In display-buffer-record-window record selected window if necessary.
[emacs.git] / lisp / frameset.el
blob17fe39be8448bc5f8362580139f4a0cee0d3c29c
1 ;;; frameset.el --- save and restore frame and window setup -*- lexical-binding: t -*-
3 ;; Copyright (C) 2013-2015 Free Software Foundation, Inc.
5 ;; Author: Juanma Barranquero <lekktu@gmail.com>
6 ;; Keywords: convenience
8 ;; This file is part of GNU Emacs.
10 ;; GNU Emacs is free software: you can redistribute it and/or modify
11 ;; it under the terms of the GNU General Public License as published by
12 ;; the Free Software Foundation, either version 3 of the License, or
13 ;; (at your option) any later version.
15 ;; GNU Emacs is distributed in the hope that it will be useful,
16 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
17 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 ;; GNU General Public License for more details.
20 ;; You should have received a copy of the GNU General Public License
21 ;; along with GNU Emacs. If not, see <http://www.gnu.org/licenses/>.
23 ;;; Commentary:
25 ;; This file provides a set of operations to save a frameset (the state
26 ;; of all or a subset of the existing frames and windows), both
27 ;; in-session and persistently, and restore it at some point in the
28 ;; future.
30 ;; It should be noted that restoring the frames' windows depends on
31 ;; the buffers they are displaying, but this package does not provide
32 ;; any way to save and restore sets of buffers (see desktop.el for
33 ;; that). So, it's up to the user of frameset.el to make sure that
34 ;; any relevant buffer is loaded before trying to restore a frameset.
35 ;; When a window is restored and a buffer is missing, the window will
36 ;; be deleted unless it is the last one in the frame, in which case
37 ;; some previous buffer will be shown instead.
39 ;;; Code:
41 (require 'cl-lib)
44 (cl-defstruct (frameset (:type vector) :named
45 (:constructor frameset--make)
46 ;; Copier is defined below.
47 (:copier nil))
49 "A frameset encapsulates a serializable view of a set of frames and windows.
51 It contains the following slots, which can be accessed with
52 \(frameset-SLOT fs) and set with (setf (frameset-SLOT fs) VALUE):
54 version A read-only version number, identifying the format
55 of the frameset struct. Currently its value is 1.
56 timestamp A read-only timestamp, the output of `current-time'.
57 app A symbol, or a list whose first element is a symbol, which
58 identifies the creator of the frameset and related info;
59 for example, desktop.el sets this slot to a list
60 `(desktop . ,desktop-file-version).
61 name A string, the name of the frameset instance.
62 description A string, a description for user consumption (to show in
63 menus, messages, etc).
64 properties A property list, to store both frameset-specific and
65 user-defined serializable data.
66 states A list of items (FRAME-PARAMETERS . WINDOW-STATE), in no
67 particular order. Each item represents a frame to be
68 restored. FRAME-PARAMETERS is a frame's parameter alist,
69 extracted with (frame-parameters FRAME) and filtered
70 through `frameset-filter-params'.
71 WINDOW-STATE is the output of `window-state-get' applied
72 to the root window of the frame.
74 To avoid collisions, it is recommended that applications wanting to add
75 private serializable data to `properties' either store all info under a
76 single, distinctive name, or use property names with a well-chosen prefix.
78 A frameset is intended to be used through the following simple API:
80 - `frameset-save', the type's constructor, captures all or a subset of the
81 live frames, and returns a serializable snapshot of them (a frameset).
82 - `frameset-restore' takes a frameset, and restores the frames and windows
83 it describes, as faithfully as possible.
84 - `frameset-p' is the predicate for the frameset type.
85 - `frameset-valid-p' checks a frameset's validity.
86 - `frameset-copy' returns a deep copy of a frameset.
87 - `frameset-prop' is a `setf'able accessor for the contents of the
88 `properties' slot.
89 - The `frameset-SLOT' accessors described above."
91 (version 1 :read-only t)
92 (timestamp (current-time) :read-only t)
93 (app nil)
94 (name nil)
95 (description nil)
96 (properties nil)
97 (states nil))
99 ;; Add nicer docstrings for built-in predicate and accessors.
100 (put 'frameset-p 'function-documentation
101 "Return non-nil if OBJECT is a frameset, nil otherwise.\n\n(fn OBJECT)")
102 (put 'frameset-version 'function-documentation
103 "Return the version number of FRAMESET.\n
104 It is an integer that identifies the format of the frameset struct.
105 This slot cannot be modified.\n\n(fn FRAMESET)")
106 (put 'frameset-timestamp 'function-documentation
107 "Return the creation timestamp of FRAMESET.\n
108 The value is in the format returned by `current-time'.
109 This slot cannot be modified.\n\n(fn FRAMESET)")
110 (put 'frameset-app 'function-documentation
111 "Return the application identifier for FRAMESET.\n
112 The value is either a symbol, like `my-app', or a list
113 \(my-app ADDITIONAL-DATA...).\n\n(fn FRAMESET)")
114 (put 'frameset-name 'function-documentation
115 "Return the name of FRAMESET (a string).\n\n(fn FRAMESET)")
116 (put 'frameset-description 'function-documentation
117 "Return the description of FRAMESET (a string).\n\n(fn FRAMESET)")
118 (put 'frameset-properties 'function-documentation
119 "Return the property list of FRAMESET.\n
120 This list is useful to store both frameset-specific and user-defined
121 serializable data. The simplest way to access and modify it is
122 through `frameset-prop' (which see).\n\n(fn FRAMESET)")
123 (put 'frameset-states 'function-documentation
124 "Return the list of frame states of FRAMESET.\n
125 A frame state is a pair (FRAME-PARAMETERS . WINDOW-STATE), where
126 FRAME-PARAMETERS is a frame's parameter alist, extracted with
127 \(frame-parameters FRAME) and filtered through `frameset-filter-params',
128 and WINDOW-STATE is the output of `window-state-get' applied to the
129 root window of the frame.\n
130 IMPORTANT: Modifying this slot may cause frameset functions to fail,
131 unless the type constraints defined above are respected.\n\n(fn FRAMESET)")
133 ;; We autoloaded this for use in register.el, but now that we use registerv
134 ;; objects, this autoload is not useful any more.
135 ;; ;;;###autoload (autoload 'frameset-p "frameset"
136 ;; ;;;###autoload "Return non-nil if OBJECT is a frameset, nil otherwise." nil)
138 (defun frameset-copy (frameset)
139 "Return a deep copy of FRAMESET.
140 FRAMESET is copied with `copy-tree'."
141 (copy-tree frameset t))
143 (defun frameset-valid-p (object)
144 "Return non-nil if OBJECT is a valid frameset, nil otherwise."
145 (and (frameset-p object)
146 (integerp (frameset-version object))
147 (consp (frameset-timestamp object))
148 (let ((app (frameset-app object)))
149 (or (null app) ; APP is nil
150 (symbolp app) ; or a symbol
151 (and (consp app) ; or a list
152 (symbolp (car app))))) ; starting with a symbol
153 (stringp (or (frameset-name object) ""))
154 (stringp (or (frameset-description object) ""))
155 (listp (frameset-properties object))
156 (let ((states (frameset-states object)))
157 (and (listp states)
158 (cl-every #'consp (frameset-states object))))
159 (frameset-version object))) ; And VERSION is non-nil.
161 (defun frameset--prop-setter (frameset property value)
162 "Setter function for `frameset-prop'. Internal use only."
