tentative support for removing old station tracks and fading-only when lookups exceed size of playlist

src/libtomahawk/playlist/dynamic/DynamicModel.cpp

@@ -25,6 +25,7 @@ DynamicModel::DynamicModel( QObject* parent )
     , m_startOnResolved( false )
     , m_onDemandRunning( false )
     , m_changeOnNext( false )
+    , m_searchingForNext( false )
     , m_currentAttempts( 0 )
     , m_lastResolvedRow( 0 )
 {
@@ -61,6 +62,7 @@ DynamicModel::startOnDemand()
     
     m_onDemandRunning = true;
     m_startOnResolved = true;
+    m_searchingForNext = false;
     m_currentAttempts = 0;
     m_lastResolvedRow = 0;
 }
@@ -73,6 +75,7 @@ DynamicModel::newTrackGenerated( const Tomahawk::query_ptr& query )
         connect( query.data(), SIGNAL( resultsAdded( QList<Tomahawk::result_ptr> ) ), this, SLOT( trackResolved() ) );
     
         append( query );
+        m_searchingForNext = true;
     }
 }
 
@@ -80,6 +83,7 @@ void
 DynamicModel::stopOnDemand()
 {
     m_onDemandRunning = false;
+    m_searchingForNext = false;
     AudioEngine::instance()->stop();
     
     disconnect( AudioEngine::instance(), SIGNAL( loading( Tomahawk::result_ptr ) ), this, SLOT( newTrackLoading() ) );
@@ -100,6 +104,7 @@ DynamicModel::trackResolved()
 {   
     Query* q = qobject_cast<Query*>(sender());
     qDebug() << "Got successful resolved track:" << q->track() << q->artist() << m_lastResolvedRow << m_currentAttempts;
+    m_searchingForNext = false;
     if( m_startOnResolved ) { // on first start
         m_startOnResolved = false;
         AudioEngine::instance()->play();

src/libtomahawk/playlist/dynamic/DynamicModel.h

@@ -43,6 +43,8 @@ public:
     void loadPlaylist( const dynplaylist_ptr& playlist );
     
     virtual void removeIndex( const QModelIndex& index, bool moreToCome = false );
+    
+    bool searchingForNext() const { return m_searchingForNext; }
 signals:
     void collapseFromTo( int startRow, int num );
     
@@ -60,6 +62,7 @@ private:
     bool m_startOnResolved;
     bool m_onDemandRunning;
     bool m_changeOnNext;
+    bool m_searchingForNext;
     int m_currentAttempts;
     int m_lastResolvedRow;
 };

src/libtomahawk/playlist/dynamic/DynamicView.cpp

@@ -61,6 +61,7 @@ DynamicView::~DynamicView()
 void 
 DynamicView::setModel( DynamicModel* model)
 {
+    m_model = model;
     PlaylistView::setModel( model );
     
     connect( model, SIGNAL( trackCountChanged( unsigned int ) ), SLOT( onTrackCountChanged( unsigned int ) ) );
@@ -70,6 +71,11 @@ void
 DynamicView::setOnDemand( bool onDemand )
 {
     m_onDemand = onDemand;
+    
+    if( m_onDemand )
+        setVerticalScrollBarPolicy( Qt::ScrollBarAlwaysOff );
+    else
+        setVerticalScrollBarPolicy( Qt::ScrollBarAsNeeded );
 }
 
 void 
@@ -117,53 +123,82 @@ DynamicView::onTrackCountChanged( unsigned int tracks )
     else
         overlay()->hide();
     
-    // make sure we can see all our tracks
-    scrollTo( proxyModel()->index( proxyModel()->rowCount() - 1, 0, QModelIndex() ), EnsureVisible );
+    if( !m_onDemand || m_model->searchingForNext() || proxyModel()->rowCount( QModelIndex() ) == 0 )
+        return;
+        
+    /// We don't want stations to grow forever, because we don't want the view to have to scroll
+    /// So if there are too many tracks, we remove some that have already been played
+    /// Our threshold is 4 rows to the end. That's when we collapse.
+    QModelIndex last = proxyModel()->index( proxyModel()->rowCount( QModelIndex() ) - 1, 0, QModelIndex() );
+    QRect lastRect = visualRect( last );
+    qDebug() << "Checking viewport height of" << viewport()->height() << "and last track bottom:" << lastRect.bottomLeft().y() << "under threshold" << 4 * lastRect.height();
+    if( viewport()->height() - lastRect.bottomLeft().y() <= ( 4 * lastRect.height() ) ) {
+        qDebug() << "Deciding to remove some tracks from this station";
+        
+        // figure out how many to remove. lets get rid of 1/3rd of the backlog, visually.
+        int toRemove = ( viewport()->height() / 3 ) / lastRect.height();
+        qDebug() << "Decided to remove" << toRemove << "rows!";
+        collapseEntries( 0, toRemove, proxyModel()->rowCount( QModelIndex() ) - toRemove );
+    }
 }
 
