Merge "[Status Bar Refactor] 3/N: Move PanelBar#onPanelExpansionChanged into PanelExpansionStateManager." into sc-v2-dev

packages/SystemUI/src/com/android/systemui/biometrics/UdfpsAnimationViewController.java

@@ -63,13 +63,13 @@ abstract class UdfpsAnimationViewController<T extends UdfpsAnimationView>
 
     @Override
     protected void onViewAttached() {
-        mPanelExpansionStateManager.addListener(mPanelExpansionListener);
+        mPanelExpansionStateManager.addExpansionListener(mPanelExpansionListener);
         mDumpManger.registerDumpable(getDumpTag(), this);
     }
 
     @Override
     protected void onViewDetached() {
-        mPanelExpansionStateManager.removeListener(mPanelExpansionListener);
+        mPanelExpansionStateManager.removeExpansionListener(mPanelExpansionListener);
         mDumpManger.unregisterDumpable(getDumpTag());
     }
 

packages/SystemUI/src/com/android/systemui/biometrics/UdfpsKeyguardViewController.java

@@ -126,7 +126,7 @@ public class UdfpsKeyguardViewController extends UdfpsAnimationViewController<Ud
         mInputBouncerHiddenAmount = KeyguardBouncer.EXPANSION_HIDDEN;
         mIsBouncerVisible = mKeyguardViewManager.bouncerIsOrWillBeShowing();
         mConfigurationController.addCallback(mConfigurationListener);
-        mPanelExpansionStateManager.addListener(mPanelExpansionListener);
+        mPanelExpansionStateManager.addExpansionListener(mPanelExpansionListener);
         updateAlpha();
         updatePauseAuth();
 
@@ -145,7 +145,7 @@ public class UdfpsKeyguardViewController extends UdfpsAnimationViewController<Ud
         mKeyguardViewManager.removeAlternateAuthInterceptor(mAlternateAuthInterceptor);
         mKeyguardUpdateMonitor.requestFaceAuthOnOccludingApp(false);
         mConfigurationController.removeCallback(mConfigurationListener);
-        mPanelExpansionStateManager.removeListener(mPanelExpansionListener);
+        mPanelExpansionStateManager.removeExpansionListener(mPanelExpansionListener);
         if (mLockScreenShadeTransitionController.getUdfpsKeyguardViewController() == this) {
             mLockScreenShadeTransitionController.setUdfpsKeyguardViewController(null);
         }

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

@@ -53,6 +53,7 @@ import com.android.systemui.statusbar.events.SystemStatusAnimationScheduler;
 import com.android.systemui.statusbar.phone.StatusBarIconController.DarkIconManager;
 import com.android.systemui.statusbar.phone.ongoingcall.OngoingCallController;
 import com.android.systemui.statusbar.phone.ongoingcall.OngoingCallListener;
+import com.android.systemui.statusbar.phone.panelstate.PanelExpansionStateManager;
 import com.android.systemui.statusbar.policy.EncryptionHelper;
 import com.android.systemui.statusbar.policy.KeyguardStateController;
 
@@ -101,6 +102,7 @@ public class CollapsedStatusBarFragment extends Fragment implements CommandQueue
     private final StatusBarLocationPublisher mLocationPublisher;
     private final FeatureFlags mFeatureFlags;
     private final NotificationIconAreaController mNotificationIconAreaController;
+    private final PanelExpansionStateManager mPanelExpansionStateManager;
     private final StatusBarIconController mStatusBarIconController;
 
     private List<String> mBlockedIcons = new ArrayList<>();
@@ -126,6 +128,7 @@ public class CollapsedStatusBarFragment extends Fragment implements CommandQueue
             SystemStatusAnimationScheduler animationScheduler,
             StatusBarLocationPublisher locationPublisher,
             NotificationIconAreaController notificationIconAreaController,
+            PanelExpansionStateManager panelExpansionStateManager,
             FeatureFlags featureFlags,
             Lazy<Optional<StatusBar>> statusBarOptionalLazy,
             StatusBarIconController statusBarIconController,
@@ -140,6 +143,7 @@ public class CollapsedStatusBarFragment extends Fragment implements CommandQueue
         mAnimationScheduler = animationScheduler;
         mLocationPublisher = locationPublisher;
         mNotificationIconAreaController = notificationIconAreaController;
+        mPanelExpansionStateManager = panelExpansionStateManager;
         mFeatureFlags = featureFlags;
         mStatusBarOptionalLazy = statusBarOptionalLazy;
         mStatusBarIconController = statusBarIconController;
@@ -363,7 +367,7 @@ public class CollapsedStatusBarFragment extends Fragment implements CommandQueue
 
     private boolean shouldHideNotificationIcons() {
         final Optional<StatusBar> statusBarOptional = mStatusBarOptionalLazy.get();
-        if (!mStatusBar.isClosed()
+        if (!mPanelExpansionStateManager.isClosed()
                 && statusBarOptional.map(
                         StatusBar::hideStatusBarIconsWhenExpanded).orElse(false)) {
             return true;
@@ -409,7 +413,7 @@ public class CollapsedStatusBarFragment extends Fragment implements CommandQueue
      * don't set the clock GONE otherwise it'll mess up the animation.
      */
     private int clockHiddenMode() {
-        if (!mStatusBar.isClosed() && !mKeyguardStateController.isShowing()
+        if (!mPanelExpansionStateManager.isClosed() && !mKeyguardStateController.isShowing()
                 && !mStatusBarStateController.isDozing()) {
             return View.INVISIBLE;
         }

