bug#38354: 27.0.50; Implement display action display-buffer-in-tab

[martin rudalics <rudalics@gmx.at>]

 >> If so, then we should decide whether we always want to stick to that
 >> limitation or, eventually allow moving tabs between frames, probably
 >> using window states for that purpose.  And we have to decide whether
 >> such moving of a tab would mean making a completely self-reliant copy
 >> of it or keep properties of it shared among frames.  And eventually we
 >> should decide whether tabs could become first-class citizens - have a
 >> life of their own without being attached to any frame.
 >
 > There are two separate cases to consider:
 >
 > 1. Moving an inactive tab to another frame.
 >     In this case we need to use its window-state, not window-configuration,
 >     i.e. just delete the window-configuration from tab data, then it
 >     could be moved to another frame without problems.
 >
 > 2. Moving the current tab to another frame.  Here we need to save
 >     window-configuration of another frame to its inactive tab, then clone
 >     the original frame to another frame.  Do you know if such a function
 >     already exists that duplicates all frame parameters with frame-root
 >     window-state to another frame?

With "moving" I really meant "copying" or "cloning" with the
additional possibility of deleting the original.  So there should be
only one question: Can we simply make a copy of a tab using its window
state (window configurations can't be used because we cannot clone
windows).  If not, what is the problem?

 > An additional question to consider is how to interactively select
 > an another frame: by frame name, or using other-frame with a numeric
 > prefix argument?

How is this question related to tabs?

 >>> (push '("test1" .
 >>>           ((display-buffer-reuse-window display-buffer-in-tab)
 >>>            (reusable-frames  . visible)
 >>>            (name . "Tab1")))
 >>>         display-buffer-alist)
 >>
 >> What would be the downside of it?  The 'reusable-frames' would specify
 >> the list of frames to investigate - the other dimension you mentioned
 >> above.
 >
 > We need an alist entry that will tell display-buffer-reuse-window
 > to search in tabs.  Maybe just the presence of the 'use-tabs' param
 > will tell display-buffer-reuse-window to search in tabs like:
 >
 > (push '("test1" .
 >           (display-buffer-reuse-window
 >            (reusable-frames  . visible)
 >            (use-tabs . t)))
 >         display-buffer-alist)

There is one thing I apparently do not understand yet: When you enable
'tab-bar-mode' it is global - that is any window ever shown on any frame
is also in at least one of that frame's tabs.  Is that right?  So what
would 'use-tabs' mean here when every window is in a tab already?

 >>    By default, a new tab starts with the current buffer that was current
 >>    before calling the command that adds a new tab.
 >>
 >> That's confusing, at least.
 >
 > Maybe this is better?
 >
 >    By default, a new tab starts with the buffer that was current
 >    before calling the command that adds a new tab.

The current buffer is IMHO a much too obscure object to consider here.
Don't you mean the buffer of the selected window?

martin