Don't animate screen brightness if there is a pending off transitionstable/cm-12.0-YNG1TA

When the DisplayPowerRequest policy is POLICY_OFF, a screen state
transition animation to DISPLAY_OFF is intiated. However, in
updatePowerState() the screen brightness setting, based on the current
display state, is set to normal brightness and an animation is
triggered. This causes a transient flash on some devices, which are
transitioning from a dimmed screen to screen off.

This change checks for a pending screen off transition before
triggering a screen brightness animation, to prevent the flashes.

Bug: 18136235
Change-Id: I37f9fb28b3ec8a4fdbb45920c40d25ebd50c220b

1 files changed, 7 insertions, 5 deletions

diff --git a/services/core/java/com/android/server/display/DisplayPowerController.java b/services/core/java/com/android/server/display/DisplayPowerController.java
index b1631f51b55..52f6eee752c 100644
--- a/services/core/java/com/android/server/display/DisplayPowerController.java
+++ b/services/core/java/com/android/server/display/DisplayPowerController.java
@@ -649,11 +649,13 @@ final class DisplayPowerController implements AutomaticBrightnessController.Call
 
         // Animate the screen brightness when the screen is on or dozing.
         // Skip the animation when the screen is off or suspended.
-        if (state == Display.STATE_ON || state == Display.STATE_DOZE) {
-            animateScreenBrightness(brightness,
-                    slowChange ? BRIGHTNESS_RAMP_RATE_SLOW : BRIGHTNESS_RAMP_RATE_FAST);
-        } else {
-            animateScreenBrightness(brightness, 0);
+        if (!mPendingScreenOff) {
+            if (state == Display.STATE_ON || state == Display.STATE_DOZE) {
+                animateScreenBrightness(brightness,
+                        slowChange ? BRIGHTNESS_RAMP_RATE_SLOW : BRIGHTNESS_RAMP_RATE_FAST);
+            } else {
+                animateScreenBrightness(brightness, 0);
+            }
         }
 
         // Determine whether the display is ready for use in the newly requested state.