Merge "Moving workspace bind logic into a separate class." into ub-launcher3-dorval-polish
diff --git a/src/com/android/launcher3/LauncherModel.java b/src/com/android/launcher3/LauncherModel.java
index b5ca301..ee06d9e 100644
--- a/src/com/android/launcher3/LauncherModel.java
+++ b/src/com/android/launcher3/LauncherModel.java
@@ -60,6 +60,7 @@
 import com.android.launcher3.model.ExtendedModelTask;
 import com.android.launcher3.model.GridSizeMigrationTask;
 import com.android.launcher3.model.LoaderCursor;
+import com.android.launcher3.model.LoaderResults;
 import com.android.launcher3.model.ModelWriter;
 import com.android.launcher3.model.PackageInstallStateChangedTask;
 import com.android.launcher3.model.PackageItemInfo;
@@ -90,13 +91,11 @@
 import java.lang.ref.WeakReference;
 import java.util.ArrayList;
 import java.util.Collections;
-import java.util.Comparator;
 import java.util.HashMap;
 import java.util.HashSet;
 import java.util.Iterator;
 import java.util.List;
 import java.util.Map;
-import java.util.Set;
 import java.util.concurrent.CancellationException;
 import java.util.concurrent.Executor;
 
@@ -112,9 +111,6 @@
 
     static final String TAG = "Launcher.Model";
 
-    private static final int ITEMS_CHUNK = 6; // batch size for the workspace icons
-    private static final long INVALID_SCREEN_ID = -1L;
-
     private final MainThreadExecutor mUiExecutor = new MainThreadExecutor();
     @Thunk final LauncherAppState mApp;
     @Thunk final Object mLock = new Object();
@@ -531,13 +527,21 @@
 
                 // If there is already one running, tell it to stop.
                 stopLoaderLocked();
-                mLoaderTask = new LoaderTask(mApp.getContext(), synchronousBindPage);
+                LoaderResults loaderResults = new LoaderResults(mApp, sBgDataModel,
+                        mBgAllAppsList, synchronousBindPage, mCallbacks);
                 if (synchronousBindPage != PagedView.INVALID_RESTORE_PAGE
                         && mModelLoaded && !mIsLoaderTaskRunning) {
-                    mLoaderTask.runBindSynchronousPage(synchronousBindPage);
+
+                    // Divide the set of loaded items into those that we are binding synchronously,
+                    // and everything else that is to be bound normally (asynchronously).
+                    loaderResults.bindWorkspace();
+                    // For now, continue posting the binding of AllApps as there are other
+                    // issues that arise from that.
+                    loaderResults.bindAllApps();
+                    loaderResults.bindDeepShortcuts();
                     return true;
                 } else {
-                    sWorkerThread.setPriority(Thread.NORM_PRIORITY);
+                    mLoaderTask = new LoaderTask(mApp.getContext(), loaderResults);
                     sWorker.post(mLoaderTask);
                 }
             }
@@ -593,13 +597,13 @@
      */
     private class LoaderTask implements Runnable {
         private Context mContext;
-        private int mPageToBindFirst;
+        private final LoaderResults mResults;
 
         private boolean mStopped;
 
-        LoaderTask(Context context, int pageToBindFirst) {
+        LoaderTask(Context context, LoaderResults results) {
             mContext = context;
-            mPageToBindFirst = pageToBindFirst;
+            mResults = results;
         }
 
         private void waitForIdle() {
@@ -614,35 +618,6 @@
             }
         }
 
-        void runBindSynchronousPage(int synchronousBindPage) {
-            if (synchronousBindPage == PagedView.INVALID_RESTORE_PAGE) {
-                // Ensure that we have a valid page index to load synchronously
-                throw new RuntimeException("Should not call runBindSynchronousPage() without " +
-                        "valid page index");
-            }
-            if (!mModelLoaded) {
-                // Ensure that we don't try and bind a specified page when the pages have not been
-                // loaded already (we should load everything asynchronously in that case)
-                throw new RuntimeException("Expecting AllApps and Workspace to be loaded");
-            }
-            synchronized (mLock) {
-                if (mIsLoaderTaskRunning) {
-                    // Ensure that we are never running the background loading at this point since
-                    // we also touch the background collections
-                    throw new RuntimeException("Error! Background loading is already running");
-                }
-            }
-
-            // Divide the set of loaded items into those that we are binding synchronously, and
-            // everything else that is to be bound normally (asynchronously).
-            bindWorkspace(synchronousBindPage);
-            // XXX: For now, continue posting the binding of AllApps as there are other issues that
-            //      arise from that.
-            onlyBindAllApps();
-
-            bindDeepShortcuts();
-        }
-
         private void verifyNotStopped() throws CancellationException {
             synchronized (LoaderTask.this) {
                 if (mStopped) {
@@ -666,7 +641,7 @@
 
                 verifyNotStopped();
                 if (DEBUG_LOADERS) Log.d(TAG, "step 1.2: bind workspace workspace");
-                bindWorkspace(mPageToBindFirst);
+                mResults.bindWorkspace();
 
