be smarter about when we reload the UI

src/libtomahawk/playlist/dynamic/widgets/DynamicControlList.cpp

@@ -92,12 +92,24 @@ DynamicControlList::init()
 void 
 DynamicControlList::setControls( const geninterface_ptr& generator, const QList< dyncontrol_ptr >& controls, bool isLocal )
 {
+    if( m_controls.size() == controls.size() ) { // check if we're setting the same controls we already have, and exit if we are
+        bool different = false;
+        for( int i = 0; i < m_controls.size(); i++ ) {
+            if( m_controls.value( i )->control().data() != controls.value( i ).data() ) {
+                different = true;
+                break;
+            }
+        }
+        if( !different ) { // no work to do
+            return;
+        }
+    }
+    
     if( !m_controls.isEmpty() ) {
         qDeleteAll( m_controls );
         m_controls.clear();
     }
     
-    
     m_layout->removeItem( m_collapseLayout );
     
     m_isLocal = isLocal;
@@ -124,11 +136,14 @@ DynamicControlList::setControls( const geninterface_ptr& generator, const QList<
 
 void DynamicControlList::addNewControl()
 {
+    m_layout->removeItem( m_collapseLayout );
+    
     dyncontrol_ptr control = m_generator->createControl();
     m_controls.append( new DynamicControlWrapper( control, m_layout, m_controls.size(), m_isLocal, this ) );
     connect( m_controls.last(), SIGNAL( removeControl() ), this, SLOT( removeControl() ) );
     connect( m_controls.last(), SIGNAL( changed() ), this, SLOT( controlChanged() ) );
     
+    m_layout->addItem( m_collapseLayout, m_layout->rowCount(), 0, 1, 4, Qt::AlignCenter );
     emit controlsChanged();
 }
 

src/libtomahawk/playlist/dynamic/widgets/DynamicControlList.h

@@ -22,6 +22,7 @@
 
 #include <QStackedWidget>
 
+class QEvent;
 class QGridLayout;
 class QPushButton;
 class QHBoxLayout;
@@ -48,7 +49,7 @@ public:
     
     void setControls( const geninterface_ptr& generator, const QList< dyncontrol_ptr >& controls, bool isLocal );
     QList< DynamicControlWrapper* > controls() const { return m_controls; }
-        
+    
 signals:
     void controlsChanged();
     void controlChanged( const Tomahawk::dyncontrol_ptr& control );

src/libtomahawk/playlist/dynamic/widgets/DynamicControlWrapper.cpp

@@ -59,7 +59,7 @@ DynamicControlWrapper::DynamicControlWrapper( const Tomahawk::dyncontrol_ptr& co
         connect( m_minusButton, SIGNAL( clicked( bool ) ), this, SIGNAL( removeControl() ) );
         
         
-        m_plusL = new QStackedLayout;
+        m_plusL = new QStackedLayout();
         m_plusL->setContentsMargins( 0, 0, 0, 0 );
         m_plusL->setMargin( 0 );
         m_plusL->addWidget( m_minusButton );
@@ -81,7 +81,7 @@ DynamicControlWrapper::DynamicControlWrapper( const Tomahawk::dyncontrol_ptr& co
     if( m_isLocal )
     {
         m_layout->addLayout( m_plusL, m_row, 3, Qt::AlignCenter );
-        m_plusL->setCurrentIndex( 1 );
+        m_plusL->setCurrentIndex( 0 );
     }
     
 }
@@ -98,6 +98,8 @@ DynamicControlWrapper::~DynamicControlWrapper()
     delete m_typeSelector;
     delete m_matchSelector;
     delete m_entryWidget;
+    delete m_minusButton;
+    delete m_plusL;
 }
 
 dyncontrol_ptr 

src/libtomahawk/playlist/dynamic/widgets/DynamicWidget.cpp

@@ -105,8 +105,18 @@ DynamicWidget::~DynamicWidget()
 {
 }
 
-void DynamicWidget::loadDynamicPlaylist(const Tomahawk::dynplaylist_ptr& playlist)
+void 
+DynamicWidget::loadDynamicPlaylist( const Tomahawk::dynplaylist_ptr& playlist )
 {
+    // if we're being told to load the same dynamic playlist over again, only do it if the controls have a different number
+    if( !m_playlist.isNull() && ( m_playlist.data() == playlist.data() ) // same playlist pointer
+        && m_playlist->generator()->controls().size() == playlist->generator()->controls().size() ) {
+        // we can skip our work. just let the dynamiccontrollist show the difference
+        m_controls->setControls( m_playlist->generator(), m_playlist->generator()->controls(), m_playlist->author()->isLocal() );
+    
+        return;
+    }
+    
     if( !m_playlist.isNull() ) {
         disconnect( m_playlist->generator().data(), SIGNAL( generated( QList<Tomahawk::query_ptr> ) ), this, SLOT( tracksGenerated( QList<Tomahawk::query_ptr> ) ) );
         disconnect( m_playlist.data(), SIGNAL( dynamicRevisionLoaded( Tomahawk::DynamicPlaylistRevision) ), this, SLOT(onRevisionLoaded( Tomahawk::DynamicPlaylistRevision) ) );

src/libtomahawk/playlist/dynamic/widgets/ReadOrWriteWidget.cpp

@@ -38,6 +38,9 @@ ReadOrWriteWidget::ReadOrWriteWidget( QWidget* writableWidget, bool writable, QW
     setWritable( m_writable );
     
     setSizePolicy( QSizePolicy::Expanding, QSizePolicy::Fixed );
+    setContentsMargins( 0, 0, 0, 0 );
+    m_layout->setContentsMargins( 0, 0, 0, 0 );
+    m_layout->setSpacing( 0 );
 }
 
 void