If frame named "xyz" exists, then switch to that frame - emacs

Could someone please give me hand with a function that detects whether a frame named "xyz" exists, and if so, then switch to that frame. I'm using frame-cmds to give each frame a user-defined name:  http://www.emacswiki.org/emacs/frame-cmds.el
I would imagine it is similar to a buffer, but I'm not finding anything on Google. Here is the buffer function:
(defun buffer-exists (bufname)
(not (eq nil (get-buffer bufname))))
(defun lawlist-switch-to-buffer-xyz ()
(interactive)
(if (buffer-exists "xyz")
(switch-to-buffer "xyz") ))
Here is a semi-related post:  https://superuser.com/questions/358037/emacsclient-create-a-frame-if-a-frame-does-not-exist
EDIT (September 15, 2014):  Modified the function ido-switch-frame to make frame-to a let-bound variable, and removed the message. Removed previous edits as the functions get-a-frame and get-frame-name written by Drew Adams are sufficient when used in conjunction with select-frame-set-input-focus -- see his answer below.
(defun ido-switch-frame ()
(interactive)
(when (not (minibufferp))
(let* (
(frames (frame-list))
(frame-to (ido-completing-read "Select Frame: "
(mapcar (lambda (frame) (frame-parameter frame 'name)) frames))))
(catch 'break
(while frames
(let ((frame (car frames)))
(if (equal (frame-parameter frame 'name) frame-to)
(throw 'break (select-frame-set-input-focus frame))
(setq frames (cdr frames)))))))))

There may be more elegant solutions but this gets the job done:
(defun switch-to-frame (frame-name)
(interactive "sFrame name:")
(let ((frames (frame-list)))
(catch 'break
(while frames
(let ((frame (car frames)))
(if (equal (frame-parameter frame 'name) frame-name)
(throw 'break (select-frame-set-input-focus frame))
(setq frames (cdr frames))))))))

Wrt your request for "a function that detects whether a frame named "xyz" exists": You already have that, since you say you are using frame-cmds.el, which requires frame-fns.el --- Function get-a-frame does just that.
Icicles provides multi-command icicle-select-frame, which lets you choose frames by name using completion.

