Made the TagEditor more reliable.

app/src/main/java/com/kabouzeid/gramophone/misc/DialogAsyncTask.java

@@ -0,0 +1,104 @@
+package com.kabouzeid.gramophone.misc;
+
+import android.app.Dialog;
+import android.content.Context;
+import android.os.AsyncTask;
+import android.os.Handler;
+import android.support.annotation.NonNull;
+import android.support.annotation.Nullable;
+
+import java.lang.ref.WeakReference;
+
+/**
+ * @author Karim Abou Zeid (kabouzeid)
+ */
+public abstract class DialogAsyncTask<Params, Progress, Result> extends AsyncTask<Params, Progress, Result> {
+    private final int delay;
+    private WeakReference<Context> contextWeakReference;
+    private WeakReference<Dialog> dialogWeakReference;
+
+    private boolean supposedToBeDismissed;
+
+    public DialogAsyncTask(Context context) {
+        this(context, 0);
+    }
+
+    public DialogAsyncTask(Context context, int showDelay) {
+        this.delay = showDelay;
+        contextWeakReference = new WeakReference<>(context);
+        dialogWeakReference = new WeakReference<>(null);
+    }
+
+    @Override
+    protected void onPreExecute() {
+        super.onPreExecute();
+        if (delay > 0) {
+            new Handler().postDelayed(new Runnable() {
+                @Override
+                public void run() {
+                    initAndShowDialog();
+                }
+            }, delay);
+        } else {
+            initAndShowDialog();
+        }
+    }
+
+    private void initAndShowDialog() {
+        Context context = getContext();
+        if (!supposedToBeDismissed && context != null) {
+            Dialog dialog = createDialog(context);
+            dialogWeakReference = new WeakReference<>(dialog);
+            dialog.show();
+        }
+    }
+
+    @SuppressWarnings("unchecked")
+    @Override
+    protected void onProgressUpdate(Progress... values) {
+        super.onProgressUpdate(values);
+        Dialog dialog = getDialog();
+        if (dialog != null) {
+            onProgressUpdate(dialog, values);
+        }
+    }
+
+    @SuppressWarnings("unchecked")
+    protected void onProgressUpdate(@NonNull Dialog dialog, Progress... values) {
+    }
+
+    @Nullable
+    protected Context getContext() {
+        return contextWeakReference.get();
+    }
+
+    @Nullable
+    protected Dialog getDialog() {
+        return dialogWeakReference.get();
+    }
+
+    @Override
+    protected void onCancelled(Result result) {
+        super.onCancelled(result);
+        tryToDismiss();
+    }
+
+    @Override
+    protected void onPostExecute(Result result) {
+        super.onPostExecute(result);
+        tryToDismiss();
+    }
+
+    private void tryToDismiss() {
+        supposedToBeDismissed = true;
+        try {
+            Dialog dialog = getDialog();
+            if (dialog != null)
+                dialog.dismiss();
+        } catch (Exception e) {
+            e.printStackTrace();
+        }
+    }
+
+    protected abstract Dialog createDialog(@NonNull Context context);
+}

app/src/main/java/com/kabouzeid/gramophone/misc/UpdateToastMediaScannerCompletionListener.java

