6 files changed, 87 insertions, 3 deletions
diff --git a/quickstep/libs/sysui_shared.jar b/quickstep/libs/sysui_shared.jar
index f508eab3d..d1ac93645 100644
--- a/quickstep/libs/sysui_shared.jar
+++ b/quickstep/libs/sysui_shared.jar
diff --git a/quickstep/src/com/android/launcher3/uioverrides/UiFactory.java b/quickstep/src/com/android/launcher3/uioverrides/UiFactory.java
index b4f40c215..92b38fe01 100644
--- a/quickstep/src/com/android/launcher3/uioverrides/UiFactory.java
+++ b/quickstep/src/com/android/launcher3/uioverrides/UiFactory.java
@@ -16,12 +16,11 @@
 
 package com.android.launcher3.uioverrides;
 
-import android.content.pm.PackageManager;
+import static com.android.launcher3.LauncherState.NORMAL;
+
 import android.graphics.Bitmap;
 import android.graphics.Canvas;
 import android.graphics.PointF;
-import android.os.Bundle;
-import android.view.View;
 import android.view.View.AccessibilityDelegate;
 
 import com.android.launcher3.Launcher;
@@ -29,6 +28,7 @@ import com.android.launcher3.LauncherStateManager.StateHandler;
 import com.android.launcher3.config.FeatureFlags;
 import com.android.launcher3.graphics.BitmapRenderer;
 import com.android.launcher3.util.TouchController;
+import com.android.quickstep.OverviewInteractionState;
 import com.android.quickstep.RecentsView;
 import com.android.systemui.shared.recents.view.RecentsTransition;
 
@@ -68,6 +68,11 @@ public class UiFactory {
         OptionsPopupView.show(launcher, touchPoint.x, touchPoint.y);
     }
 
+    public static void onLauncherStateOrFocusChanged(Launcher launcher) {
+        OverviewInteractionState.setBackButtonVisible(launcher, !launcher.isInState(NORMAL)
+                || !launcher.hasWindowFocus());
+    }
+
     public static Bitmap createFromRenderer(int width, int height, boolean forceSoftwareRenderer,
             BitmapRenderer renderer) {
         if (USE_HARDWARE_BITMAP && !forceSoftwareRenderer) {
diff --git a/quickstep/src/com/android/quickstep/OverviewInteractionState.java b/quickstep/src/com/android/quickstep/OverviewInteractionState.java
new file mode 100644
index 000000000..9be12bdb9
--- /dev/null
+++ b/quickstep/src/com/android/quickstep/OverviewInteractionState.java
@@ -0,0 +1,64 @@
+/*
+ * 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.quickstep;
+
+import static com.android.systemui.shared.system.NavigationBarCompat.FLAG_HIDE_BACK_BUTTON;
+
+import android.content.Context;
+import android.os.RemoteException;
+import android.util.Log;
+
+import com.android.systemui.shared.recents.ISystemUiProxy;
+
+/**
+ * Sets overview interaction flags, such as:
+ *
+ *   - FLAG_DISABLE_QUICK_SCRUB
+ *   - FLAG_DISABLE_SWIPE_UP
+ *   - FLAG_HIDE_BACK_BUTTON
+ *   - FLAG_SHOW_OVERVIEW_BUTTON
+ *
+ * @see com.android.systemui.shared.system.NavigationBarCompat.InteractionType and associated flags.
+ */
+public class OverviewInteractionState {
+
+    private static final String TAG = "OverviewFlags";
+
+    private static int sFlags;
+
+    public static void setBackButtonVisible(Context context, boolean visible) {
+        updateOverviewInteractionFlag(context, FLAG_HIDE_BACK_BUTTON, !visible);
+    }
+
+    private static void updateOverviewInteractionFlag(Context context, int flag, boolean enabled) {
+        if (enabled) {
+            sFlags |= flag;
+        } else {
+            sFlags &= ~flag;
+        }
+
+        ISystemUiProxy systemUiProxy = RecentsModel.getInstance(context).getSystemUiProxy();
+        if (systemUiProxy == null) {
+            Log.w(TAG, "Unable to update overview interaction flags; not bound to service");
+            return;
+        }
+        try {
+            systemUiProxy.setInteractionState(sFlags);
+        } catch (RemoteException e) {
+            Log.w(TAG, "Unable to update overview interaction flags", e);
+        }
+    }
+}
diff --git a/src/com/android/launcher3/Launcher.java b/src/com/android/launcher3/Launcher.java
index f6abae8ab..2e0483754 100644
--- a/src/com/android/launcher3/Launcher.java
+++ b/src/com/android/launcher3/Launcher.java
@@ -855,6 +855,12 @@ public class Launcher extends BaseActivity
         }
     }
 
+    @Override
+    public void onWindowFocusChanged(boolean hasFocus) {
+        super.onWindowFocusChanged(hasFocus);
+        mStateManager.onWindowFocusChanged();
+    }
+
     public interface LauncherOverlay {
 
         /**
diff --git a/src/com/android/launcher3/LauncherStateManager.java b/src/com/android/launcher3/LauncherStateManager.java
index 6050d15da..e0b84bf46 100644
--- a/src/com/android/launcher3/LauncherStateManager.java
+++ b/src/com/android/launcher3/LauncherStateManager.java
@@ -303,6 +303,12 @@ public class LauncherStateManager {
         if (state == NORMAL) {
             setRestState(null);
         }
+
+        UiFactory.onLauncherStateOrFocusChanged(mLauncher);
+    }
+
+    public void onWindowFocusChanged() {
+        UiFactory.onLauncherStateOrFocusChanged(mLauncher);
     }
 
     public LauncherState getLastState() {
diff --git a/src_ui_overrides/com/android/launcher3/uioverrides/UiFactory.java b/src_ui_overrides/com/android/launcher3/uioverrides/UiFactory.java
index 744125e15..64a29ea3e 100644
--- a/src_ui_overrides/com/android/launcher3/uioverrides/UiFactory.java
+++ b/src_ui_overrides/com/android/launcher3/uioverrides/UiFactory.java
@@ -16,6 +16,7 @@
 
 package com.android.launcher3.uioverrides;
 
+import static com.android.launcher3.LauncherState.NORMAL;
 import static com.android.launcher3.LauncherState.OVERVIEW;
 
 import android.graphics.Bitmap;
@@ -61,4 +62,6 @@ public class UiFactory {
     }
 
     public static void resetOverview(Launcher launcher) { }
+
+    public static void onLauncherStateOrFocusChanged(Launcher launcher) { }
 }