Making recents faster

Improving load time by:
- using window animation for fade-in and not
    waiting to create HW layer
- starting loading of thumbnails/icons earlier
- only initially creating views for the first
    screenful of items
- recycling views

Change-Id: I529b1085fe35d81aaafeb7433ccaed8e0537f01c

6 files changed, 507 insertions, 218 deletions

diff --git a/packages/SystemUI/src/com/android/systemui/recent/Choreographer.java b/packages/SystemUI/src/com/android/systemui/recent/Choreographer.java
index ad38a11..f8a4592 100644
--- a/packages/SystemUI/src/com/android/systemui/recent/Choreographer.java
+++ b/packages/SystemUI/src/com/android/systemui/recent/Choreographer.java
@@ -134,6 +134,7 @@ import android.view.View;
 
     void jumpTo(boolean appearing) {
         mContentView.setTranslationY(appearing ? 0 : mPanelHeight);
+        mScrimView.getBackground().setAlpha(appearing ? 255 : 0);
     }
 
     public void setPanelHeight(int h) {
diff --git a/packages/SystemUI/src/com/android/systemui/recent/RecentTasksLoader.java b/packages/SystemUI/src/com/android/systemui/recent/RecentTasksLoader.java
index 4145fc4..92f4ca9 100644
--- a/packages/SystemUI/src/com/android/systemui/recent/RecentTasksLoader.java
+++ b/packages/SystemUI/src/com/android/systemui/recent/RecentTasksLoader.java
@@ -16,12 +16,6 @@
 
 package com.android.systemui.recent;
 
-import java.util.ArrayList;
-import java.util.HashSet;
-import java.util.List;
-import java.util.Map;
-import java.util.Set;
-
 import android.app.ActivityManager;
 import android.content.ComponentName;
 import android.content.Context;
@@ -36,15 +30,17 @@ import android.graphics.drawable.Drawable;
 import android.os.AsyncTask;
 import android.os.Handler;
 import android.os.Process;
-import android.os.SystemClock;
-import android.util.DisplayMetrics;
 import android.util.Log;
-import android.util.LruCache;
 
 import com.android.systemui.R;
 import com.android.systemui.statusbar.phone.PhoneStatusBar;
 import com.android.systemui.statusbar.tablet.TabletStatusBar;
 
+import java.util.ArrayList;
+import java.util.List;
+import java.util.concurrent.BlockingQueue;
+import java.util.concurrent.LinkedBlockingQueue;
+
 public class RecentTasksLoader {
     static final String TAG = "RecentTasksLoader";
     static final boolean DEBUG = TabletStatusBar.DEBUG || PhoneStatusBar.DEBUG || false;
@@ -55,11 +51,14 @@ public class RecentTasksLoader {
     private Context mContext;
     private RecentsPanelView mRecentsPanel;
 
-    private AsyncTask<Void, Integer, Void> mThumbnailLoader;
+    private AsyncTask<Void, ArrayList<TaskDescription>, Void> mTaskLoader;
+    private AsyncTask<Void, TaskDescription, Void> mThumbnailLoader;
     private final Handler mHandler;
 
     private int mIconDpi;
     private Bitmap mDefaultThumbnailBackground;
+    private Bitmap mDefaultIconBackground;
+    private int mNumTasksInFirstScreenful;
 
     public RecentTasksLoader(Context context) {
         mContext = context;
@@ -76,12 +75,20 @@ public class RecentTasksLoader {
             mIconDpi = res.getDisplayMetrics().densityDpi;
         }
 
+        // Render default icon (just a blank image)
+        int defaultIconSize = res.getDimensionPixelSize(com.android.internal.R.dimen.app_icon_size);
+        int iconSize = (int) (defaultIconSize * mIconDpi / res.getDisplayMetrics().densityDpi);
+        mDefaultIconBackground = Bitmap.createBitmap(iconSize, iconSize, Bitmap.Config.ARGB_8888);
+
         // Render the default thumbnail background
-        int width = (int) res.getDimensionPixelSize(com.android.internal.R.dimen.thumbnail_width);
-        int height = (int) res.getDimensionPixelSize(com.android.internal.R.dimen.thumbnail_height);
+        int thumbnailWidth =
+                (int) res.getDimensionPixelSize(com.android.internal.R.dimen.thumbnail_width);
+        int thumbnailHeight =
+                (int) res.getDimensionPixelSize(com.android.internal.R.dimen.thumbnail_height);
         int color = res.getColor(R.drawable.status_bar_recents_app_thumbnail_background);
 
-        mDefaultThumbnailBackground = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);
+        mDefaultThumbnailBackground =
+                Bitmap.createBitmap(thumbnailWidth, thumbnailHeight, Bitmap.Config.ARGB_8888);
         Canvas c = new Canvas(mDefaultThumbnailBackground);
         c.drawColor(color);
 
@@ -95,12 +102,17 @@ public class RecentTasksLoader {
 
     public void setRecentsPanel(RecentsPanelView recentsPanel) {
         mRecentsPanel = recentsPanel;
+        mNumTasksInFirstScreenful = mRecentsPanel.numItemsInOneScreenful();
     }
 
     public Bitmap getDefaultThumbnail() {
         return mDefaultThumbnailBackground;
     }
 
+    public Bitmap getDefaultIcon() {
+        return mDefaultIconBackground;
+    }
+
     // Create an TaskDescription, returning null if the title or icon is null, or if it's the
     // home activity
     TaskDescription createTaskDescription(int taskId, int persistentTaskId, Intent baseIntent,
@@ -114,6 +126,12 @@ public class RecentTasksLoader {
             homeInfo = new Intent(Intent.ACTION_MAIN).addCategory(Intent.CATEGORY_HOME)
             .resolveActivityInfo(pm, 0);
         }
+        // Don't load the current home activity.
+        if (homeInfo != null
+            && homeInfo.packageName.equals(intent.getComponent().getPackageName())
+            && homeInfo.name.equals(intent.getComponent().getClassName())) {
+            return null;
+        }
 
         intent.setFlags((intent.getFlags()&~Intent.FLAG_ACTIVITY_RESET_TASK_IF_NEEDED)
                 | Intent.FLAG_ACTIVITY_NEW_TASK);
@@ -121,9 +139,8 @@ public class RecentTasksLoader {
         if (resolveInfo != null) {
             final ActivityInfo info = resolveInfo.activityInfo;
             final String title = info.loadLabel(pm).toString();
-            Drawable icon = getFullResIcon(resolveInfo, pm);
 
