Controlling the widget layout

When you create a widget base, you have the option of asking for its children to be aligned in columns or in rows (with the keywords /column or /row). Since hardcoding the widget layout sometimes results in catastrophic aspects (i.e. using xsize can lead to problems on some machines), one can be tempted to leave IDL to sort it out for the best, or assume that there is a default alignement.

In IDL 5.3, this is not the case: if you don't specify one of the two keywords, the children of your base widget will be stacked on top of each others (i.e. aligned, but in the depth direction!). This is far from a desirable layout, as only the first and the "largest" children can be seen...

Therefore, any base declaration should specify either /column or /row!