@@ -0,0 +1,59 @@
+package com.kabouzeid.gramophone.misc;
+
+import android.annotation.SuppressLint;
+import android.app.Activity;
+import android.media.MediaScannerConnection;
+import android.net.Uri;
+import android.widget.Toast;
+
+import com.kabouzeid.gramophone.R;
+
+import java.lang.ref.WeakReference;
+
+/**
+ * @author Karim Abou Zeid (kabouzeid)
+ */
+public class UpdateToastMediaScannerCompletionListener implements MediaScannerConnection.OnScanCompletedListener {
+    int scanned = 0;
+    int failed = 0;
+
+    private final String[] toBeScanned;
+
+    private final String scannedFiles;
+    private final String couldNotScanFiles;
+
+    private final WeakReference<Toast> toastWeakReference;
+    private final WeakReference<Activity> activityWeakReference;
+
+    @SuppressLint("ShowToast")
+    public UpdateToastMediaScannerCompletionListener(Activity activity, String[] toBeScanned) {
+        this.toBeScanned = toBeScanned;
+        scannedFiles = activity.getString(R.string.scanned_files);
+        couldNotScanFiles = activity.getString(R.string.could_not_scan_files);
+        toastWeakReference = new WeakReference<>(Toast.makeText(activity, "", Toast.LENGTH_SHORT));
+        activityWeakReference = new WeakReference<>(activity);
+    }
+
+    @Override
+    public void onScanCompleted(final String path, final Uri uri) {
+        Activity activity = activityWeakReference.get();
+        if (activity != null) {
+            activity.runOnUiThread(new Runnable() {
+                @Override
+                public void run() {
+                    Toast toast = toastWeakReference.get();
+                    if (toast != null) {
+                        if (uri == null) {
+                            failed++;
+                        } else {
+                            scanned++;
+                        }
+                        String text = " " + String.format(scannedFiles, scanned, toBeScanned.length) + (failed > 0 ? " " + String.format(couldNotScanFiles, failed) : "");
+                        toast.setText(text);
+                        toast.show();
+                    }
+                }
+            });
+        }
+    }
+}

app/src/main/java/com/kabouzeid/gramophone/ui/activities/tageditor/AbsTagEditorActivity.java

@@ -1,13 +1,14 @@
 package com.kabouzeid.gramophone.ui.activities.tageditor;
 
+import android.app.Activity;
+import android.app.Dialog;
 import android.app.SearchManager;
+import android.content.Context;
 import android.content.Intent;
-import android.content.pm.ActivityInfo;
 import android.graphics.Bitmap;
 import android.graphics.BitmapFactory;
 import android.media.MediaScannerConnection;
 import android.net.Uri;
-import android.os.Build;
 import android.os.Bundle;
 import android.support.annotation.NonNull;
 import android.support.annotation.Nullable;
@@ -26,7 +27,9 @@ import com.kabouzeid.appthemehelper.ThemeStore;
 import com.kabouzeid.appthemehelper.util.ColorUtil;
 import com.kabouzeid.appthemehelper.util.TintHelper;
 import com.kabouzeid.gramophone.R;
+import com.kabouzeid.gramophone.misc.DialogAsyncTask;
 import com.kabouzeid.gramophone.misc.SimpleObservableScrollViewCallbacks;
+import com.kabouzeid.gramophone.misc.UpdateToastMediaScannerCompletionListener;
 import com.kabouzeid.gramophone.ui.activities.base.AbsBaseActivity;
 import com.kabouzeid.gramophone.util.MusicUtil;
 import com.kabouzeid.gramophone.util.Util;
@@ -41,10 +44,12 @@ import org.jaudiotagger.tag.FieldKey;
 import org.jaudiotagger.tag.Tag;
 import org.jaudiotagger.tag.TagException;
 import org.jaudiotagger.tag.images.Artwork;
+import org.jaudiotagger.tag.images.ArtworkFactory;
 
 import java.io.File;
+import java.io.FileOutputStream;
 import java.io.IOException;
-import java.lang.ref.WeakReference;
+import java.util.Collection;
 import java.util.List;
 import java.util.Map;
 
@@ -89,7 +94,6 @@ public abstract class AbsTagEditorActivity extends AbsBaseActivity {
         }
     };
     private List<String> songPaths;
-    private MaterialDialog progressDialog;
 
     @Override
     protected void onCreate(Bundle savedInstanceState) {
@@ -271,133 +275,145 @@ public abstract class AbsTagEditorActivity extends AbsBaseActivity {
         setTaskDescriptionColor(paletteColorPrimary);
     }
 
-    protected void writeValuesToFiles(@NonNull final Map<FieldKey, String> fieldKeyValueMap) {
+    protected void writeValuesToFiles(@NonNull final Map<FieldKey, String> fieldKeyValueMap, @Nullable final ArtworkInfo artworkInfo) {
-        writeValuesToFiles(fieldKeyValueMap, null, false);
+        Util.hideSoftKeyboard(this);
+
+        new WriteTagsAsyncTask(this).execute(new WriteTagsAsyncTask.LoadingInfo(getSongPaths(), fieldKeyValueMap, artworkInfo));
     }
 
