Merge "Added app context to smart screen brightness."
diff --git a/api/system-current.txt b/api/system-current.txt
index dfcae63..fb9d951 100644
--- a/api/system-current.txt
+++ b/api/system-current.txt
@@ -1471,6 +1471,8 @@
 
   public final class BrightnessConfiguration implements android.os.Parcelable {
     method public int describeContents();
+    method public android.hardware.display.BrightnessCorrection getCorrectionByCategory(int);
+    method public android.hardware.display.BrightnessCorrection getCorrectionByPackageName(java.lang.String);
     method public android.util.Pair<float[], float[]> getCurve();
     method public void writeToParcel(android.os.Parcel, int);
     field public static final android.os.Parcelable.Creator<android.hardware.display.BrightnessConfiguration> CREATOR;
@@ -1478,10 +1480,22 @@
 
   public static class BrightnessConfiguration.Builder {
     ctor public BrightnessConfiguration.Builder(float[], float[]);
+    method public android.hardware.display.BrightnessConfiguration.Builder addCorrectionByCategory(int, android.hardware.display.BrightnessCorrection);
+    method public android.hardware.display.BrightnessConfiguration.Builder addCorrectionByPackageName(java.lang.String, android.hardware.display.BrightnessCorrection);
     method public android.hardware.display.BrightnessConfiguration build();
+    method public int getMaxCorrectionsByCategory();
+    method public int getMaxCorrectionsByPackageName();
     method public android.hardware.display.BrightnessConfiguration.Builder setDescription(java.lang.String);
   }
 
+  public final class BrightnessCorrection implements android.os.Parcelable {
+    method public float apply(float);
+    method public static android.hardware.display.BrightnessCorrection createScaleAndTranslateLog(float, float);
+    method public int describeContents();
+    method public void writeToParcel(android.os.Parcel, int);
+    field public static final android.os.Parcelable.Creator<android.hardware.display.BrightnessCorrection> CREATOR;
+  }
+
   public final class DisplayManager {
     method public java.util.List<android.hardware.display.AmbientBrightnessDayStats> getAmbientBrightnessStats();
     method public android.hardware.display.BrightnessConfiguration getBrightnessConfiguration();
diff --git a/core/java/android/hardware/display/BrightnessConfiguration.java b/core/java/android/hardware/display/BrightnessConfiguration.java
index 7e52ca3..be054297 100644
--- a/core/java/android/hardware/display/BrightnessConfiguration.java
+++ b/core/java/android/hardware/display/BrightnessConfiguration.java
@@ -19,26 +19,54 @@
 import android.annotation.Nullable;
 import android.annotation.SystemApi;
 import android.annotation.TestApi;
+import android.content.pm.ApplicationInfo;
 import android.os.Parcel;
 import android.os.Parcelable;
 import android.util.Pair;
 
 import com.android.internal.util.Preconditions;
+import com.android.internal.util.XmlUtils;
 
+import org.xmlpull.v1.XmlPullParser;
+import org.xmlpull.v1.XmlPullParserException;
+import org.xmlpull.v1.XmlSerializer;
+
+import java.io.IOException;
+import java.util.ArrayList;
 import java.util.Arrays;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.Map.Entry;
 import java.util.Objects;
 
 /** @hide */
 @SystemApi
 @TestApi
 public final class BrightnessConfiguration implements Parcelable {
+    private static final String TAG_BRIGHTNESS_CURVE = "brightness-curve";
+    private static final String TAG_BRIGHTNESS_POINT = "brightness-point";
+    private static final String TAG_BRIGHTNESS_CORRECTIONS = "brightness-corrections";
+    private static final String TAG_BRIGHTNESS_CORRECTION = "brightness-correction";
+    private static final String ATTR_LUX = "lux";
+    private static final String ATTR_NITS = "nits";
+    private static final String ATTR_DESCRIPTION = "description";
+    private static final String ATTR_PACKAGE_NAME = "package-name";
+    private static final String ATTR_CATEGORY = "category";
+
     private final float[] mLux;
     private final float[] mNits;
+    private final Map<String, BrightnessCorrection> mCorrectionsByPackageName;
+    private final Map<Integer, BrightnessCorrection> mCorrectionsByCategory;
     private final String mDescription;
 
-    private BrightnessConfiguration(float[] lux, float[] nits, String description) {
+    private BrightnessConfiguration(float[] lux, float[] nits,
+            Map<String, BrightnessCorrection> correctionsByPackageName,
+            Map<Integer, BrightnessCorrection> correctionsByCategory, String description) {
         mLux = lux;
         mNits = nits;
+        mCorrectionsByPackageName = correctionsByPackageName;
+        mCorrectionsByCategory = correctionsByCategory;
         mDescription = description;
     }
 
@@ -56,6 +84,38 @@
     }
 
     /**
+     * Returns a brightness correction by app, or null.
+     *
+     * @param packageName
+     *      The app's package name.
+     *
+     * @return The matching brightness correction, or null.
+     *
+     * @hide
+     */
+    @SystemApi
+    @Nullable
+    public BrightnessCorrection getCorrectionByPackageName(String packageName) {
+        return mCorrectionsByPackageName.get(packageName);
+    }
+
+    /**
+     * Returns a brightness correction by app category, or null.
+     *
+     * @param category
+     *      The app category.
+     *
+     * @return The matching brightness correction, or null.
+     *
+     * @hide
+     */
+    @SystemApi
+    @Nullable
+    public BrightnessCorrection getCorrectionByCategory(int category) {
+        return mCorrectionsByCategory.get(category);
+    }
+
+    /**
      * Returns description string.
      * @hide
      */
@@ -67,6 +127,20 @@
     public void writeToParcel(Parcel dest, int flags) {
         dest.writeFloatArray(mLux);
         dest.writeFloatArray(mNits);
+        dest.writeInt(mCorrectionsByPackageName.size());
+        for (Entry<String, BrightnessCorrection> entry : mCorrectionsByPackageName.entrySet()) {
+            final String packageName = entry.getKey();
+            final BrightnessCorrection correction = entry.getValue();
+            dest.writeString(packageName);
+            correction.writeToParcel(dest, flags);
+        }
+        dest.writeInt(mCorrectionsByCategory.size());
+        for (Entry<Integer, BrightnessCorrection> entry : mCorrectionsByCategory.entrySet()) {
+            final int category = entry.getKey();
+            final BrightnessCorrection correction = entry.getValue();
+            dest.writeInt(category);
+            correction.writeToParcel(dest, flags);
+        }
         dest.writeString(mDescription);
     }
 
@@ -85,7 +159,14 @@
             }
             sb.append("(").append(mLux[i]).append(", ").append(mNits[i]).append(")");
         }
-        sb.append("], '");
+        sb.append("], {");
+        for (Entry<String, BrightnessCorrection> entry : mCorrectionsByPackageName.entrySet()) {
+            sb.append("'" + entry.getKey() + "': " + entry.getValue() + ", ");
+        }
+        for (Entry<Integer, BrightnessCorrection> entry : mCorrectionsByCategory.entrySet()) {
+            sb.append(entry.getKey() + ": " + entry.getValue() + ", ");
+        }
+        sb.append("}, '");
         if (mDescription != null) {
             sb.append(mDescription);
         }
@@ -98,6 +179,8 @@
         int result = 1;
         result = result * 31 + Arrays.hashCode(mLux);
         result = result * 31 + Arrays.hashCode(mNits);
+        result = result * 31 + mCorrectionsByPackageName.hashCode();
+        result = result * 31 + mCorrectionsByCategory.hashCode();
         if (mDescription != null) {
             result = result * 31 + mDescription.hashCode();
         }
@@ -114,6 +197,8 @@
         }
         final BrightnessConfiguration other = (BrightnessConfiguration) o;
         return Arrays.equals(mLux, other.mLux) && Arrays.equals(mNits, other.mNits)
+                && mCorrectionsByPackageName.equals(other.mCorrectionsByPackageName)
+                && mCorrectionsByCategory.equals(other.mCorrectionsByCategory)
                 && Objects.equals(mDescription, other.mDescription);
     }
 
@@ -123,7 +208,25 @@
             float[] lux = in.createFloatArray();
             float[] nits = in.createFloatArray();
             Builder builder = new Builder(lux, nits);
-            builder.setDescription(in.readString());
+
+            int n = in.readInt();
+            for (int i = 0; i < n; i++) {
+                final String packageName = in.readString();
+                final BrightnessCorrection correction =
+                        BrightnessCorrection.CREATOR.createFromParcel(in);
+                builder.addCorrectionByPackageName(packageName, correction);
+            }
+
+            n = in.readInt();
+            for (int i = 0; i < n; i++) {
+                final int category = in.readInt();
+                final BrightnessCorrection correction =
+                        BrightnessCorrection.CREATOR.createFromParcel(in);
+                builder.addCorrectionByCategory(category, correction);
+            }
+
+            final String description = in.readString();
+            builder.setDescription(description);
             return builder.build();
         }
 
@@ -133,11 +236,146 @@
     };
 