Related

Emacs jump to next annotated words or phrases

When using Emacs, I notice that words or phrases in a buffer can be annotated or highlighted by many minor modes like hi-lock-mode, flyspell-mode, flycheck-mode...
Is there any uniform way to jump to the highlighted words or phrases created by all these minor modes? Specifically, is there any package or function support jumping to the next and previous highlighted phrases?
When using Eclipse, I can do it by pressing Ctrl-. and Ctrl-,. However, when switching to Emacs, so far, I haven't found an equivalent feature.
Developing a mode which aims to tackle that kind of tasks
https://github.com/andreas-roehler/werkstatt/tree/master/general-key
Facilitates the setting of a general command.
Than this command gets different bindings according to modes - which needs to be edited by hand once. Afterwards it allows to set/change a key at one place for all related/bound commands.
See for example inside
https://github.com/andreas-roehler/werkstatt/blob/master/general-key/general-key-python-mode.el
It's alpha still notably for the install process. Bug reports resp. feature requests welcome.
Not surprisingly, #Drew has answered something related to this.
You can programmatically use isearch with something like:
(defun foo (regexp)
(interactive (list (read-regexp "Regexp: ")))
(isearch-mode t t)
(let ((isearch-regexp nil))
(isearch-yank-string regexp)))
This will pull your previous regexp history, including those from hi-lock. I imagine it would be a fun exercise to modify this to use hi-lock-regexp-history.
If you use swiper, you can restrict the search candidates to lines with highlighted patterns by hi-lock-mode.
Here is a simple wrapper of swiper:
(require 'cl-lib)
(defun swiper-over-highlights-simple ()
(interactive)
(let ((original-swiper--candidates (symbol-function 'swiper--candidates)))
(cl-letf (((symbol-function 'swiper--candidates)
(lambda ()
(let ((pattern (mapconcat #'car hi-lock-interactive-patterns "\\|")))
(cl-remove-if-not (lambda (x) (string-match-p pattern x))
(funcall original-swiper--candidates))))))
(swiper))))
In addition, you can change ivy-read's preselect argument, which initializes the first matched line inside swiper.
The following fuction, modified from swiper, finds the closest next line with a highlighted pattern:
(defun swiper-over-highlights (&optional initial-input)
(interactive)
(let ((original-swiper--candidates (symbol-function 'swiper--candidates))
(pattern (mapconcat #'car hi-lock-interactive-patterns "\\|")))
(cl-letf (((symbol-function 'swiper--candidates)
(lambda ()
(cl-remove-if-not (lambda (x) (string-match-p pattern x))
(funcall original-swiper--candidates)))))
(let ((candidates (swiper--candidates)))
(swiper--init)
(setq swiper-invocation-face
(plist-get (text-properties-at (point)) 'face))
(let ((preselect
(save-excursion
(search-forward-regexp pattern nil t)
(let* ((current-line-value (current-line))
(candidate-line-numbers (mapcar (lambda (x) (cadr (text-properties-at 0 x)))
candidates))
(preselect-line-num (cl-find-if (lambda (x) (<= current-line-value x))
candidate-line-numbers)))
(- (length candidate-line-numbers)
(length (member preselect-line-num candidate-line-numbers))))))