-            if (title != null && title.length() > 0 && icon != null) {
+            if (title != null && title.length() > 0) {
                 if (DEBUG) Log.v(TAG, "creating activity desc for id="
                         + persistentTaskId + ", label=" + title);
 
@@ -131,14 +148,6 @@ public class RecentTasksLoader {
                         persistentTaskId, resolveInfo, baseIntent, info.packageName,
                         description);
                 item.setLabel(title);
-                item.setIcon(icon);
-
-                // Don't load the current home activity.
-                if (homeInfo != null
-                        && homeInfo.packageName.equals(intent.getComponent().getPackageName())
-                        && homeInfo.name.equals(intent.getComponent().getClassName())) {
-                    return null;
-                }
 
                 return item;
             } else {
@@ -148,10 +157,12 @@ public class RecentTasksLoader {
         return null;
     }
 
-    void loadThumbnail(TaskDescription td) {
+    void loadThumbnailAndIcon(TaskDescription td) {
         final ActivityManager am = (ActivityManager)
                 mContext.getSystemService(Context.ACTIVITY_SERVICE);
+        final PackageManager pm = mContext.getPackageManager();
         ActivityManager.TaskThumbnails thumbs = am.getTaskThumbnails(td.persistentTaskId);
+        Drawable icon = getFullResIcon(td.resolveInfo, pm);
 
         if (DEBUG) Log.v(TAG, "Loaded bitmap for task "
                 + td + ": " + thumbs.mainThumbnail);
@@ -161,6 +172,10 @@ public class RecentTasksLoader {
             } else {
                 td.setThumbnail(mDefaultThumbnailBackground);
             }
+            if (icon != null) {
+                td.setIcon(icon);
+            }
+            td.setLoaded(true);
         }
     }
 
@@ -194,111 +209,149 @@ public class RecentTasksLoader {
         return getFullResDefaultActivityIcon();
     }
 
-    public void cancelLoadingThumbnails() {
+    public void cancelLoadingThumbnailsAndIcons() {
+        if (mTaskLoader != null) {
+            mTaskLoader.cancel(false);
+            mTaskLoader = null;
+        }
         if (mThumbnailLoader != null) {
             mThumbnailLoader.cancel(false);
             mThumbnailLoader = null;
         }
     }
 
-    // return a snapshot of the current list of recent apps
-    ArrayList<TaskDescription> getRecentTasks() {
-        cancelLoadingThumbnails();
-
-        ArrayList<TaskDescription> tasks = new ArrayList<TaskDescription>();
-        final PackageManager pm = mContext.getPackageManager();
-        final ActivityManager am = (ActivityManager)
+    public void loadTasksInBackground() {
+        // cancel all previous loading of tasks and thumbnails
+        cancelLoadingThumbnailsAndIcons();
+        final LinkedBlockingQueue<TaskDescription> tasksWaitingForThumbnails =
+                new LinkedBlockingQueue<TaskDescription>();
+        final ArrayList<TaskDescription> taskDescriptionsWaitingToLoad =
+                new ArrayList<TaskDescription>();
+        mTaskLoader = new AsyncTask<Void, ArrayList<TaskDescription>, Void>() {
+            @Override
+            protected void onProgressUpdate(ArrayList<TaskDescription>... values) {
+                if (!isCancelled()) {
+                    ArrayList<TaskDescription> newTasks = values[0];
+                    // do a callback to RecentsPanelView to let it know we have more values
+                    // how do we let it know we're all done? just always call back twice
+                    mRecentsPanel.onTasksLoaded(newTasks);
+                }
+            }
+            @Override
+            protected Void doInBackground(Void... params) {
+                // We load in two stages: first, we update progress with just the first screenful
+                // of items. Then, we update with the rest of the items
+                final int origPri = Process.getThreadPriority(Process.myTid());
+                Process.setThreadPriority(Process.THREAD_GROUP_BG_NONINTERACTIVE);
+                final PackageManager pm = mContext.getPackageManager();
+                final ActivityManager am = (ActivityManager)
                 mContext.getSystemService(Context.ACTIVITY_SERVICE);
 
-        final List<ActivityManager.RecentTaskInfo> recentTasks =
-                am.getRecentTasks(MAX_TASKS, ActivityManager.RECENT_IGNORE_UNAVAILABLE);
+                final List<ActivityManager.RecentTaskInfo> recentTasks =
+                        am.getRecentTasks(MAX_TASKS, ActivityManager.RECENT_IGNORE_UNAVAILABLE);
+                int numTasks = recentTasks.size();
+                ActivityInfo homeInfo = new Intent(Intent.ACTION_MAIN)
+                        .addCategory(Intent.CATEGORY_HOME).resolveActivityInfo(pm, 0);
 
-        ActivityInfo homeInfo = new Intent(Intent.ACTION_MAIN).addCategory(Intent.CATEGORY_HOME)
-                    .resolveActivityInfo(pm, 0);
+                boolean firstScreenful = true;
+                ArrayList<TaskDescription> tasks = new ArrayList<TaskDescription>();
 
-        HashSet<Integer> recentTasksToKeepInCache = new HashSet<Integer>();
-        int numTasks = recentTasks.size();
+                // skip the first task - assume it's either the home screen or the current activity.
+                final int first = 1;
+                for (int i = first, index = 0; i < numTasks && (index < MAX_TASKS); ++i) {
+                    if (isCancelled()) {
+                        break;
+                    }
+                    final ActivityManager.RecentTaskInfo recentInfo = recentTasks.get(i);
+                    TaskDescription item = createTaskDescription(recentInfo.id,
+                            recentInfo.persistentId, recentInfo.baseIntent,
+                            recentInfo.origActivity, recentInfo.description, homeInfo);
+
+                    if (item != null) {
+                        while (true) {
+                            try {
+                                tasksWaitingForThumbnails.put(item);
+                                break;
+                            } catch (InterruptedException e) {
+                            }
+                        }
+                        tasks.add(item);
+                        if (firstScreenful && tasks.size() == mNumTasksInFirstScreenful) {
+                            publishProgress(tasks);
+                            tasks = new ArrayList<TaskDescription>();
+                            firstScreenful = false;
+                            //break;
+                        }
+                        ++index;
+                    }
+                }
 
-        // skip the first task - assume it's either the home screen or the current activity.
-        final int first = 1;
-        recentTasksToKeepInCache.add(recentTasks.get(0).persistentId);
-        for (int i = first, index = 0; i < numTasks && (index < MAX_TASKS); ++i) {
-            final ActivityManager.RecentTaskInfo recentInfo = recentTasks.get(i);
+                if (!isCancelled()) {
+                    publishProgress(tasks);
+                    if (firstScreenful) {
+                        // always should publish two updates
+                        publishProgress(new ArrayList<TaskDescription>());
+                    }
+                }
 