163 (setf (frameset-properties frameset)
164 (plist-put (frameset-properties frameset) property value))
165 value)
167 ;; A setf'able accessor to the frameset's properties
168 (defun frameset-prop (frameset property)
169 "Return the value for FRAMESET of PROPERTY.
171 Properties can be set with
173 (setf (frameset-prop FRAMESET PROPERTY) NEW-VALUE)"
174 (declare (gv-setter frameset--prop-setter))
175 (plist-get (frameset-properties frameset) property))
178 ;; Filtering
180 ;; What's the deal with these "filter alists"?
182 ;; Let's say that Emacs' frame parameters were never designed as a tool to
183 ;; precisely record (or restore) a frame's state. They grew organically,
184 ;; and their uses and behaviors reflect their history. In using them to
185 ;; implement framesets, the unwary implementer, or the prospective package
186 ;; writer willing to use framesets in their code, might fall victim of some
187 ;; unexpected... oddities.
189 ;; You can find frame parameters that:
191 ;; - can be used to get and set some data from the frame's current state
192 ;; (`height', `width')
193 ;; - can be set at creation time, and setting them afterwards has no effect
194 ;; (`window-state', `minibuffer')
195 ;; - can be set at creation time, and setting them afterwards will fail with
196 ;; an error, *unless* you set it to the same value, a noop (`border-width')
197 ;; - act differently when passed at frame creation time, and when set
198 ;; afterwards (`height')
199 ;; - affect the value of other parameters (`name', `visibility')
200 ;; - can be ignored by window managers (most positional args, like `height',
201 ;; `width', `left' and `top', and others, like `auto-raise', `auto-lower')
202 ;; - can be set externally in X resources or Window registry (again, most
203 ;; positional parameters, and also `toolbar-lines', `menu-bar-lines' etc.)
204 ;, - can contain references to live objects (`buffer-list', `minibuffer') or
205 ;; code (`buffer-predicate')
206 ;; - are set automatically, and cannot be changed (`window-id', `parent-id'),
207 ;; but setting them produces no error
208 ;; - have a noticeable effect in some window managers, and are ignored in
209 ;; others (`menu-bar-lines')
210 ;; - can not be safely set in a tty session and then copied back to a GUI
211 ;; session (`font', `background-color', `foreground-color')
213 ;; etc etc.
215 ;; Which means that, in order to save a parameter alist to disk and read it
216 ;; back later to reconstruct a frame, some processing must be done. That's
217 ;; what `frameset-filter-params' and the `frameset-*-filter-alist' variables
218 ;; are for.
220 ;; First, a clarification. The word "filter" in these names refers to both
221 ;; common meanings of filter: to filter out (i.e., to remove), and to pass
222 ;; through a transformation function (think `filter-buffer-substring').
224 ;; `frameset-filter-params' takes a parameter alist PARAMETERS, a filtering
225 ;; alist FILTER-ALIST, and a flag SAVING to indicate whether we are filtering
226 ;; parameters with the intent of saving a frame or restoring it. It then
227 ;; accumulates an output alist, FILTERED, by checking each parameter in
228 ;; PARAMETERS against FILTER-ALIST and obeying any rule found there. The
229 ;; absence of a rule just means the parameter/value pair (called CURRENT in
230 ;; filtering functions) is copied to FILTERED as is. Keyword values :save,
231 ;; :restore and :never tell the function to copy CURRENT to FILTERED in the
232 ;; respective situations, that is, when saving, restoring, or never at all.
233 ;; Values :save and :restore are not used in this package, because usually if
234 ;; you don't want to save a parameter, you don't want to restore it either.
235 ;; But they can be useful, for example, if you already have a saved frameset
236 ;; created with some intent, and want to reuse it for a different objective
237 ;; where the expected parameter list has different requirements.
239 ;; Finally, the value can also be a filtering function, or a filtering
240 ;; function plus some arguments. The function is called for each matching
241 ;; parameter, and receives CURRENT (the parameter/value pair being processed),
242 ;; FILTERED (the output alist so far), PARAMETERS (the full parameter alist),
243 ;; SAVING (the save/restore flag), plus any additional ARGS set along the
244 ;; function in the `frameset-*-filter-alist' entry. The filtering function
245 ;; then has the possibility to pass along CURRENT, or reject it altogether,
246 ;; or pass back a (NEW-PARAM . NEW-VALUE) pair, which does not even need to
247 ;; refer to the same parameter (so you can filter `width' and return `height'
248 ;; and vice versa, if you're feeling silly and want to mess with the user's
249 ;; mind). As a help in deciding what to do, the filtering function has
250 ;; access to PARAMETERS, but must not change it in any way. It also has
251 ;; access to FILTERED, which can be modified at will. This allows two or
252 ;; more filters to coordinate themselves, because in general there's no way
253 ;; to predict the order in which they will be run.
255 ;; So, which parameters are filtered by default, and why? Let's see.
257 ;; - `buffer-list', `buried-buffer-list', `buffer-predicate': They contain
258 ;; references to live objects, or in the case of `buffer-predicate', it
259 ;; could also contain an fbound symbol (a predicate function) that could
260 ;; not be defined in a later session.
262 ;; - `window-id', `outer-window-id', `parent-id': They are assigned
263 ;; automatically and cannot be set, so keeping them is harmless, but they
264 ;; add clutter. `window-system' is similar: it's assigned at frame
265 ;; creation, and does not serve any useful purpose later.
267 ;; - `left', `top': Only problematic when saving an iconified frame, because
268 ;; when the frame is iconified they are set to (- 32000), which doesn't
269 ;; really help in restoring the frame. Better to remove them and let the
270 ;; window manager choose a default position for the frame.
272 ;; - `background-color', `foreground-color': In tty frames they can be set
273 ;; to "unspecified-bg" and "unspecified-fg", which aren't understood on
274 ;; GUI sessions. They have to be filtered out when switching from tty to
275 ;; a graphical display.
277 ;; - `tty', `tty-type': These are tty-specific. When switching to a GUI
278 ;; display they do no harm, but they clutter the parameter alist.
280 ;; - `minibuffer': It can contain a reference to a live window, which cannot
281 ;; be serialized. Because of Emacs' idiosyncratic treatment of this
282 ;; parameter, frames created with (minibuffer . t) have a parameter
283 ;; (minibuffer . #<window...>), while frames created with
284 ;; (minibuffer . #<window...>) have (minibuffer . nil), which is madness
285 ;; but helps to differentiate between minibufferless and "normal" frames.
286 ;; So, changing (minibuffer . #<window...>) to (minibuffer . t) allows
287 ;; Emacs to set up the new frame correctly. Nice, uh?
289 ;; - `name': If this parameter is directly set, `explicit-name' is
290 ;; automatically set to t, and then `name' no longer changes dynamically.
291 ;; So, in general, not saving `name' is the right thing to do, though
292 ;; surely there are applications that will want to override this filter.
294 ;; - `font', `fullscreen', `height' and `width': These parameters suffer
295 ;; from the fact that they are badly mangled when going through a
296 ;; tty session, though not all in the same way. When saving a GUI frame
297 ;; and restoring it in a tty, the height and width of the new frame are
298 ;; those of the tty screen (let's say 80x25, for example); going back
299 ;; to a GUI session means getting frames of the tty screen size (so all
300 ;; your frames are 80 cols x 25 rows). For `fullscreen' there's a
301 ;; similar problem, because a tty frame cannot really be fullscreen or
302 ;; maximized, so the state is lost. The problem with `font' is a bit
303 ;; different, because a valid GUI font spec in `font' turns into
304 ;; (font . "tty") in a tty frame, and when read back into a GUI session
305 ;; it fails because `font's value is no longer a valid font spec.
