2 ;;; x-dnd.el --- drag and drop support for X.
5 ;; Free Software Foundation, Inc.
7 ;; Author: Jan Dj
\e,Ad
\e(Brv <jan.h.d@swipnet.se>
9 ;; Keywords: window, drag, drop
11 ;; This file is part of GNU Emacs.
13 ;; GNU Emacs is free software; you can redistribute it and/or modify
14 ;; it under the terms of the GNU General Public License as published by
15 ;; the Free Software Foundation; either version 2, or (at your option)
18 ;; GNU Emacs is distributed in the hope that it will be useful,
19 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
20 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
21 ;; GNU General Public License for more details.
23 ;; You should have received a copy of the GNU General Public License
24 ;; along with GNU Emacs; see the file COPYING. If not, write to the
25 ;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
26 ;; Boston, MA 02111-1307, USA.
30 ;; This file provides the drop part only. Currently supported protocols
31 ;; are XDND and the old KDE 1.x protocol.
35 ;;; Customizable variables
38 (defcustom x-dnd-test-function 'x-dnd-default-test-function
39 "The function drag and drop uses to determine if to accept or reject a drop.
40 The function takes three arguments, WINDOW ACTION and TYPES.
41 WINDOW is where the mouse is when the function is called. WINDOW may be a
42 frame if the mouse isn't over a real window (i.e. menu bar, tool bar or
43 scroll bar). ACTION is the suggested action from the drag and drop source,
44 one of the symbols move, copy link or ask. TYPES is a list of available types
47 The function shall return nil to reject the drop or a cons with two values,
48 the wanted action as car and the wanted type as cdr. The wanted action
49 can be copy, move, link, ask or private.
50 The default value for this variable is `x-dnd-default-test-function'."
54 (defcustom x-dnd-protocol-alist
56 ("^file:///" . x-dnd-open-local-file) ; XDND format.
57 ("^file://" . x-dnd-open-file) ; URL with host
58 ("^file:" . x-dnd-open-local-file) ; Old KDE, Motif, Sun
61 "The functions to call for different protocols when a drop is made.
62 This variable is used by `x-dnd-handle-uri-list' and `x-dnd-handle-moz-url'.
63 The list contains of (REGEXP . FUNCTION) pairs.
64 The functions shall take two arguments, URL, which is the URL dropped and
65 ACTION which is the action to be performed for the drop (move, copy, link,
67 If no match is found here, and the value of `browse-url-browser-function'
68 is a pair of (REGEXP . FUNCTION), those regexps are tried for a match.
69 Insertion of text is not handeled by these functions, see `x-dnd-types-alist'
71 The function shall return the action done (move, copy, link or private)
72 if some action was made, or nil if the URL is ignored."
77 (defcustom x-dnd-types-alist
79 ("text/uri-list" . x-dnd-handle-uri-list)
80 ("text/x-moz-url" . x-dnd-handle-moz-url)
81 ("FILE_NAME" . x-dnd-handle-uri-list)
82 ("_NETSCAPE_URL" . x-dnd-handle-uri-list)
83 ("UTF8_STRING" . x-dnd-insert-utf8-text)
84 ("text/plain;charset=UTF-8" . x-dnd-insert-utf8-text)
85 ("text/plain;charset=utf-8" . x-dnd-insert-utf8-text)
86 ("text/unicode" . x-dnd-insert-utf16-text)
87 ("text/plain" . x-dnd-insert-text)
88 ("STRING" . x-dnd-insert-text)
89 ("TEXT" . x-dnd-insert-text)
91 "Which function to call to handle a drop of that type.
92 If the type for the drop is not present, or the function is nil,
93 the drop is rejected. The function takes three arguments, WINDOW, ACTION
94 and DATA. WINDOW is where the drop occured, ACTION is the action for
95 this drop (copy, move, link, private or ask) as determined by a previous
96 call to `x-dnd-test-function'. DATA is the drop data.
