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.os.Binder;
22import android.provider.Settings.Secure;
23import android.view.accessibility.AccessibilityManager;
24
25import com.android.server.LocalServices;
26import com.android.server.display.DisplayTransformManager;
27
28/**
29 * Utility methods for performing accessibility display adjustments.
30 */
31class DisplayAdjustmentUtils {
32
33    /** Default inversion mode for display color correction. */
34    private static final int DEFAULT_DISPLAY_DALTONIZER =
35            AccessibilityManager.DALTONIZER_CORRECT_DEUTERANOMALY;
36
37    /** Matrix and offset used for converting color to gray-scale. */
38    private static final float[] MATRIX_GRAYSCALE = new float[] {
39        .2126f, .2126f, .2126f, 0,
40        .7152f, .7152f, .7152f, 0,
41        .0722f, .0722f, .0722f, 0,
42             0,      0,      0, 1
43    };
44
45    /**
46     * Matrix and offset used for luminance inversion. Represents a transform
47     * from RGB to YIQ color space, rotation around the Y axis by 180 degrees,
48     * transform back to RGB color space, and subtraction from 1. The last row
49     * represents a non-multiplied addition, see surfaceflinger's ProgramCache
50     * for full implementation details.
51     */
52    private static final float[] MATRIX_INVERT_COLOR = new float[] {
53        0.402f, -0.598f, -0.599f, 0,
54       -1.174f, -0.174f, -1.175f, 0,
55       -0.228f, -0.228f,  0.772f, 0,
56             1,       1,       1, 1
57    };
58
59    public static void applyDaltonizerSetting(Context context, int userId) {
60        final ContentResolver cr = context.getContentResolver();
61        final DisplayTransformManager dtm = LocalServices.getService(DisplayTransformManager.class);
62
63        int daltonizerMode = AccessibilityManager.DALTONIZER_DISABLED;
64        long identity = Binder.clearCallingIdentity();
65        try {
66            if (Secure.getIntForUser(cr,
67                    Secure.ACCESSIBILITY_DISPLAY_DALTONIZER_ENABLED, 0, userId) != 0) {
68                daltonizerMode = Secure.getIntForUser(cr,
69                        Secure.ACCESSIBILITY_DISPLAY_DALTONIZER, DEFAULT_DISPLAY_DALTONIZER, userId);
70            }
71        } finally {
72            Binder.restoreCallingIdentity(identity);
73        }
74
75        float[] grayscaleMatrix = null;
76        if (daltonizerMode == AccessibilityManager.DALTONIZER_SIMULATE_MONOCHROMACY) {
77            // Monochromacy isn't supported by the native Daltonizer.
78            grayscaleMatrix = MATRIX_GRAYSCALE;
79            daltonizerMode = AccessibilityManager.DALTONIZER_DISABLED;
80        }
81        dtm.setColorMatrix(DisplayTransformManager.LEVEL_COLOR_MATRIX_GRAYSCALE, grayscaleMatrix);
82        dtm.setDaltonizerMode(daltonizerMode);
83    }
84
85    /**
86     * Applies the specified user's display color adjustments.
87     */
88    public static void applyInversionSetting(Context context, int userId) {
89        final ContentResolver cr = context.getContentResolver();
90        final DisplayTransformManager dtm = LocalServices.getService(DisplayTransformManager.class);
91
92        long identity = Binder.clearCallingIdentity();
93        try {
94            final boolean invertColors = Secure.getIntForUser(cr,
95                    Secure.ACCESSIBILITY_DISPLAY_INVERSION_ENABLED, 0, userId) != 0;
96            dtm.setColorMatrix(DisplayTransformManager.LEVEL_COLOR_MATRIX_INVERT_COLOR,
97                    invertColors ? MATRIX_INVERT_COLOR : null);
98        } finally {
99            Binder.restoreCallingIdentity(identity);
100        }
101    }
102}
103