-            TaskDescription item = createTaskDescription(recentInfo.id,
-                    recentInfo.persistentId, recentInfo.baseIntent,
-                    recentInfo.origActivity, recentInfo.description, homeInfo);
+                while (true) {
+                    try {
+                        tasksWaitingForThumbnails.put(new TaskDescription());
+                        break;
+                    } catch (InterruptedException e) {
+                    }
+                }
 
-            if (item != null) {
-                tasks.add(item);
-                ++index;
+                Process.setThreadPriority(origPri);
+                return null;
             }
-        }
-
-        // when we're not using the TaskDescription cache, we load the thumbnails in the
-        // background
-        loadThumbnailsInBackground(new ArrayList<TaskDescription>(tasks));
-        return tasks;
+        };
+        mTaskLoader.executeOnExecutor(AsyncTask.THREAD_POOL_EXECUTOR);
+        loadThumbnailsAndIconsInBackground(tasksWaitingForThumbnails);
     }
 
-    private void loadThumbnailsInBackground(final ArrayList<TaskDescription> descriptions) {
-        if (descriptions.size() > 0) {
-            if (DEBUG) Log.v(TAG, "Showing " + descriptions.size() + " tasks");
-            loadThumbnail(descriptions.get(0));
-            if (descriptions.size() > 1) {
-                mThumbnailLoader = new AsyncTask<Void, Integer, Void>() {
-                    @Override
-                    protected void onProgressUpdate(Integer... values) {
-                        final TaskDescription td = descriptions.get(values[0]);
-                        if (!isCancelled()) {
-                            mRecentsPanel.onTaskThumbnailLoaded(td);
-                        }
-                        // This is to prevent the loader thread from getting ahead
-                        // of our UI updates.
-                        mHandler.post(new Runnable() {
-                            @Override public void run() {
-                                synchronized (td) {
-                                    td.notifyAll();
-                                }
-                            }
-                        });
+    private void loadThumbnailsAndIconsInBackground(
+            final BlockingQueue<TaskDescription> tasksWaitingForThumbnails) {
+        // continually read items from tasksWaitingForThumbnails and load
+        // thumbnails and icons for them. finish thread when cancelled or there
+        // is a null item in tasksWaitingForThumbnails
+        mThumbnailLoader = new AsyncTask<Void, TaskDescription, Void>() {
+            @Override
+            protected void onProgressUpdate(TaskDescription... values) {
+                if (!isCancelled()) {
+                    TaskDescription td = values[0];
+                    mRecentsPanel.onTaskThumbnailLoaded(td);
+                }
+            }
+            @Override
+            protected Void doInBackground(Void... params) {
+                final int origPri = Process.getThreadPriority(Process.myTid());
+                Process.setThreadPriority(Process.THREAD_GROUP_BG_NONINTERACTIVE);
+
+                while (true) {
+                    if (isCancelled()) {
+                        break;
                     }
-
-                    @Override
-                    protected Void doInBackground(Void... params) {
-                        final int origPri = Process.getThreadPriority(Process.myTid());
-                        Process.setThreadPriority(Process.THREAD_GROUP_BG_NONINTERACTIVE);
-                        long nextTime = SystemClock.uptimeMillis();
-                        for (int i=1; i<descriptions.size(); i++) {
-                            TaskDescription td = descriptions.get(i);
-                            loadThumbnail(td);
-                            long now = SystemClock.uptimeMillis();
-                            nextTime += 0;
-                            if (nextTime > now) {
-                                try {
-                                    Thread.sleep(nextTime-now);
-                                } catch (InterruptedException e) {
-                                }
-                            }
-
-                            if (isCancelled()) {
-                                break;
-                            }
-                            synchronized (td) {
-                                publishProgress(i);
-                                try {
-                                    td.wait(500);
-                                } catch (InterruptedException e) {
-                                }
-                            }
+                    TaskDescription td = null;
+                    while (td == null) {
+                        try {
+                            td = tasksWaitingForThumbnails.take();
+                        } catch (InterruptedException e) {
                         }
-                        Process.setThreadPriority(origPri);
-                        return null;
                     }
-                };
-                mThumbnailLoader.executeOnExecutor(AsyncTask.THREAD_POOL_EXECUTOR);
+                    if (td.isNull()) {
+                        break;
+                    }
+                    loadThumbnailAndIcon(td);
+                    synchronized(td) {
+                        publishProgress(td);
+                    }
+                }
+
+                Process.setThreadPriority(origPri);
+                return null;
             }
-        }
+        };
+        mThumbnailLoader.executeOnExecutor(AsyncTask.THREAD_POOL_EXECUTOR);
     }
-
 }
diff --git a/packages/SystemUI/src/com/android/systemui/recent/RecentsHorizontalScrollView.java b/packages/SystemUI/src/com/android/systemui/recent/RecentsHorizontalScrollView.java
index f971d2d..4718a17 100644
--- a/packages/SystemUI/src/com/android/systemui/recent/RecentsHorizontalScrollView.java
+++ b/packages/SystemUI/src/com/android/systemui/recent/RecentsHorizontalScrollView.java
@@ -22,11 +22,18 @@ import android.content.res.Configuration;
 import android.database.DataSetObserver;
 import android.graphics.Canvas;
 import android.util.AttributeSet;
+import android.util.DisplayMetrics;
+import android.util.FloatMath;
 import android.util.Log;
 import android.view.MotionEvent;
 import android.view.View;
-import android.view.ViewConfiguration;
+import android.view.View.MeasureSpec;
+import android.view.View.OnClickListener;
+import android.view.View.OnLongClickListener;
 import android.view.View.OnTouchListener;
+import android.view.ViewConfiguration;
+import android.view.ViewTreeObserver;
+import android.view.ViewTreeObserver.OnGlobalLayoutListener;
 import android.widget.HorizontalScrollView;
 import android.widget.LinearLayout;
 
@@ -34,6 +41,8 @@ import com.android.systemui.R;
 import com.android.systemui.SwipeHelper;
 import com.android.systemui.recent.RecentsPanelView.TaskDescriptionAdapter;
 