(minibuffer-allow-text-properties t)
res)
(unwind-protect
(and
(setq res
(ivy-read
"Swiper: "
candidates
:initial-input initial-input
:keymap swiper-map
:preselect preselect
:require-match t
:action #'swiper--action
:re-builder #'swiper--re-builder
:history 'swiper-history
:extra-props (list :fname (buffer-file-name))
:caller 'swiper))
(point))
(unless (or res swiper-stay-on-quit)
(goto-char swiper--opoint))
(isearch-clean-overlays)
(unless (or res (string= ivy-text ""))
(cl-pushnew ivy-text swiper-history))
(setq swiper--current-window-start nil)
(when swiper--reveal-mode
(reveal-mode 1))))))))

How can I cycle through only those buffers which are in a given major mode (such as Python-mode ) ?

How can I cycle through only those buffers which are in a given major mode (such as Python-mode ) ?
Currently I am using C-X-Left/Right arrows, but these also show all sorts of irrelevant (i.e. non source code) buffers, any idea how can I restrict the buffer switching only to a specific type of buffer (with a given major mode) ?
I could not find something ready-made. However, it is not very hard to make the suitable commands.
(defun buffer-mode-alist ()
"Returns a list of (<buffer-name> . <major-mode>) pairs."
(let ((all-buffers (buffer-list))
(rv nil))
(while all-buffers
(let* ((this (car all-buffers))
(name (buffer-name this)))
(setq all-buffers (cdr all-buffers))
(when name
(setq rv (cons (cons name (with-current-buffer this major-mode)) rv)))))
rv))
(defun buffers-with-major-mode (the-major-mode)
(let ((buffer-alist (buffer-mode-alist))
(rv nil))
(while buffer-alist
(let ((this (car buffer-alist)))
(setq buffer-alist (cdr buffer-alist))
(if (eql (cdr this) the-major-mode)
(setq rv (cons (car this) rv)))))
(sort rv #'string<)))
(defun spin-buffers (buffer-list current)
(cond ((not (member current buffer-list)) buffer-list)
((string= current (car buffer-list)) buffer-list)
(t (spin-buffers (append (cdr buffer-list)
(list (car buffer-list)))
current))))
(defvar next-buffer-mode nil)
(defun choose-next-buffer-mode (mode)
"Ask for what major mode should be used as a selector for next-buffer-with-mode."
(interactive "aMajor Mode: ")
(setq next-buffer-mode mode))
(defun next-buffer-with-mode (set)
"Switches to the 'next' buffer with a given mode. If the mode is not set,
require it to be set, by calling choose-next-buffer-mode. If any prefix
argument is passed, also call choose-next-buffer-mode."
(interactive "P")
(when (or (not next-buffer-mode)
set)
(call-interactively 'choose-next-buffer-mode))
(let ((buffers (spin-buffers (buffers-with-major-mode next-buffer-mode)
(buffer-name))))
(when (cdr buffers)
(switch-to-buffer (cadr buffers)))))
(defun prev-buffer-with-mode (set)
"Switches to the 'previous' buffer with a given mode. If the mode is not set,
require it to be set, by calling choose-next-buffer-mode. If any prefix
argument is passed, also call choose-next-buffer-mode."
(interactive "P")
(when (or (not next-buffer-mode)
set)
(call-interactively 'choose-next-buffer-mode))
(let ((buffers (spin-buffers (buffers-with-major-mode next-buffer-mode)
(buffer-name))))
(when buffers
(switch-to-buffer (car (last buffers))))))