                 // Take a break
                 if (DEBUG_LOADERS) {
@@ -681,8 +656,12 @@
                 if (DEBUG_LOADERS) Log.d(TAG, "step 2.1: loading all apps");
                 loadAllApps();
 
+                if (DEBUG_LOADERS) Log.d(TAG, "step 2.2: Binding all apps");
                 verifyNotStopped();
-                if (DEBUG_LOADERS) Log.d(TAG, "step 2.2: Update icon cache");
+                mResults.bindAllApps();
+
+                verifyNotStopped();
+                if (DEBUG_LOADERS) Log.d(TAG, "step 2.3: Update icon cache");
                 updateIconCache();
 
                 // Take a break
@@ -700,7 +679,7 @@
 
                 verifyNotStopped();
                 if (DEBUG_LOADERS) Log.d(TAG, "step 3.2: bind deep shortcuts");
-                bindDeepShortcuts();
+                mResults.bindDeepShortcuts();
 
                 // Take a break
                 if (DEBUG_LOADERS) Log.d(TAG, "step 3 completed, wait for idle");
@@ -741,36 +720,6 @@
             }
         }
 
-        /**
-         * Gets the callbacks object.  If we've been stopped, or if the launcher object
-         * has somehow been garbage collected, return null instead.  Pass in the Callbacks
-         * object that was around when the deferred message was scheduled, and if there's
-         * a new Callbacks object around then also return null.  This will save us from
-         * calling onto it with data that will be ignored.
-         */
-        Callbacks tryGetCallbacks(Callbacks oldCallbacks) {
-            synchronized (mLock) {
-                if (mStopped) {
-                    return null;
-                }
-
-                if (mCallbacks == null) {
-                    return null;
-                }
-
-                final Callbacks callbacks = mCallbacks.get();
-                if (callbacks != oldCallbacks) {
-                    return null;
-                }
-                if (callbacks == null) {
-                    Log.w(TAG, "no mCallbacks");
-                    return null;
-                }
-
-                return callbacks;
-            }
-        }
-
         private void loadWorkspace() {
             if (LauncherAppState.PROFILE_STARTUP) {
                 Trace.beginSection("Loading Workspace");
@@ -1313,291 +1262,6 @@
             }
         }
 
