What's this box around my function input?

Question

Whenever I write an auto-completed function call and start typing something, a black rectangle is drawn around the input, like below:

Answer 1

This is called place holder. Keep caret anywhere in between the class methods and inside the class body and type public and press Ctrl + Space and select public_method option. Then you will get a template looks like this:

Here return_type is covered with rectangle and highlighted this means you can type the return type as void, int etc and this will appear in this rectangle box.

Use TAB key to traverse next place holders i.e name is also covered with rectangle box. After typing the return type when you press TAB key you will jump to next place holder(i.e name).

You can go back to the previous place holder by pressing Shift + TAB key. Green color caret represent the end of place holders.

While you are in any place holder if you press Enter key you will be directly taken to the end of the place holder(i.e green caret).

Check the template grammar for public_method template here Windows > Preferences > Java > Editors > Templates

It looks as

public ${return_type} ${name}(${}) {
    ${cursor}
}

You can edit this. If you remove ${cursor} then green colour caret will not appear and so on.

You can turn if off by

1. Deleting template(Not recommended)
2. Editing template grammer
3. Or just by pressing Enter key(Recommended)

Also check the grammar of static_final template. Here you will get the drop down menu along with rectangular box.