307 ;; In most cases, the filtering functions just do the obvious thing: remove
308 ;; CURRENT when it is meaningless to keep it, or pass a modified copy if
309 ;; that helps (as in the case of `minibuffer').
311 ;; The exception are the parameters in the last set, which should survive
312 ;; the roundtrip though tty-land. The answer is to add "stashing
313 ;; parameters", working in pairs, to shelve the GUI-specific contents and
314 ;; restore it once we're back in pixel country. That's what functions
315 ;; `frameset-filter-shelve-param' and `frameset-filter-unshelve-param' do.
317 ;; Basically, if you set `frameset-filter-shelve-param' as the filter for
318 ;; a parameter P, it will detect when it is restoring a GUI frame into a
319 ;; tty session, and save P's value in the custom parameter X:P, but only
320 ;; if X:P does not exist already (so it is not overwritten if you enter
321 ;; the tty session more than once). If you're not switching to a tty
322 ;; frame, the filter just passes CURRENT along.
324 ;; The parameter X:P, on the other hand, must have been setup to be
325 ;; filtered by `frameset-filter-unshelve-param', which unshelves the
326 ;; value: if we're entering a GUI session, returns P instead of CURRENT,
327 ;; while in other cases it just passes it along.
329 ;; The only additional trick is that `frameset-filter-shelve-param' does
330 ;; not set P if switching back to GUI and P already has a value, because
331 ;; it assumes that `frameset-filter-unshelve-param' did set it up. And
332 ;; `frameset-filter-unshelve-param', when unshelving P, must look into
333 ;; FILTERED to determine if P has already been set and if so, modify it;
334 ;; else just returns P.
336 ;; Currently, the value of X in X:P is `GUI', but you can use any prefix,
337 ;; by passing its symbol as argument in the filter:
339 ;; (my-parameter frameset-filter-shelve-param MYPREFIX)
341 ;; instead of
343 ;; (my-parameter . frameset-filter-shelve-param)
345 ;; Note that `frameset-filter-unshelve-param' does not need MYPREFIX
346 ;; because it is available from the parameter name in CURRENT. Also note
347 ;; that the colon between the prefix and the parameter name is hardcoded.
348 ;; The reason is that X:P is quite readable, and that the colon is a
349 ;; very unusual character in symbol names, other than in initial position
350 ;; in keywords (emacs -Q has only two such symbols, and one of them is a
351 ;; URL). So the probability of a collision with existing or future
352 ;; symbols is quite insignificant.
354 ;; Now, what about the filter alist variables? There are three of them,
355 ;; though only two sets of parameters:
357 ;; - `frameset-session-filter-alist' contains these filters that allow to
358 ;; save and restore framesets in-session, without the need to serialize
359 ;; the frameset or save it to disk (for example, to save a frameset in a
360 ;; register and restore it later). Filters in this list do not remove
361 ;; live objects, except in `minibuffer', which is dealt especially by
362 ;; `frameset-save' / `frameset-restore'.
364 ;; - `frameset-persistent-filter-alist' is the whole deal. It does all
365 ;; the filtering described above, and the result is ready to be saved on
366 ;; disk without loss of information. That's the format used by the
367 ;; desktop.el package, for example.
369 ;; IMPORTANT: These variables share structure and should NEVER be modified.
371 ;; - `frameset-filter-alist': The value of this variable is the default
372 ;; value for the FILTERS arguments of `frameset-save' and
373 ;; `frameset-restore'. It is set to `frameset-persistent-filter-alist',
374 ;; though it can be changed by specific applications.
376 ;; How to use them?
378 ;; The simplest way is just do nothing. The default should work
379 ;; reasonably and sensibly enough. But, what if you really need a
380 ;; customized filter alist? Then you can create your own variable
382 ;; (defvar my-filter-alist
383 ;; '((my-param1 . :never)
384 ;; (my-param2 . :save)
385 ;; (my-param3 . :restore)
386 ;; (my-param4 . my-filtering-function-without-args)
387 ;; (my-param5 my-filtering-function-with arg1 arg2)
388 ;; ;;; many other parameters
389 ;; )
390 ;; "My customized parameter filter alist.")
392 ;; or, if you're only changing a few items,
394 ;; (defvar my-filter-alist
395 ;; (nconc '((my-param1 . :never)
396 ;; (my-param2 . my-filtering-function))
397 ;; frameset-filter-alist)
398 ;; "My brief customized parameter filter alist.")
400 ;; and pass it to the FILTER arg of the save/restore functions,
401 ;; ALWAYS taking care of not modifying the original lists; if you're
402 ;; going to do any modifying of my-filter-alist, please use
404 ;; (nconc '((my-param1 . :never) ...)
405 ;; (copy-sequence frameset-filter-alist))
407 ;; One thing you shouldn't forget is that they are alists, so searching
408 ;; in them is sequential. If you just want to change the default of
409 ;; `name' to allow it to be saved, you can set (name . nil) in your
410 ;; customized filter alist; it will take precedence over the latter
411 ;; setting. In case you decide that you *always* want to save `name',
412 ;; you can add it to `frameset-filter-alist':
414 ;; (push '(name . nil) frameset-filter-alist)
416 ;; In certain applications, having a parameter filtering function like
417 ;; `frameset-filter-params' can be useful, even if you're not using
418 ;; framesets. The interface of `frameset-filter-params' is generic
419 ;; and does not depend of global state, with one exception: it uses
420 ;; the dynamically bound variable `frameset--target-display' to decide
421 ;; if, and how, to modify the `display' parameter of FILTERED. That
422 ;; should not represent a problem, because it's only meaningful when
423 ;; restoring, and customized uses of `frameset-filter-params' are
424 ;; likely to use their own filter alist and just call
426 ;; (setq my-filtered (frameset-filter-params my-params my-filters t))
428 ;; In case you want to use it with the standard filters, you can
429 ;; wrap the call to `frameset-filter-params' in a let form to bind
430 ;; `frameset--target-display' to nil or the desired value.
433 ;;;###autoload
434 (defvar frameset-session-filter-alist
435 '((name . :never)
436 (left . frameset-filter-iconified)
437 (minibuffer . frameset-filter-minibuffer)
438 (top . frameset-filter-iconified))
439 "Minimum set of parameters to filter for live (on-session) framesets.
440 DO NOT MODIFY. See `frameset-filter-alist' for a full description.")
442 ;;;###autoload
443 (defvar frameset-persistent-filter-alist
444 (nconc
445 '((background-color . frameset-filter-sanitize-color)
446 (buffer-list . :never)
447 (buffer-predicate . :never)
448 (buried-buffer-list . :never)
449 (font . frameset-filter-shelve-param)
450 (foreground-color . frameset-filter-sanitize-color)
451 (fullscreen . frameset-filter-shelve-param)
452 (GUI:font . frameset-filter-unshelve-param)
453 (GUI:fullscreen . frameset-filter-unshelve-param)
454 (GUI:height . frameset-filter-unshelve-param)
455 (GUI:width . frameset-filter-unshelve-param)
456 (height . frameset-filter-shelve-param)
457 (outer-window-id . :never)
458 (parent-id . :never)
459 (tty . frameset-filter-tty-to-GUI)
460 (tty-type . frameset-filter-tty-to-GUI)
461 (width . frameset-filter-shelve-param)
462 (window-id . :never)
463 (window-system . :never))
464 frameset-session-filter-alist)
465 "Parameters to filter for persistent framesets.