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

@@ -35,9 +35,9 @@ import static com.android.systemui.statusbar.StatusBarState.KEYGUARD;
 import static com.android.systemui.statusbar.StatusBarState.SHADE;
 import static com.android.systemui.statusbar.StatusBarState.SHADE_LOCKED;
 import static com.android.systemui.statusbar.notification.stack.NotificationStackScrollLayout.ROWS_ALL;
-import static com.android.systemui.statusbar.phone.PanelBar.STATE_CLOSED;
+import static com.android.systemui.statusbar.phone.panelstate.PanelExpansionStateManagerKt.STATE_CLOSED;
-import static com.android.systemui.statusbar.phone.PanelBar.STATE_OPEN;
+import static com.android.systemui.statusbar.phone.panelstate.PanelExpansionStateManagerKt.STATE_OPEN;
-import static com.android.systemui.statusbar.phone.PanelBar.STATE_OPENING;
+import static com.android.systemui.statusbar.phone.panelstate.PanelExpansionStateManagerKt.STATE_OPENING;
 
 import static java.lang.Float.isNaN;
 
@@ -173,6 +173,7 @@ import com.android.systemui.statusbar.notification.stack.StackStateAnimator;
 import com.android.systemui.statusbar.phone.LockscreenGestureLogger.LockscreenUiEvent;
 import com.android.systemui.statusbar.phone.dagger.StatusBarComponent;
 import com.android.systemui.statusbar.phone.panelstate.PanelExpansionStateManager;
+import com.android.systemui.statusbar.phone.panelstate.PanelState;
 import com.android.systemui.statusbar.policy.ConfigurationController;
 import com.android.systemui.statusbar.policy.KeyguardQsUserSwitchController;
 import com.android.systemui.statusbar.policy.KeyguardStateController;
@@ -782,6 +783,8 @@ public class NotificationPanelViewController extends PanelViewController {
                 new DynamicPrivacyControlListener();
         dynamicPrivacyController.addListener(dynamicPrivacyControlListener);
 
+        panelExpansionStateManager.addStateListener(this::onPanelStateChanged);
+
         mBottomAreaShadeAlphaAnimator = ValueAnimator.ofFloat(1f, 0);
         mBottomAreaShadeAlphaAnimator.addUpdateListener(animation -> {
             mBottomAreaShadeAlpha = (float) animation.getAnimatedValue();
@@ -1561,7 +1564,7 @@ public class NotificationPanelViewController extends PanelViewController {
             // it's possible that nothing animated, so we replicate the termination
             // conditions of panelExpansionChanged here
             // TODO(b/200063118): This can likely go away in a future refactor CL.
-            mBar.updateState(STATE_CLOSED);
+            getPanelExpansionStateManager().updateState(STATE_CLOSED);
         }
     }
 
@@ -1646,7 +1649,7 @@ public class NotificationPanelViewController extends PanelViewController {
 
     @Override
     public void fling(float vel, boolean expand) {
-        GestureRecorder gr = ((PhoneStatusBarView) mBar).mBar.getGestureRecorder();
+        GestureRecorder gr = mStatusBar.getGestureRecorder();
         if (gr != null) {
             gr.tag("fling " + ((vel > 0) ? "open" : "closed"), "notifications,v=" + vel);
         }
@@ -4672,37 +4675,27 @@ public class NotificationPanelViewController extends PanelViewController {
         mView.removeCallbacks(mMaybeHideExpandedRunnable);
     }
 
-    private final PanelBar.PanelStateChangeListener mPanelStateChangeListener =
+    @PanelState
-            new PanelBar.PanelStateChangeListener() {
+    private int mCurrentPanelState = STATE_CLOSED;
 
-                @PanelBar.PanelState
+    private void onPanelStateChanged(@PanelState int state) {
-                private int mCurrentState = STATE_CLOSED;
+        mAmbientState.setIsShadeOpening(state == STATE_OPENING);
+        updateQSExpansionEnabledAmbient();
 
-                @Override
+        if (state == STATE_OPEN && mCurrentPanelState != state) {
-                public void onStateChanged(@PanelBar.PanelState int state) {
+            mView.sendAccessibilityEvent(AccessibilityEvent.TYPE_WINDOW_STATE_CHANGED);
-                    mAmbientState.setIsShadeOpening(state == STATE_OPENING);
+        }
-                    updateQSExpansionEnabledAmbient();
+        if (state == STATE_OPENING) {
-
+            mStatusBar.makeExpandedVisible(false);
-                    if (state == STATE_OPEN && mCurrentState != state) {
+        }
-                        mView.sendAccessibilityEvent(AccessibilityEvent.TYPE_WINDOW_STATE_CHANGED);
+        if (state == STATE_CLOSED) {
-                    }
+            // Close the status bar in the next frame so we can show the end of the
-                    if (state == STATE_OPENING) {
+            // animation.
-                        mStatusBar.makeExpandedVisible(false);
+            mView.post(mMaybeHideExpandedRunnable);
-                    }
+        }
-                    if (state == STATE_CLOSED) {
+        mCurrentPanelState = state;
-                        // Close the status bar in the next frame so we can show the end of the
-                        // animation.
-                        mView.post(mMaybeHideExpandedRunnable);
-                    }
-                    mCurrentState = state;
-                }
-            };
-
-    public PanelBar.PanelStateChangeListener getPanelStateChangeListener() {
-        return mPanelStateChangeListener;
     }
 
