Kid 0 - XuiDropBox
"Selection" callback when XuiPullDown item selected
v0 : item - 0 is topmost item
Kid 1 - XuiTextLine
"Selection" callback from Enter KeyDown when grid has focus
v0 : item if text string is also in XuiPullDown list, else -1
Kid 2 - XuiPressButton

XuiDropBox grids display a text string in the XuiTextLine grid, and a list of items in an XuiPullDown that toggles up and down when the XuiDropBox button is selected. XuiDropBox grids generate Selection callback messages when the user presses an Enter key when the XuiTextLine has keyboard focus, and when the user selects any item in the XuiPullDown grid.

The XuiDropBox grid manages the XuiPullDown window, so the XuiPullDown list is the its TextArray property of the XuiDropBox.