+import java.util.ArrayList;
+
 public class RecentsHorizontalScrollView extends HorizontalScrollView
     implements SwipeHelper.Callback {
     private static final String TAG = RecentsPanelView.TAG;
@@ -44,6 +53,8 @@ public class RecentsHorizontalScrollView extends HorizontalScrollView
     protected int mLastScrollPosition;
     private SwipeHelper mSwipeHelper;
     private RecentsScrollViewPerformanceHelper mPerformanceHelper;
+    private ArrayList<View> mRecycledViews;
+    private int mNumItemsInOneScreenful;
 
     public RecentsHorizontalScrollView(Context context, AttributeSet attrs) {
         super(context, attrs, 0);
@@ -51,6 +62,7 @@ public class RecentsHorizontalScrollView extends HorizontalScrollView
         float pagingTouchSlop = ViewConfiguration.get(mContext).getScaledPagingTouchSlop();
         mSwipeHelper = new SwipeHelper(SwipeHelper.Y, this, densityScale, pagingTouchSlop);
         mPerformanceHelper = RecentsScrollViewPerformanceHelper.create(context, attrs, this, false);
+        mRecycledViews = new ArrayList<View>();
     }
 
     private int scrollPositionOfMostRecent() {
@@ -58,9 +70,23 @@ public class RecentsHorizontalScrollView extends HorizontalScrollView
     }
 
     private void update() {
+        for (int i = 0; i < mLinearLayout.getChildCount(); i++) {
+            View v = mLinearLayout.getChildAt(i);
+            mRecycledViews.add(v);
+            mAdapter.recycleView(v);
+        }
+        LayoutTransition transitioner = getLayoutTransition();
+        setLayoutTransition(null);
+
         mLinearLayout.removeAllViews();
         for (int i = 0; i < mAdapter.getCount(); i++) {
-            final View view = mAdapter.getView(i, null, mLinearLayout);
+            View old = null;
+            if (mRecycledViews.size() != 0) {
+                old = mRecycledViews.remove(mRecycledViews.size() - 1);
+                old.setVisibility(VISIBLE);
+            }
+
+            final View view = mAdapter.getView(i, old, mLinearLayout);
 
             if (mPerformanceHelper != null) {
                 mPerformanceHelper.addViewCallback(view);
@@ -87,7 +113,8 @@ public class RecentsHorizontalScrollView extends HorizontalScrollView
                 }
             };
 
-            final View thumbnailView = view.findViewById(R.id.app_thumbnail);
+            RecentsPanelView.ViewHolder holder = (RecentsPanelView.ViewHolder) view.getTag();
+            final View thumbnailView = holder.thumbnailView;
             OnLongClickListener longClickListener = new OnLongClickListener() {
                 public boolean onLongClick(View v) {
                     final View anchorView = view.findViewById(R.id.app_description);
@@ -107,13 +134,21 @@ public class RecentsHorizontalScrollView extends HorizontalScrollView
             appTitle.setOnTouchListener(noOpListener);
             mLinearLayout.addView(view);
         }
+        setLayoutTransition(transitioner);
+
         // Scroll to end after layout.
-        post(new Runnable() {
-            public void run() {
-                mLastScrollPosition = scrollPositionOfMostRecent();
-                scrollTo(mLastScrollPosition, 0);
-            }
-        });
+        final ViewTreeObserver observer = getViewTreeObserver();
+
+        final OnGlobalLayoutListener updateScroll = new OnGlobalLayoutListener() {
+                public void onGlobalLayout() {
+                    mLastScrollPosition = scrollPositionOfMostRecent();
+                    scrollTo(mLastScrollPosition, 0);
+                    if (observer.isAlive()) {
+                        observer.removeOnGlobalLayoutListener(this);
+                    }
+                }
+            };
+        observer.addOnGlobalLayoutListener(updateScroll);
     }
 
     @Override
@@ -142,8 +177,10 @@ public class RecentsHorizontalScrollView extends HorizontalScrollView
     }
 
     public void onChildDismissed(View v) {
+        mRecycledViews.add(v);
         mLinearLayout.removeView(v);
         mCallback.handleSwipe(v);
+        v.setActivated(false);
     }
 
     public void onBeginDrag(View v) {
@@ -315,6 +352,24 @@ public class RecentsHorizontalScrollView extends HorizontalScrollView
                 update();
             }
         });
+        DisplayMetrics dm = getResources().getDisplayMetrics();
+        int childWidthMeasureSpec =
+                MeasureSpec.makeMeasureSpec(dm.widthPixels, MeasureSpec.AT_MOST);
+        int childheightMeasureSpec =
+                MeasureSpec.makeMeasureSpec(dm.heightPixels, MeasureSpec.AT_MOST);
+        View child = mAdapter.createView(mLinearLayout);
+        child.measure(childWidthMeasureSpec, childheightMeasureSpec);
+        mNumItemsInOneScreenful =
+                (int) FloatMath.ceil(dm.widthPixels / (float) child.getMeasuredWidth());
+        mRecycledViews.add(child);
+
+        for (int i = 0; i < mNumItemsInOneScreenful - 1; i++) {
+            mRecycledViews.add(mAdapter.createView(mLinearLayout));
+        }
+    }
+
+    public int numItemsInOneScreenful() {
+        return mNumItemsInOneScreenful;
     }
 
     @Override
diff --git a/packages/SystemUI/src/com/android/systemui/recent/RecentsPanelView.java b/packages/SystemUI/src/com/android/systemui/recent/RecentsPanelView.java
index a10e363..8706f10 100644
--- a/packages/SystemUI/src/com/android/systemui/recent/RecentsPanelView.java
+++ b/packages/SystemUI/src/com/android/systemui/recent/RecentsPanelView.java
@@ -27,6 +27,7 @@ import android.graphics.Bitmap;
 import android.graphics.Matrix;
 import android.graphics.Shader.TileMode;
 import android.graphics.drawable.BitmapDrawable;
+import android.graphics.drawable.Drawable;
 import android.net.Uri;
 import android.provider.Settings;
 import android.util.AttributeSet;
@@ -36,18 +37,18 @@ import android.view.LayoutInflater;
 import android.view.MenuItem;
 import android.view.MotionEvent;
 import android.view.View;
-import android.view.ViewConfiguration;
 import android.view.ViewGroup;
+import android.view.ViewRootImpl;
 import android.view.accessibility.AccessibilityEvent;
 import android.view.animation.AnimationUtils;
 import android.widget.AdapterView;
 import android.widget.AdapterView.OnItemClickListener;
 import android.widget.BaseAdapter;
+import android.widget.FrameLayout;
 import android.widget.HorizontalScrollView;
 import android.widget.ImageView;
 import android.widget.ImageView.ScaleType;
 import android.widget.PopupMenu;
-import android.widget.RelativeLayout;
 import android.widget.ScrollView;
 import android.widget.TextView;
 