-    protected void writeValuesToFiles(@NonNull final Map<FieldKey, String> fieldKeyValueMap, @Nullable final Artwork artwork, final boolean deleteArtwork) {
+    private static class WriteTagsAsyncTask extends DialogAsyncTask<WriteTagsAsyncTask.LoadingInfo, Integer, String[]> {
-        Util.hideSoftKeyboard(this);
+        Context applicationContext;
-        final String writingFileStr = getResources().getString(R.string.writing_file_number);
+
-        progressDialog = new MaterialDialog.Builder(AbsTagEditorActivity.this)
+        public WriteTagsAsyncTask(Context context) {
-                .title(R.string.saving_changes)
+            super(context);
-                .cancelable(false)
+            applicationContext = context;
-                .progress(true, 0)
+        }
-                .build();
+
-        if (Build.VERSION.SDK_INT >= 18)
+        @Override
-            setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_LOCKED);
+        protected String[] doInBackground(LoadingInfo... params) {
-        progressDialog.show();
+            try {
-        new Thread(new Runnable() {
+                LoadingInfo info = params[0];
-            @Override
+
-            public void run() {
+                Artwork artwork = null;
-                for (int i = 0; i < songPaths.size(); i++) {
+                File albumArtFile = null;
-                    String songPath = songPaths.get(i);
+                if (info.artworkInfo != null && info.artworkInfo.artwork != null) {
-                    final int finalI = i;
-                    runOnUiThread(new Runnable() {
-                        @Override
-                        public void run() {
-                            progressDialog.setContent(writingFileStr + " " + ((finalI + 1) + "/" + songPaths.size()));
-                        }
-                    });
                     try {
-                        AudioFile audioFile = AudioFileIO.read(new File(songPath));
+                        albumArtFile = MusicUtil.createAlbumArtFile(String.valueOf(info.artworkInfo.albumId)).getCanonicalFile();
+                        info.artworkInfo.artwork.compress(Bitmap.CompressFormat.PNG, 0, new FileOutputStream(albumArtFile));
+                        artwork = ArtworkFactory.createArtworkFromFile(albumArtFile);
+                    } catch (IOException e) {
+                        e.printStackTrace();
+                    }
+                }
+
+                int counter = 0;
+                boolean wroteArtwork = false;
+                boolean deletedArtwork = false;
+                for (String filePath : info.filePaths) {
+                    publishProgress(++counter, info.filePaths.size());
+                    try {
+                        AudioFile audioFile = AudioFileIO.read(new File(filePath));
                         Tag tag = audioFile.getTagOrCreateAndSetDefault();
-                        for (Map.Entry<FieldKey, String> entry : fieldKeyValueMap.entrySet()) {
+
-                            try {
+                        if (info.fieldKeyValueMap != null) {
-                                tag.setField(entry.getKey(), entry.getValue());
+                            for (Map.Entry<FieldKey, String> entry : info.fieldKeyValueMap.entrySet()) {
-                            } catch (NumberFormatException e) {
+                                try {
-                                tag.deleteField(entry.getKey());
+                                    tag.setField(entry.getKey(), entry.getValue());
+                                } catch (Exception e) {
+                                    e.printStackTrace();
+                                }
                             }
                         }
-                        if (deleteArtwork) {
+
-                            tag.deleteArtworkField();
+                        if (info.artworkInfo != null) {
-                        } else if (artwork != null) {
+                            if (info.artworkInfo.artwork == null) {
-                            tag.deleteArtworkField();
+                                tag.deleteArtworkField();
-                            tag.setField(artwork);
+                                deletedArtwork = true;
+                            } else if (artwork != null) {
+                                tag.deleteArtworkField();
+                                tag.setField(artwork);
+                                wroteArtwork = true;
+                            }
                         }
+
                         audioFile.commit();
-                    } catch (@NonNull CannotReadException | IOException | TagException | ReadOnlyFileException | InvalidAudioFrameException e) {
+                    } catch (@NonNull CannotReadException | IOException | CannotWriteException | TagException | ReadOnlyFileException | InvalidAudioFrameException e) {
-                        Log.e(TAG, "Error while reading audio file.", e);
+                        e.printStackTrace();
-                    } catch (CannotWriteException e) {
-                        Log.e(TAG, "Error while writing audio file.", e);
                     }
                 }
-                runOnUiThread(new Runnable() {
+
-                    @Override
+                Context context = getContext();
-                    public void run() {
+                if (context != null) {
-                        progressDialog.setContent(getString(R.string.rescanning_media));
+                    if (wroteArtwork) {
+                        MusicUtil.insertAlbumArt(context, info.artworkInfo.albumId, albumArtFile.getPath());
+                    } else if (deletedArtwork) {
+                        MusicUtil.deleteAlbumArt(context, info.artworkInfo.albumId);
                     }
-                });
-                if (deleteArtwork) {
-                    MusicUtil.deleteAlbumArt(AbsTagEditorActivity.this, getId());
-                } else if (artwork != null) {
-                    // AlbumTagEditorActivity already inserts the album cover for us
                 }
-                rescanMediaAndQuitOnFinish();
+
+                return info.filePaths.toArray(new String[info.filePaths.size()]);
+            } catch (Exception e) {
+                e.printStackTrace();
+                return null;
             }
-        }).start();
-    }
-
-    private static class FinishOnCompletedMediaScanner implements MediaScannerConnection.MediaScannerConnectionClient {
-
-        private WeakReference<AbsTagEditorActivity> activityWeakReference;
-        private MediaScannerConnection connection;
-        private String[] toBeScanned;
-        private int position;
-
-
-        private FinishOnCompletedMediaScanner(AbsTagEditorActivity activity, String[] toBeScanned) {
-            activityWeakReference = new WeakReference<>(activity);
-            this.toBeScanned = toBeScanned;
-            connection = new MediaScannerConnection(activity.getApplicationContext(), this);
-        }
-
-        public void scan() {
-            connection.connect();
         }
 