97 The function shall return the action used (copy, move, link or private) if drop
98 is successful, nil if not."
102 (defcustom x-dnd-open-file-other-window nil
103 "If non-nil, always use find-file-other-window to open dropped files."
107 ;; Internal variables
109 (defvar x-dnd-known-types
115 "text/plain;charset=UTF-8"
116 "text/plain;charset=utf-8"
122 "The types accepted by default for dropped data.
123 The types are chosen in the order they appear in the list.")
125 (defvar x-dnd-current-state nil
126 "The current state for a drop.
127 This is an alist with one entry for each display. The value for each display
128 is a vector that contains the state for drag and drop for that display.
129 Elements in the vector are:
130 Last buffer drag was in,
131 last window drag was in,
132 types available for drop,
133 the action suggested by the source,
134 the type we want for the drop,
135 the action we want for the drop.")
137 (defvar x-dnd-empty-state [nil nil nil nil nil nil])
141 (defun x-dnd-init-frame (&optional frame)
142 "Setup drag and drop for FRAME (i.e. create appropriate properties)."
143 (x-dnd-init-xdnd-for-frame frame))
145 (defun x-dnd-get-state-cons-for-frame (frame-or-window)
146 "Return the entry in x-dnd-current-state for a frame or window."
147 (let* ((frame (if (framep frame-or-window) frame-or-window
148 (window-frame frame-or-window)))
149 (display (frame-parameter frame 'display)))
150 (if (not (assoc display x-dnd-current-state))
151 (push (cons display x-dnd-empty-state) x-dnd-current-state))
152 (assoc display x-dnd-current-state)))
154 (defun x-dnd-get-state-for-frame (frame-or-window)
155 "Return the state in x-dnd-current-state for a frame or window."
156 (cdr (x-dnd-get-state-cons-for-frame frame-or-window)))
158 (defun x-dnd-default-test-function (window action types)
159 "The default test function for drag and drop.
160 WINDOW is where the mouse is when this function is called. It may be a frame
161 if the mouse is over the menu bar, scroll bar or tool bar.
162 ACTION is the suggested action from the source, and TYPES are the
163 types the drop data can have. This function only accepts drops with
164 types in `x-dnd-known-types'. It always returns the action private."
165 (let ((type (x-dnd-choose-type types)))
166 (when type (cons 'private type))))
169 (defun x-dnd-current-type (frame-or-window)
170 "Return the type we want the DND data to be in for the current drop.
171 FRAME-OR-WINDOW is the frame or window that the mouse is over."
172 (aref (x-dnd-get-state-for-frame frame-or-window) 4))
174 (defun x-dnd-forget-drop (frame-or-window)
175 "Remove all state for the last drop.
176 FRAME-OR-WINDOW is the frame or window that the mouse is over."
177 (setcdr (x-dnd-get-state-cons-for-frame frame-or-window) x-dnd-empty-state))
179 (defun x-dnd-maybe-call-test-function (window action)
180 "Call `x-dnd-test-function' if something has changed.
181 WINDOW is the window the mouse is over. ACTION is the suggested
182 action from the source. If nothing has changed, return the last
183 action and type we got from `x-dnd-test-function'."
184 (let ((buffer (when (and (windowp window) (window-live-p window))
185 (window-buffer window)))
186 (current-state (x-dnd-get-state-for-frame window)))
187 (when (or (not (equal buffer (aref current-state 0)))
188 (not (equal window (aref current-state 1)))
189 (not (equal action (aref current-state 3))))
191 (when buffer (set-buffer buffer))
192 (let* ((action-type (funcall x-dnd-test-function
195 (aref current-state 2)))
196 (handler (cdr (assoc (cdr action-type) x-dnd-types-alist))))
197 ;; Ignore action-type if we have no handler.
