Make PowerManagerService use float for brightness

Change the override brightness values to use float instead of an int in
PowerManagerService.

Bug: 150671605

Test: WmTests:RootWindowContainerTests
FrameworksServicesTests:PowerManagerServiceTest
CtsOsTestCases:android.os.cts.PowerManagerTest
FrameworksCoreTests:android.os.PowerManagerTest

Change-Id: I97e97e1500dac7f8beb112812d1347fa420afbf7

3 files changed, 28 insertions, 34 deletions

diff --git a/core/java/android/os/PowerManagerInternal.java b/core/java/android/os/PowerManagerInternal.java
index 51f01cac8138..653a5594f495 100644
--- a/core/java/android/os/PowerManagerInternal.java
+++ b/core/java/android/os/PowerManagerInternal.java
@@ -102,9 +102,9 @@ public abstract class PowerManagerInternal {
      *
      * This method must only be called by the window manager.
      *
-     * @param brightness The overridden brightness, or -1 to disable the override.
+     * @param brightness The overridden brightness, or Float.NaN to disable the override.
      */
-    public abstract void setScreenBrightnessOverrideFromWindowManager(int brightness);
+    public abstract void setScreenBrightnessOverrideFromWindowManager(float brightness);
 
     /**
      * Used by the window manager to override the user activity timeout based on the
diff --git a/services/core/java/com/android/server/power/PowerManagerService.java b/services/core/java/com/android/server/power/PowerManagerService.java
index b41bc5c2dc51..cd6c5bfaeb79 100644
--- a/services/core/java/com/android/server/power/PowerManagerService.java
+++ b/services/core/java/com/android/server/power/PowerManagerService.java
@@ -513,10 +513,7 @@ public final class PowerManagerService extends SystemService
 
     // The screen brightness setting override from the window manager
     // to allow the current foreground activity to override the brightness.
-    // Use -1 to disable.
-    private int mScreenBrightnessOverrideFromWindowManager = -1;
-
-    private float mScreenBrightnessOverrideFromWindowManagerFloat =
+    private float mScreenBrightnessOverrideFromWindowManager =
             PowerManager.BRIGHTNESS_INVALID_FLOAT;
 
     // The window manager has determined the user to be inactive via other means.
@@ -2846,7 +2843,7 @@ public final class PowerManagerService extends SystemService
                 screenBrightnessOverride = mScreenBrightnessSettingDefault;
             } else if (isValidBrightness(mScreenBrightnessOverrideFromWindowManager)) {
                 autoBrightness = false;
-                screenBrightnessOverride = mScreenBrightnessOverrideFromWindowManagerFloat;
+                screenBrightnessOverride = mScreenBrightnessOverrideFromWindowManager;
             } else {
                 autoBrightness = (mScreenBrightnessModeSetting ==
                         Settings.System.SCREEN_BRIGHTNESS_MODE_AUTOMATIC);
@@ -2927,8 +2924,8 @@ public final class PowerManagerService extends SystemService
         return !mIsVrModeEnabled && mScreenBrightnessBoostInProgress;
     }
 
-    private static boolean isValidBrightness(int value) {
-        return value >= 0 && value <= 255;
+    private static boolean isValidBrightness(float value) {
+        return value >= PowerManager.BRIGHTNESS_MIN && value <= PowerManager.BRIGHTNESS_MAX;
     }
 
     @VisibleForTesting
@@ -3583,13 +3580,11 @@ public final class PowerManagerService extends SystemService
         }
     }
 
-    // TODO(brightnessfloat): change to float
-    private void setScreenBrightnessOverrideFromWindowManagerInternal(int brightness) {
+    private void setScreenBrightnessOverrideFromWindowManagerInternal(float brightness) {
         synchronized (mLock) {
-            if (mScreenBrightnessOverrideFromWindowManager != brightness) {
+            if (!BrightnessSynchronizer.floatEquals(mScreenBrightnessOverrideFromWindowManager,
+                    brightness)) {
                 mScreenBrightnessOverrideFromWindowManager = brightness;
-                mScreenBrightnessOverrideFromWindowManagerFloat =
-                        BrightnessSynchronizer.brightnessIntToFloat(mContext, brightness);
                 mDirty |= DIRTY_SETTINGS;
                 updatePowerStateLocked();
             }
@@ -3890,8 +3885,8 @@ public final class PowerManagerService extends SystemService
                     + isMaximumScreenOffTimeoutFromDeviceAdminEnforcedLocked() + ")");
             pw.println("  mStayOnWhilePluggedInSetting=" + mStayOnWhilePluggedInSetting);
             pw.println("  mScreenBrightnessModeSetting=" + mScreenBrightnessModeSetting);
-            pw.println("  mScreenBrightnessOverrideFromWindowManagerFloat="
-                    + mScreenBrightnessOverrideFromWindowManagerFloat);
+            pw.println("  mScreenBrightnessOverrideFromWindowManager="
+                    + mScreenBrightnessOverrideFromWindowManager);
             pw.println("  mUserActivityTimeoutOverrideFromWindowManager="
                     + mUserActivityTimeoutOverrideFromWindowManager);
             pw.println("  mUserInactiveOverrideFromWindowManager="
@@ -4231,7 +4226,7 @@ public final class PowerManagerService extends SystemService
             proto.write(
                     PowerServiceSettingsAndConfigurationDumpProto
                             .SCREEN_BRIGHTNESS_OVERRIDE_FROM_WINDOW_MANAGER,
-                    mScreenBrightnessOverrideFromWindowManagerFloat);
+                    mScreenBrightnessOverrideFromWindowManager);
             proto.write(
                     PowerServiceSettingsAndConfigurationDumpProto
                             .USER_ACTIVITY_TIMEOUT_OVERRIDE_FROM_WINDOW_MANAGER_MS,
@@ -5430,10 +5425,10 @@ public final class PowerManagerService extends SystemService
     @VisibleForTesting
     final class LocalService extends PowerManagerInternal {
         @Override
-        public void setScreenBrightnessOverrideFromWindowManager(int screenBrightness) {
-            if (screenBrightness < PowerManager.BRIGHTNESS_DEFAULT
-                    || screenBrightness > PowerManager.BRIGHTNESS_ON) {
-                screenBrightness = PowerManager.BRIGHTNESS_DEFAULT;
+        public void setScreenBrightnessOverrideFromWindowManager(float screenBrightness) {
+            if (screenBrightness < PowerManager.BRIGHTNESS_MIN
+                    || screenBrightness > PowerManager.BRIGHTNESS_MAX) {
+                screenBrightness = PowerManager.BRIGHTNESS_INVALID_FLOAT;
             }
             setScreenBrightnessOverrideFromWindowManagerInternal(screenBrightness);
         }
diff --git a/services/core/java/com/android/server/wm/RootWindowContainer.java b/services/core/java/com/android/server/wm/RootWindowContainer.java
index 2764b121cc00..c532f01bd253 100644
--- a/services/core/java/com/android/server/wm/RootWindowContainer.java
+++ b/services/core/java/com/android/server/wm/RootWindowContainer.java
@@ -178,7 +178,7 @@ class RootWindowContainer extends WindowContainer<DisplayContent>
 