-        /** Filters the set of items who are directly or indirectly (via another container) on the
-         * specified screen. */
-        private void filterCurrentWorkspaceItems(long currentScreenId,
-                ArrayList<ItemInfo> allWorkspaceItems,
-                ArrayList<ItemInfo> currentScreenItems,
-                ArrayList<ItemInfo> otherScreenItems) {
-            // Purge any null ItemInfos
-            Iterator<ItemInfo> iter = allWorkspaceItems.iterator();
-            while (iter.hasNext()) {
-                ItemInfo i = iter.next();
-                if (i == null) {
-                    iter.remove();
-                }
-            }
-
-            // Order the set of items by their containers first, this allows use to walk through the
-            // list sequentially, build up a list of containers that are in the specified screen,
-            // as well as all items in those containers.
-            Set<Long> itemsOnScreen = new HashSet<Long>();
-            Collections.sort(allWorkspaceItems, new Comparator<ItemInfo>() {
-                @Override
-                public int compare(ItemInfo lhs, ItemInfo rhs) {
-                    return Utilities.longCompare(lhs.container, rhs.container);
-                }
-            });
-            for (ItemInfo info : allWorkspaceItems) {
-                if (info.container == LauncherSettings.Favorites.CONTAINER_DESKTOP) {
-                    if (info.screenId == currentScreenId) {
-                        currentScreenItems.add(info);
-                        itemsOnScreen.add(info.id);
-                    } else {
-                        otherScreenItems.add(info);
-                    }
-                } else if (info.container == LauncherSettings.Favorites.CONTAINER_HOTSEAT) {
-                    currentScreenItems.add(info);
-                    itemsOnScreen.add(info.id);
-                } else {
-                    if (itemsOnScreen.contains(info.container)) {
-                        currentScreenItems.add(info);
-                        itemsOnScreen.add(info.id);
-                    } else {
-                        otherScreenItems.add(info);
-                    }
-                }
-            }
-        }
-
-        /** Filters the set of widgets which are on the specified screen. */
-        private void filterCurrentAppWidgets(long currentScreenId,
-                ArrayList<LauncherAppWidgetInfo> appWidgets,
-                ArrayList<LauncherAppWidgetInfo> currentScreenWidgets,
-                ArrayList<LauncherAppWidgetInfo> otherScreenWidgets) {
-
-            for (LauncherAppWidgetInfo widget : appWidgets) {
-                if (widget == null) continue;
-                if (widget.container == LauncherSettings.Favorites.CONTAINER_DESKTOP &&
-                        widget.screenId == currentScreenId) {
-                    currentScreenWidgets.add(widget);
-                } else {
-                    otherScreenWidgets.add(widget);
-                }
-            }
-        }
-
-        /** Sorts the set of items by hotseat, workspace (spatially from top to bottom, left to
-         * right) */
-        private void sortWorkspaceItemsSpatially(ArrayList<ItemInfo> workspaceItems) {
-            final InvariantDeviceProfile profile = mApp.getInvariantDeviceProfile();
-            final int screenCols = profile.numColumns;
-            final int screenCellCount = profile.numColumns * profile.numRows;
-            Collections.sort(workspaceItems, new Comparator<ItemInfo>() {
-                @Override
-                public int compare(ItemInfo lhs, ItemInfo rhs) {
-                    if (lhs.container == rhs.container) {
-                        // Within containers, order by their spatial position in that container
-                        switch ((int) lhs.container) {
-                            case LauncherSettings.Favorites.CONTAINER_DESKTOP: {
-                                long lr = (lhs.screenId * screenCellCount +
-                                        lhs.cellY * screenCols + lhs.cellX);
-                                long rr = (rhs.screenId * screenCellCount +
-                                        rhs.cellY * screenCols + rhs.cellX);
-                                return Utilities.longCompare(lr, rr);
-                            }
-                            case LauncherSettings.Favorites.CONTAINER_HOTSEAT: {
-                                // We currently use the screen id as the rank
-                                return Utilities.longCompare(lhs.screenId, rhs.screenId);
-                            }
-                            default:
-                                if (FeatureFlags.IS_DOGFOOD_BUILD) {
-                                    throw new RuntimeException("Unexpected container type when " +
-                                            "sorting workspace items.");
-                                }
-                                return 0;
-                        }
-                    } else {
-                        // Between containers, order by hotseat, desktop
-                        return Utilities.longCompare(lhs.container, rhs.container);
-                    }
-                }
-            });
-        }
-
-        private void bindWorkspaceScreens(final Callbacks oldCallbacks,
-                final ArrayList<Long> orderedScreens) {
-            final Runnable r = new Runnable() {
-                @Override
-                public void run() {
-                    Callbacks callbacks = tryGetCallbacks(oldCallbacks);
-                    if (callbacks != null) {
-                        callbacks.bindScreens(orderedScreens);
-                    }
-                }
-            };
-            mUiExecutor.execute(r);
-        }
-
-        private void bindWorkspaceItems(final Callbacks oldCallbacks,
-                final ArrayList<ItemInfo> workspaceItems,
-                final ArrayList<LauncherAppWidgetInfo> appWidgets,
-                final Executor executor) {
-
-            // Bind the workspace items
-            int N = workspaceItems.size();
-            for (int i = 0; i < N; i += ITEMS_CHUNK) {
-                final int start = i;
-                final int chunkSize = (i+ITEMS_CHUNK <= N) ? ITEMS_CHUNK : (N-i);
-                final Runnable r = new Runnable() {
-                    @Override
-                    public void run() {
-                        Callbacks callbacks = tryGetCallbacks(oldCallbacks);
-                        if (callbacks != null) {
-                            callbacks.bindItems(workspaceItems, start, start+chunkSize,
-                                    false);
-                        }
-                    }
-                };
-                executor.execute(r);
-            }
-
-            // Bind the widgets, one at a time
-            N = appWidgets.size();
-            for (int i = 0; i < N; i++) {
