Qt, selector: don't rebuild the model when not necessary...

This should fix the build-twice-the-model issue and should avoid
rebuilding when clicking the already selected one.
Rebuilding the model is costly enough in time, to not do it all the
time.

modules/gui/qt4/components/playlist/selector.cpp

@@ -129,16 +129,18 @@ PLSelector::PLSelector( QWidget *p, intf_thread_t *_p_intf )
               this, inputItemUpdate( input_item_t * ) );
 
     createItems();
+
+    /***
+     * We need to react to both clicks and activation (enter-key) here.
+     * We use curItem to avoid rebuilding twice.
+     * See QStyle::SH_ItemView_ActivateItemOnSingleClick
+     ***/
+    curItem = NULL;
     CONNECT( this, itemActivated( QTreeWidgetItem *, int ),
              this, setSource( QTreeWidgetItem *) );
     CONNECT( this, itemClicked( QTreeWidgetItem *, int ),
              this, setSource( QTreeWidgetItem *) );
 
-    /* I believe this is unnecessary, seeing
-       QStyle::SH_ItemView_ActivateItemOnSingleClick
-        CONNECT( view, itemClicked( QTreeWidgetItem *, int ),
-             this, setSource( QTreeWidgetItem *) ); */
-
     /* select the first item */
 //  view->setCurrentIndex( model->index( 0, 0, QModelIndex() ) );
 
@@ -258,9 +260,11 @@ void PLSelector::createItems()
 
 void PLSelector::setSource( QTreeWidgetItem *item )
 {
-    if( !item )
+    if( !item || item == curItem )
         return;
 
+    curItem = item;
+
     bool b_ok;
     int i_type = item->data( 0, TYPE_ROLE ).toInt( &b_ok );
     if( !b_ok || i_type == CATEGORY_TYPE )

modules/gui/qt4/components/playlist/selector.hpp

@@ -135,6 +135,7 @@ private:
     intf_thread_t    *p_intf;
     QTreeWidgetItem  *podcastsParent;
     int               podcastsParentId;
+    QTreeWidgetItem  *curItem;
 
 private slots:
     void setSource( QTreeWidgetItem *item );