lisp/x-dnd.el

   1 ;;; x-dnd.el --- drag and drop support for X  -*- coding: utf-8 -*-
   2
   3 ;; Copyright (C) 2004-2015 Free Software Foundation, Inc.
   4
   5 ;; Author: Jan Djärv <jan.h.d@swipnet.se>
   6 ;; Maintainer: emacs-devel@gnu.org
   7 ;; Keywords: window, drag, drop
   8 ;; Package: emacs
   9
  10 ;; This file is part of GNU Emacs.
  11
  12 ;; GNU Emacs is free software: you can redistribute it and/or modify
  13 ;; it under the terms of the GNU General Public License as published by
  14 ;; the Free Software Foundation, either version 3 of the License, or
  15 ;; (at your option) any later version.
  16
  17 ;; GNU Emacs is distributed in the hope that it will be useful,
  18 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  19 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  20 ;; GNU General Public License for more details.
  21
  22 ;; You should have received a copy of the GNU General Public License
  23 ;; along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.
  24
  25 ;;; Commentary:
  26
  27 ;; This file provides the drop part only.  Currently supported protocols
  28 ;; are XDND, Motif and the old KDE 1.x protocol.
  29
  30 ;;; Code:
  31
  32 (require 'dnd)
  33
  34 ;;; Customizable variables
  35 (defcustom x-dnd-test-function 'x-dnd-default-test-function
  36   "The function drag and drop uses to determine if to accept or reject a drop.
  37 The function takes three arguments, WINDOW, ACTION and TYPES.
  38 WINDOW is where the mouse is when the function is called.  WINDOW may be a
  39 frame if the mouse isn't over a real window (i.e. menu bar, tool bar or
  40 scroll bar).  ACTION is the suggested action from the drag and drop source,
  41 one of the symbols move, copy, link or ask.  TYPES is a list of available
  42 types for the drop.
  43
  44 The function shall return nil to reject the drop or a cons with two values,
  45 the wanted action as car and the wanted type as cdr.  The wanted action
  46 can be copy, move, link, ask or private.
  47 The default value for this variable is `x-dnd-default-test-function'."
  48   :version "22.1"
  49   :type 'symbol
  50   :group 'x)
  51
  52
  53
  54 (defcustom x-dnd-types-alist
  55   `(
  56     (,(purecopy "text/uri-list") . x-dnd-handle-uri-list)
  57     (,(purecopy "text/x-moz-url") . x-dnd-handle-moz-url)
  58     (,(purecopy "_NETSCAPE_URL") . x-dnd-handle-uri-list)
  59     (,(purecopy "FILE_NAME") . x-dnd-handle-file-name)
  60     (,(purecopy "UTF8_STRING") . x-dnd-insert-utf8-text)
  61     (,(purecopy "text/plain;charset=UTF-8") . x-dnd-insert-utf8-text)
  62     (,(purecopy "text/plain;charset=utf-8") . x-dnd-insert-utf8-text)
  63     (,(purecopy "text/unicode") . x-dnd-insert-utf16-text)
  64     (,(purecopy "text/plain") . dnd-insert-text)
  65     (,(purecopy "COMPOUND_TEXT") . x-dnd-insert-ctext)
  66     (,(purecopy "STRING") . dnd-insert-text)
  67     (,(purecopy "TEXT")   . dnd-insert-text)
  68     )
  69   "Which function to call to handle a drop of that type.
  70 If the type for the drop is not present, or the function is nil,
  71 the drop is rejected.  The function takes three arguments, WINDOW, ACTION
  72 and DATA.  WINDOW is where the drop occurred, ACTION is the action for
  73 this drop (copy, move, link, private or ask) as determined by a previous
  74 call to `x-dnd-test-function'.  DATA is the drop data.
  75 The function shall return the action used (copy, move, link or private)
  76 if drop is successful, nil if not."
  77   :version "22.1"
  78   :type 'alist
  79   :group 'x)
  80
  81 (defcustom x-dnd-known-types
  82   (mapcar 'purecopy
  83   '("text/uri-list"
  84     "text/x-moz-url"
  85     "_NETSCAPE_URL"
  86     "FILE_NAME"
  87     "UTF8_STRING"
  88     "text/plain;charset=UTF-8"
  89     "text/plain;charset=utf-8"
  90     "text/unicode"
  91     "text/plain"
  92     "COMPOUND_TEXT"
  93     "STRING"
  94     "TEXT"
  95     ))
  96   "The types accepted by default for dropped data.