-                final LauncherAppWidgetInfo widget = appWidgets.get(i);
-                final Runnable r = new Runnable() {
-                    public void run() {
-                        Callbacks callbacks = tryGetCallbacks(oldCallbacks);
-                        if (callbacks != null) {
-                            callbacks.bindAppWidget(widget);
-                        }
-                    }
-                };
-                executor.execute(r);
-            }
-        }
-
-        /**
-         * Binds all loaded data to actual views on the main thread.
-         */
-        private void bindWorkspace(int synchronizeBindPage) {
-            final long t = SystemClock.uptimeMillis();
-            Runnable r;
-
-            // Don't use these two variables in any of the callback runnables.
-            // Otherwise we hold a reference to them.
-            final Callbacks oldCallbacks = mCallbacks.get();
-            if (oldCallbacks == null) {
-                // This launcher has exited and nobody bothered to tell us.  Just bail.
-                Log.w(TAG, "LoaderTask running with no launcher");
-                return;
-            }
-
-            // Save a copy of all the bg-thread collections
-            ArrayList<ItemInfo> workspaceItems = new ArrayList<>();
-            ArrayList<LauncherAppWidgetInfo> appWidgets = new ArrayList<>();
-            ArrayList<Long> orderedScreenIds = new ArrayList<>();
-
-            synchronized (sBgDataModel) {
-                workspaceItems.addAll(sBgDataModel.workspaceItems);
-                appWidgets.addAll(sBgDataModel.appWidgets);
-                orderedScreenIds.addAll(sBgDataModel.workspaceScreens);
-            }
-
-            final int currentScreen;
-            {
-                int currScreen = synchronizeBindPage != PagedView.INVALID_RESTORE_PAGE
-                        ? synchronizeBindPage : oldCallbacks.getCurrentWorkspaceScreen();
-                if (currScreen >= orderedScreenIds.size()) {
-                    // There may be no workspace screens (just hotseat items and an empty page).
-                    currScreen = PagedView.INVALID_RESTORE_PAGE;
-                }
-                currentScreen = currScreen;
-            }
-            final boolean validFirstPage = currentScreen >= 0;
-            final long currentScreenId =
-                    validFirstPage ? orderedScreenIds.get(currentScreen) : INVALID_SCREEN_ID;
-
-            // Separate the items that are on the current screen, and all the other remaining items
-            ArrayList<ItemInfo> currentWorkspaceItems = new ArrayList<>();
-            ArrayList<ItemInfo> otherWorkspaceItems = new ArrayList<>();
-            ArrayList<LauncherAppWidgetInfo> currentAppWidgets = new ArrayList<>();
-            ArrayList<LauncherAppWidgetInfo> otherAppWidgets = new ArrayList<>();
-
-            filterCurrentWorkspaceItems(currentScreenId, workspaceItems, currentWorkspaceItems,
-                    otherWorkspaceItems);
-            filterCurrentAppWidgets(currentScreenId, appWidgets, currentAppWidgets,
-                    otherAppWidgets);
-            sortWorkspaceItemsSpatially(currentWorkspaceItems);
-            sortWorkspaceItemsSpatially(otherWorkspaceItems);
-
-            // Tell the workspace that we're about to start binding items
-            r = new Runnable() {
-                public void run() {
-                    Callbacks callbacks = tryGetCallbacks(oldCallbacks);
-                    if (callbacks != null) {
-                        callbacks.clearPendingBinds();
-                        callbacks.startBinding();
-                    }
-                }
-            };
-            mUiExecutor.execute(r);
-
-            bindWorkspaceScreens(oldCallbacks, orderedScreenIds);
-
-            Executor mainExecutor = mUiExecutor;
-            // Load items on the current page.
-            bindWorkspaceItems(oldCallbacks, currentWorkspaceItems, currentAppWidgets, mainExecutor);
-
-            // In case of validFirstPage, only bind the first screen, and defer binding the
-            // remaining screens after first onDraw (and an optional the fade animation whichever
-            // happens later).
-            // This ensures that the first screen is immediately visible (eg. during rotation)
-            // In case of !validFirstPage, bind all pages one after other.
-            final Executor deferredExecutor =
-                    validFirstPage ? new ViewOnDrawExecutor(mUiExecutor) : mainExecutor;
-
-            mainExecutor.execute(new Runnable() {
-                @Override
-                public void run() {
-                    Callbacks callbacks = tryGetCallbacks(oldCallbacks);
-                    if (callbacks != null) {
-                        callbacks.finishFirstPageBind(
-                                validFirstPage ? (ViewOnDrawExecutor) deferredExecutor : null);
-                    }
-                }
-            });
-
-            bindWorkspaceItems(oldCallbacks, otherWorkspaceItems, otherAppWidgets, deferredExecutor);
-
-            // Tell the workspace that we're done binding items
-            r = new Runnable() {
-                public void run() {
-                    Callbacks callbacks = tryGetCallbacks(oldCallbacks);
-                    if (callbacks != null) {
-                        callbacks.finishBindingItems();
-                    }
-
-                    // If we're profiling, ensure this is the last thing in the queue.
-                    if (DEBUG_LOADERS) {
-                        Log.d(TAG, "bound workspace in "
-                            + (SystemClock.uptimeMillis()-t) + "ms");
-                    }
-
-                }
-            };
-            deferredExecutor.execute(r);
-
-            if (validFirstPage) {
-                r = new Runnable() {
-                    public void run() {
-                        Callbacks callbacks = tryGetCallbacks(oldCallbacks);
-                        if (callbacks != null) {
-                            // We are loading synchronously, which means, some of the pages will be
-                            // bound after first draw. Inform the callbacks that page binding is
-                            // not complete, and schedule the remaining pages.
-                            if (currentScreen != PagedView.INVALID_RESTORE_PAGE) {
-                                callbacks.onPageBoundSynchronously(currentScreen);
-                            }
-                            callbacks.executeOnNextDraw((ViewOnDrawExecutor) deferredExecutor);
-                        }
-                    }
-                };
-                mUiExecutor.execute(r);
-            }
-        }
-
         private void updateIconCache() {
             // Ignore packages which have a promise icon.
             HashSet<String> packagesToIgnore = new HashSet<>();
@@ -1619,44 +1283,9 @@
             mIconCache.updateDbIcons(packagesToIgnore);
         }
 
