Rewind after pause feature

The playback is rewinded X seconds after the pause and resume. The
rewind duration depends on time that elapsed between the pause and
resume.

8 files changed, 164 insertions, 37 deletions

diff --git a/core/src/main/java/de/danoeh/antennapod/core/feed/FeedMedia.java b/core/src/main/java/de/danoeh/antennapod/core/feed/FeedMedia.java
index 7397dd935..5a345b9d6 100644
--- a/core/src/main/java/de/danoeh/antennapod/core/feed/FeedMedia.java
+++ b/core/src/main/java/de/danoeh/antennapod/core/feed/FeedMedia.java
@@ -40,6 +40,7 @@ public class FeedMedia extends FeedFile implements Playable {
 
     private int duration;
     private int position; // Current position in file
+    private long lastPlayedTime; // Last time this media was played (in ms)
     private int played_duration; // How many ms of this file have been played (for autoflattring)
     private long size; // File size in Byte
     private String mime_type;
@@ -62,7 +63,8 @@ public class FeedMedia extends FeedFile implements Playable {
 
     public FeedMedia(long id, FeedItem item, int duration, int position,
                      long size, String mime_type, String file_url, String download_url,
-                     boolean downloaded, Date playbackCompletionDate, int played_duration) {
+                     boolean downloaded, Date playbackCompletionDate, int played_duration,
+                     long lastPlayedTime) {
         super(file_url, download_url, downloaded);
         this.id = id;
         this.item = item;
@@ -73,14 +75,15 @@ public class FeedMedia extends FeedFile implements Playable {
         this.mime_type = mime_type;
         this.playbackCompletionDate = playbackCompletionDate == null
                 ? null : (Date) playbackCompletionDate.clone();
+        this.lastPlayedTime = lastPlayedTime;
     }
 
     public FeedMedia(long id, FeedItem item, int duration, int position,
                      long size, String mime_type, String file_url, String download_url,
                      boolean downloaded, Date playbackCompletionDate, int played_duration,
-                     Boolean hasEmbeddedPicture) {
+                     Boolean hasEmbeddedPicture, long lastPlayedTime) {
         this(id, item, duration, position, size, mime_type, file_url, download_url, downloaded,
-                playbackCompletionDate, played_duration);
+                playbackCompletionDate, played_duration, lastPlayedTime);
         this.hasEmbeddedPicture = hasEmbeddedPicture;
     }
 
@@ -95,6 +98,7 @@ public class FeedMedia extends FeedFile implements Playable {
         int indexDownloadUrl = cursor.getColumnIndex(PodDBAdapter.KEY_DOWNLOAD_URL);
         int indexDownloaded = cursor.getColumnIndex(PodDBAdapter.KEY_DOWNLOADED);
         int indexPlayedDuration = cursor.getColumnIndex(PodDBAdapter.KEY_PLAYED_DURATION);
+        int indexLastPlayedTime = cursor.getColumnIndex(PodDBAdapter.KEY_LAST_PLAYED_TIME);
 
         long mediaId = cursor.getLong(indexId);
         Date playbackCompletionDate = null;
@@ -128,7 +132,8 @@ public class FeedMedia extends FeedFile implements Playable {
                 cursor.getInt(indexDownloaded) > 0,
                 playbackCompletionDate,
                 cursor.getInt(indexPlayedDuration),
-                hasEmbeddedPicture
+                hasEmbeddedPicture,
+                cursor.getLong(indexLastPlayedTime)
         );
     }
 
@@ -231,6 +236,11 @@ public class FeedMedia extends FeedFile implements Playable {
         this.duration = duration;
     }
 
+    @Override
+    public void setLastPlayedTime(long lastPlayedTime) {
+        this.lastPlayedTime = lastPlayedTime;
+    }
+
     public int getPlayedDuration() {
         return played_duration;
     }
@@ -243,6 +253,11 @@ public class FeedMedia extends FeedFile implements Playable {
         return position;
     }
 
