Changes for Android 9 (Pie)

* validate the stored file before start the mission
* add warning on StoredFileHelper.java
* simplify the communication between MissionAdapter and DownloadManagerService.java since shares the same looper
* simplify setVisible() "start/pause all downloads" buttons logic

app/src/main/java/us/shandian/giga/get/DownloadMission.java

@@ -1,7 +1,6 @@
 package us.shandian.giga.get;
 
 import android.os.Handler;
-import android.os.Message;
 import android.util.Log;
 
 import org.schabi.newpipe.Downloader;
@@ -264,11 +263,7 @@ public class DownloadMission extends Mission {
 
 
     private void notify(int what) {
-        Message m = new Message();
+        mHandler.obtainMessage(what, this).sendToTarget();
-        m.what = what;
-        m.obj = this;
-
-        mHandler.sendMessage(m);
     }
 
     synchronized void notifyProgress(long deltaLen) {
@@ -408,6 +403,7 @@ public class DownloadMission extends Mission {
         }
     }
 
+
     /**
      * Start downloading with multiple threads.
      */
@@ -416,14 +412,20 @@ public class DownloadMission extends Mission {
 
         // ensure that the previous state is completely paused.
         joinForThread(init);
-        if (threads != null)
+        if (threads != null) {
             for (Thread thread : threads) joinForThread(thread);
+            threads = null;
+        }
 
         running = true;
         errCode = ERROR_NOTHING;
 
+        if (hasInvalidStorage()) {
+            notifyError(ERROR_FILE_CREATION, null);
+            return;
+        }
+
         if (current >= urls.length) {
-            threads = null;
             runAsync(1, this::notifyFinished);
             return;
         }
@@ -664,7 +666,7 @@ public class DownloadMission extends Mission {
      * @return {@code true} is this mission its "healthy", otherwise, {@code false}
      */
     public boolean isCorrupt() {
-        return (isPsFailed() || errCode == ERROR_POSTPROCESSING_HOLD) || isFinished() || hasInvalidStorage();
+        return (isPsFailed() || errCode == ERROR_POSTPROCESSING_HOLD) || isFinished();
     }
 
     private boolean doPostprocessing() {

app/src/main/java/us/shandian/giga/io/StoredFileHelper.java

@@ -251,6 +251,7 @@ public class StoredFileHelper implements Serializable {
     public boolean existsAsFile() {
         if (source == null) return false;
 
+        // WARNING: DocumentFile.exists() and DocumentFile.isFile() methods are slow
         boolean exists = docFile == null ? ioFile.exists() : docFile.exists();
         boolean isFile = docFile == null ? ioFile.isFile() : docFile.isFile();// ¿docFile.isVirtual() means is no-physical?
 

app/src/main/java/us/shandian/giga/service/DownloadManager.java

@@ -424,10 +424,12 @@ public class DownloadManager {
 
             boolean flag = false;
             for (DownloadMission mission : mMissionsPending) {
-                if (mission.running || !mission.enqueued || mission.isFinished() || mission.hasInvalidStorage())
+                if (mission.running || !mission.enqueued || mission.isFinished())
                     continue;
 
                 resumeMission(mission);
+                if (mission.errCode != DownloadMission.ERROR_NOTHING) continue;
+
                 if (mPrefQueueLimit) return true;
                 flag = true;
             }

app/src/main/java/us/shandian/giga/service/DownloadManagerService.java

@@ -9,6 +9,7 @@ import android.content.Context;
 import android.content.Intent;
 import android.content.IntentFilter;
 import android.content.SharedPreferences;
+import android.content.SharedPreferences.OnSharedPreferenceChangeListener;
 import android.graphics.Bitmap;
 import android.graphics.BitmapFactory;
 import android.net.ConnectivityManager;
@@ -19,6 +20,7 @@ import android.net.Uri;
 import android.os.Binder;
 import android.os.Build;
 import android.os.Handler;
+import android.os.Handler.Callback;
 import android.os.IBinder;
 import android.os.Looper;
 import android.os.Message;
@@ -88,14 +90,14 @@ public class DownloadManagerService extends Service {
     private Builder downloadDoneNotification = null;
     private StringBuilder downloadDoneList = null;
 