-        private void onlyBindAllApps() {
-            final Callbacks oldCallbacks = mCallbacks.get();
-            if (oldCallbacks == null) {
-                // This launcher has exited and nobody bothered to tell us.  Just bail.
-                Log.w(TAG, "LoaderTask running with no launcher (onlyBindAllApps)");
-                return;
-            }
-
-            // shallow copy
-            @SuppressWarnings("unchecked")
-            final ArrayList<AppInfo> list
-                    = (ArrayList<AppInfo>) mBgAllAppsList.data.clone();
-            Runnable r = new Runnable() {
-                public void run() {
-                    final long t = SystemClock.uptimeMillis();
-                    final Callbacks callbacks = tryGetCallbacks(oldCallbacks);
-                    if (callbacks != null) {
-                        callbacks.bindAllApplications(list);
-                    }
-                    if (DEBUG_LOADERS) {
-                        Log.d(TAG, "bound all " + list.size() + " apps from cache in "
-                                + (SystemClock.uptimeMillis() - t) + "ms");
-                    }
-                }
-            };
-            mUiExecutor.execute(r);
-        }
-
         private void loadAllApps() {
             final long loadTime = DEBUG_LOADERS ? SystemClock.uptimeMillis() : 0;
 
-            final Callbacks oldCallbacks = mCallbacks.get();
-            if (oldCallbacks == null) {
-                // This launcher has exited and nobody bothered to tell us.  Just bail.
-                Log.w(TAG, "LoaderTask running with no launcher (loadAllApps)");
-                return;
-            }
-
             final List<UserHandle> profiles = mUserManager.getUserProfiles();
 
             // Clear the list of apps
@@ -1695,30 +1324,9 @@
                 }
             }
 
-            // Huh? Shouldn't this be inside the Runnable below?
-            final ArrayList<AppInfo> added = mBgAllAppsList.added;
-            mBgAllAppsList.added = new ArrayList<AppInfo>();
-
-
-            // Post callback on main thread
-            mUiExecutor.execute(new Runnable() {
-                public void run() {
-
-                    final long bindTime = SystemClock.uptimeMillis();
-                    final Callbacks callbacks = tryGetCallbacks(oldCallbacks);
-                    if (callbacks != null) {
-                        callbacks.bindAllApplications(added);
-                        if (DEBUG_LOADERS) {
-                            Log.d(TAG, "bound " + added.size() + " apps in "
-                                    + (SystemClock.uptimeMillis() - bindTime) + "ms");
-                        }
-                    } else {
-                        Log.i(TAG, "not binding apps: no Launcher activity");
-                    }
-                }
-            });
+            mBgAllAppsList.added = new ArrayList<>();
             if (DEBUG_LOADERS) {
-                Log.d(TAG, "Icons processed in "
+                Log.d(TAG, "All apps loaded in in "
                         + (SystemClock.uptimeMillis() - loadTime) + "ms");
             }
         }
@@ -1739,21 +1347,6 @@
         }
     }
 
-    public void bindDeepShortcuts() {
-        final MultiHashMap<ComponentKey, String> shortcutMapCopy =
-                sBgDataModel.deepShortcutMap.clone();
-        Runnable r = new Runnable() {
-            @Override
-            public void run() {
-                Callbacks callbacks = getCallback();
-                if (callbacks != null) {
-                    callbacks.bindDeepShortcutMap(shortcutMapCopy);
-                }
-            }
-        };
-        mUiExecutor.execute(r);
-    }
-
     /**
      * Refreshes the cached shortcuts if the shortcut permission has changed.
      * Current implementation simply reloads the workspace, but it can be optimized to
@@ -1925,15 +1518,6 @@
     }
 
