Java SE (Java Platform, Standard Edition)

I need to create a WYSIWIG HTML editor and I'm thinking of using Swing.

I realise many have done this before and that there are products already on the market ranging from Coffee Cup to Dreamweaver.

However, this will be for a specific application where my users will need to drop some composite objects on to the web page -- these objects will generate chunks of HTML containing some of my own attributes with a special syntax. These objects might be as simple as a textbox with a label, or something more complex.

So the idea is that the user selects the object they wish to create by clicking a particular icon in a palette. The cursor changes to a cross-hair as the mouse is moved across some sort of canvas pane. The user clicks where they want the top left-hand corner of the object to be (rubber banding not necessary). A dialogue pops up asking for some context-sensitive properties for the object. At this point, the system can work out the HTML object it needs to create, i.e. tags, attributes, etc.

So far the canvas pane has acted as a simple drawing surface, perhaps with a set of grid lines to aid the user in positioning. But at this point, know that we know the HTML object required, I want it to be rendered on the pane as HTML.

Is it possible for a pane to be both a canvas an an HTML renderer like this, so that I can achieve a true WYSIWYG effect ? Does anyone understand what I'm talking about ?! Are there any examples of how I would go about this ?

Thanks