Hiding split shade status bar for heads up notifications

Changing split shade status bar alpha so that it's dependent on shade expansion. This has two effects:
- it doesn't show on HUN (alpha = 0), which is the main issue
- it's animated on expansion and transition between launcher status bar and split shade status bar is less jarring - this likely needs to be adjusted in the future but for now should be good enough.

Also splitting getNotificationScrimAlpha into two separate ethods as it's usage got weirder over time and inline comments in method calls got outdated.
Also moving split of getNotificationScrimAlpha to seperate object - it feels a bit weird that this very specific interpolation calculation is in the general Interpolation object.

Bug: 198595419
Test: Receive HUN and NOT see split shade status bar on top of regular status bar
Change-Id: I3bfcd0697da4798fc845d2636303fd3616e131fc

packages/SystemUI/animation/src/com/android/systemui/animation/Interpolators.java

@@ -197,26 +197,6 @@ public class Interpolators {
         return MathUtils.max(0.0f, (float) (1.0f - Math.exp(-4 * progress)));
     }
 
-    /**
-     * Interpolate alpha for notifications background scrim during shade expansion.
-     * @param fraction Shade expansion fraction
-     * @param forUiContent If we want the alpha of the scrims, or ui that's on top of them.
-     */
-    public static float getNotificationScrimAlpha(float fraction, boolean forUiContent) {
-        if (forUiContent) {
-            fraction = MathUtils.constrainedMap(0f, 1f, 0.3f, 1f, fraction);
-        } else {
-            fraction = MathUtils.constrainedMap(0f, 1f, 0f, 0.5f, fraction);
-        }
-        fraction = fraction * 1.2f - 0.2f;
-        if (fraction <= 0) {
-            return 0;
-        } else {
-            final float oneMinusFrac = 1f - fraction;
-            return (float) (1f - 0.5f * (1f - Math.cos(3.14159f * oneMinusFrac * oneMinusFrac)));
-        }
-    }
-
     // Create the default emphasized interpolator
     private static PathInterpolator createEmphasizedInterpolator() {
         Path path = new Path();

packages/SystemUI/animation/src/com/android/systemui/animation/ShadeInterpolation.kt

@@ -0,0 +1,37 @@
+package com.android.systemui.animation
+
+import android.util.MathUtils
+
+object ShadeInterpolation {
+
+    /**
+     * Interpolate alpha for notification background scrim during shade expansion.
+     * @param fraction Shade expansion fraction
+     */
+    @JvmStatic
+    fun getNotificationScrimAlpha(fraction: Float): Float {
+        val mappedFraction = MathUtils.constrainedMap(0f, 1f, 0f, 0.5f, fraction)
+        return interpolateEaseInOut(mappedFraction)
+    }
+
+    /**
+     * Interpolate alpha for shade content during shade expansion.
+     * @param fraction Shade expansion fraction
+     */
+    @JvmStatic
+    fun getContentAlpha(fraction: Float): Float {
+        val mappedFraction = MathUtils.constrainedMap(0f, 1f, 0.3f, 1f, fraction)
+        return interpolateEaseInOut(mappedFraction)
+    }
+
+    private fun interpolateEaseInOut(fraction: Float): Float {
+        val mappedFraction = fraction * 1.2f - 0.2f
+        return if (mappedFraction <= 0) {
+            0f
+        } else {
+            val oneMinusFrac = 1f - mappedFraction
+            (1f - 0.5f * (1f - Math.cos((3.14159f * oneMinusFrac * oneMinusFrac).toDouble())))
+                    .toFloat()
+        }
+    }
+}

packages/SystemUI/src/com/android/systemui/qs/QSFragment.java

@@ -39,6 +39,7 @@ import androidx.annotation.VisibleForTesting;
 
 import com.android.systemui.R;
 import com.android.systemui.animation.Interpolators;
+import com.android.systemui.animation.ShadeInterpolation;
 import com.android.systemui.dump.DumpManager;
 import com.android.systemui.media.MediaHost;
 import com.android.systemui.plugins.FalsingManager;
@@ -573,7 +574,7 @@ public class QSFragment extends LifecycleFragment implements QS, CommandQueue.Ca
         } else if (progress > 0 && view.getVisibility() != View.VISIBLE) {
             view.setVisibility((View.VISIBLE));
         }
-        float alpha = Interpolators.getNotificationScrimAlpha(progress, true /* uiContent */);
+        float alpha = ShadeInterpolation.getContentAlpha(progress);
         view.setAlpha(alpha);
     }
 

packages/SystemUI/src/com/android/systemui/statusbar/NotificationShadeDepthController.kt

