Change latch menu item to "Catch Up" if you're already listening to that source, and allow Next button to catch you up too.

src/libtomahawk/audio/audioengine.cpp

@@ -155,9 +155,11 @@ void
 AudioEngine::previous()
 {
     qDebug() << Q_FUNC_INFO;
-    if ( m_playlist->skipSeekRestrictions() != PlaylistInterface::NoSkip &&
-         m_playlist->skipSeekRestrictions() != PlaylistInterface::NoSkipSeek )
-            loadPreviousTrack();
+    if ( m_playlist->skipRestrictions() == PlaylistInterface::NoSkip ||
+         m_playlist->skipRestrictions() == PlaylistInterface::NoSkipBackwards )
+        return;
+
+    loadPreviousTrack();
 }
 
 
@@ -165,18 +167,19 @@ void
 AudioEngine::next()
 {
     qDebug() << Q_FUNC_INFO;
-    if ( m_playlist->skipSeekRestrictions() != PlaylistInterface::NoSkip &&
-         m_playlist->skipSeekRestrictions() != PlaylistInterface::NoSkipSeek )
-            loadNextTrack();
+    if ( m_playlist->skipRestrictions() == PlaylistInterface::NoSkip ||
+         m_playlist->skipRestrictions() == PlaylistInterface::NoSkipForwards )
+        return;
+
+    loadNextTrack();
 }
 
 
 void
 AudioEngine::seek( int ms )
 {
-    if ( m_playlist->skipSeekRestrictions() == PlaylistInterface::NoSeek ||
-         m_playlist->skipSeekRestrictions() == PlaylistInterface::NoSkipSeek )
-            return;
+    if ( m_playlist->seekRestrictions() == PlaylistInterface::NoSeek )
+        return;
     
     if ( isPlaying() || isPaused() )
     {

src/libtomahawk/audio/audioengine.h

@@ -59,6 +59,8 @@ public:
     /* Returns the PlaylistInterface of the current playlist. Note: The currently playing track might still be from a different playlist! */
     Tomahawk::PlaylistInterface* playlist() const { return m_playlist; }
 
+    Tomahawk::result_ptr currentTrack() const { return m_currentTrack; }
+
 public slots:
     void playPause();
     void play();

src/libtomahawk/playlistinterface.h

@@ -35,7 +35,8 @@ class DLLEXPORT PlaylistInterface
 public:
     enum RepeatMode { NoRepeat, RepeatOne, RepeatAll };
     enum ViewMode { Unknown, Tree, Flat, Album };
-    enum SkipSeekRestrictions { NoRestrictions, NoSkip, NoSeek, NoSkipSeek };
+    enum SeekRestrictions { NoSeekRestrictions, NoSeek };
+    enum SkipRestrictions { NoSkipRestrictions, NoSkipForwards, NoSkipBackwards, NoSkip };
     enum RetryMode { NoRetry, Retry };
 
     PlaylistInterface( QObject* parent = 0 ) : m_object( parent ) {}
@@ -53,7 +54,8 @@ public:
     virtual PlaylistInterface::RepeatMode repeatMode() const = 0;
     virtual bool shuffled() const = 0;
     virtual PlaylistInterface::ViewMode viewMode() const { return Unknown; }
-    virtual PlaylistInterface::SkipSeekRestrictions skipSeekRestrictions() const { return NoRestrictions; }
+    virtual PlaylistInterface::SeekRestrictions seekRestrictions() const { return NoSeekRestrictions; }
+    virtual PlaylistInterface::SkipRestrictions skipRestrictions() const { return NoSkipRestrictions; }
 
     virtual PlaylistInterface::RetryMode retryMode() const { return NoRetry; }
     virtual quint32 retryInterval() const { return 30000; }

src/libtomahawk/sourceplaylistinterface.h

@@ -47,13 +47,16 @@ public:
     virtual Tomahawk::result_ptr nextItem();
 
     virtual PlaylistInterface::RepeatMode repeatMode() const { return PlaylistInterface::NoRepeat; }
-    virtual PlaylistInterface::SkipSeekRestrictions skipSeekRestrictions() const { return PlaylistInterface::NoSkipSeek; }
+    virtual PlaylistInterface::SeekRestrictions seekRestrictions() const { return PlaylistInterface::NoSeek; }
+    virtual PlaylistInterface::SkipRestrictions skipRestrictions() const { return PlaylistInterface::NoSkipBackwards; }
     virtual PlaylistInterface::RetryMode retryMode() const { return Retry; }
     virtual quint32 retryInterval() const { return 5000; }
 
     virtual bool shuffled() const { return false; }
     virtual void setFilter( const QString& /*pattern*/ ) {}
 
+    virtual Tomahawk::source_ptr source() const { return m_source; }
+
 public slots:
     virtual void setRepeatMode( PlaylistInterface::RepeatMode ) {}
     virtual void setShuffled( bool ) {}

src/sourcetree/sourcetreeview.cpp

@@ -25,6 +25,7 @@
 #include "sourcetree/items/playlistitems.h"
 #include "sourcetree/items/collectionitem.h"
 #include "audio/audioengine.h"
+#include "sourceplaylistinterface.h"
 
 #include <QAction>
 #include <QApplication>
@@ -141,7 +142,25 @@ SourceTreeView::setupMenus()
         }
     }
 
-    m_followAction = m_followMenu.addAction( tr( "&Follow Music Stream" ) );
+    if ( type == SourcesModel::Collection )
+    {
+        CollectionItem* item = itemFromIndex< CollectionItem >( m_contextMenuIndex );
+        source_ptr source = item->source();
+        if ( !source.isNull() )
+        {
+            PlaylistInterface* pi = AudioEngine::instance()->playlist();
+            if ( pi && dynamic_cast< SourcePlaylistInterface* >( pi ) )
+            {
+                SourcePlaylistInterface* sourcepi = dynamic_cast< SourcePlaylistInterface* >( pi );
+                if ( !sourcepi->source().isNull() && sourcepi->source()->id() == source->id() )
+                    m_followAction = m_followMenu.addAction( tr( "&Catch Up" ) );
+                else
+                    m_followAction = m_followMenu.addAction( tr( "&Listen Along" ) );
+            }
+            else
+                m_followAction = m_followMenu.addAction( tr( "&Listen Along" ) );
+        }
+    }
 
     m_loadPlaylistAction = m_playlistMenu.addAction( tr( "&Load Playlist" ) );
     m_renamePlaylistAction = m_playlistMenu.addAction( tr( "&Rename Playlist" ) );