     /**
-     * @return {@link FolderInfo} if its already loaded.
-     */
-    public FolderInfo findFolderById(Long folderId) {
-        synchronized (sBgDataModel) {
-            return sBgDataModel.folders.get(folderId);
-        }
-    }
-
-    /**
      * @return the looper for the worker thread which can be used to start background tasks.
      */
     public static Looper getWorkerLooper() {
diff --git a/src/com/android/launcher3/model/LoaderResults.java b/src/com/android/launcher3/model/LoaderResults.java
new file mode 100644
index 0000000..61fd356
--- /dev/null
+++ b/src/com/android/launcher3/model/LoaderResults.java
@@ -0,0 +1,377 @@
+/*
+ * Copyright (C) 2017 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.model;
+
+import android.util.Log;
+
+import com.android.launcher3.AllAppsList;
+import com.android.launcher3.AppInfo;
+import com.android.launcher3.InvariantDeviceProfile;
+import com.android.launcher3.ItemInfo;
+import com.android.launcher3.LauncherAppState;
+import com.android.launcher3.LauncherAppWidgetInfo;
+import com.android.launcher3.LauncherModel.Callbacks;
+import com.android.launcher3.LauncherSettings;
+import com.android.launcher3.MainThreadExecutor;
+import com.android.launcher3.PagedView;
+import com.android.launcher3.Utilities;
+import com.android.launcher3.config.FeatureFlags;
+import com.android.launcher3.util.ComponentKey;
+import com.android.launcher3.util.MultiHashMap;
+import com.android.launcher3.util.ViewOnDrawExecutor;
+
+import java.lang.ref.WeakReference;
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.Comparator;
+import java.util.HashSet;
+import java.util.Iterator;
+import java.util.Set;
+import java.util.concurrent.Executor;
+
+/**
+ * Helper class to handle results of {@link com.android.launcher3.LauncherModel.LoaderTask}.
+ */
+public class LoaderResults {
+
+    private static final String TAG = "LoaderResults";
+    private static final long INVALID_SCREEN_ID = -1L;
+    private static final int ITEMS_CHUNK = 6; // batch size for the workspace icons
+
+    private final Executor mUiExecutor;
+
+    private final LauncherAppState mApp;
+    private final BgDataModel mBgDataModel;
+    private final AllAppsList mBgAllAppsList;
+    private final int mPageToBindFirst;
+    private final WeakReference<Callbacks> mCallbacks;
+
+    public LoaderResults(LauncherAppState app, BgDataModel dataModel,
+            AllAppsList allAppsList, int pageToBindFirst, WeakReference<Callbacks> callbacks) {
+        mUiExecutor = new MainThreadExecutor();
+        mApp = app;
+        mBgDataModel = dataModel;
+        mBgAllAppsList = allAppsList;
+        mPageToBindFirst = pageToBindFirst;
+        mCallbacks = callbacks == null ? new WeakReference<Callbacks>(null) : callbacks;
+    }
+
+    /**
+     * Binds all loaded data to actual views on the main thread.
+     */
+    public void bindWorkspace() {
+        Runnable r;
+
+        Callbacks callbacks = mCallbacks.get();
+        // Don't use these two variables in any of the callback runnables.
+        // Otherwise we hold a reference to them.
+        if (callbacks == null) {
+            // This launcher has exited and nobody bothered to tell us.  Just bail.
+            Log.w(TAG, "LoaderTask running with no launcher");
+            return;
+        }
+
+        // Save a copy of all the bg-thread collections
+        ArrayList<ItemInfo> workspaceItems = new ArrayList<>();
+        ArrayList<LauncherAppWidgetInfo> appWidgets = new ArrayList<>();
+        final ArrayList<Long> orderedScreenIds = new ArrayList<>();
+
+        synchronized (mBgDataModel) {
+            workspaceItems.addAll(mBgDataModel.workspaceItems);
+            appWidgets.addAll(mBgDataModel.appWidgets);
+            orderedScreenIds.addAll(mBgDataModel.workspaceScreens);
+        }
+
+        final int currentScreen;
+        {
+            int currScreen = mPageToBindFirst != PagedView.INVALID_RESTORE_PAGE
+                    ? mPageToBindFirst : callbacks.getCurrentWorkspaceScreen();
+            if (currScreen >= orderedScreenIds.size()) {
+                // There may be no workspace screens (just hotseat items and an empty page).
+                currScreen = PagedView.INVALID_RESTORE_PAGE;
+            }
+            currentScreen = currScreen;
+        }
+        final boolean validFirstPage = currentScreen >= 0;
+        final long currentScreenId =
+                validFirstPage ? orderedScreenIds.get(currentScreen) : INVALID_SCREEN_ID;
+
+        // Separate the items that are on the current screen, and all the other remaining items
+        ArrayList<ItemInfo> currentWorkspaceItems = new ArrayList<>();
+        ArrayList<ItemInfo> otherWorkspaceItems = new ArrayList<>();
+        ArrayList<LauncherAppWidgetInfo> currentAppWidgets = new ArrayList<>();
+        ArrayList<LauncherAppWidgetInfo> otherAppWidgets = new ArrayList<>();
+
+        filterCurrentWorkspaceItems(currentScreenId, workspaceItems, currentWorkspaceItems,
+                otherWorkspaceItems);
+        filterCurrentAppWidgets(currentScreenId, appWidgets, currentAppWidgets,
+                otherAppWidgets);
+        sortWorkspaceItemsSpatially(currentWorkspaceItems);
+        sortWorkspaceItemsSpatially(otherWorkspaceItems);