466 DO NOT MODIFY. See `frameset-filter-alist' for a full description.")
468 ;;;###autoload
469 (defvar frameset-filter-alist frameset-persistent-filter-alist
470 "Alist of frame parameters and filtering functions.
472 This alist is the default value of the FILTERS argument of
473 `frameset-save' and `frameset-restore' (which see).
475 Initially, `frameset-filter-alist' is set to, and shares the value of,
476 `frameset-persistent-filter-alist'. You can override any item in
477 this alist by `push'ing a new item onto it. If, for some reason, you
478 intend to modify existing values, do
480 (setq frameset-filter-alist (copy-tree frameset-filter-alist))
482 before changing anything.
484 On saving, PARAMETERS is the parameter alist of each frame processed,
485 and FILTERED is the parameter alist that gets saved to the frameset.
487 On restoring, PARAMETERS is the parameter alist extracted from the
488 frameset, and FILTERED is the resulting frame parameter alist used
489 to restore the frame.
491 Elements of `frameset-filter-alist' are conses (PARAM . ACTION),
492 where PARAM is a parameter name (a symbol identifying a frame
493 parameter), and ACTION can be:
495 nil The parameter is copied to FILTERED.
496 :never The parameter is never copied to FILTERED.
497 :save The parameter is copied only when saving the frame.
498 :restore The parameter is copied only when restoring the frame.
499 FILTER A filter function.
501 FILTER can be a symbol FILTER-FUN, or a list (FILTER-FUN ARGS...).
502 FILTER-FUN is invoked with
504 (apply FILTER-FUN CURRENT FILTERED PARAMETERS SAVING ARGS)
506 where
508 CURRENT A cons (PARAM . VALUE), where PARAM is the one being
509 filtered and VALUE is its current value.
510 FILTERED The resulting alist (so far).
511 PARAMETERS The complete alist of parameters being filtered,
512 SAVING Non-nil if filtering before saving state, nil if filtering
513 before restoring it.
514 ARGS Any additional arguments specified in the ACTION.
516 FILTER-FUN is allowed to modify items in FILTERED, but no other arguments.
517 It must return:
518 nil Skip CURRENT (do not add it to FILTERED).
519 t Add CURRENT to FILTERED as is.
520 (NEW-PARAM . NEW-VALUE) Add this to FILTERED instead of CURRENT.
522 Frame parameters not on this alist are passed intact, as if they were
523 defined with ACTION = nil.")
525 ;; Dynamically bound in `frameset-save', `frameset-restore'.
526 (defvar frameset--target-display)
527 ;; Either (display . VALUE) or nil.
528 ;; This refers to the current frame config being processed with
529 ;; `frameset-filter-params' and its auxiliary filtering functions.
530 ;; If nil, there is no need to change the display.
531 ;; If non-nil, display parameter to use when creating the frame.
533 (defun frameset-switch-to-gui-p (parameters)
534 "True when switching to a graphic display.
535 Return non-nil if the parameter alist PARAMETERS describes a frame on a
536 text-only terminal, and the frame is being restored on a graphic display;
537 otherwise return nil. Only meaningful when called from a filtering
538 function in `frameset-filter-alist'."
539 (and frameset--target-display ; we're switching
540 (null (cdr (assq 'display parameters))) ; from a tty
541 (cdr frameset--target-display))) ; to a GUI display
543 (defun frameset-switch-to-tty-p (parameters)
544 "True when switching to a text-only terminal.
545 Return non-nil if the parameter alist PARAMETERS describes a frame on a
546 graphic display, and the frame is being restored on a text-only terminal;
547 otherwise return nil. Only meaningful when called from a filtering
548 function in `frameset-filter-alist'."
549 (and frameset--target-display ; we're switching
550 (cdr (assq 'display parameters)) ; from a GUI display
551 (null (cdr frameset--target-display)))) ; to a tty
553 (defun frameset-filter-tty-to-GUI (_current _filtered parameters saving)
554 "Remove CURRENT when switching from tty to a graphic display.
556 For the meaning of CURRENT, FILTERED, PARAMETERS and SAVING,
557 see `frameset-filter-alist'."
558 (or saving
559 (not (frameset-switch-to-gui-p parameters))))
561 (defun frameset-filter-sanitize-color (current _filtered parameters saving)
562 "When switching to a GUI frame, remove \"unspecified\" colors.
563 Useful as a filter function for tty-specific parameters.
565 For the meaning of CURRENT, FILTERED, PARAMETERS and SAVING,
566 see `frameset-filter-alist'."
567 (or saving
568 (not (frameset-switch-to-gui-p parameters))
569 (not (stringp (cdr current)))
570 (not (string-match-p "^unspecified-[fb]g$" (cdr current)))))
572 (defun frameset-filter-minibuffer (current filtered _parameters saving)
573 "Force the minibuffer parameter to have a sensible value.
575 When saving, convert (minibuffer . #<window>) to (minibuffer . t).
576 When restoring, if there are two copies, keep the one pointing to
577 a live window.
579 For the meaning of CURRENT, FILTERED, PARAMETERS and SAVING,
580 see `frameset-filter-alist'."
581 (let ((value (cdr current)) mini)
582 (cond (saving
583 (if (windowp value) '(minibuffer . t) t))
584 ((setq mini (assq 'minibuffer filtered))
585 (when (windowp value) (setcdr mini value))
586 nil)
587 (t t))))
589 (defun frameset-filter-shelve-param (current _filtered parameters saving
590 &optional prefix)
591 "When switching to a tty frame, save parameter P as PREFIX:P.
592 The parameter can be later restored with `frameset-filter-unshelve-param'.
593 PREFIX defaults to `GUI'.
595 For the meaning of CURRENT, FILTERED, PARAMETERS and SAVING,
596 see `frameset-filter-alist'."
597 (unless prefix (setq prefix 'GUI))
598 (cond (saving t)
599 ((frameset-switch-to-tty-p parameters)
600 (let ((prefix:p (intern (format "%s:%s" prefix (car current)))))
601 (if (assq prefix:p parameters)
603 (cons prefix:p (cdr current)))))
604 ((frameset-switch-to-gui-p parameters)
605 (not (assq (intern (format "%s:%s" prefix (car current))) parameters)))
606 (t t)))
608 (defun frameset-filter-unshelve-param (current filtered parameters saving)
609 "When switching to a GUI frame, restore PREFIX:P parameter as P.
610 CURRENT must be of the form (PREFIX:P . value).
612 For the meaning of CURRENT, FILTERED, PARAMETERS and SAVING,
613 see `frameset-filter-alist'."
614 (or saving
615 (not (frameset-switch-to-gui-p parameters))
616 (let* ((prefix:p (symbol-name (car current)))
617 (p (intern (substring prefix:p
618 (1+ (string-match-p ":" prefix:p)))))
619 (val (cdr current))
620 (found (assq p filtered)))
621 (if (not found)
622 (cons p val)
623 (setcdr found val)
624 nil))))
626 (defun frameset-filter-iconified (_current _filtered parameters saving)
627 "Remove CURRENT when saving an iconified frame.
628 This is used for positional parameters `left' and `top', which are
629 meaningless in an iconified frame, so the frame is restored in a
630 default position.
632 For the meaning of CURRENT, FILTERED, PARAMETERS and SAVING,
633 see `frameset-filter-alist'."
634 (not (and saving (eq (cdr (assq 'visibility parameters)) 'icon))))
636 (defun frameset-filter-params (parameters filter-alist saving)
637 "Filter parameter alist PARAMETERS and return a filtered alist.