Switch between frames by number or letter

I'd like to create a function that offers me numbered or lettered choices (1, 2, 3, or a, b, c) of available frames to switch to, instead of manually typing the name. Aspell would be the closest example I can think of.
Could someone please share an example of how this might be done? Lines 6 to 14 of the following function creates a list of all available frame names on the fly. Additional functions related to frame switching can be found here
(defun switch-frame (frame-to)
(interactive (list (read-string (format "From: (%s) => To: %s. Select: "
;; From:
(frame-parameter nil 'name)
;; To:
(mapcar
(lambda (frame) "print frame"
(reduce 'concat
(mapcar (lambda (s) (format "%s" s))
(list "|" (frame-parameter frame 'name) "|" )
)
)
)
(frame-list) )
)))) ;; end of interactive statement
(setq frame-from (frame-parameter nil 'name))
(let ((frames (frame-list)))
(catch 'break
(while frames
(let ((frame (car frames)))
(if (equal (frame-parameter frame 'name) frame-to)
(throw 'break (select-frame-set-input-focus frame))
(setq frames (cdr frames)))))) )
(message "Switched -- From: \"%s\" To: \"%s\"." frame-from frame-to) )
EDIT (November 13, 2014):  Here is a revised function using ido-completing-read:
(defun ido-switch-frame ()
(interactive)
(when (not (minibufferp))
(let* (
(frames (frame-list))
(frame-to (ido-completing-read "Select Frame: "
(mapcar (lambda (frame) (frame-parameter frame 'name)) frames))))
(catch 'break
(while frames
(let ((frame (car frames)))
(if (equal (frame-parameter frame 'name) frame-to)
(throw 'break (select-frame-set-input-focus frame))
(setq frames (cdr frames)))))))))
I see what you're trying to do. Here's how I've solved this problem:
Part 1
The files that you use every day should be bookmarked.
The reason is that you loose focus when you're reading any sort of menu,
even as short as you describe. After some time with bookmarks,
it becomes like touch-typing: you select the buffer without thinking about it.
You can check out this question
to see my system.
I've got about 20 important files and buffers bookmarked and reachable
in two keystrokes, e.g. μ k for keys.el and μ h for hooks.el.
A nice bonus is that bookmark-bmenu-list shows all this stuff, so I can
add/remove bookmarks easily
rename bookmarks (renaming changes binding)
it's clickable with mouse (sometimes useful)
bookmark+ allows function bookmarks, so I've got org-agenda on μ a
and magit on μ m.
And of course the dired bookmarks: source is on μ s and
org-files are on μ g.
Part 2
For the files that can't be bookmarked, I'm using:
(ido-mode)
(setq ido-enable-flex-matching t)
(global-set-key "η" 'ido-switch-buffer)
This is fast as well: you need one keystroke to call ido-switch-buffer
and around 2-3 letters to find the buffer you need, and RET to select.
I've also recently added this hack:
(add-hook 'ido-setup-hook
(lambda()
(define-key ido-buffer-completion-map "η" 'ido-next-match)))
With this you can use the same key to call ido-switch-buffer and cycle the selection.
Part 3
The actual function with lettered choices has been on my todo list for a while
now. I'll post back here when I get around to implementing it,
or maybe just copy the solution from a different answer:)
This answer describes Icicles command icicle-select-frame, which lets you choose frames by name using completion.
There is also Icicles command icicle-other-window-or-frame (C-x o), which combines commands icicle-select-frame, other-frame, and other-window. It lets you select a window or a frame, by its name or by order.
With no prefix arg or a non-zero numeric prefix arg:
If the selected frame has multiple windows then this is
other-window. Otherwise, it is other-frame.
With a zero prefix arg (e.g. C-0):
If the selected frame has multiple windows then this is
icicle-select-window with windows in the frame as candidates.
Otherwise (single-window frame), this is icicle-select-frame.
With plain C-u:
If the selected frame has multiple windows then this is
icicle-select-window with windows from all visible frames as
candidates. Otherwise, this is icicle-select-frame.
Depending upon the operating system, it may be necessary to use (select-frame-set-input-focus chosen-frame) instead of select-frame / raise-frame towards the end of the function.
(defface frame-number-face
'((t (:background "black" :foreground "red" )))
"Face for `frame-number-face`."
:group 'frame-fn)
(defface frame-name-face
'((t ( :background "black" :foreground "ForestGreen")))
"Face for `frame-name-face`."
:group 'frame-fn)
(defun select-frame-number ()
"Select a frame by number -- a maximum of 9 frames are supported."
(interactive)
(let* (
choice
chosen-frame
(n 0)
(frame-list (frame-list))
(total-frames (safe-length frame-list))
(frame-name-list
(mapcar
(lambda (frame) (cons frame (frame-parameter frame 'name)))
frame-list))
(frame-name-list-sorted
(sort
frame-name-list
#'(lambda (x y) (string< (cdr x) (cdr y)))))
(frame-number-list
(mapcar
(lambda (frame)
(setq n (1+ n))
(cons n (cdr frame)))
frame-name-list-sorted))
(pretty-list
(mapconcat 'identity
(mapcar
(lambda (x) (concat
"["
(propertize (format "%s" (car x)) 'face 'frame-number-face)
"] "
(propertize (format "%s" (cdr x)) 'face 'frame-name-face)))
frame-number-list)
" | ")) )
(message "%s" pretty-list)
(setq choice (read-char-exclusive))
(cond
((eq choice ?1)
(setq choice 1))
((eq choice ?2)
(setq choice 2))
((eq choice ?3)
(setq choice 3))
((eq choice ?4)
(setq choice 4))
((eq choice ?5)
(setq choice 5))
((eq choice ?6)
(setq choice 6))
((eq choice ?7)
(setq choice 7))
((eq choice ?8)
(setq choice 8))
((eq choice ?9)
(setq choice 9))
(t
(setq choice 10)))
(setq chosen-frame (car (nth (1- choice) frame-name-list-sorted)))
(when (> choice total-frames)
(let* (
(debug-on-quit nil)
(quit-message
(format "You must select a number between 1 and %s." total-frames)))
(signal 'quit `(,quit-message ))))
(select-frame chosen-frame)
(raise-frame chosen-frame)
chosen-frame))

