Some bug fix in the UIParamChildren class.

- the triggerParamUpdate() signal is now triggered only if the selected object of the combo box changed, and not if the content of the combo box changed.
- behaviour added that makes it possible to hide a UIParamChildren when it represents an empty list of items.

UIParam/UIParamChildren.cpp

@@ -18,6 +18,7 @@ UIParamChildren::UIParamChildren( const QString& id,
                                   const QStringList& typeFilter )
     : UIParam(id,name,description)
 {
+    m_HiddenIfEmpty = false;
     m_TypeFilters = typeFilter;
     m_Widget = new QComboBox();
     Widget()->addItem( QString(), QVariant::fromValue<void*>(0) );
@@ -76,5 +77,16 @@ void UIParamChildren::Update( GenericUIData *d )
     Widget()->addItem( QString(), QVariant::fromValue<void*>(0) );
     Update( d->GetChildren(), current, currentNewIndex, true );
 
+    if( m_HiddenIfEmpty )
+    {
+        if( IsVisible()  &&  Count() == 0 )
+            SetHidden();
+        else if( IsHidden()  &&  Count() != 0 )
+            SetVisible();
+    }
+
     Widget()->setCurrentIndex( currentNewIndex );
+
+    if( current != Value() )
+        emit triggerParameterUpdate();
 }

UIParam/UIParamChildren.h

@@ -19,6 +19,7 @@ class GenericUIData;
 class UIParamChildren : public UIParam
 {
     QStringList             m_TypeFilters;
+    bool                    m_HiddenIfEmpty;
 
     void                    Update( const QList<GenericUIData*>& dataList, GenericUIData *current, int &currentNewIndex, bool recursive );
 
@@ -30,7 +31,7 @@ public:
 
 	void                    SetValue( const QString& value );
     inline GenericUIData*   Value() const           { return (GenericUIData*) Widget()->currentData().value<void*>(); }
-    unsigned int            Count() const           { return Widget()->count() - 1; }
+    unsigned int            Count() const           { return std::max( Widget()->count()-1, 0 ); }
 
     inline const QComboBox* Widget() const          { return (QComboBox*) m_Widget; }
     inline QComboBox*       Widget()                { return (QComboBox*) m_Widget; }
@@ -39,12 +40,15 @@ public:
     void                    Update( GenericUIData *d );
 
     inline void             ConnectModificationSignal();
+
+    inline bool             IsHiddenIfEmpty() const         { return m_HiddenIfEmpty; }
+    inline void             SetHiddenIfEmpty( bool hidden ) { m_HiddenIfEmpty = hidden; }
 };
 
 
 inline void UIParamChildren::ConnectModificationSignal()
 {
-    QObject::connect( Widget(), SIGNAL(currentIndexChanged(int)), this, SLOT(triggerParameterUpdate()) );
+    //QObject::connect( Widget(), SIGNAL(currentIndexChanged(int)), this, SLOT(triggerParameterUpdate()) );
 }