+    @Override
+    public long getLastPlayedTime() {
+        return lastPlayedTime;
+    }
+
     public void setPosition(int position) {
         this.position = position;
         if(position > 0 && item.isNew()) {
@@ -336,6 +351,7 @@ public class FeedMedia extends FeedFile implements Playable {
         dest.writeByte((byte) ((downloaded) ? 1 : 0));
         dest.writeLong((playbackCompletionDate != null) ? playbackCompletionDate.getTime() : 0);
         dest.writeInt(played_duration);
+        dest.writeLong(lastPlayedTime);
     }
 
     @Override
@@ -438,12 +454,13 @@ public class FeedMedia extends FeedFile implements Playable {
     }
 
     @Override
-    public void saveCurrentPosition(SharedPreferences pref, int newPosition) {
-        DBWriter.setFeedMediaPlaybackInformation(this);
+    public void saveCurrentPosition(SharedPreferences pref, int newPosition, long timeStamp) {
         if(item.isNew()) {
             DBWriter.markItemPlayed(FeedItem.UNPLAYED, item.getId());
         }
         setPosition(newPosition);
+        setLastPlayedTime(timeStamp);
+        DBWriter.setFeedMediaPlaybackInformation(this);
     }
 
     @Override
@@ -488,7 +505,7 @@ public class FeedMedia extends FeedFile implements Playable {
             final long id = in.readLong();
             final long itemID = in.readLong();
             FeedMedia result = new FeedMedia(id, null, in.readInt(), in.readInt(), in.readLong(), in.readString(), in.readString(),
-                    in.readString(), in.readByte() != 0, new Date(in.readLong()), in.readInt());
+                    in.readString(), in.readByte() != 0, new Date(in.readLong()), in.readInt(), in.readLong());
             result.itemID = itemID;
             return result;
         }
diff --git a/core/src/main/java/de/danoeh/antennapod/core/service/playback/PlaybackService.java b/core/src/main/java/de/danoeh/antennapod/core/service/playback/PlaybackService.java
index cdd63ef62..ab49bad08 100644
--- a/core/src/main/java/de/danoeh/antennapod/core/service/playback/PlaybackService.java
+++ b/core/src/main/java/de/danoeh/antennapod/core/service/playback/PlaybackService.java
@@ -923,7 +923,7 @@ public class PlaybackService extends Service {
     }
 
     /**
-     * Saves the current position of the media file to the DB
+     * Persists the current position and last played time of the media file.
      *
      * @param updatePlayedDuration true if played_duration should be updated. This applies only to FeedMedia objects
      * @param deltaPlayedDuration  value by which played_duration should be increased.
@@ -948,8 +948,9 @@ public class PlaybackService extends Service {
                 }
             }
             playable.saveCurrentPosition(PreferenceManager
-                            .getDefaultSharedPreferences(getApplicationContext()),
-                    position
+                    .getDefaultSharedPreferences(getApplicationContext()),
+                    position,
+                    System.currentTimeMillis()
             );
         }
     }
diff --git a/core/src/main/java/de/danoeh/antennapod/core/service/playback/PlaybackServiceMediaPlayer.java b/core/src/main/java/de/danoeh/antennapod/core/service/playback/PlaybackServiceMediaPlayer.java
index 9d6827ed9..41a9a08f8 100644
--- a/core/src/main/java/de/danoeh/antennapod/core/service/playback/PlaybackServiceMediaPlayer.java
+++ b/core/src/main/java/de/danoeh/antennapod/core/service/playback/PlaybackServiceMediaPlayer.java
@@ -39,6 +39,7 @@ import de.danoeh.antennapod.core.feed.MediaType;
 import de.danoeh.antennapod.core.glide.ApGlideSettings;
 import de.danoeh.antennapod.core.preferences.UserPreferences;
 import de.danoeh.antennapod.core.storage.DBWriter;
+import de.danoeh.antennapod.core.util.RewindAfterPauseUtils;
 import de.danoeh.antennapod.core.util.playback.AudioPlayer;
 import de.danoeh.antennapod.core.util.playback.IPlayer;
 import de.danoeh.antennapod.core.util.playback.Playable;
@@ -330,10 +331,14 @@ public class PlaybackServiceMediaPlayer implements SharedPreferences.OnSharedPre
             if (focusGained == AudioManager.AUDIOFOCUS_REQUEST_GRANTED) {
                 acquireWifiLockIfNecessary();
                 setSpeed(Float.parseFloat(UserPreferences.getPlaybackSpeed()));
-                mediaPlayer.start();
-                if (playerStatus == PlayerStatus.PREPARED && media.getPosition() > 0) {
-                    mediaPlayer.seekTo(media.getPosition());
+
+                if (media.getPosition() > 0) {
+                    int newPosition = RewindAfterPauseUtils.calculatePositionWithRewind(
+                            media.getPosition(),
+                            media.getLastPlayedTime());
+                    mediaPlayer.seekTo(newPosition);
                 }
+                mediaPlayer.start();
 
