Defering AppWidgetHost updates if Launcher resumes in an non-NORMAL state

Change-Id: Ib0ef587de7207a3bd1bb5051fe8599293dfb4d59

3 files changed, 62 insertions, 17 deletions

diff --git a/src/com/android/launcher3/Launcher.java b/src/com/android/launcher3/Launcher.java
index 2e930662d..553d8d0e5 100644
--- a/src/com/android/launcher3/Launcher.java
+++ b/src/com/android/launcher3/Launcher.java
@@ -767,10 +767,7 @@ public class Launcher extends BaseActivity
         if (mLauncherCallbacks != null) {
             mLauncherCallbacks.onStop();
         }
-
-        if (Utilities.ATLEAST_NOUGAT_MR1) {
-            mAppWidgetHost.stopListening();
-        }
+        mAppWidgetHost.setListenIfResumed(false);
 
         if (!mAppLaunchSuccess) {
             getUserEventDispatcher().logActionCommand(Action.Command.STOP,
@@ -787,10 +784,7 @@ public class Launcher extends BaseActivity
         if (mLauncherCallbacks != null) {
             mLauncherCallbacks.onStart();
         }
-
-        if (Utilities.ATLEAST_NOUGAT_MR1) {
-            mAppWidgetHost.startListening();
-        }
+        mAppWidgetHost.setListenIfResumed(true);
 
         if (!isWorkspaceLoading()) {
             NotificationListener.setNotificationsChangedListener(mPopupDataProvider);
diff --git a/src/com/android/launcher3/LauncherAppWidgetHost.java b/src/com/android/launcher3/LauncherAppWidgetHost.java
index 70440fa30..9aa74b38d 100644
--- a/src/com/android/launcher3/LauncherAppWidgetHost.java
+++ b/src/com/android/launcher3/LauncherAppWidgetHost.java
@@ -16,7 +16,8 @@
 
 package com.android.launcher3;
 
-import android.app.Activity;
+import static android.app.Activity.RESULT_CANCELED;
+
 import android.appwidget.AppWidgetHost;
 import android.appwidget.AppWidgetHostView;
 import android.appwidget.AppWidgetManager;
@@ -41,12 +42,17 @@ import java.util.ArrayList;
  */
 public class LauncherAppWidgetHost extends AppWidgetHost {
 
+    private static final int FLAG_LISTENING = 1;
+    private static final int FLAG_RESUMED = 1 << 1;
+    private static final int FLAG_LISTEN_IF_RESUMED = 1 << 2;
+
     public static final int APPWIDGET_HOST_ID = 1024;
 
     private final ArrayList<ProviderChangedListener> mProviderChangeListeners = new ArrayList<>();
     private final SparseArray<LauncherAppWidgetHostView> mViews = new SparseArray<>();
 
     private final Context mContext;
+    private int mFlags = FLAG_RESUMED;
 
     public LauncherAppWidgetHost(Context context) {
         super(context, APPWIDGET_HOST_ID);
@@ -66,7 +72,7 @@ public class LauncherAppWidgetHost extends AppWidgetHost {
         if (FeatureFlags.GO_DISABLE_WIDGETS) {
             return;
         }
-
+        mFlags |= FLAG_LISTENING;
         try {
             super.startListening();
         } catch (Exception e) {
@@ -85,10 +91,59 @@ public class LauncherAppWidgetHost extends AppWidgetHost {
         if (FeatureFlags.GO_DISABLE_WIDGETS) {
             return;
         }
-
+        mFlags &= ~FLAG_LISTENING;
         super.stopListening();
     }
 
+    /**
+     * Updates the resumed state of the host.
+     * When a host is not resumed, it defers calls to startListening until host is resumed again.
+     * But if the host was already listening, it will not call stopListening.
+     *
+     * @see #setListenIfResumed(boolean)
+     */
+    public void setResumed(boolean isResumed) {
+        if (isResumed == ((mFlags & FLAG_RESUMED) != 0)) {
+            return;
+        }
+        if (isResumed) {
+            mFlags |= FLAG_RESUMED;
+            // Start listening if we were supposed to start listening on resume
+            if ((mFlags & FLAG_LISTEN_IF_RESUMED) != 0 && (mFlags & FLAG_LISTENING) == 0) {
+                startListening();
+            }
+        } else {
+            mFlags &= ~FLAG_RESUMED;
+        }
+    }
+
+    /**
+     * Updates the listening state of the host. If the host is not resumed, startListening is
+     * deferred until next resume.
+     *
+     * @see #setResumed(boolean)
+     */
+    public void setListenIfResumed(boolean listenIfResumed) {
+        if (!Utilities.ATLEAST_NOUGAT_MR1) {
+            return;
+        }
+        if (listenIfResumed == ((mFlags & FLAG_LISTEN_IF_RESUMED) != 0)) {
+            return;
+        }
+        if (listenIfResumed) {
+            mFlags |= FLAG_LISTEN_IF_RESUMED;
+            if ((mFlags & FLAG_RESUMED) != 0) {
+                // If we are resumed, start listening immediately. Note we do not check for
+                // duplicate calls before calling startListening as startListening is safe to call
+                // multiple times.
+                startListening();
+            }
+        } else {
+            mFlags &= ~FLAG_LISTEN_IF_RESUMED;
+            stopListening();
+        }
+    }
+
     @Override
     public int allocateAppWidgetId() {
         if (FeatureFlags.GO_DISABLE_WIDGETS) {
@@ -203,12 +258,7 @@ public class LauncherAppWidgetHost extends AppWidgetHost {
     }
 
     private void sendActionCancelled(final BaseActivity activity, final int requestCode) {
-        new Handler().post(new Runnable() {
-            @Override
-            public void run() {
-                activity.onActivityResult(requestCode, Activity.RESULT_CANCELED, null);
-            }
-        });
+        new Handler().post(() -> activity.onActivityResult(requestCode, RESULT_CANCELED, null));
     }
 
     /**
diff --git a/src/com/android/launcher3/LauncherStateManager.java b/src/com/android/launcher3/LauncherStateManager.java
index 3b58ed8e0..1e6016b4d 100644
--- a/src/com/android/launcher3/LauncherStateManager.java
+++ b/src/com/android/launcher3/LauncherStateManager.java
@@ -249,6 +249,7 @@ public class LauncherStateManager {
         mState.onStateDisabled(mLauncher);
         mState = state;
         mState.onStateEnabled(mLauncher);
+        mLauncher.getAppWidgetHost().setResumed(state == LauncherState.NORMAL);
     }
 
     /**