@@ -59,7 +60,7 @@ import com.android.systemui.statusbar.tablet.TabletStatusBar;
 
 import java.util.ArrayList;
 
-public class RecentsPanelView extends RelativeLayout implements OnItemClickListener, RecentsCallback,
+public class RecentsPanelView extends FrameLayout implements OnItemClickListener, RecentsCallback,
         StatusBarPanel, Animator.AnimatorListener, View.OnTouchListener {
     static final String TAG = "RecentsPanelView";
     static final boolean DEBUG = TabletStatusBar.DEBUG || PhoneStatusBar.DEBUG || false;
@@ -71,6 +72,10 @@ public class RecentsPanelView extends RelativeLayout implements OnItemClickListe
     private StatusBarTouchProxy mStatusBarTouchProxy;
 
     private boolean mShowing;
+    private boolean mWaitingToShow;
+    private boolean mWaitingToShowAnimated;
+    private boolean mReadyToShow;
+    private int mNumItemsWaitingForThumbnailsAndIcons;
     private Choreographer mChoreo;
     OnRecentsPanelVisibilityChangedListener mVisibilityChangedListener;
 
@@ -104,6 +109,7 @@ public class RecentsPanelView extends RelativeLayout implements OnItemClickListe
         TextView labelView;
         TextView descriptionView;
         TaskDescription taskDescription;
+        boolean loadedThumbnailAndIcon;
     }
 
     /* package */ final class TaskDescriptionAdapter extends BaseAdapter {
@@ -125,42 +131,82 @@ public class RecentsPanelView extends RelativeLayout implements OnItemClickListe
             return position; // we just need something unique for this position
         }
 
-        public View getView(int position, View convertView, ViewGroup parent) {
-            ViewHolder holder;
-            if (convertView == null) {
-                convertView = mInflater.inflate(R.layout.status_bar_recent_item, parent, false);
-                holder = new ViewHolder();
-                holder.thumbnailView = convertView.findViewById(R.id.app_thumbnail);
-                holder.thumbnailViewImage = (ImageView) convertView.findViewById(
-                        R.id.app_thumbnail_image);
-                // If we set the default thumbnail now, we avoid an onLayout when we update
-                // the thumbnail later (if they both have the same dimensions)
+        public View createView(ViewGroup parent) {
+            View convertView = mInflater.inflate(R.layout.status_bar_recent_item, parent, false);
+            ViewHolder holder = new ViewHolder();
+            holder.thumbnailView = convertView.findViewById(R.id.app_thumbnail);
+            holder.thumbnailViewImage =
+                    (ImageView) convertView.findViewById(R.id.app_thumbnail_image);
+            // If we set the default thumbnail now, we avoid an onLayout when we update
+            // the thumbnail later (if they both have the same dimensions)
+            if (mRecentTasksLoader != null) {
                 updateThumbnail(holder, mRecentTasksLoader.getDefaultThumbnail(), false, false);
+            }
+            holder.iconView = (ImageView) convertView.findViewById(R.id.app_icon);
+            if (mRecentTasksLoader != null) {
+                holder.iconView.setImageBitmap(mRecentTasksLoader.getDefaultIcon());
+            }
+            holder.labelView = (TextView) convertView.findViewById(R.id.app_label);
+            holder.descriptionView = (TextView) convertView.findViewById(R.id.app_description);
 
-                holder.iconView = (ImageView) convertView.findViewById(R.id.app_icon);
-                holder.labelView = (TextView) convertView.findViewById(R.id.app_label);
-                holder.descriptionView = (TextView) convertView.findViewById(R.id.app_description);
+            convertView.setTag(holder);
+            return convertView;
+        }
 
-                convertView.setTag(holder);
-            } else {
-                holder = (ViewHolder) convertView.getTag();
+        public View getView(int position, View convertView, ViewGroup parent) {
+            if (convertView == null) {
+                convertView = createView(parent);
             }
+            ViewHolder holder = (ViewHolder) convertView.getTag();
 
             // index is reverse since most recent appears at the bottom...
             final int index = mRecentTaskDescriptions.size() - position - 1;
 
             final TaskDescription td = mRecentTaskDescriptions.get(index);
-            holder.iconView.setImageDrawable(td.getIcon());
+
             holder.labelView.setText(td.getLabel());
             holder.thumbnailView.setContentDescription(td.getLabel());
-            updateThumbnail(holder, td.getThumbnail(), true, false);
+            holder.loadedThumbnailAndIcon = td.isLoaded();
+            if (td.isLoaded()) {
+                updateThumbnail(holder, td.getThumbnail(), true, false);
+                updateIcon(holder, td.getIcon(), true, false);
+                mNumItemsWaitingForThumbnailsAndIcons--;
+            }
 
             holder.thumbnailView.setTag(td);
             holder.thumbnailView.setOnLongClickListener(new OnLongClickDelegate(convertView));
             holder.taskDescription = td;
-
             return convertView;
         }
+
+        public void recycleView(View v) {
+            ViewHolder holder = (ViewHolder) v.getTag();
+            updateThumbnail(holder, mRecentTasksLoader.getDefaultThumbnail(), false, false);
+            holder.iconView.setImageBitmap(mRecentTasksLoader.getDefaultIcon());
+            holder.iconView.setVisibility(INVISIBLE);
+            holder.labelView.setText(null);
+            holder.thumbnailView.setContentDescription(null);
+            holder.thumbnailView.setTag(null);
+            holder.thumbnailView.setOnLongClickListener(null);
+            holder.thumbnailView.setVisibility(INVISIBLE);
+            holder.taskDescription = null;
+            holder.loadedThumbnailAndIcon = false;
+        }
+    }
+
+    public int numItemsInOneScreenful() {
+        if (mRecentsContainer instanceof RecentsHorizontalScrollView){
+            RecentsHorizontalScrollView scrollView
+                    = (RecentsHorizontalScrollView) mRecentsContainer;
+            return scrollView.numItemsInOneScreenful();
+        } else if (mRecentsContainer instanceof RecentsVerticalScrollView){
+            RecentsVerticalScrollView scrollView
+                    = (RecentsVerticalScrollView) mRecentsContainer;
+            return scrollView.numItemsInOneScreenful();
+        }
+        else {
+            throw new IllegalArgumentException("missing Recents[Horizontal]ScrollView");
+        }
     }
 
