Re: Can Emacs started with `-nw' option view pdf with pdf-tools?

[Yuri Khan <yuri.v.khan@gmail.com>]

On Wed, 21 Jul 2021 at 08:57, Hongyi Zhao <hongyi.zhao@gmail.com> wrote:

> Then I run `M-x view-pdf-in-graphical-frame', but this will open a
> second Emacs GUI instance instead of create a new GUI frame in the
> original one. See the attachment fore more detailed info.

You are confused about frames, windows and instances. Which is
understandable, given Emacs’s peculiar terminology and its rare
ability to have frames of different kinds in a single instance.

You cannot have graphics in a terminal emulator (unless you happen to
be using a terminal emulator that implements graphics display[1], and
unless somebody actually writes some Elisp code to utilize this
terminal capability).

[1]: https://sw.kovidgoyal.net/kitty/graphics-protocol/

So you have to create a graphical frame. A frame in Emacs is what is
called a window in the rest of the desktop applications. What you got
is a new GUI frame. Both this new frame and what you have in the
terminal emulator belong to the same Emacs instance; if you do a
‘list-buffers’ in both, you will see they operate on the same internal
state.

To reiterate: Your original window is a terminal emulator. You
*cannot* have graphics appear right *in* it.