     /**
+     * Writes the configuration to an XML serializer.
+     *
+     * @param serializer
+     *      The XML serializer.
+     *
+     * @hide
+     */
+    public void saveToXml(XmlSerializer serializer) throws IOException {
+        serializer.startTag(null, TAG_BRIGHTNESS_CURVE);
+        if (mDescription != null) {
+            serializer.attribute(null, ATTR_DESCRIPTION, mDescription);
+        }
+        for (int i = 0; i < mLux.length; i++) {
+            serializer.startTag(null, TAG_BRIGHTNESS_POINT);
+            serializer.attribute(null, ATTR_LUX, Float.toString(mLux[i]));
+            serializer.attribute(null, ATTR_NITS, Float.toString(mNits[i]));
+            serializer.endTag(null, TAG_BRIGHTNESS_POINT);
+        }
+        serializer.endTag(null, TAG_BRIGHTNESS_CURVE);
+        serializer.startTag(null, TAG_BRIGHTNESS_CORRECTIONS);
+        for (Map.Entry<String, BrightnessCorrection> entry :
+                mCorrectionsByPackageName.entrySet()) {
+            final String packageName = entry.getKey();
+            final BrightnessCorrection correction = entry.getValue();
+            serializer.startTag(null, TAG_BRIGHTNESS_CORRECTION);
+            serializer.attribute(null, ATTR_PACKAGE_NAME, packageName);
+            correction.saveToXml(serializer);
+            serializer.endTag(null, TAG_BRIGHTNESS_CORRECTION);
+        }
+        for (Map.Entry<Integer, BrightnessCorrection> entry : mCorrectionsByCategory.entrySet()) {
+            final int category = entry.getKey();
+            final BrightnessCorrection correction = entry.getValue();
+            serializer.startTag(null, TAG_BRIGHTNESS_CORRECTION);
+            serializer.attribute(null, ATTR_CATEGORY, Integer.toString(category));
+            correction.saveToXml(serializer);
+            serializer.endTag(null, TAG_BRIGHTNESS_CORRECTION);
+        }
+        serializer.endTag(null, TAG_BRIGHTNESS_CORRECTIONS);
+    }
+
+    /**
+     * Read a configuration from an XML parser.
+     *
+     * @param parser
+     *      The XML parser.
+     *
+     * @throws IOException
+     *      The parser failed to read the XML file.
+     * @throws XmlPullParserException
+     *      The parser failed to parse the XML file.
+     *
+     * @hide
+     */
+    public static BrightnessConfiguration loadFromXml(XmlPullParser parser)
+            throws IOException, XmlPullParserException {
+        String description = null;
+        List<Float> luxList = new ArrayList<>();
+        List<Float> nitsList = new ArrayList<>();
+        Map<String, BrightnessCorrection> correctionsByPackageName = new HashMap<>();
+        Map<Integer, BrightnessCorrection> correctionsByCategory = new HashMap<>();
+        final int configDepth = parser.getDepth();
+        while (XmlUtils.nextElementWithin(parser, configDepth)) {
+            if (TAG_BRIGHTNESS_CURVE.equals(parser.getName())) {
+                description = parser.getAttributeValue(null, ATTR_DESCRIPTION);
+                final int curveDepth = parser.getDepth();
+                while (XmlUtils.nextElementWithin(parser, curveDepth)) {
+                    if (!TAG_BRIGHTNESS_POINT.equals(parser.getName())) {
+                        continue;
+                    }
+                    final float lux = loadFloatFromXml(parser, ATTR_LUX);
+                    final float nits = loadFloatFromXml(parser, ATTR_NITS);
+                    luxList.add(lux);
+                    nitsList.add(nits);
+                }
+            }
+            if (TAG_BRIGHTNESS_CORRECTIONS.equals(parser.getName())) {
+                final int correctionsDepth = parser.getDepth();
+                while (XmlUtils.nextElementWithin(parser, correctionsDepth)) {
+                    if (!TAG_BRIGHTNESS_CORRECTION.equals(parser.getName())) {
+                        continue;
+                    }
+                    final String packageName = parser.getAttributeValue(null, ATTR_PACKAGE_NAME);
+                    final String categoryText = parser.getAttributeValue(null, ATTR_CATEGORY);
+                    BrightnessCorrection correction = BrightnessCorrection.loadFromXml(parser);
+                    if (packageName != null) {
+                        correctionsByPackageName.put(packageName, correction);
+                    } else if (categoryText != null) {
+                        try {
+                            final int category = Integer.parseInt(categoryText);
+                            correctionsByCategory.put(category, correction);
+                        } catch (NullPointerException | NumberFormatException e) {
+                            continue;
+                        }
+                    }
+                }
+            }
+        }
+        final int n = luxList.size();
+        float[] lux = new float[n];
+        float[] nits = new float[n];
+        for (int i = 0; i < n; i++) {
+            lux[i] = luxList.get(i);
+            nits[i] = nitsList.get(i);
+        }
+        final BrightnessConfiguration.Builder builder = new BrightnessConfiguration.Builder(lux,
+                nits);
+        builder.setDescription(description);
+        for (Map.Entry<String, BrightnessCorrection> entry : correctionsByPackageName.entrySet()) {
+            final String packageName = entry.getKey();
+            final BrightnessCorrection correction = entry.getValue();
+            builder.addCorrectionByPackageName(packageName, correction);
+        }
+        for (Map.Entry<Integer, BrightnessCorrection> entry : correctionsByCategory.entrySet()) {
+            final int category = entry.getKey();
+            final BrightnessCorrection correction = entry.getValue();
+            builder.addCorrectionByCategory(category, correction);
+        }
+        return builder.build();
+    }
+
+    private static float loadFloatFromXml(XmlPullParser parser, String attribute) {
+        final String string = parser.getAttributeValue(null, attribute);
+        try {
+            return Float.parseFloat(string);
+        } catch (NullPointerException | NumberFormatException e) {
+            return Float.NaN;
+        }
+    }
+
+    /**
      * A builder class for {@link BrightnessConfiguration}s.
      */
     public static class Builder {
+        private static final int MAX_CORRECTIONS_BY_PACKAGE_NAME = 20;
+        private static final int MAX_CORRECTIONS_BY_CATEGORY = 20;
+
         private float[] mCurveLux;
         private float[] mCurveNits;
+        private Map<String, BrightnessCorrection> mCorrectionsByPackageName;
+        private Map<Integer, BrightnessCorrection> mCorrectionsByCategory;
         private String mDescription;
 
         /**
@@ -169,6 +407,88 @@
             checkMonotonic(nits, false /*strictly increasing*/, "nits");
             mCurveLux = lux;
             mCurveNits = nits;
+            mCorrectionsByPackageName = new HashMap<>();
+            mCorrectionsByCategory = new HashMap<>();
+        }
+
+        /**
+         * Returns the maximum number of corrections by package name allowed.
+         *
+         * @return The maximum number of corrections by package name allowed.
+         *
+         * @hide
+         */
+        @SystemApi
+        public int getMaxCorrectionsByPackageName() {
+            return MAX_CORRECTIONS_BY_PACKAGE_NAME;
+        }
+
+        /**
+         * Returns the maximum number of corrections by category allowed.
+         *
+         * @return The maximum number of corrections by category allowed.
+         *
+         * @hide
+         */
+        @SystemApi
+        public int getMaxCorrectionsByCategory() {
+            return MAX_CORRECTIONS_BY_CATEGORY;
+        }
+
+        /**
+         * Add a brightness correction by app package name.
+         * This correction is applied whenever an app with this package name has the top activity
+         * of the focused stack.
+         *
+         * @param packageName
+         *      The app's package name.
+         * @param correction
+         *      The brightness correction.
+         *
+         * @return The builder.
+         *
+         * @throws IllegalArgumentExceptions
+         *      Maximum number of corrections by package name exceeded (see
+         *      {@link #getMaxCorrectionsByPackageName}).
+         *
+         * @hide
+         */
+        @SystemApi
+        public Builder addCorrectionByPackageName(String packageName,
+                BrightnessCorrection correction) {
+            if (mCorrectionsByPackageName.size() >= getMaxCorrectionsByPackageName()) {
+                throw new IllegalArgumentException("Too many corrections by package name");
+            }
+            mCorrectionsByPackageName.put(packageName, correction);
+            return this;
+        }
+
+        /**
+         * Add a brightness correction by app category.
+         * This correction is applied whenever an app with this category has the top activity of
+         * the focused stack, and only if a correction by package name has not been applied.
+         *
+         * @param category
+         *      The {@link android.content.pm.ApplicationInfo#category app category}.
+         * @param correction
+         *      The brightness correction.
+         *
+         * @return The builder.
+         *
+         * @throws IllegalArgumentException
+         *      Maximum number of corrections by category exceeded (see
+         *      {@link #getMaxCorrectionsByCategory}).
+         *
+         * @hide
+         */
+        @SystemApi
+        public Builder addCorrectionByCategory(@ApplicationInfo.Category int category,
+                BrightnessCorrection correction) {
+            if (mCorrectionsByCategory.size() >= getMaxCorrectionsByCategory()) {
+                throw new IllegalArgumentException("Too many corrections by category");
+            }
+            mCorrectionsByCategory.put(category, correction);
+            return this;
         }
 
