Applied EXT-X-KEY for each media segment in the writer. (#37)

* Applied EXT-X-KEY for each media segment in the writer.

* Prevented writing unnecessary duplicate EXT-X-KEY tags.

src/main/java/com/iheartradio/m3u8/ExtendedM3uWriter.java

@@ -3,12 +3,13 @@
 import java.io.IOException;
 import java.io.OutputStream;
 import java.util.ArrayList;
+import java.util.Collections;
 import java.util.List;
 
 import com.iheartradio.m3u8.data.Playlist;
 
 class ExtendedM3uWriter extends Writer {
-    private List<IExtTagWriter> mExtTagWriter = new ArrayList<IExtTagWriter>();
+    private List<SectionWriter> mExtTagWriter = new ArrayList<SectionWriter>();
 
     public ExtendedM3uWriter(OutputStream outputStream, Encoding encoding) {
         super(outputStream, encoding);
@@ -17,7 +18,6 @@ public ExtendedM3uWriter(OutputStream outputStream, Encoding encoding) {
                 ExtTagWriter.EXTM3U_HANDLER,
                 ExtTagWriter.EXT_X_VERSION_HANDLER,
                 MediaPlaylistTagWriter.EXT_X_PLAYLIST_TYPE,
-                MediaPlaylistTagWriter.EXT_X_KEY,
                 MediaPlaylistTagWriter.EXT_X_TARGETDURATION,
                 MediaPlaylistTagWriter.EXT_X_START,
                 MediaPlaylistTagWriter.EXT_X_MEDIA_SEQUENCE,
@@ -26,22 +26,20 @@ public ExtendedM3uWriter(OutputStream outputStream, Encoding encoding) {
                 MediaPlaylistTagWriter.EXT_X_ALLOW_CACHE,
                 MasterPlaylistTagWriter.EXT_X_STREAM_INF,
                 MasterPlaylistTagWriter.EXT_X_I_FRAME_STREAM_INF,
-                MediaPlaylistTagWriter.EXTINF,
+                MediaPlaylistTagWriter.MEDIA_SEGMENTS,
                 MediaPlaylistTagWriter.EXT_X_ENDLIST
         );
     }
 
-    private void putWriters(IExtTagWriter... writers) {
+    private void putWriters(SectionWriter... writers) {
         if (writers != null) {
-            for (IExtTagWriter writer : writers) {
-                mExtTagWriter.add(writer);
-            }
+            Collections.addAll(mExtTagWriter, writers);
         }
     }
 
     @Override
     void doWrite(Playlist playlist) throws IOException, ParseException, PlaylistException {
-        for (IExtTagWriter singleTagWriter : mExtTagWriter) {
+        for (SectionWriter singleTagWriter : mExtTagWriter) {
             singleTagWriter.write(tagWriter, playlist);
         }
     }

src/main/java/com/iheartradio/m3u8/IExtTagWriter.java

@@ -1,11 +1,5 @@
 package com.iheartradio.m3u8;
 
-import java.io.IOException;
-
-import com.iheartradio.m3u8.data.Playlist;
-
-interface IExtTagWriter {
+interface IExtTagWriter extends SectionWriter {
     String getTag();
-
-    void write(TagWriter tagWriter, Playlist playlist) throws IOException, ParseException;
 }

src/main/java/com/iheartradio/m3u8/MediaPlaylistTagWriter.java

@@ -188,41 +188,46 @@ public void doWrite(TagWriter tagWriter, Playlist playlist, MediaPlaylist mediaP
 
     // media segment tags
 
-    static final IExtTagWriter EXTINF = new MediaPlaylistTagWriter() {
+    static final SectionWriter MEDIA_SEGMENTS = new SectionWriter() {
         @Override
-        public String getTag() {
-            return Constants.EXTINF_TAG;
-        }
+        public void write(TagWriter tagWriter, Playlist playlist) throws IOException, ParseException {
+            if (playlist.hasMediaPlaylist()) {
+                KeyWriter keyWriter = new KeyWriter();
 
