Fixed scroll the Object List to selected item on OSX & GTK

+ fixed #1395 (maximum PresetComboBox's width limit on Ubuntu)

src/slic3r/GUI/GUI_ObjectList.cpp

@@ -1459,13 +1459,11 @@ void ObjectList::update_selections()
     
     select_items(sels);
 
-#ifdef __WXMSW__
     if (GetSelection()) {
-        const int sel_item_row = GetRowByItem(GetSelection());
-        ScrollLines(sel_item_row - m_selected_row);
-        m_selected_row = sel_item_row;
+        const wxRect& top_rc = GetItemRect(GetTopItem());
+        const wxRect& sel_rc = GetItemRect(GetSelection());
+        ScrollLines(int((sel_rc.y - top_rc.y) / top_rc.GetHeight()) - 0.5*GetCountPerPage());
     }
-#endif //__WXMSW__
 }
 
 void ObjectList::update_selections_on_canvas()

src/slic3r/GUI/GUI_ObjectList.hpp

@@ -108,8 +108,6 @@ class ObjectList : public wxDataViewCtrl
     bool        m_parts_changed = false;
     bool        m_part_settings_changed = false;
 
-    int         m_selected_row = 0;
-
 public:
     ObjectList(wxWindow* parent);
     ~ObjectList();

src/slic3r/GUI/Plater.cpp

@@ -213,7 +213,7 @@ void SlicedInfo::SetTextAndShow(SlisedInfoIdx idx, const wxString& text, const w
 }
 
 PresetComboBox::PresetComboBox(wxWindow *parent, Preset::Type preset_type) :
-    wxBitmapComboBox(parent, wxID_ANY, wxEmptyString, wxDefaultPosition, wxDefaultSize, 0, nullptr, wxCB_READONLY),
+    wxBitmapComboBox(parent, wxID_ANY, wxEmptyString, wxDefaultPosition, wxSize(200,-1), 0, nullptr, wxCB_READONLY),
     preset_type(preset_type),
     last_selected(wxNOT_FOUND)
 {