         /**
@@ -191,7 +511,8 @@
             if (mCurveLux == null || mCurveNits == null) {
                 throw new IllegalStateException("A curve must be set!");
             }
-            return new BrightnessConfiguration(mCurveLux, mCurveNits, mDescription);
+            return new BrightnessConfiguration(mCurveLux, mCurveNits, mCorrectionsByPackageName,
+                    mCorrectionsByCategory, mDescription);
         }
 
         private static void checkMonotonic(float[] vals, boolean strictlyIncreasing, String name) {
diff --git a/core/java/android/hardware/display/BrightnessCorrection.aidl b/core/java/android/hardware/display/BrightnessCorrection.aidl
new file mode 100644
index 0000000..3abe29c
--- /dev/null
+++ b/core/java/android/hardware/display/BrightnessCorrection.aidl
@@ -0,0 +1,19 @@
+/*
+ * Copyright (C) 2018 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package android.hardware.display;
+
+parcelable BrightnessCorrection;
diff --git a/core/java/android/hardware/display/BrightnessCorrection.java b/core/java/android/hardware/display/BrightnessCorrection.java
new file mode 100644
index 0000000..c4e0e3b
--- /dev/null
+++ b/core/java/android/hardware/display/BrightnessCorrection.java
@@ -0,0 +1,245 @@
+/*
+ * Copyright (C) 2018 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package android.hardware.display;
+
+import android.annotation.NonNull;
+import android.annotation.SystemApi;
+import android.os.Parcel;
+import android.os.Parcelable;
+import android.util.MathUtils;
+
+import com.android.internal.util.XmlUtils;
+
+import org.xmlpull.v1.XmlPullParser;
+import org.xmlpull.v1.XmlPullParserException;
+import org.xmlpull.v1.XmlSerializer;
+
+import java.io.IOException;
+
+/**
+ * BrightnessCorrection encapsulates a correction to the brightness, without comitting to the
+ * actual correction scheme.
+ * It is used by the BrightnessConfiguration, which maps context (e.g. the foreground app's package
+ * name and category) to corrections that need to be applied to the brightness within that context.
+ * Corrections are currently done by the app that has the top activity of the focused stack, either
+ * by its package name, or (if its package name is not mapped to any correction) by its category.
+ *
+ * @hide
+ */
+@SystemApi
+public final class BrightnessCorrection implements Parcelable {
+
+    private static final int SCALE_AND_TRANSLATE_LOG = 1;
+
+    private static final String TAG_SCALE_AND_TRANSLATE_LOG = "scale-and-translate-log";
+
+    private BrightnessCorrectionImplementation mImplementation;
+
+    // Parcelable classes must be final, and protected methods are not allowed in APIs, so we can't
+    // make this class abstract and use composition instead of inheritence.
+    private BrightnessCorrection(BrightnessCorrectionImplementation implementation) {
+        mImplementation = implementation;
+    }
+
+    /**
+     * Creates a BrightnessCorrection that given {@code brightness}, corrects it to be
+     * {@code exp(scale * log(brightness) + translate)}.
+     *
+     * @param scale
+     *      How much to scale the log brightness.
+     * @param translate
+     *      How much to translate the log brightness.
+     *
+     * @return A BrightnessCorrection that given {@code brightness}, corrects it to be
+     * {@code exp(scale * log(brightness) + translate)}.
+     *
+     * @throws IllegalArgumentException
+     *      - scale or translate are NaN.
+     */
+    @NonNull
+    public static BrightnessCorrection createScaleAndTranslateLog(float scale, float translate) {
+        BrightnessCorrectionImplementation implementation =
+                new ScaleAndTranslateLog(scale, translate);
+        return new BrightnessCorrection(implementation);
+    }
+
+    /**
+     * Applies the brightness correction to a given brightness.
+     *
+     * @param brightness
+     *      The brightness.
+     *
+     * @return The corrected brightness.
+     */
+    public float apply(float brightness) {
+        return mImplementation.apply(brightness);
+    }
+
+    /**
+     * Returns a string representation.
+     *
+     * @return A string representation.
+     */
+    public String toString() {
+        return mImplementation.toString();
+    }
+
+    public static final Creator<BrightnessCorrection> CREATOR =
+            new Creator<BrightnessCorrection>() {
+                public BrightnessCorrection createFromParcel(Parcel in) {
+                    final int type = in.readInt();
+                    switch (type) {
+                        case SCALE_AND_TRANSLATE_LOG:
+                            return ScaleAndTranslateLog.readFromParcel(in);
+                    }
+                    return null;
+                }
+
+                public BrightnessCorrection[] newArray(int size) {
+                    return new BrightnessCorrection[size];
+                }
+            };
+
+    @Override
+    public void writeToParcel(Parcel dest, int flags) {
+        mImplementation.writeToParcel(dest);
+    }
+
+    @Override
+    public int describeContents() {
+        return 0;
+    }
+
+    /**
+     * Writes the correction to an XML serializer.
+     *
+     * @param serializer
+     *      The XML serializer.
+     *
+     * @hide
+     */
+    public void saveToXml(XmlSerializer serializer) throws IOException {
+        mImplementation.saveToXml(serializer);
+    }
+
+    /**
+     * Read a correction from an XML parser.
+     *
+     * @param parser
+     *      The XML parser.
+     *
+     * @throws IOException
+     *      The parser failed to read the XML file.
+     * @throws XmlPullParserException
+     *      The parser failed to parse the XML file.
+     *
+     * @hide
+     */
+    public static BrightnessCorrection loadFromXml(XmlPullParser parser) throws IOException,
+            XmlPullParserException {
+        final int depth = parser.getDepth();
+        while (XmlUtils.nextElementWithin(parser, depth)) {
+            if (TAG_SCALE_AND_TRANSLATE_LOG.equals(parser.getName())) {
+                return ScaleAndTranslateLog.loadFromXml(parser);
+            }
+        }
+        return null;
+    }
+
+    private static float loadFloatFromXml(XmlPullParser parser, String attribute) {
+        final String string = parser.getAttributeValue(null, attribute);
+        try {
+            return Float.parseFloat(string);
+        } catch (NullPointerException | NumberFormatException e) {
+            return Float.NaN;
+        }
+    }
+
+    private interface BrightnessCorrectionImplementation {
+        float apply(float brightness);
+        String toString();
+        void writeToParcel(Parcel dest);
+        void saveToXml(XmlSerializer serializer) throws IOException;
+        // Package-private static methods:
+        // static BrightnessCorrection readFromParcel(Parcel in);
+        // static BrightnessCorrection loadFromXml(XmlPullParser parser) throws IOException,
+        //      XmlPullParserException;
+    }
+
+    /**
+     * A BrightnessCorrection that given {@code brightness}, corrects it to be
+     * {@code exp(scale * log(brightness) + translate)}.
+     */
+    private static class ScaleAndTranslateLog implements BrightnessCorrectionImplementation {
+        private static final float MIN_SCALE = 0.5f;
+        private static final float MAX_SCALE = 2.0f;
+        private static final float MIN_TRANSLATE = -0.6f;
+        private static final float MAX_TRANSLATE = 0.7f;
+
+        private static final String ATTR_SCALE = "scale";
+        private static final String ATTR_TRANSLATE = "translate";
+
+        private final float mScale;
+        private final float mTranslate;
+
+        ScaleAndTranslateLog(float scale, float translate) {
+            if (Float.isNaN(scale) || Float.isNaN(translate)) {
+                throw new IllegalArgumentException("scale and translate must be numbers");
+            }
+            mScale = MathUtils.constrain(scale, MIN_SCALE, MAX_SCALE);
+            mTranslate = MathUtils.constrain(translate, MIN_TRANSLATE, MAX_TRANSLATE);
+        }
+
+        @Override
+        public float apply(float brightness) {
+            return MathUtils.exp(mScale * MathUtils.log(brightness) + mTranslate);
+        }
+
+        @Override
+        public String toString() {
+            return "ScaleAndTranslateLog(" + mScale + ", " + mTranslate + ")";
+        }
+
+        @Override
+        public void writeToParcel(Parcel dest) {
+            dest.writeInt(SCALE_AND_TRANSLATE_LOG);
+            dest.writeFloat(mScale);
+            dest.writeFloat(mTranslate);
+        }
+
+        @Override
+        public void saveToXml(XmlSerializer serializer) throws IOException {
+            serializer.startTag(null, TAG_SCALE_AND_TRANSLATE_LOG);
+            serializer.attribute(null, ATTR_SCALE, Float.toString(mScale));
+            serializer.attribute(null, ATTR_TRANSLATE, Float.toString(mTranslate));
+            serializer.endTag(null, TAG_SCALE_AND_TRANSLATE_LOG);
+        }
+
+        static BrightnessCorrection readFromParcel(Parcel in) {
+            float scale = in.readFloat();
+            float translate = in.readFloat();
+            return BrightnessCorrection.createScaleAndTranslateLog(scale, translate);
+        }
+
+        static BrightnessCorrection loadFromXml(XmlPullParser parser) throws IOException,
+                XmlPullParserException {
+            final float scale = loadFloatFromXml(parser, ATTR_SCALE);
+            final float translate = loadFloatFromXml(parser, ATTR_TRANSLATE);
+            return BrightnessCorrection.createScaleAndTranslateLog(scale, translate);
+        }
+    }
+}
diff --git a/services/core/java/com/android/server/display/AutomaticBrightnessController.java b/services/core/java/com/android/server/display/AutomaticBrightnessController.java
index 78b3c15..52eccca 100644
--- a/services/core/java/com/android/server/display/AutomaticBrightnessController.java
+++ b/services/core/java/com/android/server/display/AutomaticBrightnessController.java
@@ -17,6 +17,13 @@
 package com.android.server.display;
 
