emacs - show the current file in other frame - emacs

I want to do something similar to iswitchb-buffer-other-frame
except, set the file name programmatically to be the current frame.
(with iswitchb-buffer-other-frame you have to chose the file interactively)
If iswitchb is obsolete, can I achieve that with ido-mode or another package (or straight Lisp)?
How can I do that?
EDIT
Based on the answer of #pickle-rick I adjusted the code to my needs.
I need to use switch-to-buffer-other-window instead of switch-to-buffer-other-frame.
I'm not sure why...
In my setting, I have 2 frames - each frame has a single window, and I need to move the current buffer to the other frame.
But it works!
Also, I populate the original frame with an arbitrary buffer (*scratch*) (to prevent showing the original buffer in the original frame)
Here is my adjusted code:
(defun my-switch-buffer-other-frame ()
(interactive)
(switch-to-buffer-other-window (current-buffer))
(other-frame 1)
(switch-to-buffer "*scratch*")
(other-frame 1))

The ido equivalent is ido-switch-buffer-other-frame, which prompts for interactive selection as well. Here is a simple modification to avoid the prompting, and use the current buffer instead,
(defun my-switch-buffer-other-frame ()
(interactive)
(switch-to-buffer-other-frame (current-buffer)))

Related

Open Org Capture buffer in specific window?

I've been an Emacs user for about a year or so. I routinely have the same window set up each session (four windows).
I've set up capture templates and can capture what I want, but: instead of capture mode temporarily jerking me out of my window setup, I'd like the chosen capture template to open in a new (fifth) window, preserving my existing layout. I typically want the capture template open for a while, so it's disruptive.
This seems like it would be an obvious option, but I can't figure it out. Thanks in advance to all the Emacs heads out there.
I came up with a easier-to-use version of Dan's answer to the linked question:
(defun my-org-capture-place-template-dont-delete-windows (oldfun &rest args)
(cl-letf (((symbol-function 'delete-other-windows) 'ignore))
(apply oldfun args)))
(with-eval-after-load "org-capture"
(advice-add 'org-capture-place-template :around 'my-org-capture-place-template-dont-delete-windows))
That is, instead of having to modify Org-mode code and remove the call to delete-other-windows, this piece of code temporarily redefines delete-other-windows to ignore while org-capture-place-template is being called.
It doesn't do quite what you want: it picks one of the existing windows and puts the capture buffer there. At least it's better than the default behaviour of removing all previous windows but one.
There's probably a way to do what you want by customising the variable display-buffer-alist, but I couldn't figure it out...
You could also use https://github.com/raxod502/el-patch and patch org-capture after loading (look for the (el-patch-remove (delete-other-windows))):
(el-patch-feature org-capture)
(with-eval-after-load 'org-capture
(el-patch-defun org-capture-place-template (&optional inhibit-wconf-store)
"Insert the template at the target location, and display the buffer.
When `inhibit-wconf-store', don't store the window configuration, as it
may have been stored before."
(unless inhibit-wconf-store
(org-capture-put :return-to-wconf (current-window-configuration)))
(el-patch-remove (delete-other-windows))
(org-switch-to-buffer-other-window
(org-capture-get-indirect-buffer (org-capture-get :buffer) "CAPTURE"))
(widen)
(org-show-all)
(goto-char (org-capture-get :pos))
(setq-local outline-level 'org-outline-level)
(pcase (org-capture-get :type)
((or `nil `entry) (org-capture-place-entry))
(`table-line (org-capture-place-table-line))
(`plain (org-capture-place-plain-text))
(`item (org-capture-place-item))
(`checkitem (org-capture-place-item)))
(org-capture-mode 1)
(setq-local org-capture-current-plist org-capture-plist)) )
For some reason, the #legoscia approach fails for me in emacs 28.
So here is the el-patch snippet as suggested previously:
(el-patch-feature org-capture)
(with-eval-after-load 'org-capture
(el-patch-define-and-eval-template
(defun org-capture-place-template)
(el-patch-remove (delete-other-windows))))