  97 The types are chosen in the order they appear in the list."
  98   :version "22.1"
  99   :type '(repeat string)
 100   :group 'x
 101 )
 102
 103 ;; Internal variables
 104
 105 (defvar x-dnd-current-state nil
 106   "The current state for a drop.
 107 This is an alist with one entry for each display.  The value for each display
 108 is a vector that contains the state for drag and drop for that display.
 109 Elements in the vector are:
 110 Last buffer drag was in,
 111 last window drag was in,
 112 types available for drop,
 113 the action suggested by the source,
 114 the type we want for the drop,
 115 the action we want for the drop,
 116 any protocol specific data.")
 117
 118 (defvar x-dnd-empty-state [nil nil nil nil nil nil nil])
 119
 120 (declare-function x-register-dnd-atom "xselect.c")
 121
 122 (defun x-dnd-init-frame (&optional frame)
 123   "Setup drag and drop for FRAME (i.e. create appropriate properties)."
 124   (when (eq 'x (window-system frame))
 125     (x-register-dnd-atom "DndProtocol" frame)
 126     (x-register-dnd-atom "_MOTIF_DRAG_AND_DROP_MESSAGE" frame)
 127     (x-register-dnd-atom "XdndEnter" frame)
 128     (x-register-dnd-atom "XdndPosition" frame)
 129     (x-register-dnd-atom "XdndLeave" frame)
 130     (x-register-dnd-atom "XdndDrop" frame)
 131     (x-dnd-init-xdnd-for-frame frame)
 132     (x-dnd-init-motif-for-frame frame)))
 133
 134 (defun x-dnd-get-state-cons-for-frame (frame-or-window)
 135   "Return the entry in `x-dnd-current-state' for a frame or window."
 136   (let* ((frame (if (framep frame-or-window) frame-or-window
 137                   (window-frame frame-or-window)))
 138          (display (frame-parameter frame 'display)))
 139     (if (not (assoc display x-dnd-current-state))
 140         (push (cons display (copy-sequence x-dnd-empty-state))
 141               x-dnd-current-state))
 142     (assoc display x-dnd-current-state)))
 143
 144 (defun x-dnd-get-state-for-frame (frame-or-window)
 145   "Return the state in `x-dnd-current-state' for a frame or window."
 146   (cdr (x-dnd-get-state-cons-for-frame frame-or-window)))
 147
 148 (defun x-dnd-default-test-function (_window _action types)
 149   "The default test function for drag and drop.
 150 WINDOW is where the mouse is when this function is called.  It may be
 151 a frame if the mouse is over the menu bar, scroll bar or tool bar.
 152 ACTION is the suggested action from the source, and TYPES are the
 153 types the drop data can have.  This function only accepts drops with
 154 types in `x-dnd-known-types'.  It always returns the action private."
 155   (let ((type (x-dnd-choose-type types)))
 156     (when type (cons 'private type))))
 157
 158
 159 (defun x-dnd-current-type (frame-or-window)
 160   "Return the type we want the DND data to be in for the current drop.
 161 FRAME-OR-WINDOW is the frame or window that the mouse is over."
 162   (aref (x-dnd-get-state-for-frame frame-or-window) 4))
 163
 164 (defun x-dnd-forget-drop (frame-or-window)
 165   "Remove all state for the last drop.
 166 FRAME-OR-WINDOW is the frame or window that the mouse is over."
 167   (setcdr (x-dnd-get-state-cons-for-frame frame-or-window)
 168           (copy-sequence x-dnd-empty-state)))
 169
 170 (defun x-dnd-maybe-call-test-function (window action)
 171   "Call `x-dnd-test-function' if something has changed.
 172 WINDOW is the window the mouse is over.  ACTION is the suggested
 173 action from the source.  If nothing has changed, return the last
 174 action and type we got from `x-dnd-test-function'."
 175   (let ((buffer (when (window-live-p window)
 176                   (window-buffer window)))
 177         (current-state (x-dnd-get-state-for-frame window)))
 178     (unless (and (equal buffer (aref current-state 0))
 179                  (equal window (aref current-state 1))
 180                  (equal action (aref current-state 3)))
 181       (save-current-buffer
 182         (when buffer (set-buffer buffer))
 183         (let* ((action-type (funcall x-dnd-test-function
 184                                      window
 185                                      action
 186                                      (aref current-state 2)))
 187                (handler (cdr (assoc (cdr action-type) x-dnd-types-alist))))
 188           ;; Ignore action-type if we have no handler.