-    private final ArrayList<Handler> mEchoObservers = new ArrayList<>(1);
+    private final ArrayList<Callback> mEchoObservers = new ArrayList<>(1);
 
     private ConnectivityManager mConnectivityManager;
     private BroadcastReceiver mNetworkStateListener = null;
     private ConnectivityManager.NetworkCallback mNetworkStateListenerL = null;
 
     private SharedPreferences mPrefs = null;
-    private final SharedPreferences.OnSharedPreferenceChangeListener mPrefChangeListener = this::handlePreferenceChange;
+    private final OnSharedPreferenceChangeListener mPrefChangeListener = this::handlePreferenceChange;
 
     private boolean mLockAcquired = false;
     private LockManager mLock = null;
@@ -128,12 +130,7 @@ public class DownloadManagerService extends Service {
         }
 
         mBinder = new DownloadManagerBinder();
-        mHandler = new Handler(Looper.myLooper()) {
+        mHandler = new Handler(this::handleMessage);
-            @Override
-            public void handleMessage(Message msg) {
-                DownloadManagerService.this.handleMessage(msg);
-            }
-        };
 
         mPrefs = PreferenceManager.getDefaultSharedPreferences(this);
 
@@ -272,7 +269,7 @@ public class DownloadManagerService extends Service {
         return mBinder;
     }
 
-    public void handleMessage(Message msg) {
+    private boolean handleMessage(@NonNull Message msg) {
         DownloadMission mission = (DownloadMission) msg.obj;
 
         switch (msg.what) {
@@ -300,14 +297,12 @@ public class DownloadManagerService extends Service {
             mFailedDownloads.delete(mFailedDownloads.indexOfValue(mission));
 
         synchronized (mEchoObservers) {
-            for (Handler handler : mEchoObservers) {
+            for (Callback observer : mEchoObservers) {
-                Message echo = new Message();
+                observer.handleMessage(msg);
-                echo.what = msg.what;
-                echo.obj = msg.obj;
-
-                handler.sendMessage(echo);
             }
         }
+
+        return true;
     }
 
     private void handleConnectivityState(boolean updateOnly) {
@@ -515,7 +510,7 @@ public class DownloadManagerService extends Service {
         return PendingIntent.getService(this, intent.hashCode(), intent, PendingIntent.FLAG_UPDATE_CURRENT);
     }
 
-    private void manageObservers(Handler handler, boolean add) {
+    private void manageObservers(Callback handler, boolean add) {
         synchronized (mEchoObservers) {
             if (add) {
                 mEchoObservers.add(handler);
@@ -596,11 +591,11 @@ public class DownloadManagerService extends Service {
             );
         }
 
-        public void addMissionEventListener(Handler handler) {
+        public void addMissionEventListener(Callback handler) {
             manageObservers(handler, true);
         }
 
-        public void removeMissionEventListener(Handler handler) {
+        public void removeMissionEventListener(Callback handler) {
             manageObservers(handler, false);
         }
 

app/src/main/java/us/shandian/giga/ui/adapter/MissionAdapter.java

@@ -9,7 +9,6 @@ import android.net.Uri;
 import android.os.AsyncTask;
 import android.os.Build;
 import android.os.Handler;
-import android.os.Looper;
 import android.os.Message;
 import android.support.annotation.NonNull;
 import android.support.annotation.Nullable;
@@ -77,7 +76,7 @@ import static us.shandian.giga.get.DownloadMission.ERROR_TIMEOUT;
 import static us.shandian.giga.get.DownloadMission.ERROR_UNKNOWN_EXCEPTION;
 import static us.shandian.giga.get.DownloadMission.ERROR_UNKNOWN_HOST;
 
-public class MissionAdapter extends Adapter<ViewHolder> {
+public class MissionAdapter extends Adapter<ViewHolder> implements Handler.Callback {
     private static final SparseArray<String> ALGORITHMS = new SparseArray<>();
     private static final String TAG = "MissionAdapter";
     private static final String UNDEFINED_PROGRESS = "--.-%";
@@ -111,21 +110,7 @@ public class MissionAdapter extends Adapter<ViewHolder> {
         mInflater = (LayoutInflater) mContext.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
         mLayout = R.layout.mission_item;
 
-        mHandler = new Handler(Looper.myLooper()) {
+        mHandler = new Handler(context.getMainLooper());
-            @Override
-            public void handleMessage(Message msg) {
-                switch (msg.what) {
-                    case DownloadManagerService.MESSAGE_PROGRESS:
-                    case DownloadManagerService.MESSAGE_ERROR:
-                    case DownloadManagerService.MESSAGE_FINISHED:
-                        onServiceMessage(msg);
-                        break;
-                }
-
-                if (mStartButton != null && mPauseButton != null)
-                    checkMasterButtonsVisibility();
-            }
-        };
 
         mEmptyMessage = emptyMessage;
 
@@ -403,29 +388,40 @@ public class MissionAdapter extends Adapter<ViewHolder> {
         return true;
     }
 