 import android.annotation.Nullable;
+import android.app.ActivityManager;
+import android.app.ActivityManager.StackInfo;
+import android.app.ActivityTaskManager;
+import android.app.IActivityTaskManager;
+import android.app.TaskStackListener;
+import android.content.pm.ApplicationInfo;
+import android.content.pm.PackageManagerInternal;
 import android.hardware.Sensor;
 import android.hardware.SensorEvent;
 import android.hardware.SensorEventListener;
@@ -27,6 +34,8 @@
 import android.os.Looper;
 import android.os.Message;
 import android.os.PowerManager;
+import android.os.Process;
+import android.os.RemoteException;
 import android.os.SystemClock;
 import android.os.Trace;
 import android.util.EventLog;
@@ -34,14 +43,15 @@
 import android.util.Slog;
 import android.util.TimeUtils;
 
+import com.android.internal.os.BackgroundThread;
 import com.android.server.EventLogTags;
+import com.android.server.LocalServices;
 
 import java.io.PrintWriter;
 
 class AutomaticBrightnessController {
     private static final String TAG = "AutomaticBrightnessController";
 
-    private static final boolean DEBUG = false;
     private static final boolean DEBUG_PRETEND_LIGHT_SENSOR_ABSENT = false;
 
     // If true, enables the use of the screen auto-brightness adjustment setting.
@@ -66,6 +76,8 @@
     private static final int MSG_UPDATE_AMBIENT_LUX = 1;
     private static final int MSG_BRIGHTNESS_ADJUSTMENT_SAMPLE = 2;
     private static final int MSG_INVALIDATE_SHORT_TERM_MODEL = 3;
+    private static final int MSG_UPDATE_FOREGROUND_APP = 4;
+    private static final int MSG_UPDATE_FOREGROUND_APP_SYNC = 5;
 
     // Length of the ambient light horizon used to calculate the long term estimate of ambient
     // light.
@@ -126,6 +138,8 @@
     private final HysteresisLevels mAmbientBrightnessThresholds;
     private final HysteresisLevels mScreenBrightnessThresholds;
 
+    private boolean mLoggingEnabled;
+
     // Amount of time to delay auto-brightness after screen on while waiting for
     // the light sensor to warm-up in milliseconds.
     // May be 0 if no warm-up is required.
@@ -192,6 +206,19 @@
     private float mShortTermModelAnchor;
     private float SHORT_TERM_MODEL_THRESHOLD_RATIO = 0.6f;
 
+    // Context-sensitive brightness configurations require keeping track of the foreground app's
+    // package name and category, which is done by registering a TaskStackListener to call back to
+    // us onTaskStackChanged, and then using the ActivityTaskManager to get the foreground app's
+    // package namd and PackageManager to get its category (so might as well cache them).
+    private int mUserId;
+    private String mForegroundAppPackageName;
+    private String mPendingForegroundAppPackageName;
+    private @ApplicationInfo.Category int mForegroundAppCategory;
+    private @ApplicationInfo.Category int mPendingForegroundAppCategory;
+    private TaskStackListenerImpl mTaskStackListener;
+    private IActivityTaskManager mActivityTaskManager;
+    private PackageManagerInternal mPackageManagerInternal;
+
     public AutomaticBrightnessController(Callbacks callbacks, Looper looper,
             SensorManager sensorManager, BrightnessMappingStrategy mapper,
             int lightSensorWarmUpTime, int brightnessMin, int brightnessMax, float dozeScaleFactor,
@@ -226,6 +253,42 @@
         if (!DEBUG_PRETEND_LIGHT_SENSOR_ABSENT) {
             mLightSensor = mSensorManager.getDefaultSensor(Sensor.TYPE_LIGHT);
         }
+
+        mUserId = ActivityManager.getCurrentUser();
+        mActivityTaskManager = ActivityTaskManager.getService();
+        mPackageManagerInternal = LocalServices.getService(PackageManagerInternal.class);
+        mTaskStackListener = new TaskStackListenerImpl();
+        mForegroundAppPackageName = null;
+        mPendingForegroundAppPackageName = null;
+        mForegroundAppCategory = ApplicationInfo.CATEGORY_UNDEFINED;
+        mPendingForegroundAppCategory = ApplicationInfo.CATEGORY_UNDEFINED;
+    }
+
+    /**
+     * Enable/disable logging.
+     *
+     * @param loggingEnabled
+     *      Whether logging should be on/off.
+     *
+     * @return Whether the method succeeded or not.
+     */
+    public boolean setLoggingEnabled(boolean loggingEnabled) {
+        if (mLoggingEnabled == loggingEnabled) {
+            return false;
+        }
+        mBrightnessMapper.setLoggingEnabled(loggingEnabled);
+        mLoggingEnabled = loggingEnabled;
+        return true;
+    }
+
+    /**
+     * Update the current user's ID.
+     *
+     * @param userId
+     *      The current user's ID.
+     */
+    public void onSwitchUser(int userId) {
+        mUserId = userId;
     }
 
     public int getAutomaticScreenBrightness() {
@@ -290,7 +353,7 @@
         }
         final int oldPolicy = mDisplayPolicy;
         mDisplayPolicy = policy;
-        if (DEBUG) {
+        if (mLoggingEnabled) {
             Slog.d(TAG, "Display policy transitioning from " + oldPolicy + " to " + policy);
         }
         if (!isInteractivePolicy(policy) && isInteractivePolicy(oldPolicy)) {
@@ -317,7 +380,7 @@
         mBrightnessMapper.addUserDataPoint(mAmbientLux, brightness);
         mShortTermModelValid = true;
         mShortTermModelAnchor = mAmbientLux;
-        if (DEBUG) {
+        if (mLoggingEnabled) {
             Slog.d(TAG, "ShortTermModel: anchor=" + mShortTermModelAnchor);
         }
         return true;
@@ -330,7 +393,7 @@
     }
 
     private void invalidateShortTermModel() {
-        if (DEBUG) {
+        if (mLoggingEnabled) {
             Slog.d(TAG, "ShortTermModel: invalidate user data");
         }
         mShortTermModelValid = false;
@@ -383,7 +446,11 @@
         pw.println("  mBrightnessAdjustmentSampleOldLux=" + mBrightnessAdjustmentSampleOldLux);
         pw.println("  mBrightnessAdjustmentSampleOldBrightness="
                 + mBrightnessAdjustmentSampleOldBrightness);
-        pw.println("  mShortTermModelValid=" + mShortTermModelValid);
+        pw.println("  mUserId=" + mUserId);
+        pw.println("  mForegroundAppPackageName=" + mForegroundAppPackageName);
+        pw.println("  mPendingForegroundAppPackageName=" + mPendingForegroundAppPackageName);
+        pw.println("  mForegroundAppCategory=" + mForegroundAppCategory);
+        pw.println("  mPendingForegroundAppCategory=" + mPendingForegroundAppCategory);
 
         pw.println();
         mBrightnessMapper.dump(pw);
@@ -399,6 +466,7 @@
                 mLightSensorEnabled = true;
                 mLightSensorEnableTime = SystemClock.uptimeMillis();
                 mCurrentLightSensorRate = mInitialLightSensorRate;
+                registerForegroundAppUpdater();
                 mSensorManager.registerListener(mLightSensorListener, mLightSensor,
                         mCurrentLightSensorRate * 1000, mHandler);
                 return true;
@@ -411,6 +479,7 @@
             mAmbientLightRingBuffer.clear();
             mCurrentLightSensorRate = -1;
             mHandler.removeMessages(MSG_UPDATE_AMBIENT_LUX);
+            unregisterForegroundAppUpdater();
             mSensorManager.unregisterListener(mLightSensorListener);
         }
         return false;
@@ -441,7 +510,7 @@
     private void adjustLightSensorRate(int lightSensorRate) {
         // if the light sensor rate changed, update the sensor listener
         if (lightSensorRate != mCurrentLightSensorRate) {
-            if (DEBUG) {
+            if (mLoggingEnabled) {
                 Slog.d(TAG, "adjustLightSensorRate: " +
                         "previousRate=" + mCurrentLightSensorRate + ", " +
                         "currentRate=" + lightSensorRate);
@@ -458,7 +527,7 @@
     }
 