638 FILTER-ALIST is an alist of parameter filters, in the format of
639 `frameset-filter-alist' (which see).
640 SAVING is non-nil while filtering parameters to save a frameset,
641 nil while the filtering is done to restore it."
642 (let ((filtered nil))
643 (dolist (current parameters)
644 ;; When saving, the parameter alist is temporary, so modifying it
645 ;; is not a problem. When restoring, the parameter alist is part
646 ;; of a frameset, so we must copy parameters to avoid inadvertent
647 ;; modifications.
648 (pcase (cdr (assq (car current) filter-alist))
649 (`nil
650 (push (if saving current (copy-tree current)) filtered))
651 (:never
652 nil)
653 (:restore
654 (unless saving (push (copy-tree current) filtered)))
655 (:save
656 (when saving (push current filtered)))
657 ((or `(,fun . ,args) (and fun (pred fboundp)))
658 (let* ((this (apply fun current filtered parameters saving args))
659 (val (if (eq this t) current this)))
660 (when val
661 (push (if saving val (copy-tree val)) filtered))))
662 (other
663 (delay-warning 'frameset (format "Unknown filter %S" other) :error))))
664 ;; Set the display parameter after filtering, so that filter functions
665 ;; have access to its original value.
666 (when frameset--target-display
667 (setf (alist-get 'display filtered) (cdr frameset--target-display)))
668 filtered))
671 ;; Frame ids
673 (defun frameset--set-id (frame)
674 "Set FRAME's id if not yet set.
675 Internal use only."
676 (unless (frame-parameter frame 'frameset--id)
677 (set-frame-parameter frame
678 'frameset--id
679 (mapconcat (lambda (n) (format "%04X" n))
680 (cl-loop repeat 4 collect (random 65536))
681 "-"))))
683 (defun frameset-cfg-id (frame-cfg)
684 "Return the frame id for frame configuration FRAME-CFG."
685 (cdr (assq 'frameset--id frame-cfg)))
687 ;;;###autoload
688 (defun frameset-frame-id (frame)
689 "Return the frame id of FRAME, if it has one; else, return nil.
690 A frame id is a string that uniquely identifies a frame.
691 It is persistent across `frameset-save' / `frameset-restore'
692 invocations, and once assigned is never changed unless the same
693 frame is duplicated (via `frameset-restore'), in which case the
694 newest frame keeps the id and the old frame's is set to nil."
695 (frame-parameter frame 'frameset--id))
697 ;;;###autoload
698 (defun frameset-frame-id-equal-p (frame id)
699 "Return non-nil if FRAME's id matches ID."
700 (string= (frameset-frame-id frame) id))
702 ;;;###autoload
703 (defun frameset-frame-with-id (id &optional frame-list)
704 "Return the live frame with id ID, if exists; else nil.
705 If FRAME-LIST is a list of frames, check these frames only.
706 If nil, check all live frames."
707 (cl-find-if (lambda (f)
708 (and (frame-live-p f)
709 (frameset-frame-id-equal-p f id)))
710 (or frame-list (frame-list))))
713 ;; Saving framesets
715 (defun frameset--record-minibuffer-relationships (frame-list)
716 "Process FRAME-LIST and record minibuffer relationships.
717 FRAME-LIST is a list of frames. Internal use only."
718 ;; Record frames with their own minibuffer
719 (dolist (frame (minibuffer-frame-list))
720 (when (memq frame frame-list)
721 (frameset--set-id frame)
722 ;; For minibuffer-owning frames, frameset--mini is a cons
723 ;; (t . DEFAULT?), where DEFAULT? is a boolean indicating whether
724 ;; the frame is the one pointed out by `default-minibuffer-frame'.
725 (set-frame-parameter frame
726 'frameset--mini
727 (cons t (eq frame default-minibuffer-frame)))))
728 ;; Now link minibufferless frames with their minibuffer frames
729 (dolist (frame frame-list)
730 (unless (frame-parameter frame 'frameset--mini)
731 (frameset--set-id frame)
732 (let ((mb-frame (window-frame (minibuffer-window frame))))
733 ;; For minibufferless frames, frameset--mini is a cons
734 ;; (nil . FRAME-ID), where FRAME-ID is the frameset--id of
735 ;; the frame containing its minibuffer window.
736 ;; FRAME-ID can be set to nil, if FRAME-LIST doesn't contain
737 ;; the minibuffer frame of a minibufferless frame; we allow
738 ;; it without trying to second-guess the user.
739 (set-frame-parameter frame
740 'frameset--mini
741 (cons nil
742 (and mb-frame
743 (frameset-frame-id mb-frame))))))))
745 ;;;###autoload
746 (cl-defun frameset-save (frame-list
747 &key app name description
748 filters predicate properties)
749 "Return a frameset for FRAME-LIST, a list of frames.
750 Dead frames and non-frame objects are silently removed from the list.
751 If nil, FRAME-LIST defaults to the output of `frame-list' (all live frames).
752 APP, NAME and DESCRIPTION are optional data; see the docstring of the
753 `frameset' defstruct for details.
754 FILTERS is an alist of parameter filters; if nil, the value of the variable
755 `frameset-filter-alist' is used instead.
756 PREDICATE is a predicate function, which must return non-nil for frames that
757 should be saved; if PREDICATE is nil, all frames from FRAME-LIST are saved.
758 PROPERTIES is a user-defined property list to add to the frameset."
759 (let* ((list (or (copy-sequence frame-list) (frame-list)))
760 (frameset--target-display nil)
761 (frames (cl-delete-if-not #'frame-live-p
762 (if predicate
763 (cl-delete-if-not predicate list)
764 list)))
766 (frameset--record-minibuffer-relationships frames)
767 (setq fs (frameset--make
768 :app app
769 :name name
770 :description description
771 :properties properties
772 :states (mapcar
773 (lambda (frame)
774 (cons
775 (frameset-filter-params (frame-parameters frame)
776 (or filters
777 frameset-filter-alist)
779 (window-state-get (frame-root-window frame) t)))
780 frames)))
781 (cl-assert (frameset-valid-p fs))
782 fs))
785 ;; Restoring framesets
787 ;; Dynamically bound in `frameset-restore'.
788 (defvar frameset--reuse-list)
789 (defvar frameset--action-map)
791 (defun frameset-compute-pos (value left/top right/bottom)
792 "Return an absolute positioning value for a frame.
793 VALUE is the value of a positional frame parameter (`left' or `top').
794 If VALUE is relative to the screen edges (like (+ -35) or (-200), it is
795 converted to absolute by adding it to the corresponding edge; if it is
796 an absolute position, it is returned unmodified.
797 LEFT/TOP and RIGHT/BOTTOM indicate the dimensions of the screen in
798 pixels along the relevant direction: either the position of the left
799 and right edges for a `left' positional parameter, or the position of
800 the top and bottom edges for a `top' parameter."
801 (pcase value
802 (`(+ ,val) (+ left/top val))
803 (`(- ,val) (+ right/bottom val))
804 (val val)))
806 (defun frameset-move-onscreen (frame force-onscreen)
807 "If FRAME is offscreen, move it back onscreen and, if necessary, resize it.
808 For the description of FORCE-ONSCREEN, see `frameset-restore'.
809 When forced onscreen, frames wider than the monitor's workarea are converted
810 to fullwidth, and frames taller than the workarea are converted to fullheight.