         @Override
-        public void onMediaScannerConnected() {
+        protected void onPostExecute(String[] toBeScanned) {
-            scanNextPath();
+            super.onPostExecute(toBeScanned);
+            scan(toBeScanned);
         }
 
         @Override
-        public void onScanCompleted(String path, Uri uri) {
+        protected void onCancelled(String[] toBeScanned) {
-            scanNextPath();
+            super.onCancelled(toBeScanned);
+            scan(toBeScanned);
         }
 
-        private void scanNextPath() {
+        private void scan(String[] toBeScanned) {
-            if (position < toBeScanned.length) {
+            Context context = getContext();
-                connection.scanFile(toBeScanned[position], null);
+            MediaScannerConnection.scanFile(applicationContext, toBeScanned, null, context instanceof Activity ? new UpdateToastMediaScannerCompletionListener((Activity) context, toBeScanned) : null);
-            }
-            checkIsDone();
-            position++;
         }
 
-        private void checkIsDone() {
+        @Override
-            if (position >= toBeScanned.length - 1) {
+        protected Dialog createDialog(@NonNull Context context) {
-                connection.disconnect();
+            return new MaterialDialog.Builder(context)
-                AbsTagEditorActivity activity = activityWeakReference.get();
+                    .title(R.string.writing_files)
-                if (activity != null) {
+                    .cancelable(false)
-                    activity.dismissDialogAndFinish();
+                    .progress(false, 0)
-                }
+                    .build();
+        }
+
+        @Override
+        protected void onProgressUpdate(@NonNull Dialog dialog, Integer... values) {
+            super.onProgressUpdate(dialog, values);
+            ((MaterialDialog) dialog).setMaxProgress(values[1]);
+            ((MaterialDialog) dialog).setProgress(values[0]);
+        }
+
+        public static class LoadingInfo {
+            public final Collection<String> filePaths;
+            @Nullable
+            public final Map<FieldKey, String> fieldKeyValueMap;
+            @Nullable
+            private ArtworkInfo artworkInfo;
+
+            private LoadingInfo(Collection<String> filePaths, @Nullable Map<FieldKey, String> fieldKeyValueMap, @Nullable ArtworkInfo artworkInfo) {
+                this.filePaths = filePaths;
+                this.fieldKeyValueMap = fieldKeyValueMap;
+                this.artworkInfo = artworkInfo;
             }
         }
     }
 
