
71            return true;
72        }
73
74        if (Settings.Secure.getIntForUser(cr,
75                Settings.Secure.ACCESSIBILITY_DISPLAY_DALTONIZER_ENABLED, 0, userId) != 0) {
76            return true;
77        }
78
79        return false;
80    }
81
82    /**
83     * Applies the specified user's display color adjustments.
84     */
85    public static void applyAdjustments(Context context, int userId) {
86        final ContentResolver cr = context.getContentResolver();
87        float[] colorMatrix = null;
88
89        if (Settings.Secure.getIntForUser(cr,
90                Settings.Secure.ACCESSIBILITY_DISPLAY_INVERSION_ENABLED, 0, userId) != 0) {
91            colorMatrix = multiply(colorMatrix, INVERSION_MATRIX_VALUE_ONLY);
92        }
93
94        if (Settings.Secure.getIntForUser(cr,
95                Settings.Secure.ACCESSIBILITY_DISPLAY_DALTONIZER_ENABLED, 0, userId) != 0) {
96            final int daltonizerMode = Settings.Secure.getIntForUser(cr,
97                    Settings.Secure.ACCESSIBILITY_DISPLAY_DALTONIZER, DEFAULT_DISPLAY_DALTONIZER,
98                    userId);
99            // Monochromacy isn't supported by the native Daltonizer.
100            if (daltonizerMode == AccessibilityManager.DALTONIZER_SIMULATE_MONOCHROMACY) {
101                colorMatrix = multiply(colorMatrix, GRAYSCALE_MATRIX);
102                setDaltonizerMode(AccessibilityManager.DALTONIZER_DISABLED);
103            } else {
104                setDaltonizerMode(daltonizerMode);
105            }
106        } else {
107            setDaltonizerMode(AccessibilityManager.DALTONIZER_DISABLED);
108        }
109
110        setColorTransform(colorMatrix);
111    }
112
113    private static float[] multiply(float[] matrix, float[] other) {
114        if (matrix == null) {
115            return other;
116        }
117        float[] result = new float[16];
118        Matrix.multiplyMM(result, 0, matrix, 0, other, 0);
119        return result;
120    }
121
122    /**
123     * Sets the surface flinger's Daltonization mode. This adjusts the color
124     * space to correct for or simulate various types of color blindness.
125     *
126     * @param mode new Daltonization mode
127     */
128    private static void setDaltonizerMode(int mode) {
129        try {
130            final IBinder flinger = ServiceManager.getService("SurfaceFlinger");
131            if (flinger != null) {
132                final Parcel data = Parcel.obtain();
133                data.writeInterfaceToken("android.ui.ISurfaceComposer");
134                data.writeInt(mode);
135                flinger.transact(1014, data, null, 0);
136                data.recycle();
137            }
138        } catch (RemoteException ex) {
139            Slog.e(LOG_TAG, "Failed to set Daltonizer mode", ex);
140        }
141    }
142
143    /**
144     * Sets the surface flinger's color transformation as a 4x4 matrix. If the
145     * matrix is null, color transformations are disabled.
146     *
147     * @param m the float array that holds the transformation matrix, or null to
148     *            disable transformation
149     */
150    private static void setColorTransform(float[] m) {
151        try {
152            final IBinder flinger = ServiceManager.getService("SurfaceFlinger");
153            if (flinger != null) {
154                final Parcel data = Parcel.obtain();
155                data.writeInterfaceToken("android.ui.ISurfaceComposer");
156                if (m != null) {
157                    data.writeInt(1);
158                    for (int i = 0; i < 16; i++) {
159                        data.writeFloat(m[i]);
160                    }
161                } else {
162                    data.writeInt(0);
163                }
164                flinger.transact(1015, data, null, 0);
165                data.recycle();
166            }
167        } catch (RemoteException ex) {
168            Slog.e(LOG_TAG, "Failed to set color transform", ex);
169        }
170    }
171
172}
173