-
     /** Returns the handler that the status bar should forward touches to. */
     public PhoneStatusBarView.TouchEventHandler getStatusBarTouchEventHandler() {
         return getTouchHandler()::onTouchForwardedFromStatusBar;

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

@@ -447,7 +447,7 @@ public class NotificationShadeWindowViewController {
         setDragDownHelper(mLockscreenShadeTransitionController.getTouchHelper());
 
         mDepthController.setRoot(mView);
-        mPanelExpansionStateManager.addListener(mDepthController);
+        mPanelExpansionStateManager.addExpansionListener(mDepthController);
     }
 
     public NotificationShadeWindowView getView() {

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

@@ -1,159 +0,0 @@
-/*
- * Copyright (C) 2012 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 com.android.systemui.statusbar.phone;
-
-import static java.lang.Float.isNaN;
-import static java.lang.annotation.RetentionPolicy.SOURCE;
-
-import android.annotation.IntDef;
-import android.content.Context;
-import android.os.Bundle;
-import android.os.Parcelable;
-import android.util.AttributeSet;
-import android.util.Log;
-import android.widget.FrameLayout;
-
-import androidx.annotation.Nullable;
-
-import java.lang.annotation.Retention;
-
-public abstract class PanelBar extends FrameLayout {
-    public static final boolean DEBUG = false;
-    public static final String TAG = PanelBar.class.getSimpleName();
-    private static final boolean SPEW = false;
-    private static final String PANEL_BAR_SUPER_PARCELABLE = "panel_bar_super_parcelable";
-    private static final String STATE = "state";
-    protected float mPanelFraction;
-
-    public static final void LOG(String fmt, Object... args) {
-        if (!DEBUG) return;
-        Log.v(TAG, String.format(fmt, args));
-    }
-
-    /** Enum for the current state of the panel. */
-    @Retention(SOURCE)
-    @IntDef({STATE_CLOSED, STATE_OPENING, STATE_OPEN})
-    @interface PanelState {}
-    public static final int STATE_CLOSED = 0;
-    public static final int STATE_OPENING = 1;
-    public static final int STATE_OPEN = 2;
-
-    @Nullable private PanelStateChangeListener mPanelStateChangeListener;
-    private int mState = STATE_CLOSED;
-    private boolean mTracking;
-
-    /** Updates the panel state if necessary. */
-    public void updateState(@PanelState int state) {
-        if (DEBUG) LOG("update state: %d -> %d", mState, state);
-        if (mState != state) {
-            go(state);
-        }
-    }
-
-    private void go(@PanelState int state) {
-        if (DEBUG) LOG("go state: %d -> %d", mState, state);
-        mState = state;
-        if (mPanelStateChangeListener != null) {
-            mPanelStateChangeListener.onStateChanged(state);
-        }
-    }
-
-    @Override
-    protected Parcelable onSaveInstanceState() {
-        Bundle bundle = new Bundle();
-        bundle.putParcelable(PANEL_BAR_SUPER_PARCELABLE, super.onSaveInstanceState());
-        bundle.putInt(STATE, mState);
-        return bundle;
-    }
-
-    @Override
-    protected void onRestoreInstanceState(Parcelable state) {
-        if (state == null || !(state instanceof Bundle)) {
-            super.onRestoreInstanceState(state);
-            return;
-        }
-
-        Bundle bundle = (Bundle) state;
-        super.onRestoreInstanceState(bundle.getParcelable(PANEL_BAR_SUPER_PARCELABLE));
-        if (((Bundle) state).containsKey(STATE)) {
-            go(bundle.getInt(STATE, STATE_CLOSED));
-        }
-    }
-
-    public PanelBar(Context context, AttributeSet attrs) {
-        super(context, attrs);
-    }
-
-    @Override
-    protected void onFinishInflate() {
-        super.onFinishInflate();
-    }
-
-    /** Sets the listener that will be notified of panel state changes. */
-    public void setPanelStateChangeListener(PanelStateChangeListener listener) {
-        mPanelStateChangeListener = listener;
-    }
-
-    /**
-     * @param frac the fraction from the expansion in [0, 1]
-     * @param expanded whether the panel is currently expanded; this is independent from the
-     *                 fraction as the panel also might be expanded if the fraction is 0
-     */
-    public void panelExpansionChanged(float frac, boolean expanded) {
-        if (isNaN(frac)) {
-            throw new IllegalArgumentException("frac cannot be NaN");
-        }
-        boolean fullyClosed = true;
-        boolean fullyOpened = false;
-        if (SPEW) LOG("panelExpansionChanged: start state=%d, f=%.1f", mState, frac);
-        mPanelFraction = frac;
-        // adjust any other panels that may be partially visible
-        if (expanded) {
-            if (mState == STATE_CLOSED) {
-                go(STATE_OPENING);
-            }
-            fullyClosed = false;
-            fullyOpened = frac >= 1f;
-        }
-        if (fullyOpened && !mTracking) {
-            go(STATE_OPEN);
-        } else if (fullyClosed && !mTracking && mState != STATE_CLOSED) {
-            go(STATE_CLOSED);
-        }
-
-        if (SPEW) LOG("panelExpansionChanged: end state=%d [%s%s ]", mState,
-                fullyOpened?" fullyOpened":"", fullyClosed?" fullyClosed":"");
-    }
-
-    public boolean isClosed() {
-        return mState == STATE_CLOSED;
-    }
-
-    public void onTrackingStarted() {
-        mTracking = true;
-    }
-
-    public void onTrackingStopped(boolean expand) {
-        mTracking = false;
-    }
-
-    /** An interface that will be notified of panel state changes. */
-    public interface PanelStateChangeListener {
-        /** Called when the state changes. */
-        void onStateChanged(@PanelState int state);
-    }
-}