     private Object mLastWindowFreezeSource = null;
     private Session mHoldScreen = null;
-    private float mScreenBrightness = -1;
+    private float mScreenBrightnessOverride = PowerManager.BRIGHTNESS_INVALID_FLOAT;
     private long mUserActivityTimeout = -1;
     private boolean mUpdateRotation = false;
     // Following variables are for debugging screen wakelock only.
@@ -826,7 +826,7 @@ class RootWindowContainer extends WindowContainer<DisplayContent>
         }
 
         mHoldScreen = null;
-        mScreenBrightness = -1;
+        mScreenBrightnessOverride = PowerManager.BRIGHTNESS_INVALID_FLOAT;
         mUserActivityTimeout = -1;
         mObscureApplicationContentOnSecondaryDisplays = false;
         mSustainedPerformanceModeCurrent = false;
@@ -936,12 +936,14 @@ class RootWindowContainer extends WindowContainer<DisplayContent>
 
         mWmService.setHoldScreenLocked(mHoldScreen);
         if (!mWmService.mDisplayFrozen) {
-            final int brightness = mScreenBrightness < 0 || mScreenBrightness > 1.0f
-                    ? -1 : toBrightnessOverride(mScreenBrightness);
-
+            final float brightnessOverride = mScreenBrightnessOverride < PowerManager.BRIGHTNESS_MIN
+                    || mScreenBrightnessOverride > PowerManager.BRIGHTNESS_MAX
+                    ? PowerManager.BRIGHTNESS_INVALID_FLOAT : mScreenBrightnessOverride;
+            int brightnessFloatAsIntBits = Float.floatToIntBits(brightnessOverride);
             // Post these on a handler such that we don't call into power manager service while
             // holding the window manager lock to avoid lock contention with power manager lock.
-            mHandler.obtainMessage(SET_SCREEN_BRIGHTNESS_OVERRIDE, brightness, 0).sendToTarget();
+            mHandler.obtainMessage(SET_SCREEN_BRIGHTNESS_OVERRIDE, brightnessFloatAsIntBits,
+                    0).sendToTarget();
             mHandler.obtainMessage(SET_USER_ACTIVITY_TIMEOUT, mUserActivityTimeout).sendToTarget();
         }
 
@@ -1125,8 +1127,9 @@ class RootWindowContainer extends WindowContainer<DisplayContent>
                                 + "has FLAG_KEEP_SCREEN_ON!!! called by%s",
                         w, Debug.getCallers(10));
             }
-            if (!syswin && w.mAttrs.screenBrightness >= 0 && mScreenBrightness < 0) {
-                mScreenBrightness = w.mAttrs.screenBrightness;
+            if (!syswin && w.mAttrs.screenBrightness >= 0
+                    && Float.isNaN(mScreenBrightnessOverride)) {
+                mScreenBrightnessOverride = w.mAttrs.screenBrightness;
             }
 
             final int type = attrs.type;
@@ -1190,10 +1193,6 @@ class RootWindowContainer extends WindowContainer<DisplayContent>
         return doRequest;
     }
 
-    private static int toBrightnessOverride(float value) {
-        return (int)(value * PowerManager.BRIGHTNESS_ON);
-    }
-
     private final class MyHandler extends Handler {
 
         public MyHandler(Looper looper) {
@@ -1205,7 +1204,7 @@ class RootWindowContainer extends WindowContainer<DisplayContent>
             switch (msg.what) {
                 case SET_SCREEN_BRIGHTNESS_OVERRIDE:
                     mWmService.mPowerManagerInternal.setScreenBrightnessOverrideFromWindowManager(
-                            msg.arg1);
+                            Float.intBitsToFloat(msg.arg1));
                     break;
                 case SET_USER_ACTIVITY_TIMEOUT:
                     mWmService.mPowerManagerInternal.