Merge "Fade back button in and out tied with the overview/shelf (1/2)" into pi-dev

packages/SystemUI/shared/src/com/android/systemui/shared/recents/ISystemUiProxy.aidl

@@ -54,4 +54,10 @@ interface ISystemUiProxy {
      * Get the secondary split screen app's rectangle when not minimized.
      */
     Rect getNonMinimizedSplitScreenSecondaryBounds() = 7;
+
+    /**
+     * Control the {@param alpha} of the back button in the navigation bar and {@param animate} if
+     * needed from current value
+     */
+    void setBackButtonAlpha(float alpha, boolean animate) = 8;
 }

packages/SystemUI/shared/src/com/android/systemui/shared/system/NavigationBarCompat.java

@@ -62,8 +62,7 @@ public class NavigationBarCompat {
     @Retention(RetentionPolicy.SOURCE)
     @IntDef({FLAG_DISABLE_SWIPE_UP,
             FLAG_DISABLE_QUICK_SCRUB,
-            FLAG_SHOW_OVERVIEW_BUTTON,
+            FLAG_SHOW_OVERVIEW_BUTTON
-            FLAG_HIDE_BACK_BUTTON
     })
     public @interface InteractionType {}
 
@@ -82,11 +81,6 @@ public class NavigationBarCompat {
      */
     public static final int FLAG_SHOW_OVERVIEW_BUTTON = 0x4;
 
-    /**
-     * Interaction type: show/hide the back button while this service is connected to launcher
-     */
-    public static final int FLAG_HIDE_BACK_BUTTON = 0x8;
-
     private static int convertDpToPixel(float dp){
         return (int) (dp * Resources.getSystem().getDisplayMetrics().density);
     }

packages/SystemUI/src/com/android/systemui/OverviewProxyService.java

@@ -161,6 +161,19 @@ public class OverviewProxyService implements CallbackController<OverviewProxyLis
                 Binder.restoreCallingIdentity(token);
             }
         }
+
+        public void setBackButtonAlpha(float alpha, boolean animate) {
+            long token = Binder.clearCallingIdentity();
+            try {
+                mHandler.post(() -> {
+                    for (int i = mConnectionCallbacks.size() - 1; i >= 0; --i) {
+                        mConnectionCallbacks.get(i).onBackButtonAlphaChanged(alpha, animate);
+                    }
+                });
+            } finally {
+                Binder.restoreCallingIdentity(token);
+            }
+        }
     };
 
     private final Runnable mDeferredConnectionCallback = () -> {
@@ -389,5 +402,6 @@ public class OverviewProxyService implements CallbackController<OverviewProxyLis
         default void onInteractionFlagsChanged(@InteractionType int flags) {}
         default void onOverviewShown(boolean fromHome) {}
         default void onQuickScrubStarted() {}
+        default void onBackButtonAlphaChanged(float alpha, boolean animate) {}
     }
 }

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

@@ -14,13 +14,15 @@
 
 package com.android.systemui.statusbar.phone;
 
+import static com.android.systemui.Interpolators.ALPHA_IN;
+import static com.android.systemui.Interpolators.ALPHA_OUT;
+
 import android.animation.Animator;
 import android.animation.AnimatorListenerAdapter;
 import android.animation.ValueAnimator;
 import android.view.View;
 
 import android.view.View.AccessibilityDelegate;
-import com.android.systemui.Interpolators;
 import com.android.systemui.plugins.statusbar.phone.NavBarButtonProvider.ButtonInterface;
 import com.android.systemui.statusbar.policy.KeyButtonDrawable;
 