811 NOTE: This only works for non-iconified frames."
812 (pcase-let* ((`(,left ,top ,width ,height) (cl-cdadr (frame-monitor-attributes frame)))
813 (right (+ left width -1))
814 (bottom (+ top height -1))
815 (fr-left (frameset-compute-pos (frame-parameter frame 'left) left right))
816 (fr-top (frameset-compute-pos (frame-parameter frame 'top) top bottom))
817 (ch-width (frame-char-width frame))
818 (ch-height (frame-char-height frame))
819 (fr-width (max (frame-pixel-width frame) (* ch-width (frame-width frame))))
820 (fr-height (max (frame-pixel-height frame) (* ch-height (frame-height frame))))
821 (fr-right (+ fr-left fr-width -1))
822 (fr-bottom (+ fr-top fr-height -1)))
823 (when (pcase force-onscreen
824 ;; A predicate.
825 ((pred functionp)
826 (funcall force-onscreen
827 frame
828 (list fr-left fr-top fr-width fr-height)
829 (list left top width height)))
830 ;; Any corner is outside the screen.
831 (:all (or (< fr-bottom top) (> fr-bottom bottom)
832 (< fr-left left) (> fr-left right)
833 (< fr-right left) (> fr-right right)
834 (< fr-top top) (> fr-top bottom)))
835 ;; Displaced to the left, right, above or below the screen.
836 (`t (or (> fr-left right)
837 (< fr-right left)
838 (> fr-top bottom)
839 (< fr-bottom top)))
840 ;; Fully inside, no need to do anything.
841 (_ nil))
842 (let ((fullwidth (> fr-width width))
843 (fullheight (> fr-height height))
844 (params nil))
845 ;; Position frame horizontally.
846 (cond (fullwidth
847 (push `(left . ,left) params))
848 ((> fr-right right)
849 (push `(left . ,(+ left (- width fr-width))) params))
850 ((< fr-left left)
851 (push `(left . ,left) params)))
852 ;; Position frame vertically.
853 (cond (fullheight
854 (push `(top . ,top) params))
855 ((> fr-bottom bottom)
856 (push `(top . ,(+ top (- height fr-height))) params))
857 ((< fr-top top)
858 (push `(top . ,top) params)))
859 ;; Compute fullscreen state, if required.
860 (when (or fullwidth fullheight)
861 (push (cons 'fullscreen
862 (cond ((not fullwidth) 'fullheight)
863 ((not fullheight) 'fullwidth)
864 (t 'maximized)))
865 params))
866 ;; Finally, move the frame back onscreen.
867 (when params
868 (modify-frame-parameters frame params))))))
870 (defun frameset--find-frame-if (predicate display &rest args)
871 "Find a reusable frame satisfying PREDICATE.
872 Look through available frames whose display property matches DISPLAY
873 and return the first one for which (PREDICATE frame ARGS) returns t.
874 If PREDICATE is nil, it is always satisfied. Internal use only."
875 (cl-find-if (lambda (frame)
876 (and (equal (frame-parameter frame 'display) display)
877 (or (null predicate)
878 (apply predicate frame args))))
879 frameset--reuse-list))
881 (defun frameset--reuse-frame (display parameters)
882 "Return an existing frame to reuse, or nil if none found.
883 DISPLAY is the display where the frame will be shown, and PARAMETERS
884 is the parameter alist of the frame being restored. Internal use only."
885 (let ((frame nil)
886 mini)
887 ;; There are no fancy heuristics there. We could implement some
888 ;; based on frame size and/or position, etc., but it is not clear
889 ;; that any "gain" (in the sense of reduced flickering, etc.) is
890 ;; worth the added complexity. In fact, the code below mainly
891 ;; tries to work nicely when M-x desktop-read is used after a
892 ;; desktop session has already been loaded. The other main use
893 ;; case, which is the initial desktop-read upon starting Emacs,
894 ;; will usually have only one frame, and should already work.
895 (cond ((null display)
896 ;; When the target is tty, every existing frame is reusable.
897 (setq frame (frameset--find-frame-if nil display)))
898 ((car (setq mini (cdr (assq 'frameset--mini parameters))))
899 ;; If the frame has its own minibuffer, let's see whether
900 ;; that frame has already been loaded (which can happen after
901 ;; M-x desktop-read).
902 (setq frame (frameset--find-frame-if
903 (lambda (f id)
904 (frameset-frame-id-equal-p f id))
905 display (frameset-cfg-id parameters)))
906 ;; If it has not been loaded, and it is not a minibuffer-only frame,
907 ;; let's look for an existing non-minibuffer-only frame to reuse.
908 (unless (or frame (eq (cdr (assq 'minibuffer parameters)) 'only))
909 (setq frame (frameset--find-frame-if
910 (lambda (f)
911 (let ((w (frame-parameter f 'minibuffer)))
912 (and (window-live-p w)
913 (window-minibuffer-p w)
914 (eq (window-frame w) f))))
915 display))))
916 (mini
917 ;; For minibufferless frames, check whether they already exist,
918 ;; and that they are linked to the right minibuffer frame.
919 (setq frame (frameset--find-frame-if
920 (lambda (f id mini-id)
921 (and (frameset-frame-id-equal-p f id)
922 (or (null mini-id) ; minibuffer frame not saved
923 (frameset-frame-id-equal-p
924 (window-frame (minibuffer-window f))
925 mini-id))))
926 display (frameset-cfg-id parameters) (cdr mini))))
928 ;; Default to just finding a frame in the same display.
929 (setq frame (frameset--find-frame-if nil display))))
930 ;; If found, remove from the list.
931 (when frame
932 (setq frameset--reuse-list (delq frame frameset--reuse-list)))
933 frame))
935 (defun frameset--initial-params (parameters)
936 "Return a list of PARAMETERS that must be set when creating the frame.
937 Setting position and size parameters as soon as possible helps reducing
938 flickering; other parameters, like `minibuffer' and `border-width', can
939 not be changed once the frame has been created. Internal use only."
940 (cl-loop for param in '(left top width height border-width minibuffer)
941 when (assq param parameters) collect it))
943 (defun frameset--restore-frame (parameters window-state filters force-onscreen)
944 "Set up and return a frame according to its saved state.
945 That means either reusing an existing frame or creating one anew.
946 PARAMETERS is the frame's parameter alist; WINDOW-STATE is its window state.
947 For the meaning of FILTERS and FORCE-ONSCREEN, see `frameset-restore'.
948 Internal use only."
949 (let* ((fullscreen (cdr (assq 'fullscreen parameters)))
950 (filtered-cfg (frameset-filter-params parameters filters nil))
951 (display (cdr (assq 'display filtered-cfg))) ;; post-filtering
952 alt-cfg frame)
954 (when fullscreen
955 ;; Currently Emacs has the limitation that it does not record the size
956 ;; and position of a frame before maximizing it, so we cannot save &
957 ;; restore that info. Instead, when restoring, we resort to creating
958 ;; invisible "fullscreen" frames of default size and then maximizing them
959 ;; (and making them visible) which at least is somewhat user-friendly
960 ;; when these frames are later de-maximized.
961 (let ((width (and (eq fullscreen 'fullheight) (cdr (assq 'width filtered-cfg))))
962 (height (and (eq fullscreen 'fullwidth) (cdr (assq 'height filtered-cfg))))
963 (visible (assq 'visibility filtered-cfg)))
964 (setq filtered-cfg (cl-delete-if (lambda (p)
965 (memq p '(visibility fullscreen width height)))
966 filtered-cfg :key #'car))
967 (when width
968 (setq filtered-cfg (append `((user-size . t) (width . ,width))
969 filtered-cfg)))
970 (when height
971 (setq filtered-cfg (append `((user-size . t) (height . ,height))
972 filtered-cfg)))
973 ;; These are parameters to apply after creating/setting the frame.