-    public void dismissDialogAndFinish() {
+    public static class ArtworkInfo {
-        runOnUiThread(new Runnable() {
+        public final int albumId;
-            @Override
+        public final Bitmap artwork;
-            public void run() {
-                progressDialog.dismiss();
-                finish();
-            }
-        });
-    }
 
-    private void rescanMediaAndQuitOnFinish() {
+        public ArtworkInfo(int albumId, Bitmap artwork) {
-        String[] toBeScanned = new String[songPaths.size()];
+            this.albumId = albumId;
-        toBeScanned = songPaths.toArray(toBeScanned);
+            this.artwork = artwork;
-        new FinishOnCompletedMediaScanner(this, toBeScanned).scan();
+        }
     }
 
     protected int getId() {

app/src/main/java/com/kabouzeid/gramophone/ui/activities/tageditor/AlbumTagEditorActivity.java

@@ -10,7 +10,6 @@ import android.support.annotation.NonNull;
 import android.text.Editable;
 import android.text.TextUtils;
 import android.text.TextWatcher;
-import android.util.Log;
 import android.widget.EditText;
 import android.widget.Toast;
 
@@ -28,16 +27,10 @@ import com.kabouzeid.gramophone.lastfm.rest.model.LastFmAlbum;
 import com.kabouzeid.gramophone.loader.AlbumLoader;
 import com.kabouzeid.gramophone.model.Song;
 import com.kabouzeid.gramophone.util.LastFMUtil;
-import com.kabouzeid.gramophone.util.MusicUtil;
 import com.kabouzeid.gramophone.util.PhonographColorUtil;
 
 import org.jaudiotagger.tag.FieldKey;
-import org.jaudiotagger.tag.images.Artwork;
-import org.jaudiotagger.tag.images.ArtworkFactory;
 
-import java.io.File;
-import java.io.FileOutputStream;
-import java.io.IOException;
 import java.util.ArrayList;
 import java.util.EnumMap;
 import java.util.List;
@@ -45,6 +38,7 @@ import java.util.Map;
 
 import butterknife.Bind;
 import butterknife.ButterKnife;
+import hugo.weaving.DebugLog;
 import retrofit2.Call;
 import retrofit2.Callback;
 import retrofit2.Response;
@@ -169,7 +163,6 @@ public class AlbumTagEditorActivity extends AbsTagEditorActivity implements Text
 
     @Override
     protected void save() {
-        Artwork artwork = null;
         Map<FieldKey, String> fieldKeyValueMap = new EnumMap<>(FieldKey.class);
         fieldKeyValueMap.put(FieldKey.ALBUM, albumTitle.getText().toString());
         //android seems not to recognize album_artist field so we additionally write the normal artist field
@@ -178,18 +171,7 @@ public class AlbumTagEditorActivity extends AbsTagEditorActivity implements Text
         fieldKeyValueMap.put(FieldKey.GENRE, genre.getText().toString());
         fieldKeyValueMap.put(FieldKey.YEAR, year.getText().toString());
 
-        File albumArtFile = MusicUtil.createAlbumArtFile(String.valueOf(getId()));
+        writeValuesToFiles(fieldKeyValueMap, deleteAlbumArt ? new ArtworkInfo(getId(), null) : albumArtBitmap == null ? null : new ArtworkInfo(getId(), albumArtBitmap));
-
-        if (albumArtBitmap != null) {
-            try {
-                albumArtBitmap.compress(Bitmap.CompressFormat.PNG, 0, new FileOutputStream(albumArtFile));
-                artwork = ArtworkFactory.createArtworkFromFile(albumArtFile);
-                MusicUtil.insertAlbumArt(this, getId(), albumArtFile.getAbsolutePath());
-            } catch (IOException e) {
-                Log.e(TAG, "error while trying to create the artwork from file", e);
-            }
-        }
-        writeValuesToFiles(fieldKeyValueMap, artwork, deleteAlbumArt);
     }
 