@@ -150,12 +152,29 @@ public class ButtonDispatcher {
     }
 
     public void setAlpha(float alpha) {
+        setAlpha(alpha, false /* animate */);
+    }
+
+    public void setAlpha(float alpha, boolean animate) {
+        if (animate) {
+            if (mFadeAnimator != null) {
+                mFadeAnimator.cancel();
+            }
+            mFadeAnimator = ValueAnimator.ofFloat(getAlpha(), alpha);
+            mFadeAnimator.setDuration(getAlpha() < alpha? FADE_DURATION_IN : FADE_DURATION_OUT);
+            mFadeAnimator.setInterpolator(getAlpha() < alpha ? ALPHA_IN : ALPHA_OUT);
+            mFadeAnimator.addListener(mFadeListener);
+            mFadeAnimator.addUpdateListener(mAlphaListener);
+            mFadeAnimator.start();
+            setVisibility(View.VISIBLE);
+        } else {
             mAlpha = alpha;
             final int N = mViews.size();
             for (int i = 0; i < N; i++) {
                 mViews.get(i).setAlpha(alpha);
             }
         }
+    }
 
     public void setDarkIntensity(float darkIntensity) {
         mDarkIntensity = darkIntensity;
@@ -233,19 +252,6 @@ public class ButtonDispatcher {
         }
     }
 
-    public void animateFade(boolean in) {
-        if (mFadeAnimator != null) {
-            mFadeAnimator.cancel();
-        }
-        mFadeAnimator = ValueAnimator.ofFloat(getAlpha(), in ? 1 : 0);
-        mFadeAnimator.setDuration(in? FADE_DURATION_IN : FADE_DURATION_OUT);
-        mFadeAnimator.setInterpolator(in ? Interpolators.ALPHA_IN : Interpolators.ALPHA_OUT);
-        mFadeAnimator.addListener(mFadeListener);
-        mFadeAnimator.addUpdateListener(mAlphaListener);
-        mFadeAnimator.start();
-        setVisibility(View.VISIBLE);
-    }
-
     public ArrayList<View> getViews() {
         return mViews;
     }

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

@@ -186,6 +186,13 @@ public class NavigationBarFragment extends Fragment implements Callbacks {
             mNavigationBarView.updateStates();
             updateScreenPinningGestures();
         }
+
+        @Override
+        public void onBackButtonAlphaChanged(float alpha, boolean animate) {
+            final ButtonDispatcher backButton = mNavigationBarView.getBackButton();
+            backButton.setVisibility(alpha > 0 ? View.VISIBLE : View.INVISIBLE);
+            backButton.setAlpha(alpha, animate);
+        }
     };
 
     // ----- Fragment Lifecycle Callbacks -----

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

@@ -85,7 +85,6 @@ import java.io.PrintWriter;
 import java.util.function.Consumer;
 
 import static com.android.systemui.shared.system.NavigationBarCompat.FLAG_DISABLE_QUICK_SCRUB;
-import static com.android.systemui.shared.system.NavigationBarCompat.FLAG_HIDE_BACK_BUTTON;
 import static com.android.systemui.shared.system.NavigationBarCompat.FLAG_SHOW_OVERVIEW_BUTTON;
 import static com.android.systemui.shared.system.NavigationBarCompat.HIT_TARGET_OVERVIEW;
 import static com.android.systemui.shared.system.NavigationBarCompat.HIT_TARGET_ROTATION;
@@ -655,8 +654,6 @@ public class NavigationBarView extends FrameLayout implements PluginListener<Nav
             disableRecent |= (flags & FLAG_SHOW_OVERVIEW_BUTTON) == 0;
             if (pinningActive) {
                 disableBack = disableHome = false;
-            } else {
-                disableBack |= (flags & FLAG_HIDE_BACK_BUTTON) != 0;
             }
         } else if (pinningActive) {
             disableBack = disableRecent = false;
@@ -863,7 +860,7 @@ public class NavigationBarView extends FrameLayout implements PluginListener<Nav
     public boolean isRotateButtonVisible() { return mShowRotateButton; }
 
     public void setMenuContainerVisibility(boolean visible) {
-        getMenuContainer().animateFade(visible);
+        getMenuContainer().setAlpha(visible ? 1 : 0, true /* animate */);
     }
 
     @Override