     private void setAmbientLux(float lux) {
-        if (DEBUG) {
+        if (mLoggingEnabled) {
             Slog.d(TAG, "setAmbientLux(" + lux + ")");
         }
         if (lux < 0) {
@@ -476,7 +545,7 @@
             final float maxAmbientLux =
                 mShortTermModelAnchor + mShortTermModelAnchor * SHORT_TERM_MODEL_THRESHOLD_RATIO;
             if (minAmbientLux < mAmbientLux && mAmbientLux < maxAmbientLux) {
-                if (DEBUG) {
+                if (mLoggingEnabled) {
                     Slog.d(TAG, "ShortTermModel: re-validate user data, ambient lux is " +
                             minAmbientLux + " < " + mAmbientLux + " < " + maxAmbientLux);
                 }
@@ -490,7 +559,7 @@
     }
 
     private float calculateAmbientLux(long now, long horizon) {
-        if (DEBUG) {
+        if (mLoggingEnabled) {
             Slog.d(TAG, "calculateAmbientLux(" + now + ", " + horizon + ")");
         }
         final int N = mAmbientLightRingBuffer.size();
@@ -509,7 +578,7 @@
                 break;
             }
         }
-        if (DEBUG) {
+        if (mLoggingEnabled) {
             Slog.d(TAG, "calculateAmbientLux: selected endIndex=" + endIndex + ", point=(" +
                     mAmbientLightRingBuffer.getTime(endIndex) + ", " +
                     mAmbientLightRingBuffer.getLux(endIndex) + ")");
@@ -527,7 +596,7 @@
             final long startTime = eventTime - now;
             float weight = calculateWeight(startTime, endTime);
             float lux = mAmbientLightRingBuffer.getLux(i);
-            if (DEBUG) {
+            if (mLoggingEnabled) {
                 Slog.d(TAG, "calculateAmbientLux: [" + startTime + ", " + endTime + "]: " +
                         "lux=" + lux + ", " +
                         "weight=" + weight);
@@ -536,7 +605,7 @@
             sum += lux * weight;
             endTime = startTime;
         }
-        if (DEBUG) {
+        if (mLoggingEnabled) {
             Slog.d(TAG, "calculateAmbientLux: " +
                     "totalWeight=" + totalWeight + ", " +
                     "newAmbientLux=" + (sum / totalWeight));
@@ -591,7 +660,7 @@
             final long timeWhenSensorWarmedUp =
                 mLightSensorWarmUpTimeConfig + mLightSensorEnableTime;
             if (time < timeWhenSensorWarmedUp) {
-                if (DEBUG) {
+                if (mLoggingEnabled) {
                     Slog.d(TAG, "updateAmbientLux: Sensor not  ready yet: " +
                             "time=" + time + ", " +
                             "timeWhenSensorWarmedUp=" + timeWhenSensorWarmedUp);
@@ -602,7 +671,7 @@
             }
             setAmbientLux(calculateAmbientLux(time, AMBIENT_LIGHT_SHORT_HORIZON_MILLIS));
             mAmbientLuxValid = true;
-            if (DEBUG) {
+            if (mLoggingEnabled) {
                 Slog.d(TAG, "updateAmbientLux: Initializing: " +
                         "mAmbientLightRingBuffer=" + mAmbientLightRingBuffer + ", " +
                         "mAmbientLux=" + mAmbientLux);
@@ -630,10 +699,10 @@
                         && fastAmbientLux <= mAmbientDarkeningThreshold
                         && nextDarkenTransition <= time)) {
             setAmbientLux(fastAmbientLux);
-            if (DEBUG) {
+            if (mLoggingEnabled) {
                 Slog.d(TAG, "updateAmbientLux: "
                         + ((fastAmbientLux > mAmbientLux) ? "Brightened" : "Darkened") + ": "
-                        + "mAmbientBrighteningThreshold=" + mAmbientBrighteningThreshold + ", "
+                        + "mBrighteningLuxThreshold=" + mAmbientBrighteningThreshold + ", "
                         + "mAmbientLightRingBuffer=" + mAmbientLightRingBuffer + ", "
                         + "mAmbientLux=" + mAmbientLux);
             }
@@ -650,7 +719,7 @@
         // weighted ambient lux or not.
         nextTransitionTime =
                 nextTransitionTime > time ? nextTransitionTime : time + mNormalLightSensorRate;
-        if (DEBUG) {
+        if (mLoggingEnabled) {
             Slog.d(TAG, "updateAmbientLux: Scheduling ambient lux update for " +
                     nextTransitionTime + TimeUtils.formatUptime(nextTransitionTime));
         }
@@ -662,7 +731,8 @@
             return;
         }
 
-        float value = mBrightnessMapper.getBrightness(mAmbientLux);
+        float value = mBrightnessMapper.getBrightness(mAmbientLux, mForegroundAppPackageName,
+                mForegroundAppCategory);
 
         int newScreenAutoBrightness =
                 clampScreenBrightness(Math.round(value * PowerManager.BRIGHTNESS_ON));
@@ -673,7 +743,7 @@
         if (mScreenAutoBrightness != -1
                 && newScreenAutoBrightness > mScreenDarkeningThreshold
                 && newScreenAutoBrightness < mScreenBrighteningThreshold) {
-            if (DEBUG) {
+            if (mLoggingEnabled) {
                 Slog.d(TAG, "ignoring newScreenAutoBrightness: " + mScreenDarkeningThreshold
                         + " < " + newScreenAutoBrightness + " < " + mScreenBrighteningThreshold);
             }
@@ -681,8 +751,7 @@
         }
 
         if (mScreenAutoBrightness != newScreenAutoBrightness) {
-
-            if (DEBUG) {
+            if (mLoggingEnabled) {
                 Slog.d(TAG, "updateAutoBrightness: " +
                         "mScreenAutoBrightness=" + mScreenAutoBrightness + ", " +
                         "newScreenAutoBrightness=" + newScreenAutoBrightness);
@@ -718,18 +787,11 @@
                 BRIGHTNESS_ADJUSTMENT_SAMPLE_DEBOUNCE_MILLIS);
     }
 
-    private void cancelBrightnessAdjustmentSample() {
-        if (mBrightnessAdjustmentSamplePending) {
-            mBrightnessAdjustmentSamplePending = false;
-            mHandler.removeMessages(MSG_BRIGHTNESS_ADJUSTMENT_SAMPLE);
-        }
-    }
-
     private void collectBrightnessAdjustmentSample() {
         if (mBrightnessAdjustmentSamplePending) {
             mBrightnessAdjustmentSamplePending = false;
             if (mAmbientLuxValid && mScreenAutoBrightness >= 0) {
-                if (DEBUG) {
+                if (mLoggingEnabled) {
                     Slog.d(TAG, "Auto-brightness adjustment changed by user: " +
                             "lux=" + mAmbientLux + ", " +
                             "brightness=" + mScreenAutoBrightness + ", " +
@@ -745,6 +807,68 @@
         }
     }
 
+    // Register a TaskStackListener to call back to us onTaskStackChanged, so we can update the
+    // foreground app's package name and category and correct the brightness accordingly.
+    private void registerForegroundAppUpdater() {
+        try {
+            mActivityTaskManager.registerTaskStackListener(mTaskStackListener);
+            // This will not get called until the foreground app changes for the first time, so
+            // call it explicitly to get the current foreground app's info.
+            updateForegroundApp();
+        } catch (RemoteException e) {
+            // Nothing to do.
+        }
+    }
+
+    private void unregisterForegroundAppUpdater() {
+        try {
+            mActivityTaskManager.unregisterTaskStackListener(mTaskStackListener);
+        } catch (RemoteException e) {
+            // Nothing to do.
+        }
+        mForegroundAppPackageName = null;
+        mForegroundAppCategory = ApplicationInfo.CATEGORY_UNDEFINED;
+    }
+
+    // Set the foreground app's package name and category, so brightness can be corrected per app.
+    private void updateForegroundApp() {
+        // The ActivityTaskManager's lock tends to get contended, so this is done in a background
+        // thread and applied via this thread's handler synchronously.
+        BackgroundThread.getHandler().post(new Runnable() {
+            public void run() {
+                try {
+                    // The foreground app is the top activity of the focused tasks stack.
+                    final StackInfo info = mActivityTaskManager.getFocusedStackInfo();
+                    if (info == null || info.topActivity == null) {
+                        return;
+                    }
+                    final String packageName = info.topActivity.getPackageName();
+                    // If the app didn't change, there's nothing to do. Otherwise, we have to
+                    // update the category and re-apply the brightness correction.
+                    if (mForegroundAppPackageName != null
+                            && mForegroundAppPackageName.equals(packageName)) {
+                        return;
+                    }
+                    mPendingForegroundAppPackageName = packageName;
+                    ApplicationInfo app = mPackageManagerInternal.getApplicationInfo(packageName,
+                            0 /* flags */, Process.SYSTEM_UID /* filterCallingUid */, mUserId);
+                    mPendingForegroundAppCategory = app.category;
+                    mHandler.sendEmptyMessage(MSG_UPDATE_FOREGROUND_APP_SYNC);
+                } catch (RemoteException e) {
+                    // Nothing to do.
+                }
+            }
+        });
+    }
+
+    private void updateForegroundAppSync() {
+        mForegroundAppPackageName = mPendingForegroundAppPackageName;
+        mPendingForegroundAppPackageName = null;
+        mForegroundAppCategory = mPendingForegroundAppCategory;
+        mPendingForegroundAppCategory = ApplicationInfo.CATEGORY_UNDEFINED;
+        updateAutoBrightness(true /* sendUpdate */);
+    }
+
     private final class AutomaticBrightnessHandler extends Handler {
         public AutomaticBrightnessHandler(Looper looper) {
             super(looper, null, true /*async*/);
@@ -764,6 +888,14 @@
                 case MSG_INVALIDATE_SHORT_TERM_MODEL:
                     invalidateShortTermModel();
                     break;
+
+                case MSG_UPDATE_FOREGROUND_APP:
+                    updateForegroundApp();
+                    break;
+
+                case MSG_UPDATE_FOREGROUND_APP_SYNC:
+                    updateForegroundAppSync();
+                    break;
             }
         }
     }
@@ -784,6 +916,15 @@
         }
     };
 
