Preview in editor window to show cursor position in large document

the key idea:
You get lost if you’re editing long documents or open a long doc you don’t know, a small window is integrated or opened in the editor window, showing you which part of the document is currently visible on the editor-display. It is showing the cursor position.

cursor preview postion in long document
(without that nasty arrow, of course!)

Seen this in other Code editors, is useful too just for editing long chunks of text, not only for programming…