199 (x-dnd-save-state window
201 (when handler action-type)))))))
202 (let ((current-state (x-dnd-get-state-for-frame window)))
203 (cons (aref current-state 5)
204 (aref current-state 4))))
206 (defun x-dnd-save-state (window action action-type &optional types)
207 "Save the state of the current drag and drop.
208 WINDOW is the window the mouse is over. ACTION is the action suggested
209 by the source. ACTION-TYPE is the result of calling `x-dnd-test-function'.
210 If given, TYPES are the types for the drop data that the source supports."
211 (let ((current-state (x-dnd-get-state-for-frame window)))
212 (aset current-state 5 (car action-type))
213 (aset current-state 4 (cdr action-type))
214 (aset current-state 3 action)
215 (if types (aset current-state 2 types))
216 (aset current-state 1 window)
217 (aset current-state 0 (if (and (windowp window)
218 (window-live-p window))
219 (window-buffer window) nil))
220 (setcdr (x-dnd-get-state-cons-for-frame window) current-state)))
223 (defun x-dnd-test-and-save-state (window action types)
224 "Test if drop shall be accepted, and save the state for future reference.
225 ACTION is the suggested action by the source.
226 TYPES is a list of types the source supports."
227 (x-dnd-save-state window
229 (x-dnd-maybe-call-test-function window action)
232 (defun x-dnd-handle-one-url (window action arg)
233 "Handle one dropped url by calling the appropriate handler.
234 The handler is first localted by looking at `x-dnd-protocol-alist'.
235 If no match is found here, and the value of `browse-url-browser-function'
236 is a pair of (REGEXP . FUNCTION), those regexps are tried for a match.
237 If no match is found, just call `x-dnd-insert-text'.
238 WINDOW is where the drop happend, ACTION is the action for the drop,
239 ARG is the URL that has been dropped.
241 (require 'browse-url)
242 (let* ((uri (replace-regexp-in-string
245 (format "%c" (string-to-number (substring arg 1) 16)))
250 (dolist (bf x-dnd-protocol-alist)
251 (when (string-match (car bf) uri)
252 (setq ret (funcall (cdr bf) uri action))
255 (when (not (functionp browse-url-browser-function))
257 (dolist (bf browse-url-browser-function)
258 (when (string-match (car bf) uri)
260 (funcall (cdr bf) uri action)
263 (x-dnd-insert-text window action uri))
267 (defun x-dnd-get-local-file-uri (uri)
268 "Return an uri converted to file:/// syntax if uri is a local file.
269 Return nil if URI is not a local file."
271 ;; The hostname may be our hostname, in that case, convert to a local
272 ;; file. Otherwise return nil. TODO: How about an IP-address as hostname?
273 (let ((hostname (when (string-match "^file://\\([^/]*\\)" uri)
274 (downcase (match-string 1 uri))))
276 (downcase (if (string-match "^[^\\.]+" system-name)
277 (match-string 0 system-name)
280 (or (string-equal "localhost" hostname)
281 (string-equal (downcase system-name) hostname)
282 (string-equal system-name-no-dot hostname)))
283 (concat "file://" (substring uri (+ 7 (length hostname)))))))
285 (defun x-dnd-get-local-file-name (uri &optional must-exist)
286 "Return file name converted from file:/// or file: syntax.
287 URI is the uri for the file. If MUST-EXIST is given and non-nil,
288 only return non-nil if the file exists.
289 Return nil if URI is not a local file."
290 (let ((f (cond ((string-match "^file:///" uri) ; XDND format.
291 (substring uri (1- (match-end 0))))
292 ((string-match "^file:" uri) ; Old KDE, Motif, Sun
293 (substring uri (match-end 0)))
295 (when (and f must-exist)
296 (let* ((decoded-f (decode-coding-string
298 (or file-name-coding-system
299 default-file-name-coding-system)))
300 (try-f (if (file-readable-p decoded-f) decoded-f f)))
301 (when (file-readable-p try-f) try-f)))))
304 (defun x-dnd-open-local-file (uri action)
306 The file is opened in the current window, or a new window if
307 `x-dnd-open-file-other-window' is set. URI is the url for the file,
308 and must have the format file:file-name or file:///file-name.
