Implement wxDataViewCtrl::SetRowHeight() for wxGTK.

Also document that this method can only be used to increase the row height
compared to the default, not to make it smaller.

See #12749.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@67920 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/gtk/dataview.h

@@ -158,7 +158,9 @@ public:
                           wxDataViewColumn *&column ) const;
     virtual wxRect GetItemRect( const wxDataViewItem &item,
                                 const wxDataViewColumn *column = NULL ) const;
-                                
+
+    virtual bool SetRowHeight( int rowHeight );
+
     virtual void StartEditor( const wxDataViewItem & item, unsigned int column );
 
     virtual void Expand( const wxDataViewItem & item );
@@ -182,6 +184,8 @@ public:
 
     virtual void OnInternalIdle();
 
+    int GTKGetUniformRowHeight() const { return m_uniformRowHeight; }
+
 protected:
     virtual void DoSetExpanderColumn();
     virtual void DoSetIndent();
@@ -209,6 +213,11 @@ private:
     wxDataViewColumnList     m_cols;
     wxDataViewItem           m_ensureVisibleDefered;
 
+    // By default this is set to -1 and the height of the rows is determined by
+    // GetRect() methods of the renderers but this can be set to a positive
+    // value to force the height of all rows to the given value.
+    int m_uniformRowHeight;
+
     virtual void AddChildGTK(wxWindowGTK* child);
     void GtkEnableSelectionEvents();
     void GtkDisableSelectionEvents();