EMBEDDING CONTROLS OR PLACEHOLDERS IN CODE EDITOR

I’m developing an application which requires interactive placeholders (or placeholder controls if possible) embedded inline with the scripts/code inside the code editor.
The application must allow the user to insert such placeholders inline with the text of the script and must allow the user to interact with the embedded placeholder objects (including deleting and copy/pasting them) using the keyboard and the mouse.
For example, imagine a placeholder for an integer value. The user may type and the application must recognize this as an integer number placeholder object embedded inline with the normal text enabling the user to see a dial and change integer values up or down using the mouse wheel button.
The drawing/rendering of the placeholders and the events/interactions with it aside, how can I do this from the document model and other aspects of code editor such as informing it that the in the above example must always be treated as a control or something special with actual values or text dimensions coming from my custom classes instead of the original ?
I do have a parser and I can use to to locate these items in the text but I like to know what I can do on the code editor side? Is it possible to do this or to at least simulate the effects somehow?
Hi Caspian,
SyntaxEdit can display popup controls for the text fragments (placeholders), for example it can display list of available choices for such placeholders once user clicks on the text (using the listbox control we use for code completion).
In theory we can support other popup controls as well.
I'm uploading a sample demo, you can try it using this link:
http://www.alternetsoft.com/forum/PlaceholderDemo.zip
regards,
Andrew