Not all widgets are controls and we don't use any of wxControl-specific
methods in the sample, so don't require RecreateWidget() to return a wxControl
when a simple wxWindow suffices.
No real changes.
This fixes the sample compilation with default configuration when using MinGW
as it uses wxUSE_GRAPHICS_CONTEXT=0 by default and so wxUSE_ACTIVITYINDICATOR
is turned off by default for it too.
This is a simple animated control indicating some program activity.
Provide native GTK+ (for > 2.20) and OS X implementations as well as a generic
one used under MSW.
Update the sample and the documentation.