-    public Handler getMessenger() {
+    @Override
-        return mHandler;
+    public boolean handleMessage(@NonNull Message msg) {
-    }
+        if (mStartButton != null && mPauseButton != null) {
-
+            checkMasterButtonsVisibility();
-    private void onServiceMessage(@NonNull Message msg) {
-        if (msg.what == DownloadManagerService.MESSAGE_PROGRESS) {
-            setAutoRefresh(true);
-            return;
         }
 
-        for (int i = 0; i < mPendingDownloadsItems.size(); i++) {
+        switch (msg.what) {
-            ViewHolderItem h = mPendingDownloadsItems.get(i);
+            case DownloadManagerService.MESSAGE_PROGRESS:
+            case DownloadManagerService.MESSAGE_ERROR:
+            case DownloadManagerService.MESSAGE_FINISHED:
+                break;
+            default:
+                return false;
+        }
+
+        if (msg.what == DownloadManagerService.MESSAGE_PROGRESS) {
+            setAutoRefresh(true);
+            return true;
+        }
+
+        for (ViewHolderItem h : mPendingDownloadsItems) {
             if (h.item.mission != msg.obj) continue;
 
             if (msg.what == DownloadManagerService.MESSAGE_FINISHED) {
                 // DownloadManager should mark the download as finished
                 applyChanges();
-                return;
+                return true;
             }
 
             updateProgress(h);
-            return;
+            return true;
         }
+
+        return false;
     }
 
     private void showError(@NonNull DownloadMission mission) {
@@ -563,16 +559,15 @@ public class MissionAdapter extends Adapter<ViewHolder> {
                     updateProgress(h);
                     return true;
                 case R.id.retry:
-                    if (mission.hasInvalidStorage()) {
+                    if (mission.isPsRunning()) {
+                        mission.psContinue(true);
+                    } else {
                         mDownloadManager.tryRecover(mission);
                         if (mission.storage.isInvalid())
                             mRecover.tryRecover(mission);
                         else
                             recoverMission(mission);
-
-                        return true;
                     }
-                    mission.psContinue(true);
                     return true;
                 case R.id.cancel:
                     mission.psContinue(false);
@@ -659,9 +654,13 @@ public class MissionAdapter extends Adapter<ViewHolder> {
 
     public void checkMasterButtonsVisibility() {
         boolean[] state = mIterator.hasValidPendingMissions();
+        setButtonVisible(mPauseButton, state[0]);
+        setButtonVisible(mStartButton, state[1]);
+    }
 
-        mPauseButton.setVisible(state[0]);
+    private static void setButtonVisible(MenuItem button, boolean visible) {
-        mStartButton.setVisible(state[1]);
+        if (button.isVisible() != visible)
+            button.setVisible(visible);
     }
 
     public void ensurePausedMissions() {

app/src/main/java/us/shandian/giga/ui/fragment/MissionsFragment.java

@@ -79,7 +79,7 @@ public class MissionsFragment extends Fragment {
 
             setAdapterButtons();
 
-            mBinder.addMissionEventListener(mAdapter.getMessenger());
+            mBinder.addMissionEventListener(mAdapter);
             mBinder.enableNotifications(false);
 
             updateList();
@@ -159,7 +159,7 @@ public class MissionsFragment extends Fragment {
         super.onDestroy();
         if (mBinder == null || mAdapter == null) return;
 
-        mBinder.removeMissionEventListener(mAdapter.getMessenger());
+        mBinder.removeMissionEventListener(mAdapter);
         mBinder.enableNotifications(true);
         mContext.unbindService(mConnection);
         mAdapter.deleterDispose(true);
@@ -197,12 +197,10 @@ public class MissionsFragment extends Fragment {
                 return true;
             case R.id.start_downloads:
                 item.setVisible(false);
-                mPause.setVisible(true);
                 mBinder.getDownloadManager().startAllMissions();
                 return true;
             case R.id.pause_downloads:
                 item.setVisible(false);
-                mStart.setVisible(true);
                 mBinder.getDownloadManager().pauseAllMissions(false);
                 mAdapter.ensurePausedMissions();// update items view
             default:
@@ -280,7 +278,7 @@ public class MissionsFragment extends Fragment {
         if (mAdapter != null) {
             mAdapter.deleterDispose(false);
             mForceUpdate = true;
-            mBinder.removeMissionEventListener(mAdapter.getMessenger());
+            mBinder.removeMissionEventListener(mAdapter);
         }
     }
 
@@ -296,7 +294,7 @@ public class MissionsFragment extends Fragment {
                 mAdapter.forceUpdate();
             }
 
-            mBinder.addMissionEventListener(mAdapter.getMessenger());
+            mBinder.addMissionEventListener(mAdapter);
             mAdapter.checkMasterButtonsVisibility();
         }
         if (mBinder != null) mBinder.enableNotifications(false);