Re: Adding transient to Emacs core

[Jonas Bernoulli]

Gregory Heytings <gregory@heytings.org> writes:

>>
>> If the selected window were repurposed to display transient's buffer, 
>> then that would change what buffer is the current buffer and it would 
>> become impossible to act on the buffer that was previously the current 
>> buffer or on "the thing under the cursor" in that buffer.
>>
>
> Yes, I understand this, but when the frame is too small to display both 
> the current window and the transient buffer window, would it not be better 
> to do that anyway, and to restore the previously current buffer before 
> executing the command?

I guess it is a matter of preference.

This is the default value of `transient-display-buffer-action:

    (display-buffer-in-side-window
     (side . bottom)
     (inhibit-same-window . t))

The (inhibit-same-window . t) is there to *prevent* it from falling back
to that behavior.

One way of dealing with the fact that different people want different
fallback behavior in this case would be to add a note about this to the
doc-string.

Another possible fallback would be to not display the popup buffer at
all when the selected frame isn't high enough and to instead display a
message in the echo area about what the issue is, while still allowing
the user to invoke suffix commands.

All of this will require some thought and experimentation.  Please share
yours and give me the time I need to try things out.