I'm coming back to Eclipse after using IntelliJ or whatever for a while, and the first thing I'm trying to do is making me crazy.
I want two editor views of the same file ("Splitting an editor" in the Eclipse documentation); and when I make a change in one of those editors, I want it to show up in the other! (Like, you know, any other editor with a "split pane" feature. I've only tried this in a Markdown editor and a Bash editor, so I suppose my problem could be with those plugins. This is using Eclipse 2019-06 (4.12.0).)
All I see in the Eclipse documentation is this:
Splitting an editor
To view or edit multiple sections of an editor at once, you can split / unsplit the currently active editor via:
Window > Editor > Toggle Split Editor (Horizontal) Window > Editor > Toggle Split Editor (Vertical)
Or just use one of the key bindings:
Ctrl+_ to split horizontally Ctrl+{ to split vertically
You can also open a second editor instance via Window > Editor > Clone.
Both Window > Editor > Toggle Split Editor
and Window > Editor > Clone
give me the same result: two views of the same file which aren't in sync, and which seem to be brain-damaged. If I type or cut/paste in one editor, the changes don't show up in the other; if I Ctrl-S in the other, the first is still marked as modified; Ctrl-S in the first (or trying to save when closing) gives an error, saying the contents have changed on disk. (No kidding! You changed them!!)
This answer from 2010 sounds like there's some drag-tabs-until-you-see-an-arrow step needed to keep the two panes in sync, but I don't think that's current, and I haven't been able to drag tabs around in a way which makes an arrow show up.
This is making me so crazy, I'm thinking about editing this definitely-non-Android-stuff in Android Studio, just because I know it will do the basic editing tasks I want to do.