 189           (setq current-state
 190                 (x-dnd-save-state window
 191                                   action
 192                                   (when handler action-type)))))))
 193   (let ((current-state (x-dnd-get-state-for-frame window)))
 194     (cons (aref current-state 5)
 195           (aref current-state 4))))
 196
 197 (defun x-dnd-save-state (window action action-type &optional types extra-data)
 198   "Save the state of the current drag and drop.
 199 WINDOW is the window the mouse is over.  ACTION is the action suggested
 200 by the source.  ACTION-TYPE is the result of calling `x-dnd-test-function'.
 201 If given, TYPES are the types for the drop data that the source supports.
 202 EXTRA-DATA is data needed for a specific protocol."
 203   (let ((current-state (x-dnd-get-state-for-frame window)))
 204     (aset current-state 5 (car action-type))
 205     (aset current-state 4 (cdr action-type))
 206     (aset current-state 3 action)
 207     (when types (aset current-state 2 types))
 208     (when extra-data (aset current-state 6 extra-data))
 209     (aset current-state 1 window)
 210     (aset current-state 0 (and (window-live-p window) (window-buffer window)))
 211     (setcdr (x-dnd-get-state-cons-for-frame window) current-state)))
 212
 213
 214 (defun x-dnd-handle-moz-url (window action data)
 215   "Handle one item of type text/x-moz-url.
 216 WINDOW is the window where the drop happened.  ACTION is ignored.
 217 DATA is the moz-url, which is formatted as two strings separated by \\r\\n.
 218 The first string is the URL, the second string is the title of that URL.
 219 DATA is encoded in utf-16.  Decode the URL and call `x-dnd-handle-uri-list'."
 220   ;; Mozilla and applications based on it (Galeon for example) uses
 221   ;; text/unicode, but it is impossible to tell if it is le or be.  Use what
 222   ;; the machine Emacs runs on use.  This loses if dropping between machines
 223   ;; with different endian, but it is the best we can do.
 224   (let* ((coding (if (eq (byteorder) ?B) 'utf-16be 'utf-16le))
 225          (string (decode-coding-string data coding))
 226          (strings (split-string string "[\r\n]" t))
 227          ;; Can one drop more than one moz-url ??  Assume not.
 228          (url (car strings)))
 229     (x-dnd-handle-uri-list window action url)))
 230
 231 (defun x-dnd-insert-utf8-text (window action text)
 232   "Decode the UTF-8 text and insert it at point.
 233 TEXT is the text as a string, WINDOW is the window where the drop happened."
 234   (dnd-insert-text window action (decode-coding-string text 'utf-8)))
 235
 236 (defun x-dnd-insert-utf16-text (window action text)
 237   "Decode the UTF-16 text and insert it at point.
 238 TEXT is the text as a string, WINDOW is the window where the drop happened."
 239   ;; See comment in x-dnd-handle-moz-url about coding.
 240   (let ((coding (if (eq (byteorder) ?B) 'utf-16be 'utf-16le)))
 241     (dnd-insert-text window action (decode-coding-string text coding))))
 242
 243 (defun x-dnd-insert-ctext (window action text)
 244   "Decode the compound text and insert it at point.
 245 TEXT is the text as a string, WINDOW is the window where the drop happened."
 246   (dnd-insert-text window action
 247                    (decode-coding-string text
 248                                          'compound-text-with-extensions)))
 249
 250 (defun x-dnd-handle-uri-list (window action string)
 251   "Split an uri-list into separate URIs and call `dnd-handle-one-url'.
 252 WINDOW is the window where the drop happened.
 253 STRING is the uri-list as a string.  The URIs are separated by \\r\\n."
 254   (let ((uri-list (split-string string "[\0\r\n]" t))
 255         retval)
 256     (dolist (bf uri-list)
 257       ;; If one URL is handled, treat as if the whole drop succeeded.
 258       (let ((did-action (dnd-handle-one-url window action bf)))
 259         (when did-action (setq retval did-action))))
 260     retval))
 261
 262 (defun x-dnd-handle-file-name (window action string)
 263   "Convert file names to URLs and call `dnd-handle-one-url'.
 264 WINDOW is the window where the drop happened.
 265 STRING is the file names as a string, separated by nulls."
 266   (let ((uri-list (split-string string "[\0\r\n]" t))
 267         (coding (and (default-value 'enable-multibyte-characters)
 268                      (or file-name-coding-system
 269                          default-file-name-coding-system)))
 270         retval)
 271     (dolist (bf uri-list)
 272       ;; If one URL is handled, treat as if the whole drop succeeded.
