Arrow placed in ComboBoxEntryText

["SaiKamesh Rathinasabapathy" <rsaikamesh gmail com>]

Hi,

I am creating an application in c++. This is going to be deployed in touch screen. I am using Gtkmm 2.8.8 . My OS is Linux - ubuntu 6.06.

Every widgets should be bigger in size, because this application is going to be deployed in touch screen. I added all the widgets bigger in size. For example I set the size of the Buttons, Entry and all to big. 

I need to add a Gtk::ComboBoxEntryText in one of my windows. I need to display the arrow placed at the right side of the ComboBoxEntryText bigger in size. Then only the user will be able to touch the arrow to select the items from the combo box.
How can I make the arrow in the ComboBoxEntryText big?. please tell me.

Thanks.