wxCode or wxCommunity has code for floating point spin controls.
Google wxCode and wxCommunity.
He didn't asked for that.
Answering the question,
Always inserting and connecting the "Custom" widget would be a bit nasty, i hope someone has a better way how to handle this
Unfortunately, using "Custom" widgets is currently the only way. (Well, or recompiling wxSmith to include support to the custom controls
).
That is one of my biggest requests for wxSmith.
There are a lot of ways to handle custom controls, it's not an easy topic, and I couldn't figure (neither byo I think) the best way to handle them. Some ideas are perhaps, for defining custom controls: XML, XRC, scripting, plugins for wxSmith, etc.
Ideally, the customs control (for example, a wxScintilla control, or some control made by yourself) could have most properties (events, looks, properties, C++ & XRC code generation, etc) defined in an XML file. So this would be a bit like the current "custom" control; but letting the user select the properties of the control, like Font, Size, Name, ACustomProperty, etc.
Of course, the drawing of the control when RAD editing will not be WYSIWYG, that would requiere something like "plugins" for wxSmith, which could be difficult to make and requieres compilation, etc.
But the first step is more important, WYSIWYG editing is not as important as letting the user create a custom control with all it's own properties, events and code generation all in a single XML file.
Some squirrel scripting can be used if necessary too.