[Gambas-user] ComboBox: Detect if the button was clicked

[Bruce]

I have tried a couple of ways to determine if the user has clicked on
the button that opens the list in a combobox with no great success. (I
am trying to discern whether they selected a list item or typed a new
string in the textbox.) 
It looks like I have to use the Mouse.X and Mouse.Y values to see if
they are inside the button, but this is extrememly fragile and painful.
Does anyone have a better idea.

tia
Bruce