974 (push visible alt-cfg)
975 (push (cons 'fullscreen fullscreen) alt-cfg)))
977 ;; Time to find or create a frame and apply the big bunch of parameters.
978 (setq frame (and frameset--reuse-list
979 (frameset--reuse-frame display filtered-cfg)))
980 (if frame
981 (puthash frame :reused frameset--action-map)
982 ;; If a frame needs to be created and it falls partially or fully offscreen,
983 ;; sometimes it gets "pushed back" onscreen; however, moving it afterwards is
984 ;; allowed. So we create the frame as invisible and then reapply the full
985 ;; parameter alist (including position and size parameters).
986 (setq frame (make-frame-on-display display
987 (cons '(visibility)
988 (frameset--initial-params filtered-cfg))))
989 (puthash frame :created frameset--action-map))
991 (modify-frame-parameters frame
992 (if (eq (frame-parameter frame 'fullscreen) fullscreen)
993 ;; Workaround for bug#14949
994 (assq-delete-all 'fullscreen filtered-cfg)
995 filtered-cfg))
997 ;; If requested, force frames to be onscreen.
998 (when (and force-onscreen
999 ;; FIXME: iconified frames should be checked too,
1000 ;; but it is impossible without deiconifying them.
1001 (not (eq (frame-parameter frame 'visibility) 'icon)))
1002 (frameset-move-onscreen frame force-onscreen))
1004 ;; Let's give the finishing touches (visibility, maximization).
1005 (when alt-cfg (modify-frame-parameters frame alt-cfg))
1006 ;; Now restore window state.
1007 (window-state-put window-state (frame-root-window frame) 'safe)
1008 frame))
1010 (defun frameset--minibufferless-last-p (state1 state2)
1011 "Predicate to sort frame states in an order suitable for creating frames.
1012 It sorts minibuffer-owning frames before minibufferless ones.
1013 Internal use only."
1014 (pcase-let ((`(,hasmini1 ,id-def1) (assq 'frameset--mini (car state1)))
1015 (`(,hasmini2 ,id-def2) (assq 'frameset--mini (car state2))))
1016 (cond ((eq id-def1 t) t)
1017 ((eq id-def2 t) nil)
1018 ((not (eq hasmini1 hasmini2)) (eq hasmini1 t))
1019 ((eq hasmini1 nil) (or id-def1 id-def2))
1020 (t t))))
1022 (defun frameset-keep-original-display-p (force-display)
1023 "True if saved frames' displays should be honored.
1024 For the meaning of FORCE-DISPLAY, see `frameset-restore'."
1025 (cond ((eq system-type 'windows-nt) nil) ;; Does ns support more than one display?
1026 ((daemonp) t)
1027 (t (not force-display))))
1029 (defun frameset-minibufferless-first-p (frame1 _frame2)
1030 "Predicate to sort minibufferless frames before other frames."
1031 (not (frame-parameter frame1 'minibuffer)))
1033 ;;;###autoload
1034 (cl-defun frameset-restore (frameset
1035 &key predicate filters reuse-frames
1036 force-display force-onscreen
1037 cleanup-frames)
1038 "Restore a FRAMESET into the current display(s).
1040 PREDICATE is a function called with two arguments, the parameter alist
1041 and the window-state of the frame being restored, in that order (see
1042 the docstring of the `frameset' defstruct for additional details).
1043 If PREDICATE returns nil, the frame described by that parameter alist
1044 and window-state is not restored.
1046 FILTERS is an alist of parameter filters; if nil, the value of
1047 `frameset-filter-alist' is used instead.
1049 REUSE-FRAMES selects the policy to reuse frames when restoring:
1050 t All existing frames can be reused.
1051 nil No existing frame can be reused.
1052 match Only frames with matching frame ids can be reused.
1053 PRED A predicate function; it receives as argument a live frame,
1054 and must return non-nil to allow reusing it, nil otherwise.
1056 FORCE-DISPLAY can be:
1057 t Frames are restored in the current display.
1058 nil Frames are restored, if possible, in their original displays.
1059 delete Frames in other displays are deleted instead of restored.
1060 PRED A function called with two arguments, the parameter alist and
1061 the window state (in that order). It must return t, nil or
1062 `delete', as above but affecting only the frame that will
1063 be created from that parameter alist.
1065 FORCE-ONSCREEN can be:
1066 t Force onscreen only those frames that are fully offscreen.
1067 nil Do not force any frame back onscreen.
1068 all Force onscreen any frame fully or partially offscreen.
1069 PRED A function called with three arguments,
1070 - the live frame just restored,
1071 - a list (LEFT TOP WIDTH HEIGHT), describing the frame,
1072 - a list (LEFT TOP WIDTH HEIGHT), describing the workarea.
1073 It must return non-nil to force the frame onscreen, nil otherwise.
1075 CLEANUP-FRAMES allows to \"clean up\" the frame list after restoring a frameset:
1076 t Delete all frames that were not created or restored upon.
1077 nil Keep all frames.
1078 FUNC A function called with two arguments:
1079 - FRAME, a live frame.
1080 - ACTION, which can be one of
1081 :rejected Frame existed, but was not a candidate for reuse.
1082 :ignored Frame existed, was a candidate, but wasn't reused.
1083 :reused Frame existed, was a candidate, and restored upon.
1084 :created Frame didn't exist, was created and restored upon.
1085 Return value is ignored.
1087 Note the timing and scope of the operations described above: REUSE-FRAMES
1088 affects existing frames; PREDICATE, FILTERS and FORCE-DISPLAY affect the frame
1089 being restored before that happens; FORCE-ONSCREEN affects the frame once
1090 it has been restored; and CLEANUP-FRAMES affects all frames alive after the
1091 restoration, including those that have been reused or created anew.
1093 All keyword parameters default to nil."
1095 (cl-assert (frameset-valid-p frameset))
1097 (let* ((frames (frame-list))
1098 (frameset--action-map (make-hash-table :test #'eq))
1099 ;; frameset--reuse-list is a list of frames potentially reusable. Later we
1100 ;; will decide which ones can be reused, and how to deal with any leftover.
1101 (frameset--reuse-list
1102 (pcase reuse-frames
1104 frames)
1105 (`nil
1106 nil)
1107 (`match
1108 (cl-loop for (state) in (frameset-states frameset)
1109 when (frameset-frame-with-id (frameset-cfg-id state) frames)
1110 collect it))
1111 ((pred functionp)
1112 (cl-remove-if-not reuse-frames frames))
1114 (error "Invalid arg :reuse-frames %s" reuse-frames)))))
1116 ;; Mark existing frames in the map; candidates to reuse are marked as :ignored;
1117 ;; they will be reassigned later, if chosen.
1118 (dolist (frame frames)
1119 (puthash frame
1120 (if (memq frame frameset--reuse-list) :ignored :rejected)
1121 frameset--action-map))
1123 ;; Sort saved states to guarantee that minibufferless frames will be created
1124 ;; after the frames that contain their minibuffer windows.
1125 (dolist (state (sort (copy-sequence (frameset-states frameset))
1126 #'frameset--minibufferless-last-p))
1127 (pcase-let ((`(,frame-cfg . ,window-cfg) state))
1128 (when (or (null predicate) (funcall predicate frame-cfg window-cfg))
1129 (condition-case-unless-debug err
1130 (let* ((d-mini (cdr (assq 'frameset--mini frame-cfg)))
1131 (mb-id (cdr d-mini))
1132 (default (and (car d-mini) mb-id))
1133 (force-display (if (functionp force-display)
1134 (funcall force-display frame-cfg window-cfg)
1135 force-display))
1136 (frameset--target-display nil)
1137 frame to-tty duplicate)
1138 ;; Only set target if forcing displays and the target display is different.