                 setPlayerStatus(PlayerStatus.PLAYING, media);
                 pausedBecauseOfTransientAudiofocusLoss = false;
diff --git a/core/src/main/java/de/danoeh/antennapod/core/storage/DBWriter.java b/core/src/main/java/de/danoeh/antennapod/core/storage/DBWriter.java
index bae31b52b..73584c40a 100644
--- a/core/src/main/java/de/danoeh/antennapod/core/storage/DBWriter.java
+++ b/core/src/main/java/de/danoeh/antennapod/core/storage/DBWriter.java
@@ -732,7 +732,7 @@ public class DBWriter {
     }
 
     /**
-     * Saves the 'position' and 'duration' attributes of a FeedMedia object
+     * Saves the 'position', 'duration' and 'last played time' attributes of a FeedMedia object
      *
      * @param media   The FeedMedia object.
      */
diff --git a/core/src/main/java/de/danoeh/antennapod/core/storage/PodDBAdapter.java b/core/src/main/java/de/danoeh/antennapod/core/storage/PodDBAdapter.java
index d55d4c231..7d1afc039 100644
--- a/core/src/main/java/de/danoeh/antennapod/core/storage/PodDBAdapter.java
+++ b/core/src/main/java/de/danoeh/antennapod/core/storage/PodDBAdapter.java
@@ -103,7 +103,7 @@ public class PodDBAdapter {
     public static final String KEY_HIDE = "hide";
     public static final String KEY_LAST_UPDATE_FAILED = "last_update_failed";
     public static final String KEY_HAS_EMBEDDED_PICTURE = "has_embedded_picture";
-
+    public static final String KEY_LAST_PLAYED_TIME = "last_played_time";
 
     // Table names
     public static final String TABLE_NAME_FEEDS = "Feeds";
@@ -160,7 +160,8 @@ public class PodDBAdapter {
             + KEY_PLAYBACK_COMPLETION_DATE + " INTEGER,"
             + KEY_FEEDITEM + " INTEGER,"
             + KEY_PLAYED_DURATION + " INTEGER,"
-            + KEY_HAS_EMBEDDED_PICTURE + " INTEGER)";
+            + KEY_HAS_EMBEDDED_PICTURE + " INTEGER,"
+            + KEY_LAST_PLAYED_TIME + " INTEGER)";
 
     public static final String CREATE_TABLE_DOWNLOAD_LOG = "CREATE TABLE "
             + TABLE_NAME_DOWNLOAD_LOG + " (" + TABLE_PRIMARY_KEY + KEY_FEEDFILE
@@ -444,6 +445,7 @@ public class PodDBAdapter {
         values.put(KEY_DOWNLOADED, media.isDownloaded());
         values.put(KEY_FILE_URL, media.getFile_url());
         values.put(KEY_HAS_EMBEDDED_PICTURE, media.hasEmbeddedPicture());
+        values.put(KEY_LAST_PLAYED_TIME, media.getLastPlayedTime());
 
         if (media.getPlaybackCompletionDate() != null) {
             values.put(KEY_PLAYBACK_COMPLETION_DATE, media.getPlaybackCompletionDate().getTime());
@@ -468,6 +470,7 @@ public class PodDBAdapter {
             values.put(KEY_POSITION, media.getPosition());
             values.put(KEY_DURATION, media.getDuration());
             values.put(KEY_PLAYED_DURATION, media.getPlayedDuration());
+            values.put(KEY_LAST_PLAYED_TIME, media.getLastPlayedTime());
             db.update(TABLE_NAME_FEED_MEDIA, values, KEY_ID + "=?",
                     new String[]{String.valueOf(media.getId())});
         } else {
@@ -1439,7 +1442,7 @@ public class PodDBAdapter {
      */
     private static class PodDBHelper extends SQLiteOpenHelper {
 