+    // Call back whenever the tasks stack changes, which includes tasks being created, removed, and
+    // moving to top.
+    class TaskStackListenerImpl extends TaskStackListener {
+        @Override
+        public void onTaskStackChanged() {
+            mHandler.sendEmptyMessage(MSG_UPDATE_FOREGROUND_APP);
+        }
+    }
+
     /** Callbacks to request updates to the display's power state. */
     interface Callbacks {
         void updateBrightness();
diff --git a/services/core/java/com/android/server/display/BrightnessMappingStrategy.java b/services/core/java/com/android/server/display/BrightnessMappingStrategy.java
index 76c191d..9fce644 100644
--- a/services/core/java/com/android/server/display/BrightnessMappingStrategy.java
+++ b/services/core/java/com/android/server/display/BrightnessMappingStrategy.java
@@ -17,9 +17,11 @@
 package com.android.server.display;
 
 import android.annotation.Nullable;
+import android.content.pm.ApplicationInfo;
 import android.content.res.Resources;
 import android.content.res.TypedArray;
 import android.hardware.display.BrightnessConfiguration;
+import android.hardware.display.BrightnessCorrection;
 import android.os.PowerManager;
 import android.util.MathUtils;
 import android.util.Pair;
@@ -42,11 +44,12 @@
  */
 public abstract class BrightnessMappingStrategy {
     private static final String TAG = "BrightnessMappingStrategy";
-    private static final boolean DEBUG = false;
 
     private static final float LUX_GRAD_SMOOTHING = 0.25f;
     private static final float MAX_GRAD = 1.0f;
 
+    protected boolean mLoggingEnabled;
+
     private static final Plog PLOG = Plog.createSystemPlog(TAG);
 
     @Nullable
@@ -161,6 +164,22 @@
     }
 
     /**
+     * Enable/disable logging.
+     *
+     * @param loggingEnabled
+     *      Whether logging should be on/off.
+     *
+     * @return Whether the method succeeded or not.
+     */
+    public boolean setLoggingEnabled(boolean loggingEnabled) {
+        if (mLoggingEnabled == loggingEnabled) {
+            return false;
+        }
+        mLoggingEnabled = loggingEnabled;
+        return true;
+    }
+
+    /**
      * Sets the {@link BrightnessConfiguration}.
      *
      * @param config The new configuration. If {@code null} is passed, the default configuration is
@@ -170,15 +189,33 @@
     public abstract boolean setBrightnessConfiguration(@Nullable BrightnessConfiguration config);
 
     /**
-     * Returns the desired brightness of the display based on the current ambient lux.
+     * Returns the desired brightness of the display based on the current ambient lux, including
+     * any context-related corrections.
      *
      * The returned brightness will be in the range [0, 1.0], where 1.0 is the display at max
      * brightness and 0 is the display at minimum brightness.
      *
      * @param lux The current ambient brightness in lux.
+     * @param packageName the foreground app package name.
+     * @param category the foreground app package category.
      * @return The desired brightness of the display normalized to the range [0, 1.0].
      */
-    public abstract float getBrightness(float lux);
+    public abstract float getBrightness(float lux, String packageName,
+            @ApplicationInfo.Category int category);
+
+    /**
+     * Returns the desired brightness of the display based on the current ambient lux.
+     *
+     * The returned brightness wil be in the range [0, 1.0], where 1.0 is the display at max
+     * brightness and 0 is the display at minimum brightness.
+     *
+     * @param lux The current ambient brightness in lux.
+     *
+     * @return The desired brightness of the display normalized to the range [0, 1.0].
+     */
+    public float getBrightness(float lux) {
+        return getBrightness(lux, null /* packageName */, ApplicationInfo.CATEGORY_UNDEFINED);
+    }
 
     /**
      * Returns the current auto-brightness adjustment.
@@ -239,13 +276,13 @@
 
     public abstract void dump(PrintWriter pw);
 
-    private static float normalizeAbsoluteBrightness(int brightness) {
+    protected float normalizeAbsoluteBrightness(int brightness) {
         brightness = MathUtils.constrain(brightness,
                 PowerManager.BRIGHTNESS_OFF, PowerManager.BRIGHTNESS_ON);
         return (float) brightness / PowerManager.BRIGHTNESS_ON;
     }
 
-    private static Pair<float[], float[]> insertControlPoint(
+    private Pair<float[], float[]> insertControlPoint(
             float[] luxLevels, float[] brightnessLevels, float lux, float brightness) {
         final int idx = findInsertionPoint(luxLevels, lux);
         final float[] newLuxLevels;
@@ -278,7 +315,7 @@
      * This assumes that {@code arr} is sorted. If all values in {@code arr} are greater
      * than val, then it will return the length of arr as the insertion point.
      */
-    private static int findInsertionPoint(float[] arr, float val) {
+    private int findInsertionPoint(float[] arr, float val) {
         for (int i = 0; i < arr.length; i++) {
             if (val <= arr[i]) {
                 return i;
@@ -287,8 +324,8 @@
         return arr.length;
     }
 
-    private static void smoothCurve(float[] lux, float[] brightness, int idx) {
-        if (DEBUG) {
+    private void smoothCurve(float[] lux, float[] brightness, int idx) {
+        if (mLoggingEnabled) {
             PLOG.logCurve("unsmoothed curve", lux, brightness);
         }
         float prevLux = lux[idx];
@@ -323,19 +360,19 @@
             prevBrightness = newBrightness;
             brightness[i] = newBrightness;
         }
-        if (DEBUG) {
+        if (mLoggingEnabled) {
             PLOG.logCurve("smoothed curve", lux, brightness);
         }
     }
 
-    private static float permissibleRatio(float currLux, float prevLux) {
+    private float permissibleRatio(float currLux, float prevLux) {
         return MathUtils.exp(MAX_GRAD
                 * (MathUtils.log(currLux + LUX_GRAD_SMOOTHING)
                     - MathUtils.log(prevLux + LUX_GRAD_SMOOTHING)));
     }
 
-    private static float inferAutoBrightnessAdjustment(float maxGamma,
-            float desiredBrightness, float currentBrightness) {
+    protected float inferAutoBrightnessAdjustment(float maxGamma, float desiredBrightness,
+            float currentBrightness) {
         float adjustment = 0;
         float gamma = Float.NaN;
         // Extreme edge cases: use a simpler heuristic, as proper gamma correction around the edges
@@ -355,7 +392,7 @@
             adjustment = -MathUtils.log(gamma) / MathUtils.log(maxGamma);
         }
         adjustment = MathUtils.constrain(adjustment, -1, +1);
-        if (DEBUG) {
+        if (mLoggingEnabled) {
             Slog.d(TAG, "inferAutoBrightnessAdjustment: " + maxGamma + "^" + -adjustment + "=" +
                     MathUtils.pow(maxGamma, -adjustment) + " == " + gamma);
             Slog.d(TAG, "inferAutoBrightnessAdjustment: " + currentBrightness + "^" + gamma + "=" +
@@ -364,16 +401,16 @@
         return adjustment;
     }
 