 void 
-DynamicView::collapseEntries( int startRow, int num )
+DynamicView::collapseEntries( int startRow, int num, int numToKeep )
 {
     if( m_fadeOutAnim.state() == QTimeLine::Running )
         qDebug() << "COLLAPSING TWICE!";
-    // TODO if we are scrolled, we can't animate this way. 
-    //      we have to animate the top coming down, which i haven't implemented yet..
-    if( verticalScrollBar()->sliderPosition() == 0 ) {
-        // we capture the image of the rows we're going to collapse
-        // then we capture the image of the target row we're going to animate downwards
-        // then we fade the first image out while sliding the second image up.
-        QModelIndex topLeft = proxyModel()->index( startRow, 0, QModelIndex() );
-        QModelIndex bottomRight = proxyModel()->index( startRow + num - 1, proxyModel()->columnCount( QModelIndex() ) - 1, QModelIndex() );
-        QItemSelection sel( topLeft, bottomRight );
-        QRect fadingRect = visualRegionForSelection( sel ).boundingRect();
-        QRect fadingRectViewport = fadingRect; // all values that we use in paintEvent() have to be in viewport coords
-        fadingRect.moveTo( viewport()->mapTo( this, fadingRect.topLeft() ) );
-        
-        m_fadingIndexes = QPixmap::grabWidget( this, fadingRect ); // but all values we use to grab the widgetr have to be in scrollarea coords :(
-        m_fadingPointAnchor = QPoint( 0, fadingRectViewport.topLeft().y() );
-        
-        qDebug() << "Grabbed fading indexes from rect:" << fadingRect << m_fadingIndexes.size();
-        
-        topLeft = proxyModel()->index( startRow + num, 0, QModelIndex() );
-        bottomRight = proxyModel()->index( startRow + num, proxyModel()->columnCount( QModelIndex() ) - 1, QModelIndex() );
+
+    /// Two options: Either we are overflowing our view, or we're not. If we are, it's because the search for a playable track
+    /// went past the limit of the view. Just fade out from the beginning to the end in that case. otherwise, animate a slide
+    bool justFade = false;
+    int realNum = num;
+    QModelIndex last = indexAt( QPoint( 3, viewport()->height() - 3 ) );
+    if( last.isValid() && last.row() < startRow + num ) {
+        justFade = true;
+        realNum = last.row();
+    }
+     // we capture the image of the rows we're going to collapse
+    // then we capture the image of the target row we're going to animate downwards
+    // then we fade the first image out while sliding the second image up.
+    QModelIndex topLeft = proxyModel()->index( startRow, 0, QModelIndex() );
+    QModelIndex bottomRight = proxyModel()->index( startRow + realNum - 1, proxyModel()->columnCount( QModelIndex() ) - 1, QModelIndex() );
+    QItemSelection sel( topLeft, bottomRight );
+    QRect fadingRect = visualRegionForSelection( sel ).boundingRect();
+    QRect fadingRectViewport = fadingRect; // all values that we use in paintEvent() have to be in viewport coords
+    fadingRect.moveTo( viewport()->mapTo( this, fadingRect.topLeft() ) );
+
+    m_fadingIndexes = QPixmap::grabWidget( this, fadingRect ); // but all values we use to grab the widgetr have to be in scrollarea coords :(
+    m_fadingPointAnchor = QPoint( 0, fadingRectViewport.topLeft().y() );
+    
+    m_fadeOutAnim.start();
+    
+    qDebug() << "Grabbed fading indexes from rect:" << fadingRect << m_fadingIndexes.size();
+    
+    if( !justFade ) {
+    /// sanity checks. make sure we have all the rows we need
+        int firstSlider = startRow + realNum;
+        Q_ASSERT( firstSlider + numToKeep - 1 <= proxyModel()->rowCount() );
+     
+        topLeft = proxyModel()->index( startRow + realNum, 0, QModelIndex() );
+        bottomRight = proxyModel()->index( startRow + realNum + numToKeep - 1, proxyModel()->columnCount( QModelIndex() ) - 1, QModelIndex() );
         QRect slidingRect = visualRegionForSelection( QItemSelection( topLeft, bottomRight ) ).boundingRect();
         QRect slidingRectViewport = slidingRect;
-        // map internal view cord to external qscrollarea
+        // map internal view coord to external qscrollarea
         slidingRect.moveTo( viewport()->mapTo( this, slidingRect.topLeft() ) );
-        
+    
         m_slidingIndex = QPixmap::grabWidget( this, slidingRect );
         m_bottomAnchor = QPoint( 0, slidingRectViewport.topLeft().y() );
         m_bottomOfAnim = QPoint( 0, slidingRectViewport.bottomLeft().y() );
         qDebug() << "Grabbed sliding index from rect:" << slidingRect << m_slidingIndex.size();
-        
+    
         // slide from the current position to the new one
         int frameRange = fadingRect.topLeft().y() - slidingRect.topLeft().y();
         m_slideAnim.setDuration( SLIDE_LENGTH + frameRange * LONG_MULT );
         m_slideAnim.setFrameRange( slidingRectViewport.topLeft().y(), fadingRectViewport.topLeft().y() );
         
-        m_fadeOutAnim.start();
         QTimer::singleShot( SLIDE_OFFSET, &m_slideAnim, SLOT( start() ) );
     }
+    
     // delete the actual indices
     QModelIndexList todel;
     for( int i = 0; i < num; i++ ) {

src/libtomahawk/playlist/dynamic/DynamicView.h

@@ -51,12 +51,14 @@ public slots:
     // collapse and animate the transition
     // there MUST be a row *after* startRow + num. that is, you can't collapse
     // entries unless there is at least one entry after the last collapsed row
-    void collapseEntries( int startRow, int num );
+    // optionally you can specify how  many rows are past the block of collapsed rows
+    void collapseEntries( int startRow, int num, int numToKeep = 1 );
     
 private slots:
     void onTrackCountChanged( unsigned int );
     
 private:
+    DynamicModel* m_model;
     QString m_title;
     QString m_body;