     @Override
@@ -216,7 +198,7 @@ public class AlbumTagEditorActivity extends AbsTagEditorActivity implements Text
                 .transcode(new BitmapPaletteTranscoder(AlbumTagEditorActivity.this), BitmapPaletteWrapper.class)
                 .diskCacheStrategy(DiskCacheStrategy.NONE)
                 .skipMemoryCache(true)
-                .into(new SimpleTarget<BitmapPaletteWrapper>(4097, 4097) {
+                .into(new SimpleTarget<BitmapPaletteWrapper>() {
                     @Override
                     public void onLoadFailed(Exception e, Drawable errorDrawable) {
                         super.onLoadFailed(e, errorDrawable);
@@ -251,6 +233,7 @@ public class AlbumTagEditorActivity extends AbsTagEditorActivity implements Text
         dataChanged();
     }
 
+    @DebugLog
     private static Bitmap getResizedAlbumCover(@NonNull Bitmap src, int maxForSmallerSize) {
         int width = src.getWidth();
         int height = src.getHeight();
@@ -274,11 +257,7 @@ public class AlbumTagEditorActivity extends AbsTagEditorActivity implements Text
             dstHeight = maxForSmallerSize;
         }
 
-        Bitmap scaledBitmap = Bitmap.createScaledBitmap(src, dstWidth, dstHeight, false);
+        return Bitmap.createScaledBitmap(src, dstWidth, dstHeight, false);
-        if (scaledBitmap != src) {
-            src.recycle();
-        }
-        return scaledBitmap;
     }
 
     @Override

app/src/main/java/com/kabouzeid/gramophone/ui/activities/tageditor/SongTagEditorActivity.java

@@ -98,7 +98,7 @@ public class SongTagEditorActivity extends AbsTagEditorActivity implements TextW
         fieldKeyValueMap.put(FieldKey.GENRE, genre.getText().toString());
         fieldKeyValueMap.put(FieldKey.YEAR, year.getText().toString());
         fieldKeyValueMap.put(FieldKey.TRACK, trackNumber.getText().toString());
-        writeValuesToFiles(fieldKeyValueMap);
+        writeValuesToFiles(fieldKeyValueMap, null);
     }
 
     @Override

app/src/main/java/com/kabouzeid/gramophone/ui/fragments/mainactivity/folders/FoldersFragment.java

@@ -1,20 +1,14 @@
 package com.kabouzeid.gramophone.ui.fragments.mainactivity.folders;
 