-    private static Pair<float[], float[]> getAdjustedCurve(float[] lux, float[] brightness,
+    protected Pair<float[], float[]> getAdjustedCurve(float[] lux, float[] brightness,
             float userLux, float userBrightness, float adjustment, float maxGamma) {
         float[] newLux = lux;
         float[] newBrightness = Arrays.copyOf(brightness, brightness.length);
-        if (DEBUG) {
+        if (mLoggingEnabled) {
             PLOG.logCurve("unadjusted curve", newLux, newBrightness);
         }
         adjustment = MathUtils.constrain(adjustment, -1, 1);
         float gamma = MathUtils.pow(maxGamma, -adjustment);
-        if (DEBUG) {
+        if (mLoggingEnabled) {
             Slog.d(TAG, "getAdjustedCurve: " + maxGamma + "^" + -adjustment + "=" +
                     MathUtils.pow(maxGamma, -adjustment) + " == " + gamma);
         }
@@ -382,7 +419,7 @@
                 newBrightness[i] = MathUtils.pow(newBrightness[i], gamma);
             }
         }
-        if (DEBUG) {
+        if (mLoggingEnabled) {
             PLOG.logCurve("gamma adjusted curve", newLux, newBrightness);
         }
         if (userLux != -1) {
@@ -390,7 +427,7 @@
                     userBrightness);
             newLux = curve.first;
             newBrightness = curve.second;
-            if (DEBUG) {
+            if (mLoggingEnabled) {
                 PLOG.logCurve("gamma and user adjusted curve", newLux, newBrightness);
                 // This is done for comparison.
                 curve = insertControlPoint(lux, brightness, userLux, userBrightness);
@@ -440,7 +477,7 @@
             mAutoBrightnessAdjustment = 0;
             mUserLux = -1;
             mUserBrightness = -1;
-            if (DEBUG) {
+            if (mLoggingEnabled) {
                 PLOG.start("simple mapping strategy");
             }
             computeSpline();
@@ -452,7 +489,8 @@
         }
 
         @Override
-        public float getBrightness(float lux) {
+        public float getBrightness(float lux, String packageName,
+                @ApplicationInfo.Category int category) {
             return mSpline.interpolate(lux);
         }
 
@@ -467,7 +505,7 @@
             if (adjustment == mAutoBrightnessAdjustment) {
                 return false;
             }
-            if (DEBUG) {
+            if (mLoggingEnabled) {
                 Slog.d(TAG, "setAutoBrightnessAdjustment: " + mAutoBrightnessAdjustment + " => " +
                         adjustment);
                 PLOG.start("auto-brightness adjustment");
@@ -485,7 +523,7 @@
         @Override
         public void addUserDataPoint(float lux, float brightness) {
             float unadjustedBrightness = getUnadjustedBrightness(lux);
-            if (DEBUG){
+            if (mLoggingEnabled) {
                 Slog.d(TAG, "addUserDataPoint: (" + lux + "," + brightness + ")");
                 PLOG.start("add user data point")
                         .logPoint("user data point", lux, brightness)
@@ -494,7 +532,7 @@
             float adjustment = inferAutoBrightnessAdjustment(mMaxGamma,
                     brightness /* desiredBrightness */,
                     unadjustedBrightness /* currentBrightness */);
-            if (DEBUG) {
+            if (mLoggingEnabled) {
                 Slog.d(TAG, "addUserDataPoint: " + mAutoBrightnessAdjustment + " => " +
                         adjustment);
             }
@@ -507,7 +545,7 @@
         @Override
         public void clearUserDataPoints() {
             if (mUserLux != -1) {
-                if (DEBUG) {
+                if (mLoggingEnabled) {
                     Slog.d(TAG, "clearUserDataPoints: " + mAutoBrightnessAdjustment + " => 0");
                     PLOG.start("clear user data points")
                             .logPoint("user data point", mUserLux, mUserBrightness);
@@ -614,7 +652,7 @@
             mBacklightToNitsSpline = Spline.createSpline(normalizedBacklight, nits);
 
             mDefaultConfig = config;
-            if (DEBUG) {
+            if (mLoggingEnabled) {
                 PLOG.start("physical mapping strategy");
             }
             mConfig = config;
@@ -629,7 +667,7 @@
             if (config.equals(mConfig)) {
                 return false;
             }
-            if (DEBUG) {
+            if (mLoggingEnabled) {
                 PLOG.start("brightness configuration");
             }
             mConfig = config;
@@ -638,9 +676,17 @@
         }
 
         @Override
-        public float getBrightness(float lux) {
+        public float getBrightness(float lux, String packageName,
+                @ApplicationInfo.Category int category) {
             float nits = mBrightnessSpline.interpolate(lux);
             float backlight = mNitsToBacklightSpline.interpolate(nits);
+            // Correct the brightness according to the current application and its category, but
+            // only if no user data point is set (as this will oevrride the user setting).
+            if (mUserLux == -1) {
+                backlight = correctBrightness(backlight, packageName, category);
+            } else if (mLoggingEnabled) {
+                Slog.d(TAG, "user point set, correction not applied");
+            }
             return backlight;
         }
 
@@ -655,7 +701,7 @@
             if (adjustment == mAutoBrightnessAdjustment) {
                 return false;
             }
-            if (DEBUG) {
+            if (mLoggingEnabled) {
                 Slog.d(TAG, "setAutoBrightnessAdjustment: " + mAutoBrightnessAdjustment + " => " +
                         adjustment);
                 PLOG.start("auto-brightness adjustment");
@@ -673,7 +719,7 @@
         @Override
         public void addUserDataPoint(float lux, float brightness) {
             float unadjustedBrightness = getUnadjustedBrightness(lux);
-            if (DEBUG){
+            if (mLoggingEnabled) {
                 Slog.d(TAG, "addUserDataPoint: (" + lux + "," + brightness + ")");
                 PLOG.start("add user data point")
                         .logPoint("user data point", lux, brightness)
@@ -682,7 +728,7 @@
             float adjustment = inferAutoBrightnessAdjustment(mMaxGamma,
                     brightness /* desiredBrightness */,
                     unadjustedBrightness /* currentBrightness */);
-            if (DEBUG) {
+            if (mLoggingEnabled) {
                 Slog.d(TAG, "addUserDataPoint: " + mAutoBrightnessAdjustment + " => " +
                         adjustment);
             }
@@ -695,7 +741,7 @@
         @Override
         public void clearUserDataPoints() {
             if (mUserLux != -1) {
-                if (DEBUG) {
+                if (mLoggingEnabled) {
                     Slog.d(TAG, "clearUserDataPoints: " + mAutoBrightnessAdjustment + " => 0");
                     PLOG.start("clear user data points")
                             .logPoint("user data point", mUserLux, mUserBrightness);
@@ -758,5 +804,21 @@
             Spline spline = Spline.createSpline(curve.first, curve.second);
             return mNitsToBacklightSpline.interpolate(spline.interpolate(lux));
         }
+
+        private float correctBrightness(float brightness, String packageName, int category) {
+            if (packageName != null) {
+                BrightnessCorrection correction = mConfig.getCorrectionByPackageName(packageName);
+                if (correction != null) {
+                    return correction.apply(brightness);
+                }
+            }
+            if (category != ApplicationInfo.CATEGORY_UNDEFINED) {
+                BrightnessCorrection correction = mConfig.getCorrectionByCategory(category);
+                if (correction != null) {
+                    return correction.apply(brightness);
+                }
+            }
+            return brightness;
+        }
     }
 }
diff --git a/services/core/java/com/android/server/display/DisplayManagerService.java b/services/core/java/com/android/server/display/DisplayManagerService.java
index 0a1a9a2..b1ba05c 100644
--- a/services/core/java/com/android/server/display/DisplayManagerService.java
+++ b/services/core/java/com/android/server/display/DisplayManagerService.java
@@ -2144,6 +2144,14 @@
                     mContext.getPackageName());
         }
 
+        void setAutoBrightnessLoggingEnabled(boolean enabled) {
+            if (mDisplayPowerController != null) {
+                synchronized (mSyncRoot) {
+                    mDisplayPowerController.setAutoBrightnessLoggingEnabled(enabled);
+                }
+            }
+        }
+
         private boolean validatePackageName(int uid, String packageName) {
             if (packageName != null) {
                 String[] packageNames = mContext.getPackageManager().getPackagesForUid(uid);
diff --git a/services/core/java/com/android/server/display/DisplayManagerShellCommand.java b/services/core/java/com/android/server/display/DisplayManagerShellCommand.java
index 27cad1e..abbfc7b 100644
--- a/services/core/java/com/android/server/display/DisplayManagerShellCommand.java
+++ b/services/core/java/com/android/server/display/DisplayManagerShellCommand.java
@@ -17,14 +17,9 @@
 package com.android.server.display;
 
 import android.content.Intent;
-import android.os.RemoteException;
-import android.os.ResultReceiver;
-import android.os.ShellCallback;
 import android.os.ShellCommand;
-import android.util.Slog;
 
 import java.io.PrintWriter;
-import java.lang.NumberFormatException;
 