309 The last / in file:/// is part of the file name. ACTION is ignored."
311 (let* ((f (x-dnd-get-local-file-name uri t)))
313 (if (file-readable-p f)
315 (if x-dnd-open-file-other-window
316 (find-file-other-window f)
319 (error "Can not read %s (%s)" f uri)))))
321 (defun x-dnd-open-file (uri action)
322 "Open a local or remote file.
323 The file is opened in the current window, or a new window if
324 `x-dnd-open-file-other-window' is set. URI is the url for the file,
325 and must have the format file://hostname/file-name. ACTION is ignored.
326 The last / in file://hostname/ is part of the file name."
328 ;; The hostname may be our hostname, in that case, convert to a local
329 ;; file. Otherwise return nil.
330 (let ((local-file (x-dnd-get-local-file-uri uri)))
331 (when local-file (x-dnd-open-local-file local-file action))))
334 (defun x-dnd-handle-moz-url (window action data)
335 "Handle one item of type text/x-moz-url.
336 WINDOW is the window where the drop happened. ACTION is ignored.
337 DATA is the moz-url, which is formatted as two strings separated by \r\n.
338 The first string is the URL, the second string is the title of that URL.
339 DATA is encoded in utf-16. Decode the URL and call `x-dnd-handle-uri-list'."
340 (let* ((string (decode-coding-string data 'utf-16le)) ;; ALWAYS LE???
341 (strings (split-string string "[\r\n]" t))
342 ;; Can one drop more than one moz-url ?? Assume not.
344 (title (car (cdr strings))))
345 (x-dnd-handle-uri-list window action url)))
347 (defun x-dnd-insert-utf8-text (window action text)
348 "Decode the UTF-8 text and insert it at point.
349 TEXT is the text as a string, WINDOW is the window where the drop happened."
350 (x-dnd-insert-text window action (decode-coding-string text 'utf-8)))
352 (defun x-dnd-insert-utf16-text (window action text)
353 "Decode the UTF-16 text and insert it at point.
354 TEXT is the text as a string, WINDOW is the window where the drop happened."
355 (x-dnd-insert-text window action (decode-coding-string text 'utf-16le)))
357 (defun x-dnd-insert-text (window action text)
358 "Insert text at point or push to the kill ring if buffer is read only.
359 TEXT is the text as a string, WINDOW is the window where the drop happened."
360 (if (or buffer-read-only
361 (not (windowp window)))
365 (substitute-command-keys
366 "The dropped text can be accessed with \\[yank]")))
370 (defun x-dnd-handle-uri-list (window action string)
371 "Split an uri-list into separate URIs and call `x-dnd-handle-one-url'.
372 WINDOW is the window where the drop happened.
373 STRING is the uri-list as a string. The URIs are separated by \r\n."
374 (let ((uri-list (split-string string "[\0\r\n]" t))
376 (dolist (bf uri-list)
377 ;; If one URL is handeled, treat as if the whole drop succeeded.
378 (let ((did-action (x-dnd-handle-one-url window action bf)))
379 (when did-action (setq retval did-action))))
383 (defun x-dnd-choose-type (types &optional known-types)
384 "Choose which type we want to receive for the drop.
385 TYPES are the types the source of the drop offers, a vector of type names
386 as strings or symbols. Select among the types in `x-dnd-known-types' or
387 KNOWN-TYPES if given, and return that type name.
388 If no suitable type is found, return nil."
389 (let* ((known-list (or known-types x-dnd-known-types))
390 (first-known-type (car known-list))
392 (found (when first-known-type
394 (dotimes (i (length types-array))
395 (let* ((type (aref types-array i))
396 (typename (if (symbolp type)
397 (symbol-name type) type)))
398 (when (equal first-known-type typename)
399 (throw 'done first-known-type))))
402 (if (and (not found) (cdr known-list))
403 (x-dnd-choose-type types (cdr known-list))
406 (defun x-dnd-drop-data (event frame window data type)
407 "Drop one data item onto a frame.