     @Override
@@ -192,15 +238,31 @@ public class RecentsPanelView extends RelativeLayout implements OnItemClickListe
     }
 
     public void show(boolean show, boolean animate) {
-        show(show, animate, null);
+        if (show) {
+            mWaitingToShow = true;
+            mWaitingToShowAnimated = animate;
+            showIfReady();
+        } else {
+            show(show, animate, null, false);
+        }
+    }
+
+    private void showIfReady() {
+        // mWaitingToShow = there was a touch up on the recents button
+        // mReadyToShow = we've created views for the first screenful of items
+        if (mWaitingToShow && mReadyToShow) { // && mNumItemsWaitingForThumbnailsAndIcons <= 0
+            show(true, mWaitingToShowAnimated, null, false);
+        }
     }
 
     public void show(boolean show, boolean animate,
-            ArrayList<TaskDescription> recentTaskDescriptions) {
+            ArrayList<TaskDescription> recentTaskDescriptions, boolean firstScreenful) {
+        // For now, disable animations. We may want to re-enable in the future
+        animate = false;
         if (show) {
             // Need to update list of recent apps before we set visibility so this view's
             // content description is updated before it gets focus for TalkBack mode
-            refreshRecentTasksList(recentTaskDescriptions);
+            refreshRecentTasksList(recentTaskDescriptions, firstScreenful);
 
             // if there are no apps, either bring up a "No recent apps" message, or just
             // quit early
@@ -209,19 +271,24 @@ public class RecentsPanelView extends RelativeLayout implements OnItemClickListe
                 mRecentsNoApps.setVisibility(noApps ? View.VISIBLE : View.INVISIBLE);
             } else {
                 if (noApps) {
-                    if (DEBUG) Log.v(TAG, "Nothing to show");
+                   if (DEBUG) Log.v(TAG, "Nothing to show");
                     // Need to set recent tasks to dirty so that next time we load, we
                     // refresh the list of tasks
-                    mRecentTasksLoader.cancelLoadingThumbnails();
+                    mRecentTasksLoader.cancelLoadingThumbnailsAndIcons();
                     mRecentTasksDirty = true;
+
+                    mWaitingToShow = false;
+                    mReadyToShow = false;
                     return;
                 }
             }
         } else {
             // Need to set recent tasks to dirty so that next time we load, we
             // refresh the list of tasks
-            mRecentTasksLoader.cancelLoadingThumbnails();
+            mRecentTasksLoader.cancelLoadingThumbnailsAndIcons();
             mRecentTasksDirty = true;
+            mWaitingToShow = false;
+            mReadyToShow = false;
         }
         if (animate) {
             if (mShowing != show) {
@@ -385,7 +452,6 @@ public class RecentsPanelView extends RelativeLayout implements OnItemClickListe
             throw new IllegalArgumentException("missing Recents[Horizontal]ScrollView");
         }
 
-
         mRecentsScrim = findViewById(R.id.recents_bg_protect);
         mRecentsNoApps = findViewById(R.id.recents_no_apps);
         mChoreo = new Choreographer(this, mRecentsScrim, mRecentsContainer, mRecentsNoApps, this);
@@ -425,6 +491,20 @@ public class RecentsPanelView extends RelativeLayout implements OnItemClickListe
         }
     }
 
+
+    private void updateIcon(ViewHolder h, Drawable icon, boolean show, boolean anim) {
+        if (icon != null) {
+            h.iconView.setImageDrawable(icon);
+            if (show && h.iconView.getVisibility() != View.VISIBLE) {
+                if (anim) {
+                    h.iconView.setAnimation(
+                            AnimationUtils.loadAnimation(mContext, R.anim.recent_appear));
+                }
+                h.iconView.setVisibility(View.VISIBLE);
+            }
+        }
+    }
+
     private void updateThumbnail(ViewHolder h, Bitmap thumbnail, boolean show, boolean anim) {
         if (thumbnail != null) {
             // Should remove the default image in the frame
@@ -458,31 +538,36 @@ public class RecentsPanelView extends RelativeLayout implements OnItemClickListe
         }
     }
 
-    void onTaskThumbnailLoaded(TaskDescription ad) {
-        synchronized (ad) {
+    void onTaskThumbnailLoaded(TaskDescription td) {
+        synchronized (td) {
             if (mRecentsContainer != null) {
                 ViewGroup container = mRecentsContainer;
                 if (container instanceof HorizontalScrollView
                         || container instanceof ScrollView) {
-                    container = (ViewGroup)container.findViewById(
+                    container = (ViewGroup) container.findViewById(
                             R.id.recents_linear_layout);
                 }
                 // Look for a view showing this thumbnail, to update.
-                for (int i=0; i<container.getChildCount(); i++) {
+                for (int i=0; i < container.getChildCount(); i++) {
                     View v = container.getChildAt(i);
                     if (v.getTag() instanceof ViewHolder) {
                         ViewHolder h = (ViewHolder)v.getTag();
-                        if (h.taskDescription == ad) {
+                        if (!h.loadedThumbnailAndIcon && h.taskDescription == td) {
                             // only fade in the thumbnail if recents is already visible-- we
                             // show it immediately otherwise
-                            boolean animateShow = mShowing &&
-                                mRecentsContainer.getAlpha() > ViewConfiguration.ALPHA_THRESHOLD;
-                            updateThumbnail(h, ad.getThumbnail(), true, animateShow);
+                            //boolean animateShow = mShowing &&
+                            //    mRecentsContainer.getAlpha() > ViewConfiguration.ALPHA_THRESHOLD;
+                            boolean animateShow = false;
+                            updateIcon(h, td.getIcon(), true, animateShow);
+                            updateThumbnail(h, td.getThumbnail(), true, animateShow);
+                            h.loadedThumbnailAndIcon = true;
+                            mNumItemsWaitingForThumbnailsAndIcons--;
                         }
                     }
                 }
             }
-        }
+            }
+        showIfReady();
     }
 
     // additional optimization when we have sofware system buttons - start loading the recent
@@ -516,7 +601,7 @@ public class RecentsPanelView extends RelativeLayout implements OnItemClickListe
     public void clearRecentTasksList() {
         // Clear memory used by screenshots
         if (mRecentTaskDescriptions != null) {
-            mRecentTasksLoader.cancelLoadingThumbnails();
+            mRecentTasksLoader.cancelLoadingThumbnailsAndIcons();
             mRecentTaskDescriptions.clear();
             mListAdapter.notifyDataSetInvalidated();
             mRecentTasksDirty = true;
@@ -524,26 +609,50 @@ public class RecentsPanelView extends RelativeLayout implements OnItemClickListe
     }
 
     public void refreshRecentTasksList() {
-        refreshRecentTasksList(null);
+        refreshRecentTasksList(null, false);
     }
 
