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      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 
     17 package com.android.server.accessibility;
     18 
     19 import android.content.ContentResolver;
     20 import android.content.Context;
     21 import android.os.Binder;
     22 import android.provider.Settings.Secure;
     23 import android.view.accessibility.AccessibilityManager;
     24 
     25 import com.android.server.LocalServices;
     26 import com.android.server.display.DisplayTransformManager;
     27 
     28 /**
     29  * Utility methods for performing accessibility display adjustments.
     30  */
     31 class 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