-        private final static int VERSION = 1040001;
+        private final static int VERSION = 1040002;
 
         private Context context;
 
@@ -1673,6 +1676,10 @@ public class PodDBAdapter {
             if(oldVersion < 1040001) {
                 db.execSQL(CREATE_TABLE_FAVORITES);
             }
+            if (oldVersion < 1040002)  {
+                db.execSQL("ALTER TABLE " + PodDBAdapter.TABLE_NAME_FEED_MEDIA
+                        + " ADD COLUMN " + PodDBAdapter.KEY_LAST_PLAYED_TIME + " INTEGER DEFAULT 0");
+            }
             EventBus.getDefault().post(ProgressEvent.end());
         }
     }
diff --git a/core/src/main/java/de/danoeh/antennapod/core/util/RewindAfterPauseUtils.java b/core/src/main/java/de/danoeh/antennapod/core/util/RewindAfterPauseUtils.java
new file mode 100644
index 000000000..b48c9ac64
--- /dev/null
+++ b/core/src/main/java/de/danoeh/antennapod/core/util/RewindAfterPauseUtils.java
@@ -0,0 +1,47 @@
+package de.danoeh.antennapod.core.util;
+
+import java.util.concurrent.TimeUnit;
+
+/**
+ * This class calculates the proper rewind time after the pause and resume.
+ * <p>
+ * User might loose context if he/she pauses and resumes the media after longer time.
+ * Media file should be "rewinded" x seconds after user resumes the playback.
+ */
+public class RewindAfterPauseUtils {
+
+    public static final long ELAPSED_TIME_FOR_SHORT_REWIND = TimeUnit.MINUTES.toMillis(3);
+    public static final long ELAPSED_TIME_FOR_MEDIUM_REWIND = TimeUnit.HOURS.toMillis(1);
+    public static final long ELAPSED_TIME_FOR_LONG_REWIND = TimeUnit.DAYS.toMillis(1);
+
+    public static final long SHORT_REWIND =  TimeUnit.SECONDS.toMillis(2);
+    public static final long MEDIUM_REWIND = TimeUnit.SECONDS.toMillis(5);
+    public static final long LONG_REWIND = TimeUnit.SECONDS.toMillis(10);
+
+    /**
+     * @param currentPosition  current position in a media file in ms
+     * @param lastPlayedTime  timestamp when was media paused
+     * @return  new rewinded position for playback in milliseconds
+     */
+    public static int calculatePositionWithRewind(int currentPosition, long lastPlayedTime) {
+        if (currentPosition > 0 && lastPlayedTime > 0) {
+            long elapsedTime = System.currentTimeMillis() - lastPlayedTime;
+            long rewindTime = 0;
+
+            if (elapsedTime > ELAPSED_TIME_FOR_LONG_REWIND) {
+                rewindTime = LONG_REWIND;
+            } else if (elapsedTime > ELAPSED_TIME_FOR_MEDIUM_REWIND) {
+                rewindTime = MEDIUM_REWIND;
+            } else if (elapsedTime > ELAPSED_TIME_FOR_SHORT_REWIND) {
+                rewindTime = SHORT_REWIND;
+            }
+
+            int newPosition = currentPosition - (int) rewindTime;
+
+            return newPosition > 0 ? newPosition : 0;
+        }
+        else {
+            return currentPosition;
+        }
+    }
+}
diff --git a/core/src/main/java/de/danoeh/antennapod/core/util/playback/ExternalMedia.java b/core/src/main/java/de/danoeh/antennapod/core/util/playback/ExternalMedia.java
index 49769f4f0..ec50dce7c 100644
--- a/core/src/main/java/de/danoeh/antennapod/core/util/playback/ExternalMedia.java
+++ b/core/src/main/java/de/danoeh/antennapod/core/util/playback/ExternalMedia.java
@@ -20,6 +20,7 @@ public class ExternalMedia implements Playable {
 	public static final String PREF_SOURCE_URL = "ExternalMedia.PrefSourceUrl";
 	public static final String PREF_POSITION = "ExternalMedia.PrefPosition";
 	public static final String PREF_MEDIA_TYPE = "ExternalMedia.PrefMediaType";
+	public static final String PREF_LAST_PLAYED_TIME = "ExternalMedia.PrefLastPlayedTime";
 