-        @Override
-        boolean hasData() {
-            return true;
-        }
-
-        @Override
-        public void doWrite(TagWriter tagWriter, Playlist playlist, MediaPlaylist mediaPlaylist) throws IOException ,ParseException {
-            for (TrackData trackData : mediaPlaylist.getTracks()) {
-                StringBuilder sb = new StringBuilder();
-                if (playlist.getCompatibilityVersion() <= 3) {
-                    sb.append(Integer.toString((int)trackData.getTrackInfo().duration));
-                } else {
-                    sb.append(Float.toString(trackData.getTrackInfo().duration));
-                }
-                if (trackData.getTrackInfo().title != null) {
-                    sb.append(Constants.COMMA).append(trackData.getTrackInfo().title);
-                }
-                if (trackData.hasDiscontinuity()) {
-                    tagWriter.writeTag(Constants.EXT_X_DISCONTINUITY_TAG);
+                for (TrackData trackData : playlist.getMediaPlaylist().getTracks()) {
+                    if (trackData.hasDiscontinuity()) {
+                        tagWriter.writeTag(Constants.EXT_X_DISCONTINUITY_TAG);
+                    }
+
+                    keyWriter.writeTrackData(tagWriter, playlist, trackData);
+                    writeExtinf(tagWriter, playlist, trackData);
+                    tagWriter.writeLine(trackData.getUri());
                 }
-                tagWriter.writeTag(getTag(), sb.toString());
-                tagWriter.writeLine(trackData.getUri());
             }
-        };
+        }
     };
 
-    static final ExtTagWriter EXT_X_KEY = new MediaPlaylistTagWriter() {
+    private static void writeExtinf(TagWriter tagWriter, Playlist playlist, TrackData trackData) throws IOException {
+        final StringBuilder builder = new StringBuilder();
+
+        if (playlist.getCompatibilityVersion() <= 3) {
+            builder.append(Integer.toString((int) trackData.getTrackInfo().duration));
+        } else {
+            builder.append(Float.toString(trackData.getTrackInfo().duration));
+        }
+
+        if (trackData.getTrackInfo().title != null) {
+            builder.append(Constants.COMMA).append(trackData.getTrackInfo().title);
+        }
+
+        tagWriter.writeTag(Constants.EXTINF_TAG, builder.toString());
+    }
+
+    static class KeyWriter extends MediaPlaylistTagWriter {
         private final Map<String, AttributeWriter<EncryptionData>> HANDLERS = new HashMap<String, AttributeWriter<EncryptionData>>();
 
+        private EncryptionData mEncryptionData;
+
         {
             HANDLERS.put(Constants.METHOD, new AttributeWriter<EncryptionData>() {
                 @Override
@@ -299,13 +304,18 @@ boolean hasData() {
 
         @Override
         public void doWrite(TagWriter tagWriter, Playlist playlist, MediaPlaylist mediaPlaylist) throws IOException, ParseException {
-            if (mediaPlaylist.getTracks().size() > 0) {
-                TrackData td = mediaPlaylist.getTracks().get(0);
-                if (td.hasEncryptionData()) {
-                    EncryptionData ed = td.getEncryptionData();
-                    writeAttributes(tagWriter, ed, HANDLERS);
+            writeAttributes(tagWriter, mEncryptionData, HANDLERS);
+        }
+
+        void writeTrackData(TagWriter tagWriter, Playlist playlist, TrackData trackData) throws IOException, ParseException {
+            if (trackData != null && trackData.hasEncryptionData()) {
+                final EncryptionData encryptionData = trackData.getEncryptionData();
+
+                if (!encryptionData.equals(mEncryptionData)) {
+                    mEncryptionData = encryptionData;
+                    write(tagWriter, playlist);
                 }
             }
         }
-    };
+    }
 }

src/main/java/com/iheartradio/m3u8/SectionWriter.java

@@ -0,0 +1,9 @@
+package com.iheartradio.m3u8;
+
+import com.iheartradio.m3u8.data.Playlist;
+
+import java.io.IOException;
+
+interface SectionWriter {
+    void write(TagWriter tagWriter, Playlist playlist) throws IOException, ParseException;
+}