#+TITLE: pip-frame.el

pip-frame.el allows displaying a floating Emacs frame with Emacs
buffers in [[https://github.com/ch11ng/exwm][EXWM]] (and possibly other) environments.

* Why?

[[https://github.com/ch11ng/exwm][EXWM]], an Emacs window manager, supports floating windows, placed above
the tiled windows.  But this doesn’t apply to Emacs buffers, there is
no way known to me to display an Emacs buffer in a floating window.

Having floating Emacs buffers looking like Picture-In-Picture is still
useful.  Imagine you start a long compilation and do other work in the
meantime.  You must poll the compilation status regularly.  Maybe the
compilation fails early and you don’t notice it until the next polling
interval.  Or you run an upgrade and forget about it, only to discover
a couple of hours later that the upgrade has hung on an interactive
question.  With a PIP frame displaying the compilation and upgrade
buffers, you always know what’s happening.

People often use secondary monitors for such overviews.  But this is
often overkill.  It’s often hard to use all the space on contemporary
wide or even very wide monitors.  I typically run Emacs with two
windows side by side, focusing mostly on the left one.  The area close
to the right bottom screen corner is the least one used and it’s a
good place to place a PIP frame there.  And it’s often better than
connecting a secondary monitor.

In theory, it’s possible to create such a window in a standard Emacs
frame.  But having a corner window is impractical, considering
applications changing window layouts (e.g. [[http://www.gnus.org][Gnus]]).  And if workspaces
are used, e.g. [[https://www.gnu.org/software/emacs/manual/html_node/emacs/Tab-Bars.html][Emacs tabs]], the window is still hidden when working in
a different workspace.  Similar problems are experienced when using
tiling window managers other than EXWM.

** Screenshot

This is an example of an Emacs buffer displayed in a PIP frame using
this utility:

#+ATTR_HTML: :alt An Emacs frame with a PIP frame
[[./screenshot.jpg]]

* How?

** Commands

The PIP frame is created using =M-x pip-frame-add-buffer= command.  You
can use the command repeatedly to add more buffers to the PIP frame.

A buffer can be removed from the PIP frame using
=M-x pip-frame-remove-buffer= command.  If the last buffer is removed
from the PIP frame, the frame is deleted.  The frame can also be
deleted any time using =M-x pip-frame-delete-frame=.

If the frame obscures anything important, you can move it elsewhere
with =M-x pip-frame-move=.

There are no key bindings.  Feel free to add them to your
configuration if needed.  But these commands are not very frequent and
tools such as [[https://www.gnu.org/software/emacs/manual/html_node/emacs/Icomplete.html][Icomplete mode]] or [[https://github.com/nonsequitur/smex][smex]] are likely to serve better than
tons of key shortcuts.

** Customization

Use =M-x customize-group RET pip-frame RET= to customize pip-frame.el.

Some customization examples:

- To place the PIP frame to right top rather than to right bottom:

  #+begin_src elisp
    (setq pip-frame-parameters '((left . 0.9) (top . 0.1)))
  #+end_src

- To better distinguish the PIP frame from the rest of the screen (the
  frame is intentionally kept out of EXWM hands and no window manager
  borders are displayed), you can show it in inverse colors:

  #+begin_src elisp
    (setq pip-frame-face-attributes '((:inverse-video . t)))
  #+end_src

  Or with a different background:

  #+begin_src elisp
    (setq pip-frame-face-attributes '((:background . "light gray")))
  #+end_src

- To add internal borders to the PIP frame and make it resizable with
  a mouse:

  #+begin_src elisp
    (setq pip-frame-parameters (append pip-frame-parameters
                                       '((drag-internal-border . t)
                                         (internal-border-width . 20))))
  #+end_src

* Contact

pip-frame.el is available at [[https://git.zamazal.org/pdm/pip-frame][git.zamazal.org]].  You can file issues
there.

If you don’t want to discuss things publicly or to bother registering
at yet another web site, you can reach me at [[mailto:pdm@zamazal.org][pdm@zamazal.org]].