-    private void refreshRecentTasksList(ArrayList<TaskDescription> recentTasksList) {
+    private void refreshRecentTasksList(
+            ArrayList<TaskDescription> recentTasksList, boolean firstScreenful) {
         if (mRecentTasksDirty) {
             if (recentTasksList != null) {
-                mRecentTaskDescriptions = recentTasksList;
+                mFirstScreenful = true;
+                onTasksLoaded(recentTasksList);
             } else {
-                mRecentTaskDescriptions = mRecentTasksLoader.getRecentTasks();
+                mFirstScreenful = true;
+                mRecentTasksLoader.loadTasksInBackground();
             }
-            mListAdapter.notifyDataSetInvalidated();
-            updateUiElements(getResources().getConfiguration());
             mRecentTasksDirty = false;
         }
     }
 
+    boolean mFirstScreenful;
+    public void onTasksLoaded(ArrayList<TaskDescription> tasks) {
+        if (!mFirstScreenful && tasks.size() == 0) {
+            return;
+        }
+        mNumItemsWaitingForThumbnailsAndIcons =
+                mFirstScreenful ? tasks.size() : mRecentTaskDescriptions.size();
+        if (mRecentTaskDescriptions == null) {
+            mRecentTaskDescriptions = new ArrayList(tasks);
+        } else {
+            mRecentTaskDescriptions.addAll(tasks);
+        }
+        mListAdapter.notifyDataSetInvalidated();
+        updateUiElements(getResources().getConfiguration());
+        mReadyToShow = true;
+        mFirstScreenful = false;
+        showIfReady();
+    }
+
     public ArrayList<TaskDescription> getRecentTasksList() {
         return mRecentTaskDescriptions;
     }
 
+    public boolean getFirstScreenful() {
+        return mFirstScreenful;
+    }
+
     private void updateUiElements(Configuration config) {
         final int items = mRecentTaskDescriptions.size();
 
diff --git a/packages/SystemUI/src/com/android/systemui/recent/RecentsVerticalScrollView.java b/packages/SystemUI/src/com/android/systemui/recent/RecentsVerticalScrollView.java
index dc13092..0605c4c 100644
--- a/packages/SystemUI/src/com/android/systemui/recent/RecentsVerticalScrollView.java
+++ b/packages/SystemUI/src/com/android/systemui/recent/RecentsVerticalScrollView.java
@@ -22,10 +22,18 @@ import android.content.res.Configuration;
 import android.database.DataSetObserver;
 import android.graphics.Canvas;
 import android.util.AttributeSet;
+import android.util.DisplayMetrics;
+import android.util.FloatMath;
 import android.util.Log;
 import android.view.MotionEvent;
 import android.view.View;
+import android.view.View.MeasureSpec;
+import android.view.View.OnClickListener;
+import android.view.View.OnLongClickListener;
+import android.view.View.OnTouchListener;
 import android.view.ViewConfiguration;
+import android.view.ViewTreeObserver;
+import android.view.ViewTreeObserver.OnGlobalLayoutListener;
 import android.widget.LinearLayout;
 import android.widget.ScrollView;
 
@@ -33,6 +41,8 @@ import com.android.systemui.R;
 import com.android.systemui.SwipeHelper;
 import com.android.systemui.recent.RecentsPanelView.TaskDescriptionAdapter;
 
+import java.util.ArrayList;
+
 public class RecentsVerticalScrollView extends ScrollView implements SwipeHelper.Callback {
     private static final String TAG = RecentsPanelView.TAG;
     private static final boolean DEBUG = RecentsPanelView.DEBUG;
@@ -42,6 +52,8 @@ public class RecentsVerticalScrollView extends ScrollView implements SwipeHelper
     protected int mLastScrollPosition;
     private SwipeHelper mSwipeHelper;
     private RecentsScrollViewPerformanceHelper mPerformanceHelper;
+    private ArrayList<View> mRecycledViews;
+    private int mNumItemsInOneScreenful;
 
     public RecentsVerticalScrollView(Context context, AttributeSet attrs) {
         super(context, attrs, 0);
@@ -50,6 +62,7 @@ public class RecentsVerticalScrollView extends ScrollView implements SwipeHelper
         mSwipeHelper = new SwipeHelper(SwipeHelper.X, this, densityScale, pagingTouchSlop);
 
         mPerformanceHelper = RecentsScrollViewPerformanceHelper.create(context, attrs, this, true);
+        mRecycledViews = new ArrayList<View>();
     }
 
     private int scrollPositionOfMostRecent() {
@@ -57,77 +70,91 @@ public class RecentsVerticalScrollView extends ScrollView implements SwipeHelper
     }
 
     private void update() {
+        for (int i = 0; i < mLinearLayout.getChildCount(); i++) {
+            View v = mLinearLayout.getChildAt(i);
+            mRecycledViews.add(v);
+            mAdapter.recycleView(v);
+        }
+        LayoutTransition transitioner = getLayoutTransition();
+        setLayoutTransition(null);
+
         mLinearLayout.removeAllViews();
         // Once we can clear the data associated with individual item views,
         // we can get rid of the removeAllViews() and the code below will
         // recycle them.
         for (int i = 0; i < mAdapter.getCount(); i++) {
             View old = null;
-            if (i < mLinearLayout.getChildCount()) {
-                old = mLinearLayout.getChildAt(i);
-                old.setVisibility(View.VISIBLE);
+            if (mRecycledViews.size() != 0) {
+                old = mRecycledViews.remove(mRecycledViews.size() - 1);
+                old.setVisibility(VISIBLE);
             }
+
             final View view = mAdapter.getView(i, old, mLinearLayout);
 
             if (mPerformanceHelper != null) {
                 mPerformanceHelper.addViewCallback(view);
             }
 
-            if (old == null) {
-                OnTouchListener noOpListener = new OnTouchListener() {
-                    @Override
-                    public boolean onTouch(View v, MotionEvent event) {
-                        return true;
-                    }
-                };
+            OnTouchListener noOpListener = new OnTouchListener() {
+                @Override
+                public boolean onTouch(View v, MotionEvent event) {
+                    return true;
+                }
+            };
 
-                view.setOnClickListener(new OnClickListener() {
-                    public void onClick(View v) {
-                        mCallback.dismiss();
-                    }
-                });
-                // We don't want a click sound when we dimiss recents
-                view.setSoundEffectsEnabled(false);
+            view.setOnClickListener(new OnClickListener() {
+                public void onClick(View v) {
+                    mCallback.dismiss();
+                }
+            });
+            // We don't want a click sound when we dimiss recents
+            view.setSoundEffectsEnabled(false);
 
