[ Version ( since = "2.4" ) ]
public void set_drop_highlight_item (ToolItem? tool_item, int index_)
Highlights this to give an idea of what it would look like if item was added to
this at the position indicated by index_.
If item is null, highlighting is turned off. In that case index_ is ignored.
The tool_item passed to this function must not be part of any widget hierarchy. When an item is set as drop highlight item
it can not added to any widget hierarchy or used as highlight item for another toolbar.
| this |
a Toolbar |
| tool_item |
a ToolItem, or null to turn of highlighting |
| index_ |
a position on this |