Comment 7 for bug 950677

<slightly off-topic>
I was wondering about the two button groups (toggles) for new gradients (part of the existing controls bar):
- Gradient Type: linear/gradient
- applied on: fill/stroke

When clicking on an inactive button, both button states in the group are toggled (to ensure that only one button is active). However, it is still possible to deactivate the current active button by clicking once on it, resulting in an inconsistent state with undefined behavior (to the user):
- With no gradient type selected, which type will be used?
- With neither fill nor stroke selected, which property of the object will have the gradient applied?
AFAICT the last used state (from the preferences (?)) is used, but the user has no obvious way to know in advance.

Maybe it would make sense to either
- add a check, and toggle both button states if one of them is deactivated, or
- use real radio switches (GtkRadioToolButton/GtkRadioButton (?)) to make sure that one button is always active.
</slightly off-topic>