 
-import android.annotation.SuppressLint;
-import android.app.Activity;
 import android.app.Dialog;
 import android.content.Context;
 import android.content.DialogInterface;
 import android.media.MediaScannerConnection;
-import android.net.Uri;
-import android.os.AsyncTask;
 import android.os.Bundle;
 import android.os.Environment;
-import android.os.Handler;
 import android.support.annotation.NonNull;
 import android.support.annotation.Nullable;
-import android.support.annotation.StringRes;
 import android.support.design.widget.AppBarLayout;
 import android.support.design.widget.CoordinatorLayout;
 import android.support.design.widget.Snackbar;
@@ -46,6 +40,8 @@ import com.kabouzeid.gramophone.helper.MusicPlayerRemote;
 import com.kabouzeid.gramophone.helper.menu.SongMenuHelper;
 import com.kabouzeid.gramophone.helper.menu.SongsMenuHelper;
 import com.kabouzeid.gramophone.interfaces.CabHolder;
+import com.kabouzeid.gramophone.misc.DialogAsyncTask;
+import com.kabouzeid.gramophone.misc.UpdateToastMediaScannerCompletionListener;
 import com.kabouzeid.gramophone.misc.WrappedAsyncTaskLoader;
 import com.kabouzeid.gramophone.model.Song;
 import com.kabouzeid.gramophone.ui.activities.MainActivity;
@@ -485,52 +481,7 @@ public class FoldersFragment extends AbsMainActivityFragment implements MainActi
         if (toBeScanned == null || toBeScanned.length < 1) {
             Toast.makeText(getActivity(), R.string.nothing_to_scan, Toast.LENGTH_SHORT).show();
         } else {
-            MediaScannerConnection.scanFile(getActivity().getApplicationContext(), toBeScanned, null, new UpdateToastCompletionListener(getActivity(), toBeScanned));
+            MediaScannerConnection.scanFile(getActivity().getApplicationContext(), toBeScanned, null, new UpdateToastMediaScannerCompletionListener(getActivity(), toBeScanned));
-        }
-    }
-
-    private static class UpdateToastCompletionListener implements MediaScannerConnection.OnScanCompletedListener {
-        int scanned = 0;
-        int failed = 0;
-
-        private final String[] toBeScanned;
-
-        private final String scannedFiles;
-        private final String couldNotScanFiles;
-
-        private final WeakReference<Toast> toastWeakReference;
-        private final WeakReference<Activity> activityWeakReference;
-
-        @SuppressLint("ShowToast")
-        public UpdateToastCompletionListener(Activity activity, String[] toBeScanned) {
-            this.toBeScanned = toBeScanned;
-            scannedFiles = activity.getString(R.string.scanned_files);
-            couldNotScanFiles = activity.getString(R.string.could_not_scan_files);
-            toastWeakReference = new WeakReference<>(Toast.makeText(activity, "", Toast.LENGTH_SHORT));
-            activityWeakReference = new WeakReference<>(activity);
-        }
-
-        @Override
-        public void onScanCompleted(final String path, final Uri uri) {
-            Activity activity = activityWeakReference.get();
-            if (activity != null) {
-                activity.runOnUiThread(new Runnable() {
-                    @Override
-                    public void run() {
-                        Toast toast = toastWeakReference.get();
-                        if (toast != null) {
-                            if (uri == null) {
-                                failed++;
-                            } else {
-                                scanned++;
-                            }
-                            String text = " " + String.format(scannedFiles, scanned, toBeScanned.length) + (failed > 0 ? " " + String.format(couldNotScanFiles, failed) : "");
-                            toast.setText(text);
-                            toast.show();
-                        }
-                    }
-                });
-            }
         }
     }
 
@@ -585,13 +536,13 @@ public class FoldersFragment extends AbsMainActivityFragment implements MainActi
         }
     }
 
-    private static class ListSongsAsyncTask extends DialogAsyncTask<ListSongsAsyncTask.LoadingInfo, Void, ArrayList<Song>> {
+    private static class ListSongsAsyncTask extends ListingFilesDialogAsyncTask<ListSongsAsyncTask.LoadingInfo, Void, ArrayList<Song>> {
         private WeakReference<Context> contextWeakReference;
         private WeakReference<OnSongsListedCallback> callbackWeakReference;
         private final Object extra;
 
         public ListSongsAsyncTask(Context context, Object extra, OnSongsListedCallback callback) {
-            super(context, R.string.listing_files);
+            super(context);
             this.extra = extra;
             contextWeakReference = new WeakReference<>(context);
             callbackWeakReference = new WeakReference<>(callback);
@@ -668,11 +619,11 @@ public class FoldersFragment extends AbsMainActivityFragment implements MainActi
         }
     }
 
-    private static class ListPathsAsyncTask extends DialogAsyncTask<ListPathsAsyncTask.LoadingInfo, String, String[]> {
+    private static class ListPathsAsyncTask extends ListingFilesDialogAsyncTask<ListPathsAsyncTask.LoadingInfo, String, String[]> {
         private WeakReference<OnPathsListedCallback> onPathsListedCallbackWeakReference;
 
         public ListPathsAsyncTask(Context context, OnPathsListedCallback callback) {
-            super(context, R.string.listing_files);
+            super(context);
             onPathsListedCallbackWeakReference = new WeakReference<>(callback);
         }
 
@@ -753,76 +704,41 @@ public class FoldersFragment extends AbsMainActivityFragment implements MainActi
         }
     }
 