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

@@ -23,7 +23,7 @@ import android.view.MotionEvent;
 import android.widget.FrameLayout;
 
 public abstract class PanelView extends FrameLayout {
-    public static final boolean DEBUG = PanelBar.DEBUG;
+    public static final boolean DEBUG = false;
     public static final String TAG = PanelView.class.getSimpleName();
     private PanelViewController.TouchHandler mTouchHandler;
 

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

@@ -67,7 +67,7 @@ import java.io.FileDescriptor;
 import java.io.PrintWriter;
 
 public abstract class PanelViewController {
-    public static final boolean DEBUG = PanelBar.DEBUG;
+    public static final boolean DEBUG = PanelView.DEBUG;
     public static final String TAG = PanelView.class.getSimpleName();
     private static final int NO_FIXED_DURATION = -1;
     private static final long SHADE_OPEN_SPRING_OUT_DURATION = 350L;
@@ -153,8 +153,6 @@ public abstract class PanelViewController {
     private boolean mAnimateAfterExpanding;
     private boolean mIsFlinging;
 
-    PanelBar mBar;
-
     private String mViewName;
     private float mInitialTouchY;
     private float mInitialTouchX;
@@ -462,7 +460,6 @@ public abstract class PanelViewController {
 
     protected void onTrackingStopped(boolean expand) {
         mTracking = false;
-        mBar.onTrackingStopped(expand);
         mStatusBar.onTrackingStopped(expand);
         updatePanelExpansionAndVisibility();
     }
@@ -470,7 +467,6 @@ public abstract class PanelViewController {
     protected void onTrackingStarted() {
         endClosing();
         mTracking = true;
-        mBar.onTrackingStarted();
         mStatusBar.onTrackingStarted();
         notifyExpandingStarted();
         updatePanelExpansionAndVisibility();
@@ -848,10 +844,6 @@ public abstract class PanelViewController {
         return mTracking;
     }
 
-    public void setBar(PanelBar panelBar) {
-        mBar = panelBar;
-    }
-
     public void collapse(boolean delayed, float speedUpFactor) {
         if (DEBUG) logf("collapse: " + this);
         if (canPanelBeCollapsed()) {
@@ -1089,12 +1081,9 @@ public abstract class PanelViewController {
      *   {@link #updateVisibility()}? That would allow us to make this method private.
      */
     public void updatePanelExpansionAndVisibility() {
-        if (mBar != null) {
-            mBar.panelExpansionChanged(mExpandedFraction, isExpanded());
-        }
-        updateVisibility();
         mPanelExpansionStateManager.onPanelExpansionChanged(
                 mExpandedFraction, isExpanded(), mTracking);
+        updateVisibility();
     }
 
     public boolean isExpanded() {
@@ -1453,4 +1442,8 @@ public abstract class PanelViewController {
     protected float getExpansionFraction() {
         return mExpandedFraction;
     }
+
+    protected PanelExpansionStateManager getPanelExpansionStateManager() {
+        return mPanelExpansionStateManager;
+    }
 }

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

@@ -33,6 +33,7 @@ import android.view.View;
 import android.view.ViewGroup;
 import android.view.WindowInsets;
 import android.view.accessibility.AccessibilityEvent;
+import android.widget.FrameLayout;
 import android.widget.LinearLayout;
 
 import com.android.internal.policy.SystemBarUtils;
@@ -45,10 +46,8 @@ import com.android.systemui.util.leak.RotationUtils;
 
 import java.util.Objects;
 
-public class PhoneStatusBarView extends PanelBar {
+public class PhoneStatusBarView extends FrameLayout {
     private static final String TAG = "PhoneStatusBarView";
-    private static final boolean DEBUG = StatusBar.DEBUG;
-    private static final boolean DEBUG_GESTURES = false;
     private final StatusBarContentInsetsProvider mContentInsetsProvider;
 
     StatusBar mBar;

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

@@ -271,7 +271,7 @@ public class ScrimController implements ViewTreeObserver.OnPreDrawListener, Dump
                 ScrimController.this.onThemeChanged();
             }
         });
-        panelExpansionStateManager.addListener(
+        panelExpansionStateManager.addExpansionListener(
                 (fraction, expanded, tracking) -> setRawPanelExpansionFraction(fraction)
         );
 