1139 (unless (or (frameset-keep-original-display-p force-display)
1140 (equal (frame-parameter nil 'display)
1141 (cdr (assq 'display frame-cfg))))
1142 (setq frameset--target-display (cons 'display
1143 (frame-parameter nil 'display))
1144 to-tty (null (cdr frameset--target-display))))
1145 ;; Time to restore frames and set up their minibuffers as they were.
1146 ;; We only skip a frame (thus deleting it) if either:
1147 ;; - we're switching displays, and the user chose the option to delete, or
1148 ;; - we're switching to tty, and the frame to restore is minibuffer-only.
1149 (unless (and frameset--target-display
1150 (or (eq force-display 'delete)
1151 (and to-tty
1152 (eq (cdr (assq 'minibuffer frame-cfg)) 'only))))
1153 ;; To avoid duplicating frame ids after restoration, we note any
1154 ;; existing frame whose id matches a frame configuration in the
1155 ;; frameset. Once the frame config is properly restored, we can
1156 ;; reset the old frame's id to nil.
1157 (setq duplicate (frameset-frame-with-id (frameset-cfg-id frame-cfg)
1158 frames))
1159 ;; Restore minibuffers. Some of this stuff could be done in a filter
1160 ;; function, but it would be messy because restoring minibuffers affects
1161 ;; global state; it's best to do it here than add a bunch of global
1162 ;; variables to pass info back-and-forth to/from the filter function.
1163 (cond
1164 ((null d-mini)) ;; No frameset--mini. Process as normal frame.
1165 (to-tty) ;; Ignore minibuffer stuff and process as normal frame.
1166 ((car d-mini) ;; Frame has minibuffer (or it is minibuffer-only).
1167 (when (eq (cdr (assq 'minibuffer frame-cfg)) 'only)
1168 (setq frame-cfg (append '((tool-bar-lines . 0) (menu-bar-lines . 0))
1169 frame-cfg))))
1170 (t ;; Frame depends on other frame's minibuffer window.
1171 (when mb-id
1172 (let ((mb-frame (frameset-frame-with-id mb-id))
1173 (mb-window nil))
1174 (if (not mb-frame)
1175 (delay-warning 'frameset
1176 (format "Minibuffer frame %S not found" mb-id)
1177 :warning)
1178 (setq mb-window (minibuffer-window mb-frame))
1179 (unless (and (window-live-p mb-window)
1180 (window-minibuffer-p mb-window))
1181 (delay-warning 'frameset
1182 (format "Not a minibuffer window %s" mb-window)
1183 :warning)
1184 (setq mb-window nil)))
1185 (when mb-window
1186 (push (cons 'minibuffer mb-window) frame-cfg))))))
1187 ;; OK, we're ready at last to create (or reuse) a frame and
1188 ;; restore the window config.
1189 (setq frame (frameset--restore-frame frame-cfg window-cfg
1190 (or filters frameset-filter-alist)
1191 force-onscreen))
1192 ;; Now reset any duplicate frameset--id
1193 (when (and duplicate (not (eq frame duplicate)))
1194 (set-frame-parameter duplicate 'frameset--id nil))
1195 ;; Set default-minibuffer if required.
1196 (when default (setq default-minibuffer-frame frame))))
1197 (error
1198 (delay-warning 'frameset (error-message-string err) :error))))))
1200 ;; In case we try to delete the initial frame, we want to make sure that
1201 ;; other frames are already visible (discussed in thread for bug#14841).
1202 (sit-for 0 t)
1204 ;; Clean up the frame list
1205 (when cleanup-frames
1206 (let ((map nil)
1207 (cleanup (if (eq cleanup-frames t)
1208 (lambda (frame action)
1209 (when (memq action '(:rejected :ignored))
1210 (delete-frame frame)))
1211 cleanup-frames)))
1212 (maphash (lambda (frame _action) (push frame map)) frameset--action-map)
1213 (dolist (frame (sort map
1214 ;; Minibufferless frames must go first to avoid
1215 ;; errors when attempting to delete a frame whose
1216 ;; minibuffer window is used by another frame.
1217 #'frameset-minibufferless-first-p))
1218 (condition-case-unless-debug err
1219 (funcall cleanup frame (gethash frame frameset--action-map))
1220 (error
1221 (delay-warning 'frameset (error-message-string err) :warning))))))
1223 ;; Make sure there's at least one visible frame.
1224 (unless (or (daemonp)
1225 (catch 'visible
1226 (maphash (lambda (frame _)
1227 (and (frame-live-p frame) (frame-visible-p frame)
1228 (throw 'visible t)))
1229 frameset--action-map)))
1230 (make-frame-visible (selected-frame)))))
1233 ;; Register support
1235 ;;;###autoload
1236 (defun frameset--jump-to-register (data)
1237 "Restore frameset from DATA stored in register.
1238 Called from `jump-to-register'. Internal use only."
1239 (frameset-restore
1240 (aref data 0)
1241 :filters frameset-session-filter-alist
1242 :reuse-frames (if current-prefix-arg t 'match)
1243 :cleanup-frames (if current-prefix-arg
1244 ;; delete frames
1246 ;; iconify frames
1247 (lambda (frame action)
1248 (pcase action
1249 (`rejected (iconify-frame frame))
1250 ;; In the unexpected case that a frame was a candidate
1251 ;; (matching frame id) and yet not restored, remove it
1252 ;; because it is in fact a duplicate.
1253 (`ignored (delete-frame frame))))))
1255 ;; Restore selected frame, buffer and point.
1256 (let ((frame (frameset-frame-with-id (aref data 1)))
1257 buffer window)
1258 (when frame
1259 (select-frame-set-input-focus frame)
1260 (when (and (buffer-live-p (setq buffer (marker-buffer (aref data 2))))
1261 (window-live-p (setq window (get-buffer-window buffer frame))))
1262 (set-frame-selected-window frame window)
1263 (with-current-buffer buffer (goto-char (aref data 2)))))))
1265 ;;;###autoload
1266 (defun frameset--print-register (data)
1267 "Print basic info about frameset stored in DATA.
1268 Called from `list-registers' and `view-register'. Internal use only."
1269 (let* ((fs (aref data 0))
1270 (ns (length (frameset-states fs))))
1271 (princ (format "a frameset (%d frame%s, saved on %s)."
1273 (if (= 1 ns) "" "s")
1274 (format-time-string "%c" (frameset-timestamp fs))))))
1276 ;;;###autoload
1277 (defun frameset-to-register (register)
1278 "Store the current frameset in register REGISTER.
1279 Use \\[jump-to-register] to restore the frameset.
1280 Argument is a character, naming the register.
1282 Interactively, reads the register using `register-read-with-preview'."
1283 (interactive (list (register-read-with-preview "Frameset to register: ")))
1284 (set-register register
1285 (registerv-make
1286 (vector (frameset-save nil
1287 :app 'register
1288 :filters frameset-session-filter-alist)
1289 ;; frameset-save does not include the value of point
1290 ;; in the current buffer, so record that separately.
1291 (frameset-frame-id nil)
1292 (point-marker))
1293 :print-func #'frameset--print-register
1294 :jump-func #'frameset--jump-to-register)))
1296 (provide 'frameset)
1298 ;;; frameset.el ends here