 273       (if coding (setq bf (encode-coding-string bf coding)))
 274       (let* ((file-uri (concat "file://"
 275                                (mapconcat 'url-hexify-string
 276                                           (split-string bf "/") "/")))
 277              (did-action (dnd-handle-one-url window action file-uri)))
 278         (when did-action (setq retval did-action))))
 279     retval))
 280
 281
 282 (defun x-dnd-choose-type (types &optional known-types)
 283   "Choose which type we want to receive for the drop.
 284 TYPES are the types the source of the drop offers, a vector of type names
 285 as strings or symbols.  Select among the types in `x-dnd-known-types' or
 286 KNOWN-TYPES if given, and return that type name.
 287 If no suitable type is found, return nil."
 288   (let* ((known-list (or known-types x-dnd-known-types))
 289          (first-known-type (car known-list))
 290          (types-array types)
 291          (found (when first-known-type
 292                   (catch 'done
 293                     (dotimes (i (length types-array))
 294                       (let* ((type (aref types-array i))
 295                              (typename (if (symbolp type)
 296                                            (symbol-name type) type)))
 297                         (when (equal first-known-type typename)
 298                           (throw 'done first-known-type))))
 299                     nil))))
 300
 301     (if (and (not found) (cdr known-list))
 302         (x-dnd-choose-type types (cdr known-list))
 303       found)))
 304
 305 (defun x-dnd-drop-data (event frame window data type)
 306   "Drop one data item onto a frame.
 307 EVENT is the client message for the drop, FRAME is the frame the drop
 308 occurred on.  WINDOW is the window of FRAME where the drop happened.
 309 DATA is the data received from the source, and type is the type for DATA,
 310 see `x-dnd-types-alist').
 311
 312 Returns the action used (move, copy, link, private) if drop was successful,
 313 nil if not."
 314   (let* ((type-info (assoc type x-dnd-types-alist))
 315          (handler (cdr type-info))
 316          (state (x-dnd-get-state-for-frame frame))
 317          (action (aref state 5))
 318          (w (posn-window (event-start event))))
 319     (when handler
 320       (if (and (window-live-p w)
 321                (not (window-minibuffer-p w))
 322                (not (window-dedicated-p w)))
 323           ;; If dropping in an ordinary window which we could use,
 324           ;; let dnd-open-file-other-window specify what to do.
 325           (progn
 326             (when (not mouse-yank-at-point)
 327               (goto-char (posn-point (event-start event))))
 328             (funcall handler window action data))
 329         ;; If we can't display the file here,
 330         ;; make a new window for it.
 331         (let ((dnd-open-file-other-window t))
 332           (select-frame frame)
 333           (funcall handler window action data))))))
 334
 335 (defun x-dnd-handle-drag-n-drop-event (event)
 336   "Receive drag and drop events (X client messages).
 337 Currently XDND, Motif and old KDE 1.x protocols are recognized."
 338   (interactive "e")
 339   (let* ((client-message (car (cdr (cdr event))))
 340          (window (posn-window (event-start event)))
 341          (message-atom (aref client-message 0))
 342          (frame (aref client-message 1))
 343          (format (aref client-message 2))
 344          (data (aref client-message 3)))
 345
 346     (cond ((equal "DndProtocol" message-atom)   ; Old KDE 1.x.
 347            (x-dnd-handle-old-kde event frame window message-atom format data))
 348
 349           ((equal "_MOTIF_DRAG_AND_DROP_MESSAGE" message-atom)  ; Motif
 350            (x-dnd-handle-motif event frame window message-atom format data))
 351
 352           ((and (> (length message-atom) 4)     ; XDND protocol.
 353                 (equal "Xdnd" (substring message-atom 0 4)))
 354            (x-dnd-handle-xdnd event frame window message-atom format data)))))
 355
 356
 357 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 358 ;;;  Old KDE protocol.  Only dropping of files.
 359
 360 (declare-function x-window-property "xfns.c"
 361                   (prop &optional frame type source delete-p vector-ret-p))
 362
 363 (defun x-dnd-handle-old-kde (_event frame window _message _format _data)
 364   "Open the files in a KDE 1.x drop."
 365   (let ((values (x-window-property "DndSelection" frame nil 0 t)))
 366     (x-dnd-handle-uri-list window 'private
 367                            (replace-regexp-in-string "\0$" "" values))))
 368 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 369
 370
 371
 372 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 373 ;;;  XDND protocol.
