DisplayAdjustmentUtils.java revision e08340645d2539ab13900b5f835b84bcfe8b99e0 
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    /** Matrix and offset used for value-only display inversion. */
45    private static final float[] INVERSION_MATRIX_VALUE_ONLY = new float[] {
46           0, -.5f, -.5f, 0,
47        -.5f,    0, -.5f, 0,
48        -.5f, -.5f,    0, 0,
49           1,    1,    1, 1
50    };
51
52    /** Default inversion mode for display color correction. */
53    private static final int DEFAULT_DISPLAY_DALTONIZER =
54            AccessibilityManager.DALTONIZER_CORRECT_DEUTERANOMALY;
55
56    /**
57     * Returns whether the specified user with has any display color
58     * adjustments.
59     */
60    public static boolean hasAdjustments(Context context, int userId) {
61        final ContentResolver cr = context.getContentResolver();
62
63        boolean hasColorTransform = Settings.Secure.getIntForUser(
64                cr, Settings.Secure.ACCESSIBILITY_DISPLAY_INVERSION_ENABLED, 0, userId) == 1;
65
66        if (!hasColorTransform) {
67            hasColorTransform |= Settings.Secure.getIntForUser(
68                cr, Settings.Secure.ACCESSIBILITY_DISPLAY_DALTONIZER_ENABLED, 0, userId) == 1;
69        }
70
71        return hasColorTransform;
72    }
73
74    /**
75     * Applies the specified user's display color adjustments.
76     */
77    public static void applyAdjustments(Context context, int userId) {
78        final ContentResolver cr = context.getContentResolver();
79        float[] colorMatrix = new float[16];
80        float[] outputMatrix = new float[16];
81        boolean hasColorTransform = false;
82
83        Matrix.setIdentityM(colorMatrix, 0);
84
85        final boolean inversionEnabled = Settings.Secure.getIntForUser(
86                cr, Settings.Secure.ACCESSIBILITY_DISPLAY_INVERSION_ENABLED, 0, userId) == 1;
87        if (inversionEnabled) {
88            final float[] inversionMatrix = INVERSION_MATRIX_VALUE_ONLY;
89            Matrix.multiplyMM(outputMatrix, 0, colorMatrix, 0, inversionMatrix, 0);
90
91            colorMatrix = outputMatrix;
92            outputMatrix = colorMatrix;
93
94            hasColorTransform = true;
95        }
96
97        final boolean daltonizerEnabled = Settings.Secure.getIntForUser(
98                cr, Settings.Secure.ACCESSIBILITY_DISPLAY_DALTONIZER_ENABLED, 0, userId) != 0;
99        if (daltonizerEnabled) {
100            final int daltonizerMode = Settings.Secure.getIntForUser(cr,
101                    Settings.Secure.ACCESSIBILITY_DISPLAY_DALTONIZER, DEFAULT_DISPLAY_DALTONIZER,
102                    userId);
103            // Monochromacy isn't supported by the native Daltonizer.
104            if (daltonizerMode == AccessibilityManager.DALTONIZER_SIMULATE_MONOCHROMACY) {
105                Matrix.multiplyMM(outputMatrix, 0, colorMatrix, 0, GRAYSCALE_MATRIX, 0);
106
107                final float[] temp = colorMatrix;
108                colorMatrix = outputMatrix;
109                outputMatrix = temp;
110
111                hasColorTransform = true;
112                nativeSetDaltonizerMode(AccessibilityManager.DALTONIZER_DISABLED);
113            } else {
114                nativeSetDaltonizerMode(daltonizerMode);
115            }
116        } else {
117            nativeSetDaltonizerMode(AccessibilityManager.DALTONIZER_DISABLED);
118        }
119
120        if (hasColorTransform) {
121            nativeSetColorTransform(colorMatrix);
122        } else {
123            nativeSetColorTransform(null);
124        }
125    }
126
127    /**
128     * Sets the surface flinger's Daltonization mode. This adjusts the color
129     * space to correct for or simulate various types of color blindness.
130     *
131     * @param mode new Daltonization mode
132     */
133    private static void nativeSetDaltonizerMode(int mode) {
134        try {
135            final IBinder flinger = ServiceManager.getService("SurfaceFlinger");
136            if (flinger != null) {
137                final Parcel data = Parcel.obtain();
138                data.writeInterfaceToken("android.ui.ISurfaceComposer");
139                data.writeInt(mode);
140                flinger.transact(1014, data, null, 0);
141                data.recycle();
142            }
143        } catch (RemoteException ex) {
144            Slog.e(LOG_TAG, "Failed to set Daltonizer mode", ex);
145        }
146    }
147
148    /**
149     * Sets the surface flinger's color transformation as a 4x4 matrix. If the
150     * matrix is null, color transformations are disabled.
151     *
152     * @param m the float array that holds the transformation matrix, or null to
153     *            disable transformation
154     */
155    private static void nativeSetColorTransform(float[] m) {
156        try {
157            final IBinder flinger = ServiceManager.getService("SurfaceFlinger");
158            if (flinger != null) {
159                final Parcel data = Parcel.obtain();
160                data.writeInterfaceToken("android.ui.ISurfaceComposer");
161                if (m != null) {
162                    data.writeInt(1);
163                    for (int i = 0; i < 16; i++) {
164                        data.writeFloat(m[i]);
165                    }
166                } else {
167                    data.writeInt(0);
168                }
169                flinger.transact(1015, data, null, 0);
170                data.recycle();
171            }
172        } catch (RemoteException ex) {
173            Slog.e(LOG_TAG, "Failed to set color transform", ex);
174        }
175    }
176
177}
178