Cleanup how we set back button alpha

Add BackButtonAlphaHandler to set back button alpha, instead of setting
it from multiple places.

Also force back button alpha to be 1 if swipe up is disabled (b/80091187)

Change-Id: I49b63a0e6b033a3a947a847669a398f1b9ff0564

6 files changed, 78 insertions, 29 deletions

diff --git a/quickstep/src/com/android/launcher3/uioverrides/BackButtonAlphaHandler.java b/quickstep/src/com/android/launcher3/uioverrides/BackButtonAlphaHandler.java
new file mode 100644
index 000000000..2e6dcc0e7
--- /dev/null
+++ b/quickstep/src/com/android/launcher3/uioverrides/BackButtonAlphaHandler.java
@@ -0,0 +1,62 @@
+/*
+ * Copyright (C) 2018 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.launcher3.uioverrides;
+
+import android.animation.ValueAnimator;
+
+import com.android.launcher3.Launcher;
+import com.android.launcher3.LauncherState;
+import com.android.launcher3.LauncherStateManager;
+import com.android.launcher3.anim.AnimatorSetBuilder;
+import com.android.quickstep.OverviewInteractionState;
+
+public class BackButtonAlphaHandler implements LauncherStateManager.StateHandler {
+
+    private static final String TAG = "BackButtonAlphaHandler";
+
+    private final Launcher mLauncher;
+    private final OverviewInteractionState mOverviewInteractionState;
+
+    public BackButtonAlphaHandler(Launcher launcher) {
+        mLauncher = launcher;
+        mOverviewInteractionState = OverviewInteractionState.getInstance(mLauncher);
+    }
+
+    @Override
+    public void setState(LauncherState state) {
+        UiFactory.onLauncherStateOrFocusChanged(mLauncher);
+    }
+
+    @Override
+    public void setStateWithAnimation(LauncherState toState,
+            AnimatorSetBuilder builder, LauncherStateManager.AnimationConfig config) {
+        if (!config.playNonAtomicComponent()) {
+            return;
+        }
+        float fromAlpha = mOverviewInteractionState.getBackButtonAlpha();
+        float toAlpha = toState.hideBackButton ? 0 : 1;
+        if (Float.compare(fromAlpha, toAlpha) != 0) {
+            ValueAnimator anim = ValueAnimator.ofFloat(fromAlpha, toAlpha);
+            anim.setDuration(config.duration);
+            anim.addUpdateListener(valueAnimator -> {
+                final float alpha = (float) valueAnimator.getAnimatedValue();
+                mOverviewInteractionState.setBackButtonAlpha(alpha, false);
+            });
+            builder.play(anim);
+        }
+    }
+}
diff --git a/quickstep/src/com/android/launcher3/uioverrides/UiFactory.java b/quickstep/src/com/android/launcher3/uioverrides/UiFactory.java
index b371677f3..76820b6aa 100644
--- a/quickstep/src/com/android/launcher3/uioverrides/UiFactory.java
+++ b/quickstep/src/com/android/launcher3/uioverrides/UiFactory.java
@@ -78,11 +78,13 @@ public class UiFactory {
     }
 
     public static StateHandler[] getStateHandler(Launcher launcher) {
-        return new StateHandler[] {
-                launcher.getAllAppsController(), launcher.getWorkspace(),
-                new RecentsViewStateController(launcher)};
+        return new StateHandler[] {launcher.getAllAppsController(), launcher.getWorkspace(),
+                new RecentsViewStateController(launcher), new BackButtonAlphaHandler(launcher)};
     }
 
+    /**
+     * Sets the back button visibility based on the current state/window focus.
+     */
     public static void onLauncherStateOrFocusChanged(Launcher launcher) {
         boolean shouldBackButtonBeHidden = launcher != null
                 && launcher.getStateManager().getState().hideBackButton
@@ -96,10 +98,6 @@ public class UiFactory {
                 .setBackButtonAlpha(shouldBackButtonBeHidden ? 0 : 1, true /* animate */);
     }
 
-    public static void setBackButtonAlpha(Launcher launcher, float alpha, boolean animate) {
-         OverviewInteractionState.getInstance(launcher).setBackButtonAlpha(alpha,animate);
-    }
-
     public static void resetOverview(Launcher launcher) {
         RecentsView recents = launcher.getOverviewPanel();
         recents.reset();
diff --git a/quickstep/src/com/android/quickstep/OverviewInteractionState.java b/quickstep/src/com/android/quickstep/OverviewInteractionState.java
index d60574676..922a7ff29 100644
--- a/quickstep/src/com/android/quickstep/OverviewInteractionState.java
+++ b/quickstep/src/com/android/quickstep/OverviewInteractionState.java
@@ -91,6 +91,7 @@ public class OverviewInteractionState {
     // These are updated on the background thread
     private ISystemUiProxy mISystemUiProxy;
     private boolean mSwipeUpEnabled = true;
+    private float mBackButtonAlpha = 1;
 
     private Runnable mOnSwipeUpSettingChangedListener;
 
@@ -117,7 +118,14 @@ public class OverviewInteractionState {
         return mSwipeUpEnabled;
     }
 