emacs dispatch help window from original buffer

Whenever I do apropos, describe-key, or some other help function in emacs, it displays the help in my other window. In order to get rid of it, I must change windows/buffers to go there, type "q", and then change back to my original working buffer.
Is there a way I can do this in code somehow? I know how to save-excursion, switch buffers, etc, but I don't know how to send the "q" to the minibuffer/emacs while I'm over in the other buffer. Thanks
The help-window-select variable might be exactly what you want.
If you set its value to true (setq help-window-select t) then the help window will automatically be selected when you open it via one of the help commands. You can then press q to quit out of it and go back to your original buffer. There are many other options so you should check those out too.
For the apropos window or any window that uses display-buffer you can use.
(add-to-list 'display-buffer-alist
'("*Apropos*" display-buffer-same-window))
display-buffer-same-window is one options of many; it opens the buffer in the current window. The other possible options can be seen by looking up the docs on the display-buffer function.
Here's my solution to this problem. I bind this command to C-c q:
(defvar my/help-window-names
'(
;; Ubiquitous help buffers
"*Help*"
"*Apropos*"
"*Messages*"
"*Completions*"
;; Other general buffers
"*Command History*"
"*Compile-Log*"
"*disabled command*")
"Names of buffers that `my/quit-help-windows' should quit.")
(defun my/quit-help-windows (&optional kill frame)
"Quit all windows with help-like buffers.
Call `quit-windows-on' for every buffer named in
`my/help-windows-name'. The optional parameters KILL and FRAME
are just as in `quit-windows-on', except FRAME defaults to t (so
that only windows on the selected frame are considered).
Note that a nil value for FRAME cannot be distinguished from an
omitted parameter and will be ignored; use some other value if
you want to quit windows on all frames."
(interactive)
(let ((frame (or frame t)))
(dolist (name my/help-window-names)
(ignore-errors
(quit-windows-on name kill frame)))))
I suggest putting (winner-mode 1) in your init file, and then using C-c<left> to call winner-undo (repeatedly, if necessary) to return to a previous window configuration.

Emacs: How do I create a new "empty" buffer whenever creating a new frame?

My Emacs is on OS X system. Is there any way to make a new frame defaulted to an empty buffer whenever I use ⌘N (just like the way TextEdit works)? I prefer to write contents first and decide an appropriate filename later. However, Emacs wants me to decide the filename first and write contents later. I don't see any advantage for it. Does anyone know why Emacs works that way?
Basically, if I use C-x 5 2, Emacs always pops up a frame with whatever file I am currently working on. This is inconvenient. I also don't want my Emacs to pop up a new frame defaulted to *scratch* (many Google search results somehow suggest this approach). I prefer it to have a buffer temporarily called "Untitled" in the new frame, and if I use ⌘N again, Emacs pops up another temporarily "Untitled 2" buffer, and so on. In this way, I can decide the buffer filenames later.
You can create new buffers with switch-to-buffer. Type C-x b, enter a buffer name, and press RET. If no buffer with that name exists, Emacs creates a new one automatically in Fundamental Mode. You may switch to any other mode as usual with M-x, e.g. M-x python-mode. To change the default buffer, set the default value of major-mode to the desired buffer.
If you'd like to have a buffer name chosen automatically, and create a new frame, however, you need to write your own command:
(defun lunaryorn-new-buffer-frame ()
"Create a new frame with a new empty buffer."
(interactive)
(let ((buffer (generate-new-buffer "untitled")))
(set-buffer-major-mode buffer)
(display-buffer buffer '(display-buffer-pop-up-frame . nil))))
Bind this to C-c n:
(global-set-key (kbd "C-c n") #'lunaryorn-new-buffer-frame)
Now pressing C-c n creates a new frame with a new empty buffer named “untitled” where x is a consecutive number.
The following will create a buffer with a unique name. The buffer is not associated with any file, so if/when you ever C-x C-s save-buffer, you will be prompted to supply a filename.
(defun empty-frame ()
"Open a new frame with a buffer named Untitled<N>.
The buffer is not associated with a file."
(interactive)
(switch-to-buffer-other-frame (generate-new-buffer "Untitled")))
This might work for you, if I understand your request:
(defun empty-frame ()
(interactive)
(let ((fl (make-temp-file "Untitled")))
(switch-to-buffer-other-frame fl)))
This will open a new temporary file for each new buffer. If you'd rather not actually create the file, you can use this instead:
(defun empty-frame ()
(interactive)
(let ((bn "Untitled-")
(num 1))
(while
(get-buffer (concat bn (number-to-string num)))
(setq num (1+ num)))
(switch-to-buffer-other-frame
(concat bn (number-to-string num)))))
You've seen answers as to how to create new "Untitled" buffers, but as for why Emacs wants you to first choose a name, some of the reasons are:
Historical: that's just how it worked, and once you get used to it, it's no worse than the alternative.
Major modes and various other details are usually chosen based on the name of the file. So instead of creating an Untitled buffer and having to choose whether to put it into LaTeX mode or C mode, you just open a file with extension ".tex" or ".c".
Having a file name means that Emacs can use the standard auto-save procedure, whereas with the Untitled approach, applications need to have some special way to auto-save those Untitled documents at some "standard" place.
C-x b *untitled* will open new buffer if not exist. Also, see Emacs manual

How can I open a new frame which always displays the active buffer of its parent frame in emacs?

