OK, found and fixed it.michiguel wrote:I can ask for smaller sizes but the empty space is still there and cannot be resized. Seems to be like the clock size remains big and does not adjust.
Anyway, if I start with -buttons, the problem is solved. That seems to correct the size of the clocks. If I start with -xbuttons is when the clocks are big.
It was an entirely unrelated problem. XBoard GTK dialogs are formatted as a table with 3 columns (label, text entry, browse button), where elements that need to be broader span multiple columns (e.g. a text-edit that doesn't need a browse button would span column 2 and 3). A bare text label, like the message widget, should have spanned all 3 columns.
The problem was that it only spanned columns 1 and 2. So GTK though there was still a column behind it, but the entire window has nothing in this column. I noticed before that GTK's auto-sizing gets completely confused when this happens, and in stead of assigning it width 0, gives it some random width. Which caused the extra space we were seeing.
When I let bare labels span all 3 columns the problem disappears. (When the button bar was on the same row, this problem was masked, because then all stuff that is on that row is packed into a hbox, which then was told to span all 3 columns. And when there is at least one element in each column, GTK doesn't mess up.)