+
+        // Tell the workspace that we're about to start binding items
+        r = new Runnable() {
+            public void run() {
+                Callbacks callbacks = mCallbacks.get();
+                if (callbacks != null) {
+                    callbacks.clearPendingBinds();
+                    callbacks.startBinding();
+                }
+            }
+        };
+        mUiExecutor.execute(r);
+
+        // Bind workspace screens
+        mUiExecutor.execute(new Runnable() {
+            @Override
+            public void run() {
+                Callbacks callbacks = mCallbacks.get();
+                if (callbacks != null) {
+                    callbacks.bindScreens(orderedScreenIds);
+                }
+            }
+        });
+
+        Executor mainExecutor = mUiExecutor;
+        // Load items on the current page.
+        bindWorkspaceItems(currentWorkspaceItems, currentAppWidgets, mainExecutor);
+
+        // In case of validFirstPage, only bind the first screen, and defer binding the
+        // remaining screens after first onDraw (and an optional the fade animation whichever
+        // happens later).
+        // This ensures that the first screen is immediately visible (eg. during rotation)
+        // In case of !validFirstPage, bind all pages one after other.
+        final Executor deferredExecutor =
+                validFirstPage ? new ViewOnDrawExecutor(mUiExecutor) : mainExecutor;
+
+        mainExecutor.execute(new Runnable() {
+            @Override
+            public void run() {
+                Callbacks callbacks = mCallbacks.get();
+                if (callbacks != null) {
+                    callbacks.finishFirstPageBind(
+                            validFirstPage ? (ViewOnDrawExecutor) deferredExecutor : null);
+                }
+            }
+        });
+
+        bindWorkspaceItems(otherWorkspaceItems, otherAppWidgets, deferredExecutor);
+
+        // Tell the workspace that we're done binding items
+        r = new Runnable() {
+            public void run() {
+                Callbacks callbacks = mCallbacks.get();
+                if (callbacks != null) {
+                    callbacks.finishBindingItems();
+                }
+            }
+        };
+        deferredExecutor.execute(r);
+
+        if (validFirstPage) {
+            r = new Runnable() {
+                public void run() {
+                    Callbacks callbacks = mCallbacks.get();
+                    if (callbacks != null) {
+                        // We are loading synchronously, which means, some of the pages will be
+                        // bound after first draw. Inform the callbacks that page binding is
+                        // not complete, and schedule the remaining pages.
+                        if (currentScreen != PagedView.INVALID_RESTORE_PAGE) {
+                            callbacks.onPageBoundSynchronously(currentScreen);
+                        }
+                        callbacks.executeOnNextDraw((ViewOnDrawExecutor) deferredExecutor);
+                    }
+                }
+            };
+            mUiExecutor.execute(r);
+        }
+    }
+
+
+    /** Filters the set of items who are directly or indirectly (via another container) on the
+     * specified screen. */
+    private void filterCurrentWorkspaceItems(long currentScreenId,
+            ArrayList<ItemInfo> allWorkspaceItems,
+            ArrayList<ItemInfo> currentScreenItems,
+            ArrayList<ItemInfo> otherScreenItems) {
+        // Purge any null ItemInfos
+        Iterator<ItemInfo> iter = allWorkspaceItems.iterator();
+        while (iter.hasNext()) {
+            ItemInfo i = iter.next();
+            if (i == null) {
+                iter.remove();
+            }
+        }
+
+        // Order the set of items by their containers first, this allows use to walk through the
+        // list sequentially, build up a list of containers that are in the specified screen,
+        // as well as all items in those containers.
+        Set<Long> itemsOnScreen = new HashSet<Long>();
+        Collections.sort(allWorkspaceItems, new Comparator<ItemInfo>() {
+            @Override
+            public int compare(ItemInfo lhs, ItemInfo rhs) {
+                return Utilities.longCompare(lhs.container, rhs.container);
+            }
+        });
+        for (ItemInfo info : allWorkspaceItems) {
+            if (info.container == LauncherSettings.Favorites.CONTAINER_DESKTOP) {
+                if (info.screenId == currentScreenId) {
+                    currentScreenItems.add(info);
+                    itemsOnScreen.add(info.id);
+                } else {
+                    otherScreenItems.add(info);
+                }
+            } else if (info.container == LauncherSettings.Favorites.CONTAINER_HOTSEAT) {
+                currentScreenItems.add(info);
+                itemsOnScreen.add(info.id);
+            } else {
+                if (itemsOnScreen.contains(info.container)) {
+                    currentScreenItems.add(info);
+                    itemsOnScreen.add(info.id);
+                } else {
+                    otherScreenItems.add(info);
+                }
+            }
+        }
+    }
+
