Re: Suggestion: Add discussion of input focus handling to select-window; add select-frame-window

[Stefan Monnier]

> ​Hyperbole has a feature that lets you either drag a dired item (or
> other item type) to another frame (input switches to that frame) or
> throw the dired item to another frame (input stays in the same frame).
> The throw command calls the drag command to reuse its logic, since it
> is fairly involved and doesn't make sense to duplicate, but then needs
> to restore the focus to original frame.

Wouldn't it make sense to solve this by doing it the other around:
implement drag on top of throw?

The kind of "undo" we get from save-excursion and friends is very handy
and powerful, but in many cases "undoing" is either very difficult or
even impossible (e.g. save-window-excursion can undo changes to the
current frame, but there is simply no way to implement the equivalent
for frames, because once a frame is created the user has seen it (and
in my case, had to position it with his mouse) and once a frame has been
deleted you've lost some of the information attached to it which Emacs
can't recreate because it's specific to your particular window-manager).

When you request to change the focus, the window-manager may immediately
execute some user-visible action, so you can't fully "undo" it.


        Stefan