+    public float getBackButtonAlpha() {
+        return mBackButtonAlpha;
+    }
+
     public void setBackButtonAlpha(float alpha, boolean animate) {
+        if (!mSwipeUpEnabled) {
+            alpha = 1;
+        }
         mUiHandler.removeMessages(MSG_SET_BACK_BUTTON_ALPHA);
         mUiHandler.obtainMessage(MSG_SET_BACK_BUTTON_ALPHA, animate ? 1 : 0, 0, alpha)
                 .sendToTarget();
@@ -128,6 +136,9 @@ public class OverviewInteractionState {
     }
 
     private boolean handleUiMessage(Message msg) {
+        if (msg.what == MSG_SET_BACK_BUTTON_ALPHA) {
+            mBackButtonAlpha = (float) msg.obj;
+        }
         mBgHandler.obtainMessage(msg.what, msg.arg1, msg.arg2, msg.obj).sendToTarget();
         return true;
     }
diff --git a/src/com/android/launcher3/LauncherStateManager.java b/src/com/android/launcher3/LauncherStateManager.java
index e6fc4c6d4..3fcdee934 100644
--- a/src/com/android/launcher3/LauncherStateManager.java
+++ b/src/com/android/launcher3/LauncherStateManager.java
@@ -396,7 +396,6 @@ public class LauncherStateManager {
             setRestState(null);
         }
 
-        UiFactory.onLauncherStateOrFocusChanged(mLauncher);
         UiFactory.onLauncherStateOrResumeChanged(mLauncher);
     }
 
diff --git a/src/com/android/launcher3/allapps/AllAppsTransitionController.java b/src/com/android/launcher3/allapps/AllAppsTransitionController.java
index b5c821ac2..2c3e3ee7b 100644
--- a/src/com/android/launcher3/allapps/AllAppsTransitionController.java
+++ b/src/com/android/launcher3/allapps/AllAppsTransitionController.java
@@ -25,11 +25,9 @@ import com.android.launcher3.LauncherState;
 import com.android.launcher3.LauncherStateManager.AnimationConfig;
 import com.android.launcher3.LauncherStateManager.StateHandler;
 import com.android.launcher3.R;
-import com.android.launcher3.Utilities;
 import com.android.launcher3.anim.AnimationSuccessListener;
 import com.android.launcher3.anim.AnimatorSetBuilder;
 import com.android.launcher3.anim.PropertySetter;
-import com.android.launcher3.uioverrides.UiFactory;
 import com.android.launcher3.util.Themes;
 import com.android.launcher3.views.ScrimView;
 
@@ -184,13 +182,6 @@ public class AllAppsTransitionController implements StateHandler, OnDeviceProfil
         anim.setDuration(config.duration);
         anim.setInterpolator(builder.getInterpolator(ANIM_VERTICAL_PROGRESS, interpolator));
         anim.addListener(getProgressAnimatorListener());
-        if (toState.hideBackButton) {
-            anim.addUpdateListener(animation -> {
-                final float alpha = (float) animation.getAnimatedValue();
-                UiFactory.setBackButtonAlpha(mLauncher, 1 - Utilities.boundToRange(alpha, 0, 1),
-                        false /* animate */);
-            });
-        }
 
         builder.play(anim);
 
diff --git a/src/com/android/launcher3/touch/AbstractStateChangeTouchController.java b/src/com/android/launcher3/touch/AbstractStateChangeTouchController.java
index 0e6853869..24382b7d0 100644
--- a/src/com/android/launcher3/touch/AbstractStateChangeTouchController.java
+++ b/src/com/android/launcher3/touch/AbstractStateChangeTouchController.java
@@ -42,7 +42,6 @@ import com.android.launcher3.Utilities;
 import com.android.launcher3.anim.AnimationSuccessListener;
 import com.android.launcher3.anim.AnimatorPlaybackController;
 import com.android.launcher3.anim.AnimatorSetBuilder;
-import com.android.launcher3.uioverrides.UiFactory;
 import com.android.launcher3.userevent.nano.LauncherLogProto.Action.Direction;
 import com.android.launcher3.userevent.nano.LauncherLogProto.Action.Touch;
 import com.android.launcher3.userevent.nano.LauncherLogProto.ContainerType;
@@ -224,8 +223,6 @@ public abstract class AbstractStateChangeTouchController
             cancelAtomicComponentsController();
         }
         mProgressMultiplier = initCurrentAnimation(animComponents);
-        mCurrentAnimation.getAnimationPlayer().addUpdateListener(animation ->
-                setBackButtonAlphaWithProgress((float) animation.getAnimatedValue()));
         mCurrentAnimation.dispatchOnStart();
         return true;
     }
@@ -284,7 +281,6 @@ public abstract class AbstractStateChangeTouchController
             mAtomicComponentsController.setPlayFraction(fraction - mAtomicComponentsStartProgress);
         }
         maybeUpdateAtomicAnim(mFromState, mToState, fraction);
-        setBackButtonAlphaWithProgress(fraction);
     }
 
     /**
@@ -477,14 +473,6 @@ public abstract class AbstractStateChangeTouchController
         }
     }
 
-    private void setBackButtonAlphaWithProgress(float progress) {
-        if (mFromState.hideBackButton ^ mToState.hideBackButton) {
-            progress = Utilities.boundToRange(progress, 0, 1);
-            final float alpha = mToState.hideBackButton ? 1 - progress : progress;
-            UiFactory.setBackButtonAlpha(mLauncher, alpha, false /* animate */);
-        }
-    }
-
     private void logReachedState(int logAction) {
         // Transition complete. log the action
         mLauncher.getUserEventDispatcher().logStateChangeAction(logAction,