+    /** Filters the set of widgets which are on the specified screen. */
+    private void filterCurrentAppWidgets(long currentScreenId,
+            ArrayList<LauncherAppWidgetInfo> appWidgets,
+            ArrayList<LauncherAppWidgetInfo> currentScreenWidgets,
+            ArrayList<LauncherAppWidgetInfo> otherScreenWidgets) {
+
+        for (LauncherAppWidgetInfo widget : appWidgets) {
+            if (widget == null) continue;
+            if (widget.container == LauncherSettings.Favorites.CONTAINER_DESKTOP &&
+                    widget.screenId == currentScreenId) {
+                currentScreenWidgets.add(widget);
+            } else {
+                otherScreenWidgets.add(widget);
+            }
+        }
+    }
+
+    /** Sorts the set of items by hotseat, workspace (spatially from top to bottom, left to
+     * right) */
+    private void sortWorkspaceItemsSpatially(ArrayList<ItemInfo> workspaceItems) {
+        final InvariantDeviceProfile profile = mApp.getInvariantDeviceProfile();
+        final int screenCols = profile.numColumns;
+        final int screenCellCount = profile.numColumns * profile.numRows;
+        Collections.sort(workspaceItems, new Comparator<ItemInfo>() {
+            @Override
+            public int compare(ItemInfo lhs, ItemInfo rhs) {
+                if (lhs.container == rhs.container) {
+                    // Within containers, order by their spatial position in that container
+                    switch ((int) lhs.container) {
+                        case LauncherSettings.Favorites.CONTAINER_DESKTOP: {
+                            long lr = (lhs.screenId * screenCellCount +
+                                    lhs.cellY * screenCols + lhs.cellX);
+                            long rr = (rhs.screenId * screenCellCount +
+                                    rhs.cellY * screenCols + rhs.cellX);
+                            return Utilities.longCompare(lr, rr);
+                        }
+                        case LauncherSettings.Favorites.CONTAINER_HOTSEAT: {
+                            // We currently use the screen id as the rank
+                            return Utilities.longCompare(lhs.screenId, rhs.screenId);
+                        }
+                        default:
+                            if (FeatureFlags.IS_DOGFOOD_BUILD) {
+                                throw new RuntimeException("Unexpected container type when " +
+                                        "sorting workspace items.");
+                            }
+                            return 0;
+                    }
+                } else {
+                    // Between containers, order by hotseat, desktop
+                    return Utilities.longCompare(lhs.container, rhs.container);
+                }
+            }
+        });
+    }
+
+    private void bindWorkspaceItems(final ArrayList<ItemInfo> workspaceItems,
+            final ArrayList<LauncherAppWidgetInfo> appWidgets,
+            final Executor executor) {
+
+        // Bind the workspace items
+        int N = workspaceItems.size();
+        for (int i = 0; i < N; i += ITEMS_CHUNK) {
+            final int start = i;
+            final int chunkSize = (i+ITEMS_CHUNK <= N) ? ITEMS_CHUNK : (N-i);
+            final Runnable r = new Runnable() {
+                @Override
+                public void run() {
+                    Callbacks callbacks = mCallbacks.get();
+                    if (callbacks != null) {
+                        callbacks.bindItems(workspaceItems, start, start+chunkSize, false);
+                    }
+                }
+            };
+            executor.execute(r);
+        }
+
+        // Bind the widgets, one at a time
+        N = appWidgets.size();
+        for (int i = 0; i < N; i++) {
+            final LauncherAppWidgetInfo widget = appWidgets.get(i);
+            final Runnable r = new Runnable() {
+                public void run() {
+                    Callbacks callbacks = mCallbacks.get();
+                    if (callbacks != null) {
+                        callbacks.bindAppWidget(widget);
+                    }
+                }
+            };
+            executor.execute(r);
+        }
+    }
+
+    public void bindDeepShortcuts() {
+        final MultiHashMap<ComponentKey, String> shortcutMapCopy;
+        synchronized (mBgDataModel) {
+            shortcutMapCopy = mBgDataModel.deepShortcutMap.clone();
+        }
+        Runnable r = new Runnable() {
+            @Override
+            public void run() {
+                Callbacks callbacks = mCallbacks.get();
+                if (callbacks != null) {
+                    callbacks.bindDeepShortcutMap(shortcutMapCopy);
+                }
+            }
+        };
+        mUiExecutor.execute(r);
+    }
+
+
+    public void bindAllApps() {
+        // shallow copy
+        @SuppressWarnings("unchecked")
+        final ArrayList<AppInfo> list = (ArrayList<AppInfo>) mBgAllAppsList.data.clone();
+
+        Runnable r = new Runnable() {
+            public void run() {
+                Callbacks callbacks = mCallbacks.get();
+                if (callbacks != null) {
+                    callbacks.bindAllApplications(list);
+                }
+            }
+        };
+        mUiExecutor.execute(r);
+    }
+}