 374
 375 (defconst x-dnd-xdnd-to-action
 376   '(("XdndActionPrivate" . private)
 377     ("XdndActionCopy" . copy)
 378     ("XdndActionMove" . move)
 379     ("XdndActionLink" . link)
 380     ("XdndActionAsk" . ask))
 381   "Mapping from XDND action types to lisp symbols.")
 382
 383 (declare-function x-change-window-property "xfns.c"
 384                   (prop value &optional frame type format outer-P))
 385
 386 (defun x-dnd-init-xdnd-for-frame (frame)
 387   "Set the XdndAware property for FRAME to indicate that we do XDND."
 388   (x-change-window-property "XdndAware"
 389                             '(5)        ;; The version of XDND we support.
 390                             frame "ATOM" 32 t))
 391
 392 (defun x-dnd-get-drop-width-height (frame w accept)
 393   "Return the width/height to be sent in a XDndStatus message.
 394 FRAME is the frame and W is the window where the drop happened.
 395 If ACCEPT is nil return 0 (empty rectangle),
 396 otherwise if W is a window, return its width/height,
 397 otherwise return the frame width/height."
 398   (if accept
 399       (if (windowp w)   ;; w is not a window if dropping on the menu bar,
 400                         ;; scroll bar or tool bar.
 401           (let ((edges (window-inside-pixel-edges w)))
 402             (cons
 403              (- (nth 2 edges) (nth 0 edges))    ;; right - left
 404              (- (nth 3 edges) (nth 1 edges))))  ;; bottom - top
 405         (cons (frame-pixel-width frame)
 406               (frame-pixel-height frame)))
 407     0))
 408
 409 (defun x-dnd-get-drop-x-y (frame w)
 410   "Return the x/y coordinates to be sent in a XDndStatus message.
 411 Coordinates are required to be absolute.
 412 FRAME is the frame and W is the window where the drop happened.
 413 If W is a window, return its absolute coordinates,
 414 otherwise return the frame coordinates."
 415   (let* ((frame-left (frame-parameter frame 'left))
 416          ;; If the frame is outside the display, frame-left looks like
 417          ;; '(0 -16).  Extract the -16.
 418          (frame-real-left (if (consp frame-left) (car (cdr frame-left))
 419                             frame-left))
 420          (frame-top (frame-parameter frame 'top))
 421          (frame-real-top (if (consp frame-top) (car (cdr frame-top))
 422                            frame-top)))
 423     (if (windowp w)
 424         (let ((edges (window-inside-pixel-edges w)))
 425           (cons
 426            (+ frame-real-left (nth 0 edges))
 427            (+ frame-real-top (nth 1 edges))))
 428       (cons frame-real-left frame-real-top))))
 429
 430 (declare-function x-get-atom-name "xselect.c" (value &optional frame))
 431 (declare-function x-send-client-message "xselect.c"
 432                   (display dest from message-type format values))
 433 (declare-function x-get-selection-internal "xselect.c"
 434                   (selection-symbol target-type &optional time-stamp terminal))
 435
 436 (defun x-dnd-version-from-flags (flags)
 437   "Return the version byte from the 32 bit FLAGS in an XDndEnter message"
 438   (if (consp flags)   ;; Long as cons
 439       (ash (car flags) -8)
 440     (ash flags -24))) ;; Ordinary number
 441
 442 (defun x-dnd-more-than-3-from-flags (flags)
 443   "Return the nmore-than3 bit from the 32 bit FLAGS in an XDndEnter message"
 444   (if (consp flags)
 445       (logand (cdr flags) 1)
 446     (logand flags 1)))
 447
 448 (defun x-dnd-handle-xdnd (event frame window message _format data)
 449   "Receive one XDND event (client message) and send the appropriate reply.
 450 EVENT is the client message.  FRAME is where the mouse is now.
 451 WINDOW is the window within FRAME where the mouse is now.
 452 FORMAT is 32 (not used).  MESSAGE is the data part of an XClientMessageEvent."
 453   (cond ((equal "XdndEnter" message)
 454          (let* ((flags (aref data 1))
 455                 (version (x-dnd-version-from-flags flags))
 456                 (more-than-3 (x-dnd-more-than-3-from-flags flags))
 457                 (dnd-source (aref data 0)))
 458         (message "%s %s" version  more-than-3)
 459            (if version  ;; If flags is bad, version will be nil.