408 EVENT is the client message for the drop, FRAME is the frame the drop occurred
409 on. WINDOW is the window of FRAME where the drop happened. DATA is the data
410 received from the source, and type is the type for DATA, see
411 `x-dnd-types-alist').
413 Returns the action used (move, copy, link, private) if drop was successful,
415 (let* ((type-info (assoc type x-dnd-types-alist))
416 (handler (cdr type-info))
417 (state (x-dnd-get-state-for-frame frame))
418 (action (aref state 5))
419 (w (posn-window (event-start event))))
421 (if (and (windowp w) (window-live-p w))
422 ;; If dropping in a window, open files in that window rather
423 ;; than in a new widow.
424 (let ((x-dnd-open-file-other-window nil))
425 (goto-char (posn-point (event-start event)))
426 (funcall handler window action data))
427 (let ((x-dnd-open-file-other-window t)) ;; Dropping on non-window.
429 (funcall handler window action data))))))
431 (defun x-dnd-handle-drag-n-drop-event (event)
432 "Receive drag and drop events (X client messages).
433 Currently XDND and old KDE 1.x protocols are recognized.
434 TODO: Add Motif and OpenWindows."
436 (let* ((client-message (car (cdr (cdr event))))
437 (window (posn-window (event-start event)))
438 (message-atom (aref client-message 0))
439 (frame (aref client-message 1))
440 (format (aref client-message 2))
441 (data (aref client-message 3)))
443 (cond ((equal "DndProtocol" message-atom) ;; Old KDE 1.x.
444 (x-dnd-handle-old-kde event frame window message-atom format data))
446 ((and (> (length message-atom) 4) ;; XDND protocol.
447 (equal "Xdnd" (substring message-atom 0 4)))
448 (x-dnd-handle-xdnd event frame window message-atom format data))
450 (t (error "Unknown DND atom: %s" message-atom)))))
452 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
453 ;;; Old KDE protocol. Only dropping of files.
455 (defun x-dnd-handle-old-kde (event frame window message format data)
456 "Open the files in a KDE 1.x drop."
457 (let ((values (x-window-property "DndSelection" frame nil 0 t)))
458 (x-dnd-handle-uri-list window 'private
459 (replace-regexp-in-string "\0$" "" values))))
460 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
464 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
467 (defvar x-dnd-xdnd-to-action
468 '(("XdndActionPrivate" . private)
469 ("XdndActionCopy" . copy)
470 ("XdndActionMove" . move)
471 ("XdndActionLink" . link)
472 ("XdndActionAsk" . ask))
473 "Mapping from XDND action types to lisp symbols.")
475 (defun x-dnd-init-xdnd-for-frame (frame)
476 "Set the XdndAware for FRAME to indicate that we do XDND."
477 (x-change-window-property "XdndAware"
478 '(5) ;; The version of XDND we support.
481 (defun x-dnd-get-drop-width-height (frame w accept)
482 "Return the widht/height to be sent in a XDndStatus message.
483 FRAME is the frame and W is the window where the drop happened.
484 If ACCEPT is nil return 0 (empty rectangle),
485 otherwise if W is a window, return its widht/height,
486 otherwise return the frame width/height."
488 (if (windowp w) ;; w is not a window if dropping on the menu bar,
489 ;; scroll bar or tool bar.
490 (let ((edges (window-inside-pixel-edges w)))
492 (- (nth 2 edges) (nth 0 edges)) ;; right - left
493 (- (nth 3 edges) (nth 1 edges)))) ;; bottom - top
494 (cons (frame-pixel-width frame)
495 (frame-pixel-height frame)))
498 (defun x-dnd-get-drop-x-y (frame w)
499 "Return the x/y coordinates to be sent in a XDndStatus message.
