I noticed the following behavior in AutoCompletion.java:
I have written Autocompletion for XPath expressions.
If the user enters an XPath like "Store/Items/Books", then presses "Ctrl-Space" while the cursor is at the end of the XPath, performing an autocomplete replaces the "Books" correctly.
If on the other hand, the cursor is between B and o while performing the autocomplete, the autocomplete only replaces the "B" with the new word and the "ooks" remains at the end, thus getting for example "Store/Items/Bananasooks".
I wonder if the current behavior is the behavior you have expected, since it does not behave like - for example - eclipse.
I have found the method AutoCompletion.insertCompletion(..) to be the source of this and changed the behavior for my implementation in a subclass of AutoCompletion. Unfortunately this implementation does not integrate with the framework very well, since it requires the use of the "isValidChar(char ch)" method from my custom completion implementation. If you are interested, I could provide you with a proposal for AutoCompletion which adds a "replaceTypedWord" option. However it would require an additional method in the "CompletionProvider" interface and changing all implementors would be out of scope for me.
With kind regards,