 460                (x-dnd-save-state
 461                 window nil nil
 462                 (if (> more-than-3 0)
 463                     (x-window-property "XdndTypeList"
 464                                        frame "AnyPropertyType"
 465                                        dnd-source nil t)
 466                   (vector (x-get-atom-name (aref data 2))
 467                           (x-get-atom-name (aref data 3))
 468                           (x-get-atom-name (aref data 4))))))))
 469
 470         ((equal "XdndPosition" message)
 471          (let* ((action (x-get-atom-name (aref data 4)))
 472                 (dnd-source (aref data 0))
 473                 (action-type (x-dnd-maybe-call-test-function
 474                               window
 475                               (cdr (assoc action x-dnd-xdnd-to-action))))
 476                 (reply-action (car (rassoc (car action-type)
 477                                            x-dnd-xdnd-to-action)))
 478                 (accept ;; 1 = accept, 0 = reject
 479                  (if (and reply-action action-type) 1 0))
 480                 (list-to-send
 481                  (list (string-to-number
 482                         (frame-parameter frame 'outer-window-id))
 483                        accept ;; 1 = Accept, 0 = reject.
 484                        (x-dnd-get-drop-x-y frame window)
 485                        (x-dnd-get-drop-width-height
 486                         frame window (eq accept 1))
 487                        (or reply-action 0)
 488                        )))
 489            (x-send-client-message
 490             frame dnd-source frame "XdndStatus" 32 list-to-send)
 491            ))
 492
 493         ((equal "XdndLeave" message)
 494          (x-dnd-forget-drop window))
 495
 496         ((equal "XdndDrop" message)
 497          (if (windowp window) (select-window window))
 498          (let* ((dnd-source (aref data 0))
 499                 (value (and (x-dnd-current-type window)
 500                             (x-get-selection-internal
 501                              'XdndSelection
 502                              (intern (x-dnd-current-type window)))))
 503                 success action)
 504
 505            (setq action (if value
 506                             (condition-case info
 507                                 (x-dnd-drop-data event frame window value
 508                                                  (x-dnd-current-type window))
 509                               (error
 510                                (message "Error: %s" info)
 511                                nil))))
 512
 513            (setq success (if action 1 0))
 514
 515            (x-send-client-message
 516             frame dnd-source frame "XdndFinished" 32
 517             (list (string-to-number (frame-parameter frame 'outer-window-id))
 518                   success       ;; 1 = Success, 0 = Error
 519                   (if success "XdndActionPrivate" 0)
 520                   ))
 521            (x-dnd-forget-drop window)))
 522
 523         (t (error "Unknown XDND message %s %s" message data))))
 524
 525 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 526 ;;;  Motif protocol.
 527
 528 (defun x-dnd-init-motif-for-frame (frame)
 529   "Set _MOTIF_DRAG_RECEIVER_INFO for FRAME to indicate that we do Motif DND."
 530   (x-change-window-property "_MOTIF_DRAG_RECEIVER_INFO"
 531                             (list
 532                              (byteorder)
 533                              0                  ; The Motif DND version.
 534                              5                  ; We want drag dynamic.
 535                              0 0 0 0 0 0 0
 536                              0 0 0 0 0 0)       ; Property must be 16 bytes.
 537                             frame "_MOTIF_DRAG_RECEIVER_INFO" 8 t))
 538
 539 (defun x-dnd-get-motif-value (data offset size byteorder)
 540   (cond ((eq size 2)
 541          (if (eq byteorder ?l)
 542              (+ (ash (aref data (1+ offset)) 8)
 543                 (aref data offset))
 544            (+ (ash (aref data offset) 8)
 545               (aref data (1+ offset)))))
 546
 547         ((eq size 4)
 548          (if (eq byteorder ?l)
 549              (cons (+ (ash (aref data (+ 3 offset)) 8)
 550                       (aref data (+ 2 offset)))
 551                    (+ (ash (aref data (1+ offset)) 8)
 552                       (aref data offset)))
 553            (cons (+ (ash (aref data offset) 8)
 554                     (aref data (1+ offset)))
 555                  (+ (ash (aref data (+ 2 offset)) 8)
 556                     (aref data (+ 3 offset))))))))
 557
 558 (defun x-dnd-motif-value-to-list (value size byteorder)
 559   (let ((bytes (cond ((eq size 2)
 560                       (list (logand (lsh value -8) ?\xff)
 561                             (logand value ?\xff)))
 562
 563                      ((eq size 4)
 564                       (if (consp value)
 565                           (list (logand (lsh (car value) -8) ?\xff)
 566                                 (logand (car value) ?\xff)
 567                                 (logand (lsh (cdr value) -8) ?\xff)
 568                                 (logand (cdr value) ?\xff))
 569                         (list (logand (lsh value -24) ?\xff)
 570                               (logand (lsh value -16) ?\xff)
 571                               (logand (lsh value -8) ?\xff)
 572                               (logand value ?\xff)))))))
 573     (if (eq byteorder ?l)
 574         (reverse bytes)
 575       bytes)))
 576
 577
 578 (defvar x-dnd-motif-message-types
 579   '((0 . XmTOP_LEVEL_ENTER)
 580     (1 . XmTOP_LEVEL_LEAVE)
 581     (2 . XmDRAG_MOTION)
 582     (3 . XmDROP_SITE_ENTER)
 583     (4 . XmDROP_SITE_LEAVE)
 584     (5 . XmDROP_START)
 585     (6 . XmDROP_FINISH)
 586     (7 . XmDRAG_DROP_FINISH)
 587     (8 . XmOPERATION_CHANGED))
 588   "Mapping from numbers to Motif DND message types.")