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

@@ -887,7 +887,7 @@ public class StatusBar extends SystemUI implements
         mStartingSurfaceOptional = startingSurfaceOptional;
         lockscreenShadeTransitionController.setStatusbar(this);
 
-        mPanelExpansionStateManager.addListener(this::onPanelExpansionChanged);
+        mPanelExpansionStateManager.addExpansionListener(this::onPanelExpansionChanged);
 
         mBubbleExpandListener =
                 (isExpanding, key) -> mContext.getMainExecutor().execute(() -> {
@@ -1128,7 +1128,7 @@ public class StatusBar extends SystemUI implements
         mNotificationLogger.setUpWithContainer(notifListContainer);
 
         mNotificationIconAreaController.setupShelf(mNotificationShelfController);
-        mPanelExpansionStateManager.addListener(mWakeUpCoordinator);
+        mPanelExpansionStateManager.addExpansionListener(mWakeUpCoordinator);
 
         mUserSwitcherController.init(mNotificationShadeWindowView);
 
@@ -1143,12 +1143,8 @@ public class StatusBar extends SystemUI implements
                     PhoneStatusBarView oldStatusBarView = mStatusBarView;
                     mStatusBarView = (PhoneStatusBarView) statusBarFragment.getView();
                     mStatusBarView.setBar(this);
-                    mStatusBarView.setPanelStateChangeListener(
-                            mNotificationPanelViewController.getPanelStateChangeListener());
                     mStatusBarView.setScrimController(mScrimController);
 
-                    mNotificationPanelViewController.setBar(mStatusBarView);
-
                     mPhoneStatusBarViewController = mPhoneStatusBarViewControllerFactory
                             .create(mStatusBarView, mNotificationPanelViewController
                                     .getStatusBarTouchEventHandler());
@@ -1200,6 +1196,7 @@ public class StatusBar extends SystemUI implements
                                 mAnimationScheduler,
                                 mStatusBarLocationPublisher,
                                 mNotificationIconAreaController,
+                                mPanelExpansionStateManager,
                                 mFeatureFlags,
                                 () -> Optional.of(this),
                                 mStatusBarIconController,

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

@@ -279,7 +279,7 @@ public class StatusBarKeyguardViewManager implements RemoteInputController.Callb
         mBouncer = mKeyguardBouncerFactory.create(container, mExpansionCallback);
         mNotificationPanelViewController = notificationPanelViewController;
         if (panelExpansionStateManager != null) {
-            panelExpansionStateManager.addListener(this);
+            panelExpansionStateManager.addExpansionListener(this);
         }
         mBypassController = bypassController;
         mNotificationContainer = notificationContainer;

packages/SystemUI/src/com/android/systemui/statusbar/phone/panelstate/PanelExpansionStateManager.kt

@@ -16,6 +16,8 @@
 
 package com.android.systemui.statusbar.phone.panelstate
 
+import android.annotation.IntDef
+import android.util.Log
 import androidx.annotation.FloatRange
 import com.android.systemui.dagger.SysUISingleton
 import javax.inject.Inject
@@ -23,42 +25,136 @@ import javax.inject.Inject
 /**
  * A class responsible for managing the notification panel's current state.
  *
- * TODO(b/200063118): Move [PanelBar.panelExpansionChanged] logic to this class and make this class
+ * TODO(b/200063118): Make this class the one source of truth for the state of panel expansion.
- *   the one source of truth for the state of panel expansion.
  */
 @SysUISingleton
 class PanelExpansionStateManager @Inject constructor() {
 
-    private val listeners: MutableList<PanelExpansionListener> = mutableListOf()
+    private val expansionListeners = mutableListOf<PanelExpansionListener>()
+    private val stateListeners = mutableListOf<PanelStateListener>()
 
+    @PanelState private var state: Int = STATE_CLOSED
     @FloatRange(from = 0.0, to = 1.0) private var fraction: Float = 0f
     private var expanded: Boolean = false
     private var tracking: Boolean = false
 
     /**
-     * Adds a listener that will be notified when the panel expansion has changed.
+     * Adds a listener that will be notified when the panel expansion fraction has changed.
      *
      * Listener will also be immediately notified with the current values.
      */
-    fun addListener(listener: PanelExpansionListener) {
+    fun addExpansionListener(listener: PanelExpansionListener) {
-        listeners.add(listener)
+        expansionListeners.add(listener)
         listener.onPanelExpansionChanged(fraction, expanded, tracking)
     }
 
-    /** Removes a listener. */
+    /** Removes an expansion listener. */
-    fun removeListener(listener: PanelExpansionListener) {
+    fun removeExpansionListener(listener: PanelExpansionListener) {
-        listeners.remove(listener)
+        expansionListeners.remove(listener)
     }
 
