**Implemented Widgets**

All Tk widget commands are implemented in namespace ::tk but for compatibility there are interp aliases to be able to use for example button without the ::tk:: namespace prefix for creating a new button instance.

So we have the following commands:
   * ::tk::button
   * ::tk::entry
   * ::tk::frame
   * ::tk::label
   * ::tk::toplevel

From experiments I found out, that you need a
 <div>
element around most of these widgets to be able to force width and height requirements and also when packing these widgets. So in [HTML] a [button] [widget] would look like so:
 <div>
    <button>button1</button
 </div>

The sub commands for a button could not be implemented directly as a [namespace] ensemble, as the  button itself is implemented like an [itcl] class, so that [namespace] cannot be additionally be used for a [namespace] ensemble.
 
So for example the cget and configure command of a button widget are implemented as ::tk::button::configure and ::tk::button::cget and are handled like [itcl] class methods. As a result you can use .b1 cget … and .b1 configure ..., if .b1 has been created as a [button] [widget] instance using: button .b1 …

But be aware: a [Tk] [widget] instance in this implementation is no class object and a sub command of the [widget] is no class method. It is only handled very similar to these parts, to be able to use common code! 

(Part of [Tk Widgets in Javascript Paper])

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