I want to have a shortcut to create a new frame in emacs which will always display the active buffer of the frame that created it. This way the frame could be moved to another workspace to keep as sort of a small preview of another emacs frame.
The following is my attempt at a function that will get the new frame to always show the parent frame's buffer. get-active-buffer is pseudo-code, but aside from that the rest should do the trick.
(defun display-active-buffer (parent-frame)
(while t
(let ((active-buffer (get-current-buffer parent-frame)))
(cond (/= active-buffer (current-buffer))
(switch-to-buffer-other-frame active-buffer)))))
Really I mostly just want to know what sort of function there is like get-current-buffer, which would act like current-buffer, except it would take a frame as an argument, instead of just using the current frame. I also would need to figure out some way to pass the name of the parent-frame to this function. I'm also not sure how smart it is to be using an infinite while loop for this though. If anybody knows of a better way, please tell.
I feel like this could be a really useful feature to add to emacs, and so if I figure all of this out I'll be sure to edit this post to add my finished code for anybody to use.
I have no idea why you would want to do this, but I think this does what you described:
(defun make-frame-synced-to-current-frame-current-buffer ()
(interactive)
(let ((parent-frame (selected-frame))
(synced-frame (make-frame)))
(add-hook
'window-configuration-change-hook
`(lambda ()
(if (eq (selected-frame) ,parent-frame)
(save-excursion
(select-frame ,synced-frame)
(switch-to-buffer (window-buffer
(frame-selected-window
,parent-frame)))
(select-frame ,parent-frame)))))))

Emacs shell-mode display is too wide after splitting window

If I run M-x shell in emacs to get a terminal, it knows where to wrap lines automatically. For example, the output of ls is formatted into columns that fit the window properly.
My problem is if I then split the window vertically with C-x 3, shell-mode still thinks the window fills the whole frame. The result is ugly wrapping of command output. Is there a way to let shell-mode know it has to update the screen width?
EDIT:
Using HN's answer below, I came up with this fix:
(defun my-resize-window ()
"Reset the COLUMNS environment variable to the current width of the window."
(interactive)
(let ((proc (get-buffer-process (current-buffer)))
(str (format "export COLUMNS=%s" (window-width))))
(funcall comint-input-sender proc str)))
(defun my-shell-mode-hook ()
(local-set-key "\C-cw" 'my-resize-window))
I'm a bit late to the party, but COLUMNS isn't the way to do this. Here is an excerpt from my .emacs:
(defun comint-fix-window-size ()
"Change process window size."
(when (derived-mode-p 'comint-mode)
(set-process-window-size (get-buffer-process (current-buffer))
(window-height)
(window-width))))
(defun my-shell-mode-hook ()
;; add this hook as buffer local, so it runs once per window.
(add-hook 'window-configuration-change-hook 'comint-fix-window-size nil t))
(add-hook 'shell-mode-hook 'my-shell-mode-hook)
Unlike exporting COLUMNS each time, this method doesn't require you to be in
bash at the moment and it doesn't spam your session with blank prompts. This
code should probably be in comint itself, maybe I will file a bug report.
EDIT: If you modify window-configuration-change-hook in a buffer-local-way
the hook runs once per window, as opposed once per frame.
Here is a slightly improved resize function from #Christopher Monsanto's answer. The original one will cause a problem due to nil process. (e.g exit in shell-mode)
(defun comint-fix-window-size ()
"Change process window size."
(when (derived-mode-p 'comint-mode)
(let ((process (get-buffer-process (current-buffer))))
(unless (eq nil process)
(set-process-window-size process (window-height) (window-width))))))
This display is dictated by the COLUMNS environment variable. In my setup COLUMNS has a value of 202, after a vertical split ls displays correctly on shell-mode if I set columns to 80 via
export COLUMNS=80
There must be a way to code this up but I don't have enough elisp-fu to do that. If you'd rather avoid the hassle multi-term manages this automagically.
http://www.emacswiki.org/emacs/MultiTerm
Try M-x eshell; it doesn't have this problem.