 	private String source;
 
@@ -29,6 +30,7 @@ public class ExternalMedia implements Playable {
 	private List<Chapter> chapters;
 	private int duration;
 	private int position;
+	private long lastPlayedTime;
 
 	public ExternalMedia(String source, MediaType mediaType) {
 		super();
@@ -36,9 +38,10 @@ public class ExternalMedia implements Playable {
 		this.mediaType = mediaType;
 	}
 
-	public ExternalMedia(String source, MediaType mediaType, int position) {
+	public ExternalMedia(String source, MediaType mediaType, int position, long lastPlayedTime) {
 		this(source, mediaType);
 		this.position = position;
+		this.lastPlayedTime = lastPlayedTime;
 	}
 
 	@Override
@@ -51,6 +54,7 @@ public class ExternalMedia implements Playable {
 		dest.writeString(source);
 		dest.writeString(mediaType.toString());
 		dest.writeInt(position);
+		dest.writeLong(lastPlayedTime);
 	}
 
 	@Override
@@ -58,6 +62,7 @@ public class ExternalMedia implements Playable {
 		prefEditor.putString(PREF_SOURCE_URL, source);
 		prefEditor.putString(PREF_MEDIA_TYPE, mediaType.toString());
 		prefEditor.putInt(PREF_POSITION, position);
+		prefEditor.putLong(PREF_LAST_PLAYED_TIME, lastPlayedTime);
 	}
 
 	@Override
@@ -145,6 +150,11 @@ public class ExternalMedia implements Playable {
 	}
 
 	@Override
+	public long getLastPlayedTime() {
+		return lastPlayedTime;
+	}
+
+	@Override
 	public MediaType getMediaType() {
 		return mediaType;
 	}
@@ -170,10 +180,12 @@ public class ExternalMedia implements Playable {
 	}
 
 	@Override
-	public void saveCurrentPosition(SharedPreferences pref, int newPosition) {
+	public void saveCurrentPosition(SharedPreferences pref, int newPosition, long timestamp) {
 		SharedPreferences.Editor editor = pref.edit();
 		editor.putInt(PREF_POSITION, newPosition);
+		editor.putLong(PREF_LAST_PLAYED_TIME, timestamp);
 		position = newPosition;
+		lastPlayedTime = timestamp;
 		editor.commit();
 	}
 
@@ -188,6 +200,11 @@ public class ExternalMedia implements Playable {
 	}
 
 	@Override
+	public void setLastPlayedTime(long lastPlayedTime) {
+		this.lastPlayedTime = lastPlayedTime;
+	}
+
+	@Override
 	public void onPlaybackStart() {
 
 	}
@@ -215,8 +232,12 @@ public class ExternalMedia implements Playable {
 			if (in.dataAvail() > 0) {
 				position = in.readInt();
 			}
-			ExternalMedia extMedia = new ExternalMedia(source, type, position);
-			return extMedia;
+			long lastPlayedTime = 0;
+			if (in.dataAvail() > 0) {
+				lastPlayedTime = in.readLong();
+			}
+
+			return new ExternalMedia(source, type, position, lastPlayedTime);
 		}
 
 		public ExternalMedia[] newArray(int size) {
diff --git a/core/src/main/java/de/danoeh/antennapod/core/util/playback/Playable.java b/core/src/main/java/de/danoeh/antennapod/core/util/playback/Playable.java
index 6e306d30a..86ec4fbd0 100644
--- a/core/src/main/java/de/danoeh/antennapod/core/util/playback/Playable.java
+++ b/core/src/main/java/de/danoeh/antennapod/core/util/playback/Playable.java
@@ -82,6 +82,12 @@ public interface Playable extends Parcelable,
     public int getPosition();
 