-                OnClickListener launchAppListener = new OnClickListener() {
-                    public void onClick(View v) {
-                        mCallback.handleOnClick(view);
-                    }
-                };
-
-                final View thumbnailView = view.findViewById(R.id.app_thumbnail);
-                OnLongClickListener longClickListener = new OnLongClickListener() {
-                    public boolean onLongClick(View v) {
-                        final View anchorView = view.findViewById(R.id.app_description);
-                        mCallback.handleLongPress(view, anchorView, thumbnailView);
-                        return true;
-                    }
-                };
-                thumbnailView.setClickable(true);
-                thumbnailView.setOnClickListener(launchAppListener);
-                thumbnailView.setOnLongClickListener(longClickListener);
-
-                // We don't want to dismiss recents if a user clicks on the app title
-                // (we also don't want to launch the app either, though, because the
-                // app title is a small target and doesn't have great click feedback)
-                final View appTitle = view.findViewById(R.id.app_label);
-                appTitle.setContentDescription(" ");
-                appTitle.setOnTouchListener(noOpListener);
-                final View calloutLine = view.findViewById(R.id.recents_callout_line);
-                calloutLine.setOnTouchListener(noOpListener);
-                mLinearLayout.addView(view);
-            }
-        }
-        for (int i = mAdapter.getCount(); i < mLinearLayout.getChildCount(); i++) {
-            mLinearLayout.getChildAt(i).setVisibility(View.GONE);
+            OnClickListener launchAppListener = new OnClickListener() {
+                public void onClick(View v) {
+                    mCallback.handleOnClick(view);
+                }
+            };
+
+            RecentsPanelView.ViewHolder holder = (RecentsPanelView.ViewHolder) view.getTag();
+            final View thumbnailView = holder.thumbnailView;
+            OnLongClickListener longClickListener = new OnLongClickListener() {
+                public boolean onLongClick(View v) {
+                    final View anchorView = view.findViewById(R.id.app_description);
+                    mCallback.handleLongPress(view, anchorView, thumbnailView);
+                    return true;
+                }
+            };
+            thumbnailView.setClickable(true);
+            thumbnailView.setOnClickListener(launchAppListener);
+            thumbnailView.setOnLongClickListener(longClickListener);
+
+            // We don't want to dismiss recents if a user clicks on the app title
+            // (we also don't want to launch the app either, though, because the
+            // app title is a small target and doesn't have great click feedback)
+            final View appTitle = view.findViewById(R.id.app_label);
+            appTitle.setContentDescription(" ");
+            appTitle.setOnTouchListener(noOpListener);
+            final View calloutLine = view.findViewById(R.id.recents_callout_line);
+            calloutLine.setOnTouchListener(noOpListener);
+
+            mLinearLayout.addView(view);
         }
+        setLayoutTransition(transitioner);
+
         // Scroll to end after layout.
-        post(new Runnable() {
-            public void run() {
-                mLastScrollPosition = scrollPositionOfMostRecent();
-                scrollTo(0, mLastScrollPosition);
-            }
-        });
+        final ViewTreeObserver observer = getViewTreeObserver();
+
+        final OnGlobalLayoutListener updateScroll = new OnGlobalLayoutListener() {
+                public void onGlobalLayout() {
+                    mLastScrollPosition = scrollPositionOfMostRecent();
+                    scrollTo(0, mLastScrollPosition);
+                    if (observer.isAlive()) {
+                        observer.removeOnGlobalLayoutListener(this);
+                    }
+                }
+            };
+        observer.addOnGlobalLayoutListener(updateScroll);
     }
 
     @Override
@@ -156,8 +183,10 @@ public class RecentsVerticalScrollView extends ScrollView implements SwipeHelper
     }
 
     public void onChildDismissed(View v) {
+        mRecycledViews.add(v);
         mLinearLayout.removeView(v);
         mCallback.handleSwipe(v);
+        v.setActivated(false);
     }
 
     public void onBeginDrag(View v) {
@@ -330,6 +359,25 @@ public class RecentsVerticalScrollView extends ScrollView implements SwipeHelper
                 update();
             }
         });
+
+        DisplayMetrics dm = getResources().getDisplayMetrics();
+        int childWidthMeasureSpec =
+                MeasureSpec.makeMeasureSpec(dm.widthPixels, MeasureSpec.AT_MOST);
+        int childheightMeasureSpec =
+                MeasureSpec.makeMeasureSpec(dm.heightPixels, MeasureSpec.AT_MOST);
+        View child = mAdapter.createView(mLinearLayout);
+        child.measure(childWidthMeasureSpec, childheightMeasureSpec);
+        mNumItemsInOneScreenful =
+                (int) FloatMath.ceil(dm.heightPixels / (float) child.getMeasuredHeight());
+        mRecycledViews.add(child);
+
+        for (int i = 0; i < mNumItemsInOneScreenful - 1; i++) {
+            mRecycledViews.add(mAdapter.createView(mLinearLayout));
+        }
+    }
+
+    public int numItemsInOneScreenful() {
+        return mNumItemsInOneScreenful;
     }
 
     @Override
diff --git a/packages/SystemUI/src/com/android/systemui/recent/TaskDescription.java b/packages/SystemUI/src/com/android/systemui/recent/TaskDescription.java
index dcfd6d8..7e979b7 100644
--- a/packages/SystemUI/src/com/android/systemui/recent/TaskDescription.java
+++ b/packages/SystemUI/src/com/android/systemui/recent/TaskDescription.java
@@ -32,6 +32,7 @@ public final class TaskDescription {
     private Bitmap mThumbnail; // generated by Activity.onCreateThumbnail()
     private Drawable mIcon; // application package icon
     private CharSequence mLabel; // application package label
+    private boolean mLoaded;
 
     public TaskDescription(int _taskId, int _persistentTaskId,
             ResolveInfo _resolveInfo, Intent _intent,
@@ -45,6 +46,28 @@ public final class TaskDescription {
         packageName = _packageName;
     }
 
+    public TaskDescription() {
+        resolveInfo = null;
+        intent = null;
+        taskId = -1;
+        persistentTaskId = -1;
+
+        description = null;
+        packageName = null;
+    }
+
+    public void setLoaded(boolean loaded) {
+        mLoaded = loaded;
+    }
+
+    public boolean isLoaded() {
+        return mLoaded;
+    }
+
+    public boolean isNull() {
+        return resolveInfo == null;
+    }
+
     // mark all these as locked?
     public CharSequence getLabel() {
         return mLabel;