-    /** Called when the panel expansion has changed. Notifies all listeners of change. */
+    /** Adds a listener that will be notified when the panel state has changed. */
+    fun addStateListener(listener: PanelStateListener) {
+        stateListeners.add(listener)
+    }
+
+    /** Removes a state listener. */
+    fun removeStateListener(listener: PanelStateListener) {
+        stateListeners.remove(listener)
+    }
+
+    /** Returns true if the panel is currently closed and false otherwise. */
+    fun isClosed(): Boolean = state == STATE_CLOSED
+
+    /**
+     * Called when the panel expansion has changed.
+     *
+     * @param fraction the fraction from the expansion in [0, 1]
+     * @param expanded whether the panel is currently expanded; this is independent from the
+     * fraction as the panel also might be expanded if the fraction is 0.
+     * @param tracking whether we're currently tracking the user's gesture.
+     */
     fun onPanelExpansionChanged(
         @FloatRange(from = 0.0, to = 1.0) fraction: Float,
         expanded: Boolean,
         tracking: Boolean
     ) {
+        require(!fraction.isNaN()) { "fraction cannot be NaN" }
+        val oldState = state
+
         this.fraction = fraction
         this.expanded = expanded
         this.tracking = tracking
-        listeners.forEach { it.onPanelExpansionChanged(fraction, expanded, tracking) }
+
+        var fullyClosed = true
+        var fullyOpened = false
+
+        if (expanded) {
+            if (this.state == STATE_CLOSED) {
+                updateStateInternal(STATE_OPENING)
+            }
+            fullyClosed = false
+            fullyOpened = fraction >= 1f
+        }
+
+        if (fullyOpened && !tracking) {
+            updateStateInternal(STATE_OPEN)
+        } else if (fullyClosed && !tracking && this.state != STATE_CLOSED) {
+            updateStateInternal(STATE_CLOSED)
+        }
+
+        debugLog(
+            "panelExpansionChanged:" +
+                    "start state=${oldState.stateToString()} " +
+                    "end state=${state.stateToString()} " +
+                    "f=$fraction " +
+                    "expanded=$expanded " +
+                    "tracking=$tracking" +
+                    "${if (fullyOpened) " fullyOpened" else ""} " +
+                    if (fullyClosed) " fullyClosed" else ""
+        )
+
+        expansionListeners.forEach { it.onPanelExpansionChanged(fraction, expanded, tracking) }
+    }
+
+    /** Updates the panel state if necessary.  */
+    fun updateState(@PanelState state: Int) {
+        debugLog("update state: ${this.state.stateToString()} -> ${state.stateToString()}")
+        if (this.state != state) {
+            updateStateInternal(state)
+        }
+    }
+
+    private fun updateStateInternal(@PanelState state: Int) {
+        debugLog("go state: ${this.state.stateToString()} -> ${state.stateToString()}")
+        this.state = state
+        stateListeners.forEach { it.onPanelStateChanged(state) }
+    }
+
+    private fun debugLog(msg: String) {
+        if (!DEBUG) return
+        Log.v(TAG, msg)
     }
 }
+
+/** Enum for the current state of the panel.  */
+@Retention(AnnotationRetention.SOURCE)
+@IntDef(value = [STATE_CLOSED, STATE_OPENING, STATE_OPEN])
+internal annotation class PanelState
+
+const val STATE_CLOSED = 0
+const val STATE_OPENING = 1
+const val STATE_OPEN = 2
+
+@PanelState
+private fun Int.stateToString(): String {
+    return when (this) {
+        STATE_CLOSED -> "CLOSED"
+        STATE_OPENING -> "OPENING"
+        STATE_OPEN -> "OPEN"
+        else -> this.toString()
+    }
+}
+
+private const val DEBUG = false
+private val TAG = PanelExpansionStateManager::class.simpleName

packages/SystemUI/src/com/android/systemui/statusbar/phone/panelstate/PanelStateListener.kt

@@ -0,0 +1,23 @@
+/*
+ * Copyright (C) 2021 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 com.android.systemui.statusbar.phone.panelstate
+
+/** A listener interface to be notified of state change events for the notification panel. */
+interface PanelStateListener {
+    /** Called when the panel's expansion state has changed.   */
+    fun onPanelStateChanged(@PanelState state: Int)
+}

packages/SystemUI/tests/src/com/android/systemui/biometrics/UdfpsKeyguardViewControllerTest.java

@@ -171,7 +171,7 @@ public class UdfpsKeyguardViewControllerTest extends SysuiTestCase {
 
         verify(mStatusBarStateController).removeCallback(mStatusBarStateListener);
         for (PanelExpansionListener listener : mExpansionListeners) {
-            verify(mPanelExpansionStateManager).removeListener(listener);
+            verify(mPanelExpansionStateManager).removeExpansionListener(listener);
         }
         verify(mKeyguardStateController).removeCallback(mKeyguardStateControllerCallback);
     }
@@ -435,7 +435,7 @@ public class UdfpsKeyguardViewControllerTest extends SysuiTestCase {
 
     private void captureExpansionListeners() {
         verify(mPanelExpansionStateManager, times(2))
-                .addListener(mExpansionListenerCaptor.capture());
+                .addExpansionListener(mExpansionListenerCaptor.capture());
         // first (index=0) is from super class, UdfpsAnimationViewController.
         // second (index=1) is from UdfpsKeyguardViewController
         mExpansionListeners = mExpansionListenerCaptor.getAllValues();

packages/SystemUI/tests/src/com/android/systemui/statusbar/phone/CollapsedStatusBarFragmentTest.java