 class DisplayManagerShellCommand extends ShellCommand {
     private static final String TAG = "DisplayManagerShellCommand";
@@ -46,6 +41,10 @@
                 return setBrightness();
             case "reset-brightness-configuration":
                 return resetBrightnessConfiguration();
+            case "ab-logging-enable":
+                return setAutoBrightnessLoggingEnabled(true);
+            case "ab-logging-disable":
+                return setAutoBrightnessLoggingEnabled(false);
             default:
                 return handleDefaultCommands(cmd);
         }
@@ -62,6 +61,10 @@
         pw.println("    Sets the current brightness to BRIGHTNESS (a number between 0 and 1).");
         pw.println("  reset-brightness-configuration");
         pw.println("    Reset the brightness to its default configuration.");
+        pw.println("  ab-logging-enable");
+        pw.println("    Enable auto-brightness logging.");
+        pw.println("  ab-logging-disable");
+        pw.println("    Disable auto-brightness logging.");
         pw.println();
         Intent.printIntentArgsHelp(pw , "");
     }
@@ -89,4 +92,9 @@
         mService.resetBrightnessConfiguration();
         return 0;
     }
+
+    private int setAutoBrightnessLoggingEnabled(boolean enabled) {
+        mService.setAutoBrightnessLoggingEnabled(enabled);
+        return 0;
+    }
 }
diff --git a/services/core/java/com/android/server/display/DisplayPowerController.java b/services/core/java/com/android/server/display/DisplayPowerController.java
index 249270b..c9ed9f7 100644
--- a/services/core/java/com/android/server/display/DisplayPowerController.java
+++ b/services/core/java/com/android/server/display/DisplayPowerController.java
@@ -523,6 +523,9 @@
     public void onSwitchUser(@UserIdInt int newUserId) {
         handleSettingsChange(true /* userSwitch */);
         mBrightnessTracker.onSwitchUser(newUserId);
+        if (mAutomaticBrightnessController != null) {
+            mAutomaticBrightnessController.onSwitchUser(newUserId);
+        }
     }
 
     public ParceledListSlice<AmbientBrightnessDayStats> getAmbientBrightnessStats(
@@ -1836,4 +1839,10 @@
             mHandler.sendMessage(msg);
         }
     }
+
+    void setAutoBrightnessLoggingEnabled(boolean enabled) {
+        if (mAutomaticBrightnessController != null) {
+            mAutomaticBrightnessController.setLoggingEnabled(enabled);
+        }
+    }
 }
diff --git a/services/core/java/com/android/server/display/PersistentDataStore.java b/services/core/java/com/android/server/display/PersistentDataStore.java
index 89cef62..9aec43b 100644
--- a/services/core/java/com/android/server/display/PersistentDataStore.java
+++ b/services/core/java/com/android/server/display/PersistentDataStore.java
@@ -16,13 +16,6 @@
 
 package com.android.server.display;
 
-import com.android.internal.util.FastXmlSerializer;
-import com.android.internal.util.XmlUtils;
-
-import org.xmlpull.v1.XmlPullParser;
-import org.xmlpull.v1.XmlPullParserException;
-import org.xmlpull.v1.XmlSerializer;
-
 import android.annotation.Nullable;
 import android.graphics.Point;
 import android.hardware.display.BrightnessConfiguration;
@@ -30,13 +23,20 @@
 import android.util.AtomicFile;
 import android.util.Slog;
 import android.util.SparseArray;
-import android.util.Pair;
 import android.util.SparseLongArray;
 import android.util.TimeUtils;
 import android.util.Xml;
 import android.view.Display;
 
 import com.android.internal.annotations.VisibleForTesting;
+import com.android.internal.util.FastXmlSerializer;
+import com.android.internal.util.XmlUtils;
+
+import libcore.io.IoUtils;
+
+import org.xmlpull.v1.XmlPullParser;
+import org.xmlpull.v1.XmlPullParserException;
+import org.xmlpull.v1.XmlSerializer;
 
 import java.io.BufferedInputStream;
 import java.io.BufferedOutputStream;
@@ -50,12 +50,9 @@
 import java.nio.charset.StandardCharsets;
 import java.util.ArrayList;
 import java.util.HashMap;
-import java.util.List;
 import java.util.Map;
 import java.util.Objects;
 
-import libcore.io.IoUtils;
-
 /**
  * Manages persistent state recorded by the display manager service as an XML file.
  * Caller must acquire lock on the data store before accessing it.
@@ -110,14 +107,9 @@
 
     private static final String TAG_BRIGHTNESS_CONFIGURATIONS = "brightness-configurations";
     private static final String TAG_BRIGHTNESS_CONFIGURATION = "brightness-configuration";
-    private static final String TAG_BRIGHTNESS_CURVE = "brightness-curve";
-    private static final String TAG_BRIGHTNESS_POINT = "brightness-point";
     private static final String ATTR_USER_SERIAL = "user-serial";
     private static final String ATTR_PACKAGE_NAME = "package-name";
     private static final String ATTR_TIME_STAMP = "timestamp";
-    private static final String ATTR_LUX = "lux";
-    private static final String ATTR_NITS = "nits";
-    private static final String ATTR_DESCRIPTION = "description";
 
     // Remembered Wifi display devices.
     private ArrayList<WifiDisplay> mRememberedWifiDisplays = new ArrayList<WifiDisplay>();
@@ -646,7 +638,8 @@
                     }
 
                     try {
-                        BrightnessConfiguration config = loadConfigurationFromXml(parser);
+                        BrightnessConfiguration config =
+                                BrightnessConfiguration.loadFromXml(parser);
                         if (userSerial >= 0 && config != null) {
                             mConfigurations.put(userSerial, config);
                             if (timeStamp != -1) {
@@ -663,56 +656,6 @@
             }
         }
 
-        private static BrightnessConfiguration loadConfigurationFromXml(XmlPullParser parser)
-                throws IOException, XmlPullParserException {
-            final int outerDepth = parser.getDepth();
-            String description = null;
-            Pair<float[], float[]> curve = null;
-            while (XmlUtils.nextElementWithin(parser, outerDepth)) {
-                if (TAG_BRIGHTNESS_CURVE.equals(parser.getName())) {
-                    description = parser.getAttributeValue(null, ATTR_DESCRIPTION);
-                    curve = loadCurveFromXml(parser);
-                }
-            }
-            if (curve == null) {
-                return null;
-            }
-            final BrightnessConfiguration.Builder builder = new BrightnessConfiguration.Builder(
-                    curve.first, curve.second);
-            builder.setDescription(description);
-            return builder.build();
-        }
-
-        private static Pair<float[], float[]> loadCurveFromXml(XmlPullParser parser)
-                throws IOException, XmlPullParserException {
-            final int outerDepth = parser.getDepth();
-            List<Float> luxLevels = new ArrayList<>();
-            List<Float> nitLevels = new ArrayList<>();
-            while (XmlUtils.nextElementWithin(parser, outerDepth)) {
-                if (TAG_BRIGHTNESS_POINT.equals(parser.getName())) {
-                    luxLevels.add(loadFloat(parser.getAttributeValue(null, ATTR_LUX)));
-                    nitLevels.add(loadFloat(parser.getAttributeValue(null, ATTR_NITS)));
-                }
-            }
-            final int N = luxLevels.size();
-            float[] lux = new float[N];
-            float[] nits = new float[N];
-            for (int i = 0; i < N; i++) {
-                lux[i] = luxLevels.get(i);
-                nits[i] = nitLevels.get(i);
-            }
-            return Pair.create(lux, nits);
-        }
-
-        private static float loadFloat(String val) {
-            try {
-                return Float.parseFloat(val);
-            } catch (NullPointerException | NumberFormatException e) {
-                Slog.e(TAG, "Failed to parse float loading brightness config", e);
-                return Float.NEGATIVE_INFINITY;
-            }
-        }
-
         public void saveToXml(XmlSerializer serializer) throws IOException {
             for (int i = 0; i < mConfigurations.size(); i++) {
                 final int userSerial = mConfigurations.keyAt(i);
@@ -728,27 +671,11 @@
                 if (timestamp != -1) {
                     serializer.attribute(null, ATTR_TIME_STAMP, Long.toString(timestamp));
                 }
-                saveConfigurationToXml(serializer, config);
+                config.saveToXml(serializer);
                 serializer.endTag(null, TAG_BRIGHTNESS_CONFIGURATION);
             }
         }
 
-        private static void saveConfigurationToXml(XmlSerializer serializer,
-                BrightnessConfiguration config) throws IOException {
-            serializer.startTag(null, TAG_BRIGHTNESS_CURVE);
-            if (config.getDescription() != null) {
-                serializer.attribute(null, ATTR_DESCRIPTION, config.getDescription());
-            }
-            final Pair<float[], float[]> curve = config.getCurve();
-            for (int i = 0; i < curve.first.length; i++) {
-                serializer.startTag(null, TAG_BRIGHTNESS_POINT);
-                serializer.attribute(null, ATTR_LUX, Float.toString(curve.first[i]));
-                serializer.attribute(null, ATTR_NITS, Float.toString(curve.second[i]));
-                serializer.endTag(null, TAG_BRIGHTNESS_POINT);
-            }
-            serializer.endTag(null, TAG_BRIGHTNESS_CURVE);
-        }
-
         public void dump(final PrintWriter pw, final String prefix) {
             for (int i = 0; i < mConfigurations.size(); i++) {
                 final int userSerial = mConfigurations.keyAt(i);