The mechanism iswtichb used to show completions

all.
I decided to hack iswitchb this morning, and found a confusing thing.
Usually,when we command iswitchb,we got someting in minibuffer like:
iswitch {buffer1,buffer2 ...}
What in braces is the completions, as we typing its number
is shrinking.
And I didn't find how iswitchb achieved this when hacking on
its code (sorry for my dullness ).
This is original iswitchb-read-buffer with doc-string ripped
off:
(defun iswitchb-read-buffer (prompt &optional default require-match
start matches-set)
(let
(
buf-sel
iswitchb-final-text
(icomplete-mode nil) ;; prevent icomplete starting up
)
(iswitchb-define-mode-map)
(setq iswitchb-exit nil)
(setq iswitchb-default
(if (bufferp default)
(buffer-name default)
default))
(setq iswitchb-text (or start ""))
(unless matches-set
(setq iswitchb-rescan t)
(iswitchb-make-buflist iswitchb-default)
(iswitchb-set-matches))
(let
((minibuffer-local-completion-map iswitchb-mode-map)
;; Record the minibuffer depth that we expect to find once
;; the minibuffer is set up and iswitchb-entryfn-p is called.
(iswitchb-minibuf-depth (1+ (minibuffer-depth)))
(iswitchb-require-match require-match))
;; prompt the user for the buffer name
(setq iswitchb-final-text (completing-read
prompt ;the prompt
'(("dummy" . 1)) ;table
nil ;predicate
nil ;require-match [handled elsewhere]
start ;initial-contents
'iswitchb-history)))
(if (and (not (eq iswitchb-exit 'usefirst))
(get-buffer iswitchb-final-text))
;; This happens for example if the buffer was chosen with the mouse.
(setq iswitchb-matches (list iswitchb-final-text)
iswitchb-virtual-buffers nil))
;; If no buffer matched, but a virtual buffer was selected, visit
;; that file now and act as though that buffer had been selected.
(if (and iswitchb-virtual-buffers
(not (iswitchb-existing-buffer-p)))
(let ((virt (car iswitchb-virtual-buffers))
(new-buf))
;; Keep the name of the buffer returned by find-file-noselect, as
;; the buffer 'virt' could be a symlink to a file of a different name.
(setq new-buf (buffer-name (find-file-noselect (cdr virt))))
(setq iswitchb-matches (list new-buf)
iswitchb-virtual-buffers nil)))
;; Handling the require-match must be done in a better way.
(if (and require-match
(not (iswitchb-existing-buffer-p)))
(error "Must specify valid buffer"))
(if (or (eq iswitchb-exit 'takeprompt)
(null iswitchb-matches))
(setq buf-sel iswitchb-final-text)
;; else take head of list
(setq buf-sel (car iswitchb-matches)))
;; Or possibly choose the default buffer
(if (equal iswitchb-final-text "")
(setq buf-sel (car iswitchb-matches)))
buf-sel))
And this is the part of iswitchb-read buffer,which I thought
is responsible for functioning completion mechanism.
(defun iswitchb-read-buffer (prompt &optional default require-match
start matches-set)
(let
(
(iswitchb-minibuf-depth (1+ (minibuffer-depth)))
)
;; prompt the user for the buffer name
(completing-read
prompt ;the prompt
'(("dummy" . 1)) ;table
nil ;predicate
nil ;require-match [handled elsewhere]
start ;initial-contents
'iswitchb-history)))
Eval
(iswitchb-read-buffer "Test: ")
resulting
Test: {buffer1,buffer2,...}
So, I think I'm right.
So,what confused me is how can sexp:
(iswitchb-minibuf-depth (1+ (minibuffer-depth)))
has effect on what echos in minibuffer. Comment this
sexp,or replace iswitchb-minibuffer-depth with another
variable, the completions will disappear.
Any advice?
This variable is used in iswitchb-entryfn-p which is called from iswitchb-minibuffer-setup
(defun iswitchb-minibuffer-setup ()
"Set up minibuffer for `iswitchb-buffer'.
Copied from `icomplete-minibuffer-setup-hook'."
(when (iswitchb-entryfn-p)
(set (make-local-variable 'iswitchb-use-mycompletion) t)
(add-hook 'pre-command-hook 'iswitchb-pre-command nil t)
(add-hook 'post-command-hook 'iswitchb-post-command nil t)
(run-hooks 'iswitchb-minibuffer-setup-hook)))
When iswitchb-minibuf-depth is null then iswitchb-entryfn-p is null and the setup is not done.
The iswitchb-minibuffer-setup is a hook which is added to the iswitchb-mode.
BTW, while this may not directly answer your question, this part of iswitchb's behavior is also provided by icomplete-mode (for the normal completion code).

In emacs, can I set up the *Messages* buffer so that it tails?