 589
 590 (defvar x-dnd-motif-to-action
 591   '((1 . move)
 592     (2 . copy)
 593     (3 . link)  ; Both 3 and 4 has been seen as link.
 594     (4 . link)
 595     (2 . private)) ; Motif does not have private, so use copy for private.
 596   "Mapping from number to operation for Motif DND.")
 597
 598 (defun x-dnd-handle-motif (event frame window message-atom _format data)
 599   (let* ((message-type (cdr (assoc (aref data 0) x-dnd-motif-message-types)))
 600          (source-byteorder (aref data 1))
 601          (my-byteorder (byteorder))
 602          (source-flags (x-dnd-get-motif-value data 2 2 source-byteorder))
 603          (source-action (cdr (assoc (logand ?\xF source-flags)
 604                                     x-dnd-motif-to-action))))
 605
 606     (cond ((eq message-type 'XmTOP_LEVEL_ENTER)
 607            (let* ((dnd-source (x-dnd-get-motif-value
 608                                data 8 4 source-byteorder))
 609                   (selection-atom (x-dnd-get-motif-value
 610                                    data 12 4 source-byteorder))
 611                   (atom-name (x-get-atom-name selection-atom))
 612                   (types (when atom-name
 613                            (x-get-selection-internal (intern atom-name)
 614                                                      'TARGETS))))
 615              (x-dnd-forget-drop frame)
 616              (when types (x-dnd-save-state window nil nil
 617                                            types
 618                                            dnd-source))))
 619
 620           ;; Can not forget drop here, LEAVE comes before DROP_START and
 621           ;; we need the state in DROP_START.
 622           ((eq message-type 'XmTOP_LEVEL_LEAVE)
 623            nil)
 624
 625           ((eq message-type 'XmDRAG_MOTION)
 626            (let* ((state (x-dnd-get-state-for-frame frame))
 627                   (timestamp (x-dnd-motif-value-to-list
 628                               (x-dnd-get-motif-value data 4 4
 629                                                      source-byteorder)
 630                               4 my-byteorder))
 631                   (x (x-dnd-motif-value-to-list
 632                       (x-dnd-get-motif-value data 8 2 source-byteorder)
 633                       2 my-byteorder))
 634                   (y (x-dnd-motif-value-to-list
 635                       (x-dnd-get-motif-value data 10 2 source-byteorder)
 636                       2 my-byteorder))
 637                   (dnd-source (aref state 6))
 638                   (first-move (not (aref state 3)))
 639                   (action-type (x-dnd-maybe-call-test-function
 640                                 window
 641                                 source-action))
 642                   (reply-action (car (rassoc (car action-type)
 643                                              x-dnd-motif-to-action)))
 644                   (reply-flags
 645                    (x-dnd-motif-value-to-list
 646                     (if reply-action
 647                         (+ reply-action
 648                            ?\x30        ; 30:  valid drop site
 649                            ?\x700)      ; 700: can do copy, move or link
 650                       ?\x30)            ; 30:  drop site, but noop.
 651                     2 my-byteorder))
 652                   (reply (append
 653                           (list
 654                            (+ ?\x80     ; 0x80 indicates a reply.
 655                               (if first-move
 656                                   3     ; First time, reply is SITE_ENTER.
 657                                 2))     ; Not first time, reply is DRAG_MOTION.