500 Coordinates are required to be absolute.
501 FRAME is the frame and W is the window where the drop happened.
502 If W is a window, return its absolute corrdinates,
503 otherwise return the frame coordinates."
504 (let* ((frame-left (frame-parameter frame 'left))
505 ;; If the frame is outside the display, frame-left looks like
506 ;; '(0 -16). Extract the -16.
507 (frame-real-left (if (consp frame-left) (car (cdr frame-left))
509 (frame-top (frame-parameter frame 'top))
510 (frame-real-top (if (consp frame-top) (car (cdr frame-top))
513 (let ((edges (window-inside-pixel-edges w)))
515 (+ frame-real-left (nth 0 edges))
516 (+ frame-real-top (nth 1 edges))))
517 (cons frame-real-left frame-real-top))))
519 (defun x-dnd-handle-xdnd (event frame window message format data)
520 "Receive one XDND event (client message) and send the appropriate reply.
521 EVENT is the client message. FRAME is where the mouse is now.
522 WINDOW is the window within FRAME where the mouse is now.
523 FORMAT is 32 (not used). MESSAGE is the data part of an XClientMessageEvent."
524 (cond ((equal "XdndEnter" message)
525 (let ((version (ash (car (aref data 1)) -8))
526 (more-than-3 (cdr (aref data 1)))
527 (dnd-source (aref data 0)))
530 (if (> more-than-3 0)
531 (x-window-property "XdndTypeList"
532 frame "AnyPropertyType"
534 (vector (x-get-atom-name (aref data 2))
535 (x-get-atom-name (aref data 3))
536 (x-get-atom-name (aref data 4)))))))
538 ((equal "XdndPosition" message)
539 (let* ((x (car (aref data 2)))
540 (y (cdr (aref data 2)))
541 (action (x-get-atom-name (aref data 4)))
542 (dnd-source (aref data 0))
543 (dnd-time (aref data 3))
544 (action-type (x-dnd-maybe-call-test-function
546 (cdr (assoc action x-dnd-xdnd-to-action))))
547 (reply-action (car (rassoc (car action-type)
548 x-dnd-xdnd-to-action)))
549 (accept ;; 1 = accept, 0 = reject
550 (if (and reply-action action-type) 1 0))
552 (list (string-to-number
553 (frame-parameter frame 'outer-window-id))
554 accept ;; 1 = Accept, 0 = reject.
555 (x-dnd-get-drop-x-y frame window)
556 (x-dnd-get-drop-width-height
557 frame window (eq accept 1))
560 (x-send-client-message
561 frame dnd-source frame "XdndStatus" 32 list-to-send)
564 ((equal "XdndLeave" message)
565 (x-dnd-forget-drop window))
567 ((equal "XdndDrop" message)
568 (if (windowp window) (select-window window))
569 (let* ((dnd-source (aref data 0))
570 (value (and (x-dnd-current-type window)
571 ;; Get selection with target DELETE if move.
572 (x-get-selection-internal
574 (intern (x-dnd-current-type window)))))
575 success action ret-action)
577 (setq action (if value
579 (x-dnd-drop-data event frame window value
580 (x-dnd-current-type window))
582 (message "Error: %s" info)
585 (setq success (if action 1 0))
588 (or (car (rassoc action x-dnd-xdnd-to-action))
592 (x-send-client-message
593 frame dnd-source frame "XdndFinished" 32
594 (list (string-to-number (frame-parameter frame 'outer-window-id))
595 success ;; 1 = Success, 0 = Error
596 (if success "XdndActionPrivate" 0)
598 (x-dnd-forget-drop window)))
600 (t (error "Unknown XDND message %s %s" message data))))
605 ;;; x-dnd.el ends here