@@ -48,6 +48,7 @@ import com.android.systemui.statusbar.OperatorNameViewController;
 import com.android.systemui.statusbar.connectivity.NetworkController;
 import com.android.systemui.statusbar.events.SystemStatusAnimationScheduler;
 import com.android.systemui.statusbar.phone.ongoingcall.OngoingCallController;
+import com.android.systemui.statusbar.phone.panelstate.PanelExpansionStateManager;
 import com.android.systemui.statusbar.policy.KeyguardStateController;
 
 import org.junit.Before;
@@ -259,6 +260,7 @@ public class CollapsedStatusBarFragmentTest extends SysuiBaseFragmentTest {
                 mAnimationScheduler,
                 mLocationPublisher,
                 mMockNotificationAreaController,
+                new PanelExpansionStateManager(),
                 mock(FeatureFlags.class),
                 () -> Optional.of(mStatusBar),
                 mStatusBarIconController,

packages/SystemUI/tests/src/com/android/systemui/statusbar/phone/NotificationPanelViewControllerTest.java

@@ -176,8 +176,6 @@ public class NotificationPanelViewControllerTest extends SysuiTestCase {
     @Mock
     private HeadsUpTouchHelper.Callback mHeadsUpCallback;
     @Mock
-    private PanelBar mPanelBar;
-    @Mock
     private KeyguardUpdateMonitor mUpdateMonitor;
     @Mock
     private KeyguardBypassController mKeyguardBypassController;
@@ -460,7 +458,6 @@ public class NotificationPanelViewControllerTest extends SysuiTestCase {
                 () -> {},
                 mNotificationShelfController);
         mNotificationPanelViewController.setHeadsUpManager(mHeadsUpManager);
-        mNotificationPanelViewController.setBar(mPanelBar);
         mNotificationPanelViewController.setKeyguardIndicationController(
                 mKeyguardIndicationController);
         ArgumentCaptor<View.OnAttachStateChangeListener> onAttachStateChangeListenerArgumentCaptor =

packages/SystemUI/tests/src/com/android/systemui/statusbar/phone/PhoneStatusBarViewTest.kt

@@ -53,40 +53,6 @@ class PhoneStatusBarViewTest : SysuiTestCase() {
         view.setBar(statusBar)
     }
 
-    @Test
-    fun panelStateChanged_toStateOpening_listenerNotified() {
-        val listener = TestStateChangedListener()
-        view.setPanelStateChangeListener(listener)
-
-        view.panelExpansionChanged(0.5f, true)
-
-        assertThat(listener.state).isEqualTo(PanelBar.STATE_OPENING)
-    }
-
-    @Test
-    fun panelStateChanged_toStateOpen_listenerNotified() {
-        val listener = TestStateChangedListener()
-        view.setPanelStateChangeListener(listener)
-
-        view.panelExpansionChanged(1f, true)
-
-        assertThat(listener.state).isEqualTo(PanelBar.STATE_OPEN)
-    }
-
-    @Test
-    fun panelStateChanged_toStateClosed_listenerNotified() {
-        val listener = TestStateChangedListener()
-        view.setPanelStateChangeListener(listener)
-
-        // First, open the panel
-        view.panelExpansionChanged(1f, true)
-
-        // Then, close it again
-        view.panelExpansionChanged(0f, false)
-
-        assertThat(listener.state).isEqualTo(PanelBar.STATE_CLOSED)
-    }
-
     @Test
     fun onTouchEvent_listenerNotified() {
         val handler = TestTouchEventHandler()
@@ -126,13 +92,6 @@ class PhoneStatusBarViewTest : SysuiTestCase() {
         // No assert needed, just testing no crash
     }
 
-    private class TestStateChangedListener : PanelBar.PanelStateChangeListener {
-        var state: Int = 0
-        override fun onStateChanged(state: Int) {
-            this.state = state
-        }
-    }
-
     private class TestTouchEventHandler : PhoneStatusBarView.TouchEventHandler {
         var lastEvent: MotionEvent? = null
         var returnValue: Boolean = false

packages/SystemUI/tests/src/com/android/systemui/statusbar/phone/panelstate/PanelExpansionStateManagerTest.kt

@@ -33,9 +33,9 @@ class PanelExpansionStateManagerTest : SysuiTestCase() {
     }
 
     @Test
-    fun onPanelExpansionChanged_listenersNotified() {
+    fun onPanelExpansionChanged_listenerNotified() {
         val listener = TestPanelExpansionListener()
-        panelExpansionStateManager.addListener(listener)
+        panelExpansionStateManager.addExpansionListener(listener)
         val fraction = 0.6f
         val expanded = true
         val tracking = true
@@ -48,20 +48,143 @@ class PanelExpansionStateManagerTest : SysuiTestCase() {
     }
 
     @Test
-    fun addPanelExpansionListener_listenerNotifiedOfCurrentValues() {
+    fun addExpansionListener_listenerNotifiedOfCurrentValues() {
         val fraction = 0.6f
         val expanded = true
         val tracking = true
         panelExpansionStateManager.onPanelExpansionChanged(fraction, expanded, tracking)
         val listener = TestPanelExpansionListener()
 
-        panelExpansionStateManager.addListener(listener)
+        panelExpansionStateManager.addExpansionListener(listener)
 
         assertThat(listener.fraction).isEqualTo(fraction)
         assertThat(listener.expanded).isEqualTo(expanded)
         assertThat(listener.tracking).isEqualTo(tracking)
     }
 