@@ -32,6 +32,7 @@ import androidx.dynamicanimation.animation.SpringAnimation
 import androidx.dynamicanimation.animation.SpringForce
 import com.android.systemui.Dumpable
 import com.android.systemui.animation.Interpolators
+import com.android.systemui.animation.ShadeInterpolation
 import com.android.systemui.dagger.SysUISingleton
 import com.android.systemui.dump.DumpManager
 import com.android.systemui.plugins.statusbar.StatusBarStateController
@@ -184,12 +185,12 @@ class NotificationShadeDepthController @Inject constructor(
         val animationRadius = MathUtils.constrain(shadeAnimation.radius,
                 blurUtils.minBlurRadius.toFloat(), blurUtils.maxBlurRadius.toFloat())
         val expansionRadius = blurUtils.blurRadiusOfRatio(
-                Interpolators.getNotificationScrimAlpha(
-                        if (shouldApplyShadeBlur()) shadeExpansion else 0f, false))
+                ShadeInterpolation.getNotificationScrimAlpha(
+                        if (shouldApplyShadeBlur()) shadeExpansion else 0f))
         var combinedBlur = (expansionRadius * INTERACTION_BLUR_FRACTION +
                 animationRadius * ANIMATION_BLUR_FRACTION)
-        val qsExpandedRatio = Interpolators.getNotificationScrimAlpha(qsPanelExpansion,
-                false /* notification */) * shadeExpansion
+        val qsExpandedRatio = ShadeInterpolation.getNotificationScrimAlpha(qsPanelExpansion) *
+                shadeExpansion
         combinedBlur = max(combinedBlur, blurUtils.blurRadiusOfRatio(qsExpandedRatio))
         combinedBlur = max(combinedBlur, blurUtils.blurRadiusOfRatio(transitionToFullShadeProgress))
         var shadeRadius = max(combinedBlur, wakeAndUnlockBlurRadius)

packages/SystemUI/src/com/android/systemui/statusbar/NotificationShelf.java

@@ -31,7 +31,7 @@ import android.view.animation.PathInterpolator;
 
 import com.android.internal.annotations.VisibleForTesting;
 import com.android.systemui.R;
-import com.android.systemui.animation.Interpolators;
+import com.android.systemui.animation.ShadeInterpolation;
 import com.android.systemui.plugins.statusbar.StatusBarStateController.StateListener;
 import com.android.systemui.statusbar.notification.NotificationUtils;
 import com.android.systemui.statusbar.notification.row.ActivatableNotificationView;
@@ -168,8 +168,8 @@ public class NotificationShelf extends ActivatableNotificationView implements
             viewState.clipTopAmount = 0;
 
             if (ambientState.isExpansionChanging() && !ambientState.isOnKeyguard()) {
-                viewState.alpha = Interpolators.getNotificationScrimAlpha(
-                        ambientState.getExpansionFraction(), true /* notification */);
+                float expansion = ambientState.getExpansionFraction();
+                viewState.alpha = ShadeInterpolation.getContentAlpha(expansion);
             } else {
                 viewState.alpha = 1f - ambientState.getHideAmount();
             }

packages/SystemUI/src/com/android/systemui/statusbar/notification/stack/StackScrollAlgorithm.java

@@ -25,7 +25,7 @@ import android.view.View;
 import android.view.ViewGroup;
 
 import com.android.systemui.R;
-import com.android.systemui.animation.Interpolators;
+import com.android.systemui.animation.ShadeInterpolation;
 import com.android.systemui.statusbar.NotificationShelf;
 import com.android.systemui.statusbar.notification.row.ActivatableNotificationView;
 import com.android.systemui.statusbar.notification.row.ExpandableNotificationRow;
@@ -407,8 +407,8 @@ public class StackScrollAlgorithm {
             viewState.alpha = 1f - ambientState.getHideAmount();
         } else if (ambientState.isExpansionChanging()) {
             // Adjust alpha for shade open & close.
-            viewState.alpha = Interpolators.getNotificationScrimAlpha(
-                    ambientState.getExpansionFraction(), true /* notification */);
+            float expansion = ambientState.getExpansionFraction();
+            viewState.alpha = ShadeInterpolation.getContentAlpha(expansion);
         }
 
         if (ambientState.isShadeExpanded() && view.mustStayOnScreen()

packages/SystemUI/src/com/android/systemui/statusbar/phone/NotificationPanelViewController.java