     /**
+     * Returns last time (in ms) when this playable was played or 0
+     * if last played time is unknown.
+     */
+    public long getLastPlayedTime();
+
+    /**
      * Returns the type of media. This method should return the correct value
      * BEFORE loadMetadata() is called.
      */
@@ -115,14 +121,23 @@ public interface Playable extends Parcelable,
      * Saves the current position of this object. Implementations can use the
      * provided SharedPreference to save this information and retrieve it later
      * via PlayableUtils.createInstanceFromPreferences.
+     *
+     * @param pref  shared prefs that might be used to store this object
+     * @param newPosition  new playback position in ms
+     * @param timestamp  current time in ms
      */
-    public void saveCurrentPosition(SharedPreferences pref, int newPosition);
+    public void saveCurrentPosition(SharedPreferences pref, int newPosition, long timestamp);
 
     public void setPosition(int newPosition);
 
     public void setDuration(int newDuration);
 
     /**
+     * @param lastPlayedTimestamp  timestamp in ms
+     */
+    public void setLastPlayedTime(long lastPlayedTimestamp);
+
+    /**
      * Is called by the PlaybackService when playback starts.
      */
     public void onPlaybackStart();
@@ -159,28 +174,42 @@ public interface Playable extends Parcelable,
          */
         public static Playable createInstanceFromPreferences(Context context, int type,
                                                              SharedPreferences pref) {
+            Playable result = null;
             // ADD new Playable types here:
             switch (type) {
                 case FeedMedia.PLAYABLE_TYPE_FEEDMEDIA:
-                    long mediaId = pref.getLong(FeedMedia.PREF_MEDIA_ID, -1);
-                    if (mediaId != -1) {
-                        return DBReader.getFeedMedia(mediaId);
-                    }
+                    result = createFeedMediaInstance(pref);
                     break;
                 case ExternalMedia.PLAYABLE_TYPE_EXTERNAL_MEDIA:
-                    String source = pref.getString(ExternalMedia.PREF_SOURCE_URL,
-                            null);
-                    String mediaType = pref.getString(
-                            ExternalMedia.PREF_MEDIA_TYPE, null);
-                    if (source != null && mediaType != null) {
-                        int position = pref.getInt(ExternalMedia.PREF_POSITION, 0);
-                        return new ExternalMedia(source,
-                                MediaType.valueOf(mediaType), position);
-                    }
+                    result = createExternalMediaInstance(pref);
                     break;
             }
-            Log.e(TAG, "Could not restore Playable object from preferences");
-            return null;
+            if (result == null) {
+                Log.e(TAG, "Could not restore Playable object from preferences");
+            }
+            return result;
+        }
+
+        private static Playable createFeedMediaInstance(SharedPreferences pref) {
+            Playable result = null;
+            long mediaId = pref.getLong(FeedMedia.PREF_MEDIA_ID, -1);
+            if (mediaId != -1) {
+                result =  DBReader.getFeedMedia(mediaId);
+            }
+            return result;
+        }
+
+        private static Playable createExternalMediaInstance(SharedPreferences pref) {
+            Playable result = null;
+            String source = pref.getString(ExternalMedia.PREF_SOURCE_URL, null);
+            String mediaType = pref.getString(ExternalMedia.PREF_MEDIA_TYPE, null);
+            if (source != null && mediaType != null) {
+                int position = pref.getInt(ExternalMedia.PREF_POSITION, 0);
+                long lastPlayedTime = pref.getLong(ExternalMedia.PREF_LAST_PLAYED_TIME, 0);
+                result = new ExternalMedia(source, MediaType.valueOf(mediaType),
+                        position, lastPlayedTime);
+            }
+            return result;
         }
     }