Basically I want the *Messages* buffer to always scroll to the bottom when a new message arrives.
Can I do that?
I found auto-revert-tail-mode but that works for buffers that are visiting files.
When I tried it in the Messages buffer, it popped an error:
auto-revert-tail-mode: This buffer is not visiting a file
For multiple frames you probably want:
(defadvice message (after message-tail activate)
"goto point max after a message"
(with-current-buffer "*Messages*"
(goto-char (point-max))
(walk-windows (lambda (window)
(if (string-equal (buffer-name (window-buffer window)) "*Messages*")
(set-window-point window (point-max))))
nil
t)))
Just put point at the end of the buffer M->. If you don't manually move it it will stay there -- IOW, you will always see the tail.
This code seems a bit overkill, but a the simple (goto-char (point-max)) wasn't working for me:
(defadvice message (after message-tail activate)
"goto point max after a message"
(with-current-buffer "*Messages*"
(goto-char (point-max))
(let ((windows (get-buffer-window-list (current-buffer) nil t)))
(while windows
(set-window-point (car windows) (point-max))
(setq windows (cdr windows))))))
Here's an implementation that uses the new advice style.
(defun message-buffer-goto-end-of-buffer (&rest args)
(let* ((win (get-buffer-window "*Messages*"))
(buf (and win (window-buffer win))))
(and win (not (equal (current-buffer) buf))
(set-window-point
win (with-current-buffer buf (point-max))))))
(advice-add 'message :after 'message-buffer-goto-end-of-buffer)
i run 23.3 and there were still way too many occasions where the built-in 'solution' and the orginal defadvice on the message function just didn't cut it, so i wrapped that code in a list / toggle / timer set up and it's working beautifully - no more frustration when debugging!
it's generic, so works on any buffer, although i only really use it for..
(toggle-buffer-tail "*Messages*" "on")
..hope it's useful to someone.
;alist of 'buffer-name / timer' items
(defvar buffer-tail-alist nil)
(defun buffer-tail (name)
"follow buffer tails"
(cond ((or (equal (buffer-name (current-buffer)) name)
(string-match "^ \\*Minibuf.*?\\*$" (buffer-name (current-buffer)))))
((get-buffer name)
(with-current-buffer (get-buffer name)
(goto-char (point-max))
(let ((windows (get-buffer-window-list (current-buffer) nil t)))
(while windows (set-window-point (car windows) (point-max))
(with-selected-window (car windows) (recenter -3)) (setq windows (cdr windows))))))))
(defun toggle-buffer-tail (name &optional force)
"toggle tailing of buffer NAME. when called non-interactively, a FORCE arg of 'on' or 'off' can be used to to ensure a given state for buffer NAME"
(interactive (list (cond ((if name name) (read-from-minibuffer
(concat "buffer name to tail"
(if buffer-tail-alist (concat " (" (caar buffer-tail-alist) ")") "") ": ")
(if buffer-tail-alist (caar buffer-tail-alist)) nil nil
(mapcar '(lambda (x) (car x)) buffer-tail-alist)
(if buffer-tail-alist (caar buffer-tail-alist)))) nil)))
(let ((toggle (cond (force force) ((assoc name buffer-tail-alist) "off") (t "on")) ))
(if (not (or (equal toggle "on") (equal toggle "off")))
(error "invalid 'force' arg. required 'on'/'off'")
(progn
(while (assoc name buffer-tail-alist)
(cancel-timer (cdr (assoc name buffer-tail-alist)))
(setq buffer-tail-alist (remove* name buffer-tail-alist :key 'car :test 'equal)))
(if (equal toggle "on")
(add-to-list 'buffer-tail-alist (cons name (run-at-time t 1 'buffer-tail name))))
(message "toggled 'tail buffer' for '%s' %s" name toggle)))))
edit: changed functionality to display tail at the bottom of the window
Here's an amendment over Peter's / Trey's solutions
(defun modi/messages-auto-tail (&rest _)
"Make *Messages* buffer auto-scroll to the end after each message."
(let* ((buf-name "*Messages*")
;; Create *Messages* buffer if it does not exist
(buf (get-buffer-create buf-name)))
;; Activate this advice only if the point is _not_ in the *Messages* buffer
;; to begin with. This condition is required; otherwise you will not be
;; able to use `isearch' and other stuff within the *Messages* buffer as
;; the point will keep moving to the end of buffer :P
(when (not (string= buf-name (buffer-name)))
;; Go to the end of buffer in all *Messages* buffer windows that are
;; *live* (`get-buffer-window-list' returns a list of only live windows).
(dolist (win (get-buffer-window-list buf-name nil :all-frames))
(with-selected-window win
(goto-char (point-max))))
;; Go to the end of the *Messages* buffer even if it is not in one of
;; the live windows.
(with-current-buffer buf
(goto-char (point-max))))))
(advice-add 'message :after #'modi/messages-auto-tail)