@@ -1247,6 +1247,7 @@ public class NotificationPanelViewController extends PanelViewController {
             stackScrollerPadding = mClockPositionResult.stackScrollerPaddingExpanded;
         }
 
+        mSplitShadeHeaderController.setShadeExpandedFraction(getExpandedFraction());
         mNotificationStackScrollLayoutController.setIntrinsicPadding(stackScrollerPadding);
         mKeyguardBottomArea.setAntiBurnInOffsetX(mClockPositionResult.clockX);
 

packages/SystemUI/src/com/android/systemui/statusbar/phone/ScrimController.java

@@ -47,7 +47,7 @@ import com.android.settingslib.Utils;
 import com.android.systemui.DejankUtils;
 import com.android.systemui.Dumpable;
 import com.android.systemui.R;
-import com.android.systemui.animation.Interpolators;
+import com.android.systemui.animation.ShadeInterpolation;
 import com.android.systemui.dagger.SysUISingleton;
 import com.android.systemui.dagger.qualifiers.Main;
 import com.android.systemui.dock.DockManager;
@@ -579,8 +579,7 @@ public class ScrimController implements ViewTreeObserver.OnPreDrawListener, Dump
         if (isNaN(expansionFraction)) {
             return;
         }
-        expansionFraction = Interpolators
-                .getNotificationScrimAlpha(expansionFraction, false /* notification */);
+        expansionFraction = ShadeInterpolation.getNotificationScrimAlpha(expansionFraction);
         boolean qsBottomVisible = qsPanelBottomY > 0;
         if (mQsExpansion != expansionFraction || mQsBottomVisible != qsBottomVisible) {
             mQsExpansion = expansionFraction;
@@ -915,8 +914,7 @@ public class ScrimController implements ViewTreeObserver.OnPreDrawListener, Dump
     }
 
     private float getInterpolatedFraction() {
-        return Interpolators.getNotificationScrimAlpha(
-                mPanelExpansionFraction, false /* notification */);
+        return ShadeInterpolation.getNotificationScrimAlpha(mPanelExpansionFraction);
     }
 
     private void setScrimAlpha(ScrimView scrim, float alpha) {

packages/SystemUI/src/com/android/systemui/statusbar/phone/SplitShadeHeaderController.kt

@@ -18,6 +18,7 @@ package com.android.systemui.statusbar.phone
 
 import android.view.View
 import com.android.systemui.R
+import com.android.systemui.animation.ShadeInterpolation
 import com.android.systemui.battery.BatteryMeterView
 import com.android.systemui.battery.BatteryMeterViewController
 import com.android.systemui.flags.FeatureFlags
@@ -53,6 +54,14 @@ class SplitShadeHeaderController @Inject constructor(
             updateVisibility()
         }
 
+    var shadeExpandedFraction = -1f
+        set(value) {
+            if (visible && field != value) {
+                statusBar.alpha = ShadeInterpolation.getContentAlpha(value)
+                field = value
+            }
+        }
+
     init {
         batteryMeterViewController.init()
         val batteryIcon: BatteryMeterView = statusBar.findViewById(R.id.batteryRemainingIcon)

packages/SystemUI/tests/src/com/android/systemui/statusbar/NotificationShadeDepthControllerTest.kt

@@ -24,7 +24,7 @@ import android.view.View
 import android.view.ViewRootImpl
 import androidx.test.filters.SmallTest
 import com.android.systemui.SysuiTestCase
-import com.android.systemui.animation.Interpolators
+import com.android.systemui.animation.ShadeInterpolation
 import com.android.systemui.dump.DumpManager
 import com.android.systemui.plugins.statusbar.StatusBarStateController
 import com.android.systemui.statusbar.phone.BiometricUnlockController
@@ -208,7 +208,7 @@ class NotificationShadeDepthControllerTest : SysuiTestCase() {
         notificationShadeDepthController.onPanelExpansionChanged(1f, tracking = false)
         notificationShadeDepthController.updateBlurCallback.doFrame(0)
         verify(wallpaperController).setNotificationShadeZoom(
-                eq(Interpolators.getNotificationScrimAlpha(0.25f, false /* notifications */)))
+                eq(ShadeInterpolation.getNotificationScrimAlpha(0.25f)))
     }
 
     @Test