 658                            my-byteorder)
 659                           reply-flags
 660                           timestamp
 661                           x
 662                           y)))
 663              (x-send-client-message frame
 664                                     dnd-source
 665                                     frame
 666                                     "_MOTIF_DRAG_AND_DROP_MESSAGE"
 667                                     8
 668                                     reply)))
 669
 670           ((eq message-type 'XmOPERATION_CHANGED)
 671            (let* ((state (x-dnd-get-state-for-frame frame))
 672                   (timestamp (x-dnd-motif-value-to-list
 673                               (x-dnd-get-motif-value data 4 4 source-byteorder)
 674                               4 my-byteorder))
 675                   (dnd-source (aref state 6))
 676                   (action-type (x-dnd-maybe-call-test-function
 677                                 window
 678                                 source-action))
 679                   (reply-action (car (rassoc (car action-type)
 680                                              x-dnd-motif-to-action)))
 681                   (reply-flags
 682                    (x-dnd-motif-value-to-list
 683                     (if reply-action
 684                         (+ reply-action
 685                            ?\x30        ; 30:  valid drop site
 686                            ?\x700)      ; 700: can do copy, move or link
 687                       ?\x30)            ; 30:  drop site, but noop
 688                     2 my-byteorder))
 689                   (reply (append
 690                           (list
 691                            (+ ?\x80     ; 0x80 indicates a reply.
 692                               8)        ; 8 is OPERATION_CHANGED
 693                            my-byteorder)
 694                           reply-flags
 695                           timestamp)))
 696              (x-send-client-message frame
 697                                     dnd-source
 698                                     frame
 699                                     "_MOTIF_DRAG_AND_DROP_MESSAGE"
 700                                     8
 701                                     reply)))
 702
 703           ((eq message-type 'XmDROP_START)
 704            (let* ((x (x-dnd-motif-value-to-list
 705                       (x-dnd-get-motif-value data 8 2 source-byteorder)
 706                       2 my-byteorder))
 707                   (y (x-dnd-motif-value-to-list
 708                       (x-dnd-get-motif-value data 10 2 source-byteorder)
 709                       2 my-byteorder))
 710                   (selection-atom (x-dnd-get-motif-value
 711                                    data 12 4 source-byteorder))
 712                   (atom-name (x-get-atom-name selection-atom))
 713                   (dnd-source (x-dnd-get-motif-value
 714                                data 16 4 source-byteorder))
 715                   (action-type (x-dnd-maybe-call-test-function
 716                                 window
 717                                 source-action))
 718                   (reply-action (car (rassoc (car action-type)
 719                                              x-dnd-motif-to-action)))
 720                   (reply-flags
 721                    (x-dnd-motif-value-to-list
 722                     (if reply-action
 723                         (+ reply-action
 724                            ?\x30        ; 30:  valid drop site
 725                            ?\x700)      ; 700: can do copy, move or link
 726                       (+ ?\x30          ; 30:  drop site, but noop.
 727                          ?\x200))       ; 200: drop cancel.
 728                     2 my-byteorder))
 729                   (reply (append
 730                           (list
 731                            (+ ?\x80     ; 0x80 indicates a reply.
 732                               5)        ; DROP_START.
 733                            my-byteorder)
 734                           reply-flags
 735                           x
 736                           y))
 737                   (timestamp (x-dnd-get-motif-value
 738                               data 4 4 source-byteorder))
 739                   action)
 740
 741              (x-send-client-message frame
 742                                     dnd-source
 743                                     frame
 744                                     "_MOTIF_DRAG_AND_DROP_MESSAGE"
 745                                     8
 746                                     reply)
 747              (setq action
 748                    (when (and reply-action atom-name)
 749                      (let* ((value (x-get-selection-internal
 750                                     (intern atom-name)
 751                                     (intern (x-dnd-current-type window)))))
 752                        (when value
 753                          (condition-case info
 754                              (x-dnd-drop-data event frame window value
 755                                               (x-dnd-current-type window))
 756                            (error
 757                             (message "Error: %s" info)
 758                             nil))))))
 759              (x-get-selection-internal
 760               (intern atom-name)
 761               (if action 'XmTRANSFER_SUCCESS 'XmTRANSFER_FAILURE)
 762               timestamp)
 763              (x-dnd-forget-drop frame)))
 764
 765           (t (error "Unknown Motif DND message %s %s" message-atom data)))))
 766
 767
 768 ;;;
 769
 770 (provide 'x-dnd)
 771
 772 ;;; x-dnd.el ends here