-    private static abstract class DialogAsyncTask<Params, Progress, Result> extends AsyncTask<Params, Progress, Result> {
+    private static abstract class ListingFilesDialogAsyncTask<Params, Progress, Result> extends DialogAsyncTask<Params, Progress, Result> {
-        private final int title;
+        public ListingFilesDialogAsyncTask(Context context) {
-        private WeakReference<Context> contextWeakReference;
+            super(context);
-        private WeakReference<Dialog> dialogWeakReference;
+        }
 
-        private boolean supposedToBeDismissed;
+        public ListingFilesDialogAsyncTask(Context context, int showDelay) {
-
+            super(context, showDelay);
-        public DialogAsyncTask(Context context, @StringRes int title) {
-            contextWeakReference = new WeakReference<>(context);
-            dialogWeakReference = new WeakReference<>(null);
-            this.title = title;
         }
 
         @Override
-        protected void onPreExecute() {
+        protected Dialog createDialog(@NonNull Context context) {
-            super.onPreExecute();
+            return new MaterialDialog.Builder(context)
-            new Handler().postDelayed(new Runnable() {
+                    .title(R.string.listing_files)
-                @Override
+                    .progress(true, 0)
-                public void run() {
+                    .progressIndeterminateStyle(true)
-                    if (!supposedToBeDismissed && contextWeakReference.get() != null) {
+                    .cancelListener(new DialogInterface.OnCancelListener() {
-                        Dialog dialog = new MaterialDialog.Builder(contextWeakReference.get())
+                        @Override
-                                .title(title)
+                        public void onCancel(DialogInterface dialog) {
-                                .progress(true, 0)
+                            cancel(false);
-                                .progressIndeterminateStyle(true)
+                        }
-                                .cancelListener(new DialogInterface.OnCancelListener() {
+                    })
-                                    @Override
+                    .dismissListener(new DialogInterface.OnDismissListener() {
-                                    public void onCancel(DialogInterface dialog) {
+                        @Override
-                                        cancel(false);
+                        public void onDismiss(DialogInterface dialog) {
-                                    }
+                            cancel(false);
-                                })
+                        }
-                                .dismissListener(new DialogInterface.OnDismissListener() {
+                    })
-                                    @Override
+                    .negativeText(android.R.string.cancel)
-                                    public void onDismiss(DialogInterface dialog) {
+                    .onNegative(new MaterialDialog.SingleButtonCallback() {
-                                        cancel(false);
+                        @Override
-                                    }
+                        public void onClick(@NonNull MaterialDialog dialog, @NonNull DialogAction which) {
-                                })
+                            cancel(false);
-                                .negativeText(android.R.string.cancel)
+                        }
-                                .onNegative(new MaterialDialog.SingleButtonCallback() {
+                    })
-                                    @Override
+                    .show();
-                                    public void onClick(@NonNull MaterialDialog dialog, @NonNull DialogAction which) {
-                                        cancel(false);
-                                    }
-                                })
-                                .show();
-                        dialogWeakReference = new WeakReference<>(dialog);
-                    }
-                }
-            }, 200);
-        }
-
-        @Override
-        protected void onCancelled(Result result) {
-            super.onCancelled(result);
-            tryToDismiss();
-        }
-
-        @Override
-        protected void onPostExecute(Result result) {
-            super.onPostExecute(result);
-            tryToDismiss();
-        }
-
-        private void tryToDismiss() {
-            supposedToBeDismissed = true;
-            try {
-                if (dialogWeakReference.get() != null)
-                    dialogWeakReference.get().dismiss();
-            } catch (Exception e) {
-                e.printStackTrace();
-            }
         }
     }
 }

app/src/main/res/values/strings.xml

@@ -46,7 +46,7 @@
     <string name="track">Track</string>
     <string name="track_hint">"Track (2 for track 2 or 3004 for CD3 track 4)"</string>
     <string name="album_or_artist_empty">The title or artist is empty.</string>
-    <string name="writing_file_number">Writing file</string>
+    <string name="writing_files">Writing files</string>
     <string name="saving_changes">Saving changes…</string>
     <string name="saving_to_file">Saving to file…</string>
     <string name="label_details">Details</string>