+    @Test
+    fun updateState_listenerNotified() {
+        val listener = TestPanelStateListener()
+        panelExpansionStateManager.addStateListener(listener)
+
+        panelExpansionStateManager.updateState(STATE_OPEN)
+
+        assertThat(listener.state).isEqualTo(STATE_OPEN)
+    }
+
+    /* ***** [PanelExpansionStateManager.onPanelExpansionChanged] test cases *******/
+
+    /* Fraction < 1 test cases */
+
+    @Test
+    fun onPEC_fractionLessThanOne_expandedTrue_trackingFalse_becomesStateOpening() {
+        val listener = TestPanelStateListener()
+        panelExpansionStateManager.addStateListener(listener)
+
+        panelExpansionStateManager.onPanelExpansionChanged(
+            fraction = 0.5f, expanded = true, tracking = false
+        )
+
+        assertThat(listener.state).isEqualTo(STATE_OPENING)
+    }
+
+    @Test
+    fun onPEC_fractionLessThanOne_expandedTrue_trackingTrue_becomesStateOpening() {
+        val listener = TestPanelStateListener()
+        panelExpansionStateManager.addStateListener(listener)
+
+        panelExpansionStateManager.onPanelExpansionChanged(
+            fraction = 0.5f, expanded = true, tracking = true
+        )
+
+        assertThat(listener.state).isEqualTo(STATE_OPENING)
+    }
+
+    @Test
+    fun onPEC_fractionLessThanOne_expandedFalse_trackingFalse_becomesStateClosed() {
+        val listener = TestPanelStateListener()
+        panelExpansionStateManager.addStateListener(listener)
+        // Start out on a different state
+        panelExpansionStateManager.updateState(STATE_OPEN)
+
+        panelExpansionStateManager.onPanelExpansionChanged(
+            fraction = 0.5f, expanded = false, tracking = false
+        )
+
+        assertThat(listener.state).isEqualTo(STATE_CLOSED)
+    }
+
+    @Test
+    fun onPEC_fractionLessThanOne_expandedFalse_trackingTrue_doesNotBecomeStateClosed() {
+        val listener = TestPanelStateListener()
+        panelExpansionStateManager.addStateListener(listener)
+        // Start out on a different state
+        panelExpansionStateManager.updateState(STATE_OPEN)
+
+        panelExpansionStateManager.onPanelExpansionChanged(
+            fraction = 0.5f, expanded = false, tracking = true
+        )
+
+        assertThat(listener.state).isEqualTo(STATE_OPEN)
+    }
+
+    /* Fraction = 1 test cases */
+
+    @Test
+    fun onPEC_fractionOne_expandedTrue_trackingFalse_becomesStateOpeningThenStateOpen() {
+        val listener = TestPanelStateListener()
+        panelExpansionStateManager.addStateListener(listener)
+
+        panelExpansionStateManager.onPanelExpansionChanged(
+            fraction = 1f, expanded = true, tracking = false
+        )
+
+        assertThat(listener.previousState).isEqualTo(STATE_OPENING)
+        assertThat(listener.state).isEqualTo(STATE_OPEN)
+    }
+
+    @Test
+    fun onPEC_fractionOne_expandedTrue_trackingTrue_becomesStateOpening() {
+        val listener = TestPanelStateListener()
+        panelExpansionStateManager.addStateListener(listener)
+
+        panelExpansionStateManager.onPanelExpansionChanged(
+            fraction = 1f, expanded = true, tracking = true
+        )
+
+        assertThat(listener.state).isEqualTo(STATE_OPENING)
+    }
+
+    @Test
+    fun onPEC_fractionOne_expandedFalse_trackingFalse_becomesStateClosed() {
+        val listener = TestPanelStateListener()
+        panelExpansionStateManager.addStateListener(listener)
+        // Start out on a different state
+        panelExpansionStateManager.updateState(STATE_OPEN)
+
+        panelExpansionStateManager.onPanelExpansionChanged(
+            fraction = 1f, expanded = false, tracking = false
+        )
+
+        assertThat(listener.state).isEqualTo(STATE_CLOSED)
+    }
+
+    @Test
+    fun onPEC_fractionOne_expandedFalse_trackingTrue_doesNotBecomeStateClosed() {
+        val listener = TestPanelStateListener()
+        panelExpansionStateManager.addStateListener(listener)
+        // Start out on a different state
+        panelExpansionStateManager.updateState(STATE_OPEN)
+
+        panelExpansionStateManager.onPanelExpansionChanged(
+            fraction = 1f, expanded = false, tracking = true
+        )
+
+        assertThat(listener.state).isEqualTo(STATE_OPEN)
+    }
+
+    /* ***** end [PanelExpansionStateManager.onPanelExpansionChanged] test cases ******/
+
     class TestPanelExpansionListener : PanelExpansionListener {
         var fraction: Float = 0f
         var expanded: Boolean = false
@@ -77,4 +200,14 @@ class PanelExpansionStateManagerTest : SysuiTestCase() {
             this.tracking = tracking
         }
     }
+
+    class TestPanelStateListener : PanelStateListener {
+        @PanelState var previousState: Int = STATE_CLOSED
+        @PanelState var state: Int = STATE_CLOSED
+
+        override fun onPanelStateChanged(state: Int) {
+            this.previousState = this.state
+            this.state = state
+        }
+    }
 }