I noticed when I commented out the WindowRefresh, that on the top of the screen the elements that needed to be inserted were drawn, before inserting them. The situation is like this:
1. In the lower left corner of the screen is a RepeatControl, that is automatically filled with data from a query. The query is stripped and the various parts are inserted into the RepeatControl, showing attributes, data and options like ‘equal to’, ‘less than’, etc.
2. When the RepeatControl is filled, I see that the FieldControls that are inserted into the RepeatControl are drawn on the top of the screen, being followed by a screen redraw.
3. When the WindowRefresh is commented out, I notice that the FieldControl on top of the screen contains the data that is finally inserted into the RepeatControl, but the FieldControl has a very different shape. It is about 4 times higher and 4 times larger then when it is inserted into the RepeatControl.
What it seems to me is that the Control method Construct is building the FieldControl, then resizes it, fits it into the RepeatControl and then forces a WindowRefresh to wipe out the